Engineers should maintain their positions on electrical system design, whether for code issues, good design practice- or the owner’s best interest
"Why on earth did you design it that way?"
This is a plaint often heard from the contractor, construction manager, or owner when documents are issued for construction. More often than not, the statement is liberally littered with modifying expletives.
The engineer so challenged, must first decide if the question has a legitimate basis. If so, is it a National Electrical Code (NEC) requirement, good practice, or merely designer preference?
The key is to examine code requirements, how the engineer can maintain a position, and the potential impacts to both the engineer and the project if they fold on their position.
Engineers are charged with a mandate to "safeguard life, health and property, and promote the public welfare," as well as meet project requirements. In addition, there are instances in which they are called upon to certify that drawings to which they have affixed their seals meet all requirements of the NEC and the Authority Having Jurisdiction (AHJ). To meet these weighty obligations engineers must consider seriously their mandate and- on a more practical level- interpret applicable NEC sections for each project and assure that their design meets all requirements.
By stamping and signing design drawings, engineers are signifying that they believe the documents meet project and code. When these documents are sent to contractors for construction bidding, the questions begin. The most common topics of discussion- from contractors, owners and others, comprise the following:
Wire Sizing
• Ampacity. There have been numerous articles written on the subject of conductor sizing to meet the NEC requirements as described in Article 310 (see sidebar, "NEC Conductor Sizing,") These articles agree
The Cast of Characters
Like it or not, there are differing viewpoints on a construction project, and as long as we live in a free market society,there always will be. Participants each have their own agendas and issues of paramount importance. A description of the
cast of character every engineer encounters (and often embodies) follows. While these stereotypes are certainly unfair to many, at the same time there is an underlying truth to the generalizations.
The Owner. The owner wants the best project for either the lowest first cost or life-cycle cost. Meeting code is not always a top priority, particularly when code requirements conflict with project requirements-and when the cost of
compliance increases the budget.
The Construction Manager. Typically hired by the owner, the CM’s views, for the most part, parallel those to the owner.
The AHJ. The Authority Having Jurisdiction (AHJ) wants to project that is safe and meets their interpretation of the various codes. They are usually not interested at all in whether their interpretations impact the cost of the project.
The Contractor. The builder wants to complete the project and make a profit; they’re not necessarily interested in whether the project meets Code, but only that it passes inspection. Also, the contractor be interested in changes to the
design after the contract is signed that mean greater profit for the contractor. So, all opportunities to reduce cost or find design errors can increase the contractor’s profit margin-and his influence with the owner.
The engineer must consider all of these viewpoints, and make value judgments in light of code, cost, constructability, safety and consumer satisfaction (as well as their own profit picture). They must advise the owner on the future operation of the project. Any changes proposed by the contractor must be beneficial to the owner.
That a number of issues must be addressed to properly size conductors, including ambient temperature, termination temperature, number of current-carrying conductors in a raceway, character of the load and type of conductor insulation. While
now included in NEC Appendix B- which is not a code mandate- the Neher-Macgrath calculations for sizing of conductors installed in underground duct banks should also be considered to properly size conductors in a partially insulated environment.
The diligent engineer applies each requirement in the appropriate manner and arrives at a conductor size suitable for the load, the environment and the overcurrent protection. Yet, the controversy often begins when a member of the
construction team compares the conductor sizes on the contract documents to the uncorrected, 75°C column in table 310-16 in the NEC and concludes that the engineer has sized the conductors incorrectly.
The owner or contractor then takes the position that the conductors are too large and, to economize, suggests that the sizes be reduced to match the referenced column.
• Voltage Drop. Ampacities are just one factor in proper conductor sizing. Just as important, though often neglected, is voltage drop. NEC Articles 210-19 (a) (FPN No. 4) and 215-2(b) (FPN No.2)- which are not mandatory rules-recommend sizing both feeders and branch circuits to prevent a voltage drop exceeding 3 percent at the farthest outlet, where the maximum total voltage drop of the feeders and branch circuits does not exceed 5 percent
When the feeder and branch circuit conductors for long circuits are sized on this basis, the conductor sizes are increased even more than that required for ampacity. Perhaps because it is not mandatory, contractors and owners sometimes forget this basic fact. It should not be overlooked, however, because performance and the operating life of utilization equipment can be adversely affected.
Electrical Working Clearance
Clearance for electrical equipment are specified in NEC Articles 110-16 and 384. Working clearances are based on voltage level and conditions of installation, and for installations below 600 volts, these clearances range from 3 to 4 feet in front and in back of equipment (where the equipment has rear access). Headroom is also given as a minimum of 6.5 feet to prevent the installation of electrical equipment in crawlspaces.
Article 384 covers dedicated space in the vicinity of electrical equipment for the installation of conduit and limited physical protection of equipment. Generally speaking, this space is equal to the footprint of the equipment extending from the floor on which the equipment is mounted to the next structural floor, or 25 feet, whichever is less. The article also restricts the intrusion of pipes and ducts into this space.
While the passage clearly states that no equipment foreign to the electrical installation shall be installed in the zones, this often becomes a point of contention between engineer and contractor. In the contractor’s view, the shortest distance between two points is a straight line, even if that line is a pipe passing directly over electrical equipment.
While the code seems clear and straightforward, this is a frequent problem at the construction site. Clearance requirements are often violated to the extent that equipment doors cannot be opened, and Owners and even AHJs may prefer to look the
other way. Many engineering firms have specific coordination stipulations, both in drawings and specifications, to prevent space conflicts between mechanical and electrical systems. In the field, however, there must be a commitment to implement them,
Transformer Protection
Transformer overload and short-circuit protection are addressed in Article 450 of the NEC. Depending on voltage levels and conditions of maintenance and supervision, one of two protection schemes can be used: either primary overcurrent protection
only, or primary and secondary overcurrent protection. Also, the NEC permits fairly wide latitude in the sizing of overcurrent devices.
As a matter of good practice, however, better protection will be realized with breaker settings or fuse ratings lower than the maximum allowable. Likewise, primary-only protection is a minimum-only requirement, which – unlike primary and secondary
protection- does not provide the best protection under all types of fault conditions. Plus, it may introduce nuisance tripping due to magnetizing inrush, cold load pickup and emergency operating conditions.
Using primary and secondary protection, with the primary breaker set between 175 and 200 percent, there is less opportunity for nuisance tripping while offering adequate short-circuit protection for both primary conductors and the transformer. The
secondary overcurrent device, set at 125 percent of full load, provides overload protection. In addition, the primary overcurrent device should be examined to ensure that the transformer damage curve (defined by ANSI/IEEE C57.109) is fully
protected by the primary device, while allowing the transformer magnetizing inrush point to fall below trip characteristics. That way, energizing the transformer will not cause a nuisance trip.
Unfortunately, contractors routinely question the use of larger overcurrent devices and primary conductors on the primary side of the transformer.
Engineers are accused of "overdesigning" projects, overlooking cost savings from reduced conductor and overurrent device sizing. Yet, in most instances, the larger overcurrent device is the same frame size; so, for example, reducing the trip
size from a 200-ampere to a 125-ampere trip on a breaker results in no savings at all. The difference in cost between the conductors and conduit that is perhaps 4 feet long is negligible. In reality, the time wasted in asking the question is
probably more valuable than the cost of the materials needed for the more reliable, better protected installation.
Grounding/Earthing
Conflicts on grounding most often occur between the engineer and the owner’s equipment suppliers. The NEC is very clear. In Article 250-54, it spells out the standard for connecting all grounding conductors to a single grounding electrode.
When electronic systems are installed in a facility, the equipment installation technicians typically request an isolated ground not connected to any other ground in the building, often stating that their equipment will not work without the isolated ground.
The conflict between the NEC requirement and the supplier’s desire is easily resolved: Connect the ground for the electronic system as close to the grounding electrode as possible; this meets the NEC requirement and gives electronic systems their solid, earth ground connection.
The real issue for the systems is having a minimum voltage above ground on the signal ground for the system. By connecting the system ground close to the grounding electrode, there is minimum impedance between the system ground and earth ground,
reducing the voltage to a low value, no matter what the ground current.
An associated but less common request from system technicians is that the voltage difference between neutral and ground at the utilization equipment be less than 1 volt. The equipment ground installed as noted above will minimize the voltage on the
ground; reducing voltage level on the neutral at the utilization equipment is more problematic. Utilization equipment often has a switching power supply, which generates significant harmonic currents that are impressed on to the neutral of the system with a resultant increase in neutral current.
As Ohm’s Law states, when current is increased through the constant circuit impedance, voltage increases. Therefore, the neutral has an inherent voltage impressed at the utilization equipment terminals well above the requirement outside of 1 volt over ground. In fact, no equipment manufacturer has been able to demonstrate either:
1) Good reason for maintaining the neutral-to-ground voltage less than 1 volt; or
2) Any equipment malfunctions attributed to this voltage difference.
Fault Duty
Fault duty on distribution equipment should be a focal point of the engineer’s concentration. Not only is it critical to safety and reliability, but it is an NEC-mandated issue in Article 110-9, which says that equipment intended to break current at fault levels shall have an interrupting rating sufficient for the current that is available at the line terminals.
Contractors, Owners and Construction Managers often seem to think that fault duty of electrical equipment is a myth propagated by engineers to increase the costs of projects. Yet, the fact is that the engineer must meet the NEC requirement by either designing a fully rated system or, as permitted by Underwriters Laboratories (UL), designing a series-rated system. NEC enforces UL requirements in Article 110-3(b), which says that listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
The Contractor that has some passing knowledge of fault duty will suggest that the distribution system be series rated in place of a fully rated system. This suggestion becomes difficult when the series connected rating is applied to systems with a mixture of multiple manufacturers or with various overcurrent devices that are not listed as series connected by UL.
As UL plainly states, "These ratings are applicable only when the series connected devices have been investigated by UL in combination with the end-use equipment and the equipment in which these devices are used is marked with the series connected
rating." Therefore, if series connected devices are not listed in UL Recognized Component directory, they are not suitable for series-rated application.
Between the NEC and UL requirements, engineers very carefully must meet the specific requirements for series ratings confirming in shop drawings equipment labeled for that specific rating- or maintain that all systems must be full-rated.
Resolving Codes and Costs
With all of these viewpoints clouding the issues, the engineer has a difficult problem. Because the engineering firm is hired by the owner, either directly or indirectly, their first commitment must be to the client- the owner.
Along with this commitment, however, engineers must also meet the mandate to protect public safety and welfare. This becomes one of the most sensitive issues engineers face, especially when they choose to hold to a design or specification
against the owner’s wishes. When this happens, these options are available to engineers:
• A Simple Approach: Show the owner where the code does not allow a proposed change. In most cases this is enough
• A Cost-Based Approach: Connect the code-mandated design with construction cost savings or operational savings,
• A Diplomatic Approach: Develop an alternative solution meeting the owner’s requirements and code requirements.
Sometimes, this implies more design time and additional construction cost, but it may be the path of least resistance when owners are adamant about a change.
If these approaches don’t work, further options become less pleasant. Where there appears to be no major hazards, engineers may comply with the owner’s desires and go on record with a letter to the owner stating the engineer’s objection to the approach and recording the reasons why.
For more critical issues, engineers can send a letter absolving themselves of any responsibility- and simply not incorporate the requested approach into the contract documents. This position may risk the loss of future work with the same owner, but this may be a better option than violating a public mandate to design safe buildings.
NEC Conductor Sizing
There are four criteria used for conductor sizing to meet the NEC requirements:
1) The overcurrent device must be sized for the sum of the non-continuous load plus 125 percent of the continuous load.
The overcurrent device may be rounded up to the next available standard size, as long as the device does not exceed 800 amperes.
2) The conductor must be sized so that termination temperatures do not exceed 60°C for conductors smaller than 100 amperes or #1 American wire gauge (AWG), and 75°C for conductors larger than 100 amperes or #1/0 AWG. This results in using the 60°C column of 310-16 for all conductor sizing of circuits 100 amperes and smaller, and the 75°C column of 310-16 for conductors larger than 100 amperes. Even if insulations are utilized, such as XHHW, Z, TFE, etc. two columns must be used to determine conductor sizes.
3) Conductor size and insulation type must take into consideration conditions of use to prevent insulation damage. Conditions of use include more than three current-carrying conductors in a single raceway and high-temperature ambients. High temperature ambients are-according to the heading of the correction-factor chart for 310-16-any ambient conditions that exceed 30°C or 86°F Most electrical rooms and mechanical rooms and mechanical rooms where mechanical rooms where electrical equipment is installed will exceed 86°F under typical operating conditions
Wire sizing and conductor sizing must not only meet code requirements, they must also meet special needs, such as those for partially insulated environments.
4.) The overcurrent device must protect the conductor under all conditions of use.
Saturday, February 07, 2009
Friday, February 06, 2009
PRICE AND COST ANALYSIS
Some form of price or cost analysis should be performed in connection with every procurement action, regardless of whether the organization is a vendor or a subrecipient. The form and degree of analysis, however, are dependent on the particular subcontract or purchase, and the pricing situation. Determination of price
reasonableness through price or cost analysis is required even though the procurement
is source directed by the contracting officer of the sponsoring agency.
In some purchases, price analysis alone will be sufficient; in others, price analysis will be used to corroborate the conclusions arrived at through cost analysis. The form and degree of analysis are dependent on facts surrounding a particular subcontracting or purchasing situation. The scope of price analysis performed and the particular techniques used will depend on whether or not cost analysis is done, as well as on such factors as type of product or service, dollar value, purchase method, and extent of competition.
The words "vendor" and "subcontractor" used herein are interchangeable.
Price Analysis is the process of deciding if the asking price for a product or service is fair and reasonable, without examining the specific cost and profit calculations the manufacturer and/or supplier used in arriving at the price. It is basically a process of comparing the price with known indicators of reasonableness.
When adequate price competition does not exist, some other form of analysis is
required. Some reasons that could affect adequate price competition are: specifications are not definitive, tolerances are restrictive, or production capacity limits those eligible to bid.
Examples of other forms of price analysis information include:
• analysis of previous prices paid
• comparison of vendor's price with the in-house estimate
• comparison of quotations or published price lists from multiple vendors
Cost Analysis is the element -by-element examination of the estimated or actual cost of contract performance to determine the probable cost to the vendor. The goal is to form an opinion on whether the proposed costs are in line with what reasonably economical and efficient performance should cost.
Cost or pricing data, which should be provided by the subcontractor, are the means for conducting cost analysis. Such data provide factual information about the costs that the subcontractor says may be incurred in performing the contract. Cost analysis should be performed in those situations where price analysis does not yield a fair and reasonable price and where cost data are required in accordance with prime contract clauses.
Cost analysis techniques are used to break down a contractor's cost or pricing data so as to verify and evaluate each component. Some of the cost elements examined for
necessity and reasonableness are materials costs, labor costs, equipment and overhead. These costs can be compared with actual costs previously incurred for similar work, the cost or pricing data received from other manufacturer and/or supplier, and independent cost estimate breakdowns.
reasonableness through price or cost analysis is required even though the procurement
is source directed by the contracting officer of the sponsoring agency.
In some purchases, price analysis alone will be sufficient; in others, price analysis will be used to corroborate the conclusions arrived at through cost analysis. The form and degree of analysis are dependent on facts surrounding a particular subcontracting or purchasing situation. The scope of price analysis performed and the particular techniques used will depend on whether or not cost analysis is done, as well as on such factors as type of product or service, dollar value, purchase method, and extent of competition.
The words "vendor" and "subcontractor" used herein are interchangeable.
Price Analysis is the process of deciding if the asking price for a product or service is fair and reasonable, without examining the specific cost and profit calculations the manufacturer and/or supplier used in arriving at the price. It is basically a process of comparing the price with known indicators of reasonableness.
When adequate price competition does not exist, some other form of analysis is
required. Some reasons that could affect adequate price competition are: specifications are not definitive, tolerances are restrictive, or production capacity limits those eligible to bid.
Examples of other forms of price analysis information include:
• analysis of previous prices paid
• comparison of vendor's price with the in-house estimate
• comparison of quotations or published price lists from multiple vendors
Cost Analysis is the element -by-element examination of the estimated or actual cost of contract performance to determine the probable cost to the vendor. The goal is to form an opinion on whether the proposed costs are in line with what reasonably economical and efficient performance should cost.
Cost or pricing data, which should be provided by the subcontractor, are the means for conducting cost analysis. Such data provide factual information about the costs that the subcontractor says may be incurred in performing the contract. Cost analysis should be performed in those situations where price analysis does not yield a fair and reasonable price and where cost data are required in accordance with prime contract clauses.
Cost analysis techniques are used to break down a contractor's cost or pricing data so as to verify and evaluate each component. Some of the cost elements examined for
necessity and reasonableness are materials costs, labor costs, equipment and overhead. These costs can be compared with actual costs previously incurred for similar work, the cost or pricing data received from other manufacturer and/or supplier, and independent cost estimate breakdowns.
Monday, August 18, 2008
Electrical Engineer Job Description
Electrical Engineers design and develop electrical systems and/or components to high specifications, focusing on:
• Economy;
• Safety;
• Reliability;
• Quality;
• Sustainability
They are involved in projects from the concept and detail of the design through to implementation, testing and handover.
Most electrical engineers work in a multi-disciplinary project team, including engineers from other specialisms, as well as architects, marketing and sales staff, manufacturers, technicians and customer service personnel.
Electrical engineers need technical knowledge as well as the ability to project manage and multitask. Additional attributes, such as team leadership skills and commercial awareness, are required as careers progress.
» Typical Work Activities
Many organizations now operate cross-functional teams in which the electrical engineer is involved at every stage of design and development in collaboration with colleagues in other engineering functions, as well as those working in production, research, marketing and after-sales services.
The nature of the role varies according to industry or sector, but the range of activities common to many posts is likely to include the following:
• Identifying customer requirements;
• Designing systems and products;
• Reading design specifications and technical drawings;
• Researching suitable solutions and estimating costs and timescales;
• Making models and prototypes of products;
• Working to BS and EN standards;
• Liaising with others in the design team;
• Liaising with clients and contractors;
• Attending meetings on site;
• Designing and conducting tests;
• Recording, analyzing and interpreting test data;
• Proposing modifications and retesting products;
• Qualifying the final product or system;
• Servicing and maintaining equipment;
• Preparing product documentation, writing reports and giving presentations;
• Monitoring a product in use so as to improve on future design.
• Economy;
• Safety;
• Reliability;
• Quality;
• Sustainability
They are involved in projects from the concept and detail of the design through to implementation, testing and handover.
Most electrical engineers work in a multi-disciplinary project team, including engineers from other specialisms, as well as architects, marketing and sales staff, manufacturers, technicians and customer service personnel.
Electrical engineers need technical knowledge as well as the ability to project manage and multitask. Additional attributes, such as team leadership skills and commercial awareness, are required as careers progress.
» Typical Work Activities
Many organizations now operate cross-functional teams in which the electrical engineer is involved at every stage of design and development in collaboration with colleagues in other engineering functions, as well as those working in production, research, marketing and after-sales services.
The nature of the role varies according to industry or sector, but the range of activities common to many posts is likely to include the following:
• Identifying customer requirements;
• Designing systems and products;
• Reading design specifications and technical drawings;
• Researching suitable solutions and estimating costs and timescales;
• Making models and prototypes of products;
• Working to BS and EN standards;
• Liaising with others in the design team;
• Liaising with clients and contractors;
• Attending meetings on site;
• Designing and conducting tests;
• Recording, analyzing and interpreting test data;
• Proposing modifications and retesting products;
• Qualifying the final product or system;
• Servicing and maintaining equipment;
• Preparing product documentation, writing reports and giving presentations;
• Monitoring a product in use so as to improve on future design.
ENCLOSURE CLASSIFICATIONS
Industry Standards
Enclosure Types for All Locations
National Electrical Manufacturers Association (NEMA Standard 250)
NEMA/EEC to IEC
TYPE Intended Use & Description
Type 1 General purpose enclosures are suitable for general purpose application indoors, where atmospheric conditions are normal. These enclosures serve as protection against falling dust, but are not dust tight.
Type 2 Drip tight (indoor) enclosures are similar to NEMA 1 enclosures, with the addition for drip shields, and are suitable for application where condensation may be severe, such as that encountered in cooling rooms or laundries.
Type 3 Dust, rain proof and sleet resistant enclosures provide proper protection against windblown dust and weather hazards such as rain, sleet or snow. They are suitable for applications outdoors on ship docks, canal locks, construction work, and for applications in subways and tunnels; use indoors where dripping water is a problem.
Type 3R Dust, rain proof and sleet resistant enclosures provide proper protection against falling dirt and weather hazards such as rain, sleet or snow. They are suitable for applications outdoors on ship docks, canal locks, construction work, and for applications in subways and tunnels; use indoors where dripping water is a problem.
Type 4 Water tight enclosures are suitable for dairies, breweries, etc., where the enclosure may be subjected to large amounts of water from any angle. (They are not submersible)
Type 4X Corrosion resistant enclosures satisfy the same requirements as NEMA 4; in addition they are suitable for food processing plants, dairies, refineries, and other industries where corrosion is prominent.
Type 6 Submersible enclosures are suitable for application where the equipment may be subject to submersion, such as quarries, mines, and manholes. The enclosure design will depend upon the specified conditions of pressure and time.
Type 9 Hazardous location enclosures - Class II, Group E, F or G. These enclosures are designed to meet the requirements of the "Canadian Electrical Code" Part I for Class II hazardous locations, and CSA codes section 18 Class II Group E,F, and G.
Class II Group E - atmosphere containing metal dust
Class II Group F - atmosphere containing carbon black, coal, or coke dust.
Class II Group G - atmosphere containing flour, starch or grain dust.
Type 12 Industrial use enclosures are oil tight. Hammond type 12 enclosures meet JIC standard and also satisfy requirements of NEMA.
Type 13 The cover is held in place with screws, bolts or other suitable fasteners, with a continuous gasket construction. The fastener parts are held captive when the door is opened. There are no holes through the enclosures for mounting or attaching controls inside the enclosure, and no conduit knock-outs or openings. Mounting feet, brackets, or other mounting means are provided. These enclosures are suitable for application to machine tools and other industrial processing machines where oil, coolants, water, filings, dust or lint may enter, seep into or infiltrate the enclosure through mounting holes, unused conduit knock-outs, or holes used for mounting equipment with the enclosure.
The preceding descriptions are not intended to be complete representations
of the National Electrical Manufacturers Association standards for enclosures.
Underwriter Laboratories Inc. (UL 50 and UL 508)
TYPE Intended Use and Description (Approximate IP equivalents)
Type 1 Indoor use primarily to provide protection against contact with the enclosed equipment and against limited amount of falling dirt (IP30).
Type 2 Indoor use to provide a degree of protection against limited amounts of falling water and dirt (IP31).
Type 3 Outdoor use to provide a degree of protection against windblown dust and windblown rain; undamaged by the formation of ice on the enclosure (IP64).
Type 3R Outdoor use to provide a degree of protection against falling rain and sleet; undamaged by the formation of ice on the enclosure (IP32).
Type 3S Outdoor use to provide a degree of protection against windblown dust, rain and sleet; external mechanisms remain operable while ice laden.
Type 4 Either indoor or outdoor use to provide a degree of protection against falling rain, splashing water, and hose-directed water; undamaged by the formation of ice on the enclosure(IP66).
Type 4X Same as type 4 except this one is corrosion resistant (IP66).
Type 6 Indoor or outdoor use to provide a degree of protection against entry of water during temporary submersion at a limited depth; undamaged by formation of ice on the enclosure.
Type 6P Indoor or outdoor use to provide a degree of protection against entry of water during prolong submersion at a limited depth.
Type 11 Indoor use to provide by oil immersion a degree of protection of the enclosed equipment against the corrosive effects of corrosive liquids and gases.
Type 12/12K Indoor use to provide a degree of protection against dust, falling dirt, fiber flyings, dripping water, and external condensation or dripping of non corrosive liquids (IP65).
Type 13 Indoor use to provide a degree of protection against lint, dust seepage, external condensation and spraying of water, oil, and non corrosive liquids (IP65).
If there is anything you would like to add or if you have any comments please feel free to email at electrical_engineer@alriyadh.cc
Enclosure Types for All Locations
National Electrical Manufacturers Association (NEMA Standard 250)
NEMA/EEC to IEC
TYPE Intended Use & Description
Type 1 General purpose enclosures are suitable for general purpose application indoors, where atmospheric conditions are normal. These enclosures serve as protection against falling dust, but are not dust tight.
Type 2 Drip tight (indoor) enclosures are similar to NEMA 1 enclosures, with the addition for drip shields, and are suitable for application where condensation may be severe, such as that encountered in cooling rooms or laundries.
Type 3 Dust, rain proof and sleet resistant enclosures provide proper protection against windblown dust and weather hazards such as rain, sleet or snow. They are suitable for applications outdoors on ship docks, canal locks, construction work, and for applications in subways and tunnels; use indoors where dripping water is a problem.
Type 3R Dust, rain proof and sleet resistant enclosures provide proper protection against falling dirt and weather hazards such as rain, sleet or snow. They are suitable for applications outdoors on ship docks, canal locks, construction work, and for applications in subways and tunnels; use indoors where dripping water is a problem.
Type 4 Water tight enclosures are suitable for dairies, breweries, etc., where the enclosure may be subjected to large amounts of water from any angle. (They are not submersible)
Type 4X Corrosion resistant enclosures satisfy the same requirements as NEMA 4; in addition they are suitable for food processing plants, dairies, refineries, and other industries where corrosion is prominent.
Type 6 Submersible enclosures are suitable for application where the equipment may be subject to submersion, such as quarries, mines, and manholes. The enclosure design will depend upon the specified conditions of pressure and time.
Type 9 Hazardous location enclosures - Class II, Group E, F or G. These enclosures are designed to meet the requirements of the "Canadian Electrical Code" Part I for Class II hazardous locations, and CSA codes section 18 Class II Group E,F, and G.
Class II Group E - atmosphere containing metal dust
Class II Group F - atmosphere containing carbon black, coal, or coke dust.
Class II Group G - atmosphere containing flour, starch or grain dust.
Type 12 Industrial use enclosures are oil tight. Hammond type 12 enclosures meet JIC standard and also satisfy requirements of NEMA.
Type 13 The cover is held in place with screws, bolts or other suitable fasteners, with a continuous gasket construction. The fastener parts are held captive when the door is opened. There are no holes through the enclosures for mounting or attaching controls inside the enclosure, and no conduit knock-outs or openings. Mounting feet, brackets, or other mounting means are provided. These enclosures are suitable for application to machine tools and other industrial processing machines where oil, coolants, water, filings, dust or lint may enter, seep into or infiltrate the enclosure through mounting holes, unused conduit knock-outs, or holes used for mounting equipment with the enclosure.
The preceding descriptions are not intended to be complete representations
of the National Electrical Manufacturers Association standards for enclosures.
Underwriter Laboratories Inc. (UL 50 and UL 508)
TYPE Intended Use and Description (Approximate IP equivalents)
Type 1 Indoor use primarily to provide protection against contact with the enclosed equipment and against limited amount of falling dirt (IP30).
Type 2 Indoor use to provide a degree of protection against limited amounts of falling water and dirt (IP31).
Type 3 Outdoor use to provide a degree of protection against windblown dust and windblown rain; undamaged by the formation of ice on the enclosure (IP64).
Type 3R Outdoor use to provide a degree of protection against falling rain and sleet; undamaged by the formation of ice on the enclosure (IP32).
Type 3S Outdoor use to provide a degree of protection against windblown dust, rain and sleet; external mechanisms remain operable while ice laden.
Type 4 Either indoor or outdoor use to provide a degree of protection against falling rain, splashing water, and hose-directed water; undamaged by the formation of ice on the enclosure(IP66).
Type 4X Same as type 4 except this one is corrosion resistant (IP66).
Type 6 Indoor or outdoor use to provide a degree of protection against entry of water during temporary submersion at a limited depth; undamaged by formation of ice on the enclosure.
Type 6P Indoor or outdoor use to provide a degree of protection against entry of water during prolong submersion at a limited depth.
Type 11 Indoor use to provide by oil immersion a degree of protection of the enclosed equipment against the corrosive effects of corrosive liquids and gases.
Type 12/12K Indoor use to provide a degree of protection against dust, falling dirt, fiber flyings, dripping water, and external condensation or dripping of non corrosive liquids (IP65).
Type 13 Indoor use to provide a degree of protection against lint, dust seepage, external condensation and spraying of water, oil, and non corrosive liquids (IP65).
If there is anything you would like to add or if you have any comments please feel free to email at electrical_engineer@alriyadh.cc
PROJECT MANAGEMENT
A successful project starts with solid planning and ends with a smooth hand-off…
The phrases “on time” and “within budget” are often used in discussions of project delivery, but how often can they actually be used to describe a project? Project schedules can fall apart for any number of reasons, but it's often a case of poor planning and a lack of communication. And if participants have uncommon goals or are left out of the early planning stages, a project can be doomed from the start. The lesson to be learned is that early decisions — both good and bad — have a cascading effect throughout the entire life of the project. Taking the time to establish a well-thought-out plan before the first drawing is printed may seem daunting, but it can help you improve both your budget and schedule performance by 30% or more.
Industry-wide studies conducted by the Philadelphia - based Center for Business Practices (CBP) found that organizations that implemented project-planning initiatives report a 34% improvement in schedule performance, a 30% improvement in budget performance, and a 50% increase in projects completed.
You may not want to take the time to put together a formal plan, but the alternative could be even less desirable. When our firm was contracted to install the electrical portion of a food processing plant, we learned just what kind of an effect poor planning can have. Not only did the various trades not coordinate well with each other, nobody knew who was responsible for completing important tasks on the job. Part way through the project, we discovered large gaps where critical tasks hadn't been assigned to anyone, and other areas where the same task had been assigned to multiple groups. This created mass confusion for all. By the time the project reached completion, the value of our contract had doubled due to extra work and change orders.
The extra money you can make on all those change orders may seem worth it, but it can come back to bite you in the long run. Change orders interrupt or alter the original work sequence and result in additional coordination and planning. They can also extend the use of tools and labor. Sometimes, they may even require you to completely redo your work.
Even a project as simple as switching out light fixtures and outlets requires adequate planning to be successful. It can be very time consuming and expensive to use a trial and error method (Fig. 1). Moving things around and making changes is much easier on paper than it is once you've got the space torn apart. The dry-waller, painter, and electrician must all do their part to make everything come together in a smooth manner.
Whether you're wiring a new office building or retrofitting a multi-million dollar processing plant, the four keys to completing the project successfully are the same.
Key #1: Determine the Overall Goal of the Project. Are you trying to improve the light levels in an office or change the electrical wiring to fit a new room layout? Does the industrial facility want to increase production capacity, improve safety, or reduce utility costs? Focus on the ultimate business goal rather than simply how to complete your given task.
The cost and duration of a project can slowly rise unnoticed until it's too late, so make sure that you understand and define a successful “complete project” so everyone involved — including the owner — is aware of expectations. Early planning and collaboration between the electrical professional and everyone else involved can take into consideration issues like reliability, upgrades, change readiness, operating costs, and energy savings. A good plan will help everyone win, including the customer and the other contractors involved.
Key #2: Get All the Right People Involved Early. Everyone participating in the project must be involved and up-to-date from the beginning. Call a meeting and share all pertinent project information with other subcontractors, suppliers, internal engineering groups, accountants, and maintenance personnel. Early feedback from the assembled team regarding the design can go a long way in both adding value and preventing potential snags farther down the road (Fig. 2). It's much easier to make adjustments to the project/schedule now than later.
Each project has dependencies that need to be mapped out. For example, during office construction, it would be problematic if the electrician didn't know where each office was going to be located in the final layout or if the painter and dry-waller had not received a copy of his work schedule. The carpenter must put up the stud walls before the electrician can rough in the wiring. The painter can't begin until the drywall has been mudded and sanded. Carpeting can't be ordered until the office dimensions and layouts are known.
Trade coordination is especially important to a project in a processing plant. Many parts of a process plant must interface or other components will be negatively affected. One of our firm's recent projects faced both budgetary and technical challenges. By having engineering, construction, instrumentation, and control engineering work together on designing intrinsically safe instrumentation and control hardware in a hazardous area, we found that although more was spent on the initial devices, the reduced wiring costs that resulted (conventional instead of classified) not only compensated for the additional hardware cost but also resulted in overall savings on the project. On top of that, this design now allows the owner to maintain the equipment during operations in the sensitive area.
A big part of getting people involved is also getting their buy-in. Involving everyone in early discussion and decision-making creates a sense of ownership. When people understand why a decision was made, what's considered successful, and feel that their concerns have been adequately addressed; they'll be much more willing to cooperate. This sense of ownership will lead them away from a “looking out for me” mentality and promote overall project success.
Key #3: Coordinate and Communicate — the Earlier the Better. Having a plan is great but it's not worth the paper it's printed on if no one follows it. Owner involvement is the key to ensuring that the plan is followed. Explain what needs to happen when and what the consequences will be if the schedule isn't adhered to.
Often once the “what” of the project is completed, the owner steps out and isn't involved in the “how.” All that matters is that it gets done. As one player among many, electrical contractors are very dependent on others to complete their work.
It's very important to make sure that the owner understands how important each piece in the schedule is to the ultimate success of the project. The owner can then hold everyone accountable and make sure things get done when and how they're supposed to.
Knowing when things are going to happen allows team members to better schedule their time and resources. A Contractor Productivity Survey reported highly improved productivity when their field managers planned for resources more than five days in advance. Early & consistent planning & communication will help identify the team's concerns & resource conflicts early enough to adjust without causing many problems.
During another recent project, our firm needed to install 2,000 feet of conduit within the concrete foundation, all during a very aggressive plant shutdown. By planning effectively, we were able to identify problems early, like drawing errors regarding existing conduit and concrete pier locations, trade stacking, and scheduling inconsistencies, that wouldn't have been discovered until installation. Instead of putting the entire project behind schedule, working closely with the other contractors helped cut three days out of the shutdown schedule.
Unforeseen issues always come up and put people behind schedule. But when the owner stays involved in the project schedule and everyone on the team communicates effectively, it's much easier to manage expectations and adapt accordingly.
Key #4: Hand Off the Completed Project. A complex industrial project can be a once in a lifetime opportunity, so getting things right is critical. And a chief component of that is making sure that the right personnel are involved in the project wrap-up. Too often, while the installer is busy testing the equipment and making sure things are running smoothly, the people that will be responsible for operating the plant when they leave are busy painting railings, sweeping floors, or simply not around.
It's not enough to just get the owner's approval. You must also set up the appropriate support system to help those who will take over. Training and support can often leave a lasting impression on those who now have to operate and maintain the newly installed equipment. Appropriate documentation will make future support and maintenance much easier and also simplify the work for the next person who might have to modify your work.
No project goes exactly as planned, but it will be much easier to resolve problems if you understand the overall project goal, get early input from everyone involved, make sure people are communicating and working together, and leave behind an appropriate support system. These keys will go a long way in helping you achieve your “on time” and “within budget” goals.
The phrases “on time” and “within budget” are often used in discussions of project delivery, but how often can they actually be used to describe a project? Project schedules can fall apart for any number of reasons, but it's often a case of poor planning and a lack of communication. And if participants have uncommon goals or are left out of the early planning stages, a project can be doomed from the start. The lesson to be learned is that early decisions — both good and bad — have a cascading effect throughout the entire life of the project. Taking the time to establish a well-thought-out plan before the first drawing is printed may seem daunting, but it can help you improve both your budget and schedule performance by 30% or more.
Industry-wide studies conducted by the Philadelphia - based Center for Business Practices (CBP) found that organizations that implemented project-planning initiatives report a 34% improvement in schedule performance, a 30% improvement in budget performance, and a 50% increase in projects completed.
You may not want to take the time to put together a formal plan, but the alternative could be even less desirable. When our firm was contracted to install the electrical portion of a food processing plant, we learned just what kind of an effect poor planning can have. Not only did the various trades not coordinate well with each other, nobody knew who was responsible for completing important tasks on the job. Part way through the project, we discovered large gaps where critical tasks hadn't been assigned to anyone, and other areas where the same task had been assigned to multiple groups. This created mass confusion for all. By the time the project reached completion, the value of our contract had doubled due to extra work and change orders.
The extra money you can make on all those change orders may seem worth it, but it can come back to bite you in the long run. Change orders interrupt or alter the original work sequence and result in additional coordination and planning. They can also extend the use of tools and labor. Sometimes, they may even require you to completely redo your work.
Even a project as simple as switching out light fixtures and outlets requires adequate planning to be successful. It can be very time consuming and expensive to use a trial and error method (Fig. 1). Moving things around and making changes is much easier on paper than it is once you've got the space torn apart. The dry-waller, painter, and electrician must all do their part to make everything come together in a smooth manner.
Whether you're wiring a new office building or retrofitting a multi-million dollar processing plant, the four keys to completing the project successfully are the same.
Key #1: Determine the Overall Goal of the Project. Are you trying to improve the light levels in an office or change the electrical wiring to fit a new room layout? Does the industrial facility want to increase production capacity, improve safety, or reduce utility costs? Focus on the ultimate business goal rather than simply how to complete your given task.
The cost and duration of a project can slowly rise unnoticed until it's too late, so make sure that you understand and define a successful “complete project” so everyone involved — including the owner — is aware of expectations. Early planning and collaboration between the electrical professional and everyone else involved can take into consideration issues like reliability, upgrades, change readiness, operating costs, and energy savings. A good plan will help everyone win, including the customer and the other contractors involved.
Key #2: Get All the Right People Involved Early. Everyone participating in the project must be involved and up-to-date from the beginning. Call a meeting and share all pertinent project information with other subcontractors, suppliers, internal engineering groups, accountants, and maintenance personnel. Early feedback from the assembled team regarding the design can go a long way in both adding value and preventing potential snags farther down the road (Fig. 2). It's much easier to make adjustments to the project/schedule now than later.
Each project has dependencies that need to be mapped out. For example, during office construction, it would be problematic if the electrician didn't know where each office was going to be located in the final layout or if the painter and dry-waller had not received a copy of his work schedule. The carpenter must put up the stud walls before the electrician can rough in the wiring. The painter can't begin until the drywall has been mudded and sanded. Carpeting can't be ordered until the office dimensions and layouts are known.
Trade coordination is especially important to a project in a processing plant. Many parts of a process plant must interface or other components will be negatively affected. One of our firm's recent projects faced both budgetary and technical challenges. By having engineering, construction, instrumentation, and control engineering work together on designing intrinsically safe instrumentation and control hardware in a hazardous area, we found that although more was spent on the initial devices, the reduced wiring costs that resulted (conventional instead of classified) not only compensated for the additional hardware cost but also resulted in overall savings on the project. On top of that, this design now allows the owner to maintain the equipment during operations in the sensitive area.
A big part of getting people involved is also getting their buy-in. Involving everyone in early discussion and decision-making creates a sense of ownership. When people understand why a decision was made, what's considered successful, and feel that their concerns have been adequately addressed; they'll be much more willing to cooperate. This sense of ownership will lead them away from a “looking out for me” mentality and promote overall project success.
Key #3: Coordinate and Communicate — the Earlier the Better. Having a plan is great but it's not worth the paper it's printed on if no one follows it. Owner involvement is the key to ensuring that the plan is followed. Explain what needs to happen when and what the consequences will be if the schedule isn't adhered to.
Often once the “what” of the project is completed, the owner steps out and isn't involved in the “how.” All that matters is that it gets done. As one player among many, electrical contractors are very dependent on others to complete their work.
It's very important to make sure that the owner understands how important each piece in the schedule is to the ultimate success of the project. The owner can then hold everyone accountable and make sure things get done when and how they're supposed to.
Knowing when things are going to happen allows team members to better schedule their time and resources. A Contractor Productivity Survey reported highly improved productivity when their field managers planned for resources more than five days in advance. Early & consistent planning & communication will help identify the team's concerns & resource conflicts early enough to adjust without causing many problems.
During another recent project, our firm needed to install 2,000 feet of conduit within the concrete foundation, all during a very aggressive plant shutdown. By planning effectively, we were able to identify problems early, like drawing errors regarding existing conduit and concrete pier locations, trade stacking, and scheduling inconsistencies, that wouldn't have been discovered until installation. Instead of putting the entire project behind schedule, working closely with the other contractors helped cut three days out of the shutdown schedule.
Unforeseen issues always come up and put people behind schedule. But when the owner stays involved in the project schedule and everyone on the team communicates effectively, it's much easier to manage expectations and adapt accordingly.
Key #4: Hand Off the Completed Project. A complex industrial project can be a once in a lifetime opportunity, so getting things right is critical. And a chief component of that is making sure that the right personnel are involved in the project wrap-up. Too often, while the installer is busy testing the equipment and making sure things are running smoothly, the people that will be responsible for operating the plant when they leave are busy painting railings, sweeping floors, or simply not around.
It's not enough to just get the owner's approval. You must also set up the appropriate support system to help those who will take over. Training and support can often leave a lasting impression on those who now have to operate and maintain the newly installed equipment. Appropriate documentation will make future support and maintenance much easier and also simplify the work for the next person who might have to modify your work.
No project goes exactly as planned, but it will be much easier to resolve problems if you understand the overall project goal, get early input from everyone involved, make sure people are communicating and working together, and leave behind an appropriate support system. These keys will go a long way in helping you achieve your “on time” and “within budget” goals.
Thursday, December 13, 2007
ACHIEVE IT! QUOTES
"Aim for success not perfection... Remember that fear always lurks behind perfectionism. Confronting your fears and allowing yourself the right to be human can, paradoxically, make you a far happier and more productive person." - Dr. David Burns
"The secret to productive goal setting is in establishing clearly defined goals, writing them down and then focusing on them several times a day with words, pictures and emotions as if we've already achieved them." - Denis Waitley
"Your own mind is a sacred enclosure into which nothing harmful can enter except by your permission." - Ralph Waldo Emerson
"Work as though you would live forever, and live as though you would die today" - Og Mandino
"You don't have to be a fantastic hero to do certain things - to compete. You can be just an ordinary chap, sufficiently motivated to reach challenging goals" - Edmund Hillary
"Goals are dreams with deadlines" - Diana Scharf Hunt
"If you're bored with life -- you don't get up every morning with a burning desire to do things -- you don't have enough goals." - Lou Holtz
"Goals are not only absolutely necessary to motivate us. They are essential to really keep us alive." - Robert H. Schuller
"You have to set goals that are almost out of reach. If you set a goal that is attainable without much work or thought, you are stuck with something below your true talent and potential." - Steve Garvey
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals." - Booker T. Washington
"It’s always fun to do the impossible." - Walt Disney
"My philosophy of life is that if we make up our mind what we are going to make of our lives, then work hard toward that goal, we never lose - somehow we win out." - Ronald Regan
"Goals. There's not telling what you can do when you get inspired by them. There's no telling what you can do when you believe in them. There's no telling what will happen when you act upon them." - Jim Rohn
"Your goals are the road maps that guide you and show you what is possible for your life." - Les Brown
"Big goals get big results. No goals get no results or somebody else's results." - Mark Victor Hansen
"Goals give you more than a reason to get up in the morning; they are an incentive to keep you going all day. Goals tend to tap the deeper resources and draw the best out of life." - Harvey Mackay
"Emptiness is a symptom that you are not living creatively. You either have not goal that is important enough to you, or you are not using your talents and efforts in a striving toward an important goal." - Maxwell Maltz
"Remember, what you get by reaching your destination isn't nearly as important as what you become by reaching your goals -- what you will become is the winner you were born to be!" - Zig Ziglar
"If you aim at nothing, you'll hit it every time." – Anonymous
"All you have to do is know where you're going. The answers will come to you of their own accord." - Earl Nightingale
"The secret to productive goal setting is in establishing clearly defined goals, writing them down and then focusing on them several times a day with words, pictures and emotions as if we've already achieved them." - Denis Waitley
"Your own mind is a sacred enclosure into which nothing harmful can enter except by your permission." - Ralph Waldo Emerson
"Work as though you would live forever, and live as though you would die today" - Og Mandino
"You don't have to be a fantastic hero to do certain things - to compete. You can be just an ordinary chap, sufficiently motivated to reach challenging goals" - Edmund Hillary
"Goals are dreams with deadlines" - Diana Scharf Hunt
"If you're bored with life -- you don't get up every morning with a burning desire to do things -- you don't have enough goals." - Lou Holtz
"Goals are not only absolutely necessary to motivate us. They are essential to really keep us alive." - Robert H. Schuller
"You have to set goals that are almost out of reach. If you set a goal that is attainable without much work or thought, you are stuck with something below your true talent and potential." - Steve Garvey
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals." - Booker T. Washington
"It’s always fun to do the impossible." - Walt Disney
"My philosophy of life is that if we make up our mind what we are going to make of our lives, then work hard toward that goal, we never lose - somehow we win out." - Ronald Regan
"Goals. There's not telling what you can do when you get inspired by them. There's no telling what you can do when you believe in them. There's no telling what will happen when you act upon them." - Jim Rohn
"Your goals are the road maps that guide you and show you what is possible for your life." - Les Brown
"Big goals get big results. No goals get no results or somebody else's results." - Mark Victor Hansen
"Goals give you more than a reason to get up in the morning; they are an incentive to keep you going all day. Goals tend to tap the deeper resources and draw the best out of life." - Harvey Mackay
"Emptiness is a symptom that you are not living creatively. You either have not goal that is important enough to you, or you are not using your talents and efforts in a striving toward an important goal." - Maxwell Maltz
"Remember, what you get by reaching your destination isn't nearly as important as what you become by reaching your goals -- what you will become is the winner you were born to be!" - Zig Ziglar
"If you aim at nothing, you'll hit it every time." – Anonymous
"All you have to do is know where you're going. The answers will come to you of their own accord." - Earl Nightingale
Tuesday, December 11, 2007
GENERAL SPECIFICATION FOR LV SWITCHBOARDS
PART 1 - GENERAL
1.01 DESCRIPTION
A. This section covers the manufacture, furnish, installation and testing of all equipment, accessories and materials required for the installation of LV Switchboards (Type Tested Assemblies) in accordance with the specifications and drawings.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO 1609 Saudi Standard for low voltage switchgear and controlgear
assemblies-Part 1 : Type tested and partially type tested assemblies
2. IEC 60439-1 Low voltage switchgear and controlgear assemblies-
Part 1 : Type tested and partially type tested assemblies
3. IEC 60529 Degrees of protection provided by enclosure (IP Code)
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed switchboards.
C. If requested by the Ministry, the supplier shall provide proof of application of a quality procedure complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
D. The manufacturer must have a sound experience in the field of LV switchboards for not less than ten years, and should have a presentable reference list of the already supplied equipment of the same type and same make and that this equipment has been in satisfactory operation in Kingdom of Saudi Arabia for at least five years.
1.04 SUBMITTAL
A. Shop Drawings and Manufacturer's Data:
The contractor shall submit to the Ministry representative for review, detailed dimensioned shop drawings and manufacturer's literature where deviations from the contract drawings or specification exist. Shop drawings and/or data sheets shall be based on information stated in the specifications and as shown on the contract drawings and shall show all pertinent deviations and data for the fabrication and complete installation.
Manufacturer's data sheets shall be submitted indicating the necessary installation dimensions, weights, materials and performance information. The above information may be provided by standard catalogue sheets marked to indicate the specific items provided.
B. Operation and Maintenance Instructions:
The contractor shall furnish data covering model, type and serial numbers, capacities, maintenance and operation of each major item of equipment or apparatus in accordance with the requirements of the contract documents. Operating instructions shall cover all phases of control.
C. Test Reports:
The contractor shall submit test reports to the Ministry representative for review.
D. Recommended Spare Parts List:
The contractor shall submit recommended spare parts list to the Ministry representative for review.
E. As Built Drawings:
The contractor shall submit the as built drawings to the Ministry representative for review and approval.
1.05 COORDINATION
A. The contractor shall be held responsible for the proper coordination of all phases of the work under this contract.
B. It shall be the responsibility of the contractor to coordinate the work and equipment as specified herein with work to be performed and equipment to be furnished under other sections of the specifications in order to assure a complete and satisfactory installation.
1.06 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Deliver, store, protect and handle products to site as per manufacturer’s instructions.
B. Store swithboards in clean and dry space. Inspect for damage. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect units from dirt, water, construction debris and traffic.
C. Lift only with lugs provided for the purpose. Handle carfully to avoid damage to switchboard internal components, enclosure and finish.
PART 2 - PRODUCTION
2.01 GENERAL
A. The following specifications apply to LV Switchboards rated above 250 Amps and upto 4000 Amps, classified as ‘Main Distribution Boards’ and ‘Sub-Main Distribution Boards’.
B. Extensions to the low voltage electrical switchboards shall be possible on either side (right or left).
C. The Switchboard and the associated Switchgear and Controlgear like Circuit Breakers, Contactors, Switches, Meters etc. should be from the same manufacturer.
2.02 TECHNICAL CHARACTERISTIC
A. The switchboards shall be designed and tested for the following electrical values:
1. Rated voltage 1000 V three-phase.
2. Rated operating voltage 690V
3. Frequency 60 Hz.
4. Insulation level 2.5 kV- 60 Hz, 1min
8 kV-1,2/50µs.
5. Busbar rated current As shown on the drawings.
6. Short-circuit withstand current As shown on the drawings.
7. Degree of protection (IP) IP 31 for Indoor Application and IP55 for Outdoor
Application or as indicated on the drawings
8 Impact strength (IK) IK08 for Indoor Application and IK10 for Outdoor Application.
2.03 SERVICE CONDITIONS
A. The switchboard shall be suitable for operations at a height of less than 2000 meters above sea level.
B. The switchboards shall be capable of operating normally within the following temperature range
1. Maximum air temperature + 40 ° C
2. Minimum air temperature - 5 ° C
C. Manufacturer shall declare wether switchboard is able to operate in air temperature higher than + 40 °C and if current derating is necessary.
2.04 CONSTRUCTION AND OPERATION
A. The low voltage switchboard shall have a permissible asymmetrical short circuit current up to short circuit current shown on the drawings for 1 second. The busbars shall be designed for mounting on insulated supports that are sufficient in number to accept the electro-dynamic forces resulting from the flow of the peak asymmetrical short circuit current.
B. The low voltage switchboard shall have an earthing circuit including a bar that can be removed for isolation purposes during the necessary insulation measurements (removal of the bar shall require a tool)
C. The switchboard shall be suitable for front or rear connections.
D. Cable entry shall be via the bottom or the top.
E. The low voltage switchboard shall not be heigher than 2000mm.
F. Natural ventilation shall make it possible for the Switchboard components to operate with in the recommended temperature ranges.
G. The low voltage electrical switchboard shall have small depths, thus optimizing layout in electrical rooms:
1. Max. 400 mm up to 1600A.
2. Max.1200 mm up to 4000 A.
H. The system shall make it possible to implement fixed or withdrawable distribution switchgear.
I. Selection of switchboard components shall be made in compliance with standard IEC 60947 and related specification in the contract documents.
J. The low voltage electrical switchboard shall be made up of identified functional volumes including the busbar compartment, switchgear and controlgear component compartment, connection compartment and auxiliaries compartment.
1. The different types of busbars shall be the main busbars, distribution busbars and auxiliary busbars.
2. The busbars shall be made of electrolytic copper.
3. The compartment shall be located inside a metal enclosure with walls providing protection against direct contact with live parts and guaranteeing a degree of protection (IP) requested. The frame, the external panels (doors, side and rear panels, tops) and internal elements (ducts) shall be made of 1.5-mm thick folded metal steel sheet and protected by epoxy polyester powder paint coating.
K. Withdrawable circuit breakers shall have four different positions:
1. Connected
2. Test
3. Disconnected
4. Removed
L. The switchboard shall be suitable for installation side by side and back to back and capable of receiving lateral ducts for busbar, cables and terminals.
M. The switchboard cover panel shall be removable.
N. The construction system shall provide a complete set of elements for installing fixed or withdrawable switching and protective devices, measurement devices and control/ monitoring devices in the switchboard.
2.05 Protection and safety
A. The low voltage electrical switchboards shall ensure the safety of life and property as well as provide a high level of continuity to service
1. Switching safety shall be ensured by mechanical device preventing on load withdrawal
2. Operating safety shall be ensured by compartmenting in compliance with standard IEC 60439-1 and according to Form 2b. However, if specifically asked, the same Switchboard should be capable of upgrading to Form 3a, 3b, 4a or 4b.
3. Current interruption shall be of the “ visible break isolation “or “positive contact indication “type as defined by standard IEC 60947-3.
B. In view of reducing the risk of electrical shock
1. Power and control circuit shall be separate and completely isolated.
2. Auxiliary circuits shall be of the extra low voltage type.
2.06 TYPE TESTS AND ROUTINE TESTS
A. Routine Tests
The switchboard shall be subject to Routine Factory Test carried out by the Panelbuilder and shall be substantiated by a test report signed by the factory quality control department., in accordance with IEC 60439 –1 as follows:
1. Conformity with drawings and diagrams.
2. Visual Inspection.
3. Functional electrical and mechanical operation
4. Dielectric test.
B. Type Tests
In accordance with IEC 60439 –1, the Switchboard Design must have qualified fully to the Seven Type-Tests detailed below, conducted by an Accredited Independent Testing Laboratory like ASEFA, ASTA, KEMA etc. Certificates for each Test shall be submitted to the Ministry Representative for Review.
1. Temperature-rise test.
2. Dielectric test.
3. Short-circuit withstand test.
4. Effectiveness of the protective circuits test.
5. Clearance and creepage distance test.
6. Mechanical operation test.
7. Degree of protection test.
PART 3 - EXECUTION
3.01 WORKMANSHIP
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
3.02 FOUNDATIONS AND SUPPORTS
A. The contractor shall provide concrete pedestals, anchor bolts, hangers, channels, saddles, etc., for installation of equipment and apparatus shown on the drawings and specified in the various sections.
3.03 EQUIPMENT INSTALLATION
A. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly. The connections shall be tightened with manual torque wrenches to the manufacturer's erection instructions.
C. Splices shall be implemented to ensure the electrical continuity of the horizontal busbars, auxiliary buses and the proactive conductor between adjacent sections.
D. It shall be possible to secure the sections to a floor that is flat by nchoring directly to a concrete floor using anchor bolts or by securing to ordinary metal profiles.
3.04 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.
1.01 DESCRIPTION
A. This section covers the manufacture, furnish, installation and testing of all equipment, accessories and materials required for the installation of LV Switchboards (Type Tested Assemblies) in accordance with the specifications and drawings.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO 1609 Saudi Standard for low voltage switchgear and controlgear
assemblies-Part 1 : Type tested and partially type tested assemblies
2. IEC 60439-1 Low voltage switchgear and controlgear assemblies-
Part 1 : Type tested and partially type tested assemblies
3. IEC 60529 Degrees of protection provided by enclosure (IP Code)
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed switchboards.
C. If requested by the Ministry, the supplier shall provide proof of application of a quality procedure complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
D. The manufacturer must have a sound experience in the field of LV switchboards for not less than ten years, and should have a presentable reference list of the already supplied equipment of the same type and same make and that this equipment has been in satisfactory operation in Kingdom of Saudi Arabia for at least five years.
1.04 SUBMITTAL
A. Shop Drawings and Manufacturer's Data:
The contractor shall submit to the Ministry representative for review, detailed dimensioned shop drawings and manufacturer's literature where deviations from the contract drawings or specification exist. Shop drawings and/or data sheets shall be based on information stated in the specifications and as shown on the contract drawings and shall show all pertinent deviations and data for the fabrication and complete installation.
Manufacturer's data sheets shall be submitted indicating the necessary installation dimensions, weights, materials and performance information. The above information may be provided by standard catalogue sheets marked to indicate the specific items provided.
B. Operation and Maintenance Instructions:
The contractor shall furnish data covering model, type and serial numbers, capacities, maintenance and operation of each major item of equipment or apparatus in accordance with the requirements of the contract documents. Operating instructions shall cover all phases of control.
C. Test Reports:
The contractor shall submit test reports to the Ministry representative for review.
D. Recommended Spare Parts List:
The contractor shall submit recommended spare parts list to the Ministry representative for review.
E. As Built Drawings:
The contractor shall submit the as built drawings to the Ministry representative for review and approval.
1.05 COORDINATION
A. The contractor shall be held responsible for the proper coordination of all phases of the work under this contract.
B. It shall be the responsibility of the contractor to coordinate the work and equipment as specified herein with work to be performed and equipment to be furnished under other sections of the specifications in order to assure a complete and satisfactory installation.
1.06 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Deliver, store, protect and handle products to site as per manufacturer’s instructions.
B. Store swithboards in clean and dry space. Inspect for damage. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect units from dirt, water, construction debris and traffic.
C. Lift only with lugs provided for the purpose. Handle carfully to avoid damage to switchboard internal components, enclosure and finish.
PART 2 - PRODUCTION
2.01 GENERAL
A. The following specifications apply to LV Switchboards rated above 250 Amps and upto 4000 Amps, classified as ‘Main Distribution Boards’ and ‘Sub-Main Distribution Boards’.
B. Extensions to the low voltage electrical switchboards shall be possible on either side (right or left).
C. The Switchboard and the associated Switchgear and Controlgear like Circuit Breakers, Contactors, Switches, Meters etc. should be from the same manufacturer.
2.02 TECHNICAL CHARACTERISTIC
A. The switchboards shall be designed and tested for the following electrical values:
1. Rated voltage 1000 V three-phase.
2. Rated operating voltage 690V
3. Frequency 60 Hz.
4. Insulation level 2.5 kV- 60 Hz, 1min
8 kV-1,2/50µs.
5. Busbar rated current As shown on the drawings.
6. Short-circuit withstand current As shown on the drawings.
7. Degree of protection (IP) IP 31 for Indoor Application and IP55 for Outdoor
Application or as indicated on the drawings
8 Impact strength (IK) IK08 for Indoor Application and IK10 for Outdoor Application.
2.03 SERVICE CONDITIONS
A. The switchboard shall be suitable for operations at a height of less than 2000 meters above sea level.
B. The switchboards shall be capable of operating normally within the following temperature range
1. Maximum air temperature + 40 ° C
2. Minimum air temperature - 5 ° C
C. Manufacturer shall declare wether switchboard is able to operate in air temperature higher than + 40 °C and if current derating is necessary.
2.04 CONSTRUCTION AND OPERATION
A. The low voltage switchboard shall have a permissible asymmetrical short circuit current up to short circuit current shown on the drawings for 1 second. The busbars shall be designed for mounting on insulated supports that are sufficient in number to accept the electro-dynamic forces resulting from the flow of the peak asymmetrical short circuit current.
B. The low voltage switchboard shall have an earthing circuit including a bar that can be removed for isolation purposes during the necessary insulation measurements (removal of the bar shall require a tool)
C. The switchboard shall be suitable for front or rear connections.
D. Cable entry shall be via the bottom or the top.
E. The low voltage switchboard shall not be heigher than 2000mm.
F. Natural ventilation shall make it possible for the Switchboard components to operate with in the recommended temperature ranges.
G. The low voltage electrical switchboard shall have small depths, thus optimizing layout in electrical rooms:
1. Max. 400 mm up to 1600A.
2. Max.1200 mm up to 4000 A.
H. The system shall make it possible to implement fixed or withdrawable distribution switchgear.
I. Selection of switchboard components shall be made in compliance with standard IEC 60947 and related specification in the contract documents.
J. The low voltage electrical switchboard shall be made up of identified functional volumes including the busbar compartment, switchgear and controlgear component compartment, connection compartment and auxiliaries compartment.
1. The different types of busbars shall be the main busbars, distribution busbars and auxiliary busbars.
2. The busbars shall be made of electrolytic copper.
3. The compartment shall be located inside a metal enclosure with walls providing protection against direct contact with live parts and guaranteeing a degree of protection (IP) requested. The frame, the external panels (doors, side and rear panels, tops) and internal elements (ducts) shall be made of 1.5-mm thick folded metal steel sheet and protected by epoxy polyester powder paint coating.
K. Withdrawable circuit breakers shall have four different positions:
1. Connected
2. Test
3. Disconnected
4. Removed
L. The switchboard shall be suitable for installation side by side and back to back and capable of receiving lateral ducts for busbar, cables and terminals.
M. The switchboard cover panel shall be removable.
N. The construction system shall provide a complete set of elements for installing fixed or withdrawable switching and protective devices, measurement devices and control/ monitoring devices in the switchboard.
2.05 Protection and safety
A. The low voltage electrical switchboards shall ensure the safety of life and property as well as provide a high level of continuity to service
1. Switching safety shall be ensured by mechanical device preventing on load withdrawal
2. Operating safety shall be ensured by compartmenting in compliance with standard IEC 60439-1 and according to Form 2b. However, if specifically asked, the same Switchboard should be capable of upgrading to Form 3a, 3b, 4a or 4b.
3. Current interruption shall be of the “ visible break isolation “or “positive contact indication “type as defined by standard IEC 60947-3.
B. In view of reducing the risk of electrical shock
1. Power and control circuit shall be separate and completely isolated.
2. Auxiliary circuits shall be of the extra low voltage type.
2.06 TYPE TESTS AND ROUTINE TESTS
A. Routine Tests
The switchboard shall be subject to Routine Factory Test carried out by the Panelbuilder and shall be substantiated by a test report signed by the factory quality control department., in accordance with IEC 60439 –1 as follows:
1. Conformity with drawings and diagrams.
2. Visual Inspection.
3. Functional electrical and mechanical operation
4. Dielectric test.
B. Type Tests
In accordance with IEC 60439 –1, the Switchboard Design must have qualified fully to the Seven Type-Tests detailed below, conducted by an Accredited Independent Testing Laboratory like ASEFA, ASTA, KEMA etc. Certificates for each Test shall be submitted to the Ministry Representative for Review.
1. Temperature-rise test.
2. Dielectric test.
3. Short-circuit withstand test.
4. Effectiveness of the protective circuits test.
5. Clearance and creepage distance test.
6. Mechanical operation test.
7. Degree of protection test.
PART 3 - EXECUTION
3.01 WORKMANSHIP
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
3.02 FOUNDATIONS AND SUPPORTS
A. The contractor shall provide concrete pedestals, anchor bolts, hangers, channels, saddles, etc., for installation of equipment and apparatus shown on the drawings and specified in the various sections.
3.03 EQUIPMENT INSTALLATION
A. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly. The connections shall be tightened with manual torque wrenches to the manufacturer's erection instructions.
C. Splices shall be implemented to ensure the electrical continuity of the horizontal busbars, auxiliary buses and the proactive conductor between adjacent sections.
D. It shall be possible to secure the sections to a floor that is flat by nchoring directly to a concrete floor using anchor bolts or by securing to ordinary metal profiles.
3.04 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.
SPECIFICATION FOR LV FINAL DISTRIBUTION BOARDS
PART 1 - GENERAL
1.01 DESCRIPTION
A. This section covers the manufacture, furnish, installation and testing of all equipment, accessories and materials required for the installation of LV Final Distribution Boards rated upto 250 Amps.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO 1611 Saudi Standard for Low Voltage Distribution Boards
2. IEC 60439-3 Low voltage Final Distribution Boards.
3. IEC 60529 Degree of Protection provided by the encloure (IP Code)
4. IEC 60947-2 Low Voltage Switchgear and Controlgear – Circuit breakers.
5. IEC 61008-1 Residual Current operated Circuit Breakers without integral Overcurrent Protection (RCCB’s)
6. IEC 61009 Residual Current operated Circuit Breakers with integral
Overcurrent Protection. (RCBO)
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed Distribution Boards.
C. The supplier shall provide proof of application of a quality procedure in the manufacturing facility complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
PART 2 - PRODUCTION
2.01 GENERAL
A. These specifications apply to LV Final Distribution Boards rated upto 250 Amps.
B. The Distribution Board and the associated Switchgear and Controlgear like Circuit Breakers, Contactors, Switches, etc. should be from the same manufacturer.
2.02 TECHNICAL CHARACTERISTICS
A. The Distribution Boards shall be designed and tested for the following electrical values:
1. Rated Insulation Voltage 690 V AC.
2. Rated Operating Voltage 415 V AC.
3. Frequency 50/60 Hz.
4. Busbar rated current upto 250 Amps. (or as indicated on the drawings)
5. Short-time withstand current 17 kA RMS for 200ms.
6. Peak Short Time withstand 34 kA
7. Degree of protection (IP) IP31 as per IEC 60529
2.03 CONSTRUCTION AND OPERATION
A. Metal enclosure of the low-voltage distribution board shall be made of electro galvanised steel sheet metal without any welding Points which shall have received an anti-corrosion coating (hot polymerised polyester/epoxy powder).
B. One central slotted hole should be provided to ease accurate levelling of the distribution board.
C. Additional slotted holes for ease at wall fixing should be provided.
D. The front face of the switchboards shall be removable to facilitate servicing.
E. Removable gland plate should be available at the top and the bottom of the distribution board
F. Cable knockouts should be available on sides, top and bottom of the distribution board for quicker and easier installation.
G. Main busbar should be made of tin-plated copper and fully shrouded.
H. Main busbar, in vertical position, should be installed into a rigid and adjustable suspended pan assembly.
I. In order to provide easy connection and maximum cable space, split neutral bars should be provided as standard in both sides.
J. Earth bar should be provided as standard.
K. Number of holes per terminal bar should not be less than the number of outgoings.
L. Switchgear and controlgear should be of DIN installation type.
M. Switchgear and controlgear connections to the busbar should be of bolt-on type.
2.04 PROTECTION AND SAFETY
A. The main busbar of the Distribution Board should be fully shrouded to prevent any accidental direct contact.
B. The split neutral busbar should be completely shrouded to prevent any accidental direct contact.
C. The Main Incoming Circuit-Breakers should provide additional Earth Leakage Protection. All the protection features of the Main Circuit Breaker, including Earth Leakage Protection, should be in full discrimination with those of the outgoing feeders (as per the relevant clauses of IEC 60947-2, IEC 61008 and IEC 61009) to minimise the isolation of a faulty part of the network.
D. All outgoing feeders to bathrooms, socket-outlets, AC units and Heaters should be provided with Residual Current Protection Devices for protection against direct and indirect contact, which should be coordinated with the Earth Protection of the Main Incoming Circuit Breaker.
E. All incoming switchgears should be suitable for isolation as per IEC 60947-2.
F. For critical loads requiring Continuity of Supply, all outgoing Branch Circuit-Breakers should be connected to the Main Bus bar by a fully shrouded OFF-LOAD Isolating Switch which should facilitate the replacement or removal of this Branch Breaker without de-energisation of the Distribution Board or any of the other adjacent Branches, and also provide complete protection against a direct contact with any energised part of the Distribution Board.
G. Keylock facility should be available in order to prevent the opening of the distribution board by non authorized persons.
H. Keylock should be field installable.
2.05 INDICATION
A. Identification labels should be provided for incoming and outgoing circuits, earth and neutral busbar.
B. Outgoer labels should be provided next to the branch circuit breakers for easy and direct outgoers identification
PART 3 - EXECUTION
3.01 WORKMANSHIP & INSTALLATION
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
B. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
3.02 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
a) General equipment check.
b) Field wiring and ground system verification.
c) Equipment adjustment.
1.01 DESCRIPTION
A. This section covers the manufacture, furnish, installation and testing of all equipment, accessories and materials required for the installation of LV Final Distribution Boards rated upto 250 Amps.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO 1611 Saudi Standard for Low Voltage Distribution Boards
2. IEC 60439-3 Low voltage Final Distribution Boards.
3. IEC 60529 Degree of Protection provided by the encloure (IP Code)
4. IEC 60947-2 Low Voltage Switchgear and Controlgear – Circuit breakers.
5. IEC 61008-1 Residual Current operated Circuit Breakers without integral Overcurrent Protection (RCCB’s)
6. IEC 61009 Residual Current operated Circuit Breakers with integral
Overcurrent Protection. (RCBO)
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed Distribution Boards.
C. The supplier shall provide proof of application of a quality procedure in the manufacturing facility complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
PART 2 - PRODUCTION
2.01 GENERAL
A. These specifications apply to LV Final Distribution Boards rated upto 250 Amps.
B. The Distribution Board and the associated Switchgear and Controlgear like Circuit Breakers, Contactors, Switches, etc. should be from the same manufacturer.
2.02 TECHNICAL CHARACTERISTICS
A. The Distribution Boards shall be designed and tested for the following electrical values:
1. Rated Insulation Voltage 690 V AC.
2. Rated Operating Voltage 415 V AC.
3. Frequency 50/60 Hz.
4. Busbar rated current upto 250 Amps. (or as indicated on the drawings)
5. Short-time withstand current 17 kA RMS for 200ms.
6. Peak Short Time withstand 34 kA
7. Degree of protection (IP) IP31 as per IEC 60529
2.03 CONSTRUCTION AND OPERATION
A. Metal enclosure of the low-voltage distribution board shall be made of electro galvanised steel sheet metal without any welding Points which shall have received an anti-corrosion coating (hot polymerised polyester/epoxy powder).
B. One central slotted hole should be provided to ease accurate levelling of the distribution board.
C. Additional slotted holes for ease at wall fixing should be provided.
D. The front face of the switchboards shall be removable to facilitate servicing.
E. Removable gland plate should be available at the top and the bottom of the distribution board
F. Cable knockouts should be available on sides, top and bottom of the distribution board for quicker and easier installation.
G. Main busbar should be made of tin-plated copper and fully shrouded.
H. Main busbar, in vertical position, should be installed into a rigid and adjustable suspended pan assembly.
I. In order to provide easy connection and maximum cable space, split neutral bars should be provided as standard in both sides.
J. Earth bar should be provided as standard.
K. Number of holes per terminal bar should not be less than the number of outgoings.
L. Switchgear and controlgear should be of DIN installation type.
M. Switchgear and controlgear connections to the busbar should be of bolt-on type.
2.04 PROTECTION AND SAFETY
A. The main busbar of the Distribution Board should be fully shrouded to prevent any accidental direct contact.
B. The split neutral busbar should be completely shrouded to prevent any accidental direct contact.
C. The Main Incoming Circuit-Breakers should provide additional Earth Leakage Protection. All the protection features of the Main Circuit Breaker, including Earth Leakage Protection, should be in full discrimination with those of the outgoing feeders (as per the relevant clauses of IEC 60947-2, IEC 61008 and IEC 61009) to minimise the isolation of a faulty part of the network.
D. All outgoing feeders to bathrooms, socket-outlets, AC units and Heaters should be provided with Residual Current Protection Devices for protection against direct and indirect contact, which should be coordinated with the Earth Protection of the Main Incoming Circuit Breaker.
E. All incoming switchgears should be suitable for isolation as per IEC 60947-2.
F. For critical loads requiring Continuity of Supply, all outgoing Branch Circuit-Breakers should be connected to the Main Bus bar by a fully shrouded OFF-LOAD Isolating Switch which should facilitate the replacement or removal of this Branch Breaker without de-energisation of the Distribution Board or any of the other adjacent Branches, and also provide complete protection against a direct contact with any energised part of the Distribution Board.
G. Keylock facility should be available in order to prevent the opening of the distribution board by non authorized persons.
H. Keylock should be field installable.
2.05 INDICATION
A. Identification labels should be provided for incoming and outgoing circuits, earth and neutral busbar.
B. Outgoer labels should be provided next to the branch circuit breakers for easy and direct outgoers identification
PART 3 - EXECUTION
3.01 WORKMANSHIP & INSTALLATION
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
B. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
3.02 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
a) General equipment check.
b) Field wiring and ground system verification.
c) Equipment adjustment.
LV Air Circuit Breakers – (Typical Specifications)
1. General
(a) LV Air circuit breakers shall comply with standards IEC 60 947-1 and 2 or standards derived from the latter.
(b) The Air circuit breakers shall have a breaking capacity justified by calculations taking into account their installation location.
(c) The number of circuit-breaker poles shall be as indicated on the single-line diagram.
(d) The Air Circuit Breaker should be available from 800 Amps to 4000 Amps in only one Frame size.
2. Construction
2.1. General
(a) Circuit breakers shall be designed in such a way that maintenance may be carried out as a function of their use. To reduce maintenance, electrical endurance shall be greater than 12 500 cycles up to 1600 A, 10 000 cycles up to 4000 A and 5000 cycles for values greater than 4000 A.
(b) No safety clearance shall be required around drawout circuit breakers. For fixed circuit breakers, 150 mm of free space shall be provided above the arc chutes to allow removal of the latter.
(c) The operating mechanism shall be of the Open/Closed/Open stored-energy type. The closing time shall be less than or equal to 70 milliseconds.
2.2. Main contacts
(a) The main contacts shall be designed such that no maintenance shall be required under normal conditions of use.
(b) The main contacts shall be equipped with a visual wear indicator that may be accessed by removing the arc chutes, for immediate assessment of contact wear without requiring measurements or specific tools.
2.3. Arc chutes
(a) The arc chutes shall be removable on site.
(b) They shall be equipped with metal filters to reduce effects perceptible from the outside during current interruption.
2.4. Connection/disconnection mechanism
(a) It shall be possible to disconnect the circuit breaker without having to open the door. The three possible positions (connected, disconnected and test) shall be indicated.
(b) Before carrying out a disconnection or connection operation, the operator shall be required to press a release button located on the front of the chassis.
(c) The door shall be equipped with a locking system preventing door opening with circuit breaker in the connected position. Safety shutters shall be placed over the main incoming and outgoing circuits. A mismatch-prevention system shall block insertion of a drawout circuit breaker with a power rating greater than that of the fixed part.
2.6. Electrical auxiliaries
(a) All electrical auxiliaries, including the spring-charging gear motor, shall be installable on site without requiring adjustments or any tools other than a screwdriver.
(b) The auxiliaries shall be placed in a compartment which, under normal operating conditions, shall not contain any conducting parts capable of entering into electrical contact with the circuit-breaker poles. It shall be possible to connect all auxiliary wiring from the front of the circuit breaker.
2.7. Mechanical indicators
Mechanical indicators on the front panel of the power circuit breakers shall indicate the following status conditions:
1. "ON" (main contacts closed) Spring charged
2. "ON" (main contacts closed) Spring discharged
3. "OFF" (main contacts open) Spring charged – circuit breaker ready to close
4. "OFF" (main contacts open) Spring charged – circuit breaker not ready to close
5. "OFF" (main contacts open) Spring discharged
3. Protection / Control unit
3.1. General
(a) The control unit shall be interchangeable on site for adaptation to changes in the installation.
(b) Sensors shall be non-magnetic or of the Rogosky type for accurate current measurements.
(c) The control unit shall measure the true rms value of the current.
(d) The control unit shall comprise a thermal memory to store temperature-rise data in the event of repeated overloads or earth faults.
3.2. Protection
The control unit shall offer the following protection functions as standard:
(a) Long-time (LT) protection with an adjustable current setting and time delay;
(b) Short-time (ST) protection with an adjustable pick-up and time delay;
(c) Instantaneous (INST) protection with an adjustable pick-up and an OFF position.
(d) Current and time-delay settings shall be indicated in amperes and seconds respectively on a digital display.
(e) Earth-fault protection with an adjustable pick-up and time delay shall be provided if indicated on the appended single-line diagram.
3.3. Measurements
(a) An ammeter with a digital display shall indicate the true rms values of the currents for each phase.
(b) A LED bargraph shall simultaneously display the load level on the three phases.
(c) A maximeter shall store in memory and display the maximum current value observed since the last reset. The data shall continue to be stored and displayed even after opening of the circuit breaker.
3.3 Power measurements
(a) The control unit shall measure voltages and calculate power and energy values.
(b) These values shall be displayable on the screen and updated every second. The minimum and maximum values shall be stored in memory.
(c) Accuracy
Energy (kWh) 2.5%
Real power (kW) 2.5%
Apparent power (kVA) 2.5%
Demand power (kWh) 2.5%
3.4Measurement of power quality
The control unit shall offer functions allowing the analysis of the quality of AC distribution system power, including:
Measurement of the amplitude and phase of current and voltage harmonics up to the 50th order;
Measurement of the fundamental components of the voltage, current, active power, reactive power and apparent power;
Measurement of total current and voltage harmonic distortion.
3.5 Additional protection functions
The control unit shall offer the protection functions listed below.
Threshold Time delay
Minimum voltage
Maximum voltage
Voltage imbalance 25 to 690 V
100 to 931 V
10 to 90% Umean 0.5 to 3s
0.25 to 1 s
1 to 15 s
Minimum frequency
Maximum frequency 33 to 400 Hz
33 to 540 Hz 0.5 to 3 s
0.25 to 1 s
Current imbalance
Maximum current 5 to 90% Imax
0.4 In to Isd 1 to 15 s
0.5 to 1000 s
Phase sequence * 1/2/3
Instantaneous
Reverse power 2 to 20% of Pn 0 to 20 s
3.6 Communication
The circuit breaker shall be capable of communicating the following data via a bus:
Circuit-breaker status (open/closed, connected/disconnected/test, tripped on a fault, ready to close);
Control-unit settings;
Tripping causes;
The measurements processed by the control unit: current, voltage, frequency, power, power quality.
It shall be possible to remotely control the circuit breaker.
It shall be possible to remotely modify circuit-breaker settings:
Settings within the range defined by the switches on the front panel of the control unit;
Settings of the protection functions and the alarms.
Communications functions shall be independent of the control unit.
3.7Maintenance
The last ten trips and alarms shall be stored in two registers that may be consulted locally (date and time, type of fault or alarm).
Maintenance indicators shall be displayable on request on the front panel:
Percent wear of contacts;
Operations counter.
4.End of service life
The manufacturer shall provide instructions on the removal, dismantling and processing of circuit-breaker materials at the end of service life (material composition, weight, toxicity).
(a) LV Air circuit breakers shall comply with standards IEC 60 947-1 and 2 or standards derived from the latter.
(b) The Air circuit breakers shall have a breaking capacity justified by calculations taking into account their installation location.
(c) The number of circuit-breaker poles shall be as indicated on the single-line diagram.
(d) The Air Circuit Breaker should be available from 800 Amps to 4000 Amps in only one Frame size.
2. Construction
2.1. General
(a) Circuit breakers shall be designed in such a way that maintenance may be carried out as a function of their use. To reduce maintenance, electrical endurance shall be greater than 12 500 cycles up to 1600 A, 10 000 cycles up to 4000 A and 5000 cycles for values greater than 4000 A.
(b) No safety clearance shall be required around drawout circuit breakers. For fixed circuit breakers, 150 mm of free space shall be provided above the arc chutes to allow removal of the latter.
(c) The operating mechanism shall be of the Open/Closed/Open stored-energy type. The closing time shall be less than or equal to 70 milliseconds.
2.2. Main contacts
(a) The main contacts shall be designed such that no maintenance shall be required under normal conditions of use.
(b) The main contacts shall be equipped with a visual wear indicator that may be accessed by removing the arc chutes, for immediate assessment of contact wear without requiring measurements or specific tools.
2.3. Arc chutes
(a) The arc chutes shall be removable on site.
(b) They shall be equipped with metal filters to reduce effects perceptible from the outside during current interruption.
2.4. Connection/disconnection mechanism
(a) It shall be possible to disconnect the circuit breaker without having to open the door. The three possible positions (connected, disconnected and test) shall be indicated.
(b) Before carrying out a disconnection or connection operation, the operator shall be required to press a release button located on the front of the chassis.
(c) The door shall be equipped with a locking system preventing door opening with circuit breaker in the connected position. Safety shutters shall be placed over the main incoming and outgoing circuits. A mismatch-prevention system shall block insertion of a drawout circuit breaker with a power rating greater than that of the fixed part.
2.6. Electrical auxiliaries
(a) All electrical auxiliaries, including the spring-charging gear motor, shall be installable on site without requiring adjustments or any tools other than a screwdriver.
(b) The auxiliaries shall be placed in a compartment which, under normal operating conditions, shall not contain any conducting parts capable of entering into electrical contact with the circuit-breaker poles. It shall be possible to connect all auxiliary wiring from the front of the circuit breaker.
2.7. Mechanical indicators
Mechanical indicators on the front panel of the power circuit breakers shall indicate the following status conditions:
1. "ON" (main contacts closed) Spring charged
2. "ON" (main contacts closed) Spring discharged
3. "OFF" (main contacts open) Spring charged – circuit breaker ready to close
4. "OFF" (main contacts open) Spring charged – circuit breaker not ready to close
5. "OFF" (main contacts open) Spring discharged
3. Protection / Control unit
3.1. General
(a) The control unit shall be interchangeable on site for adaptation to changes in the installation.
(b) Sensors shall be non-magnetic or of the Rogosky type for accurate current measurements.
(c) The control unit shall measure the true rms value of the current.
(d) The control unit shall comprise a thermal memory to store temperature-rise data in the event of repeated overloads or earth faults.
3.2. Protection
The control unit shall offer the following protection functions as standard:
(a) Long-time (LT) protection with an adjustable current setting and time delay;
(b) Short-time (ST) protection with an adjustable pick-up and time delay;
(c) Instantaneous (INST) protection with an adjustable pick-up and an OFF position.
(d) Current and time-delay settings shall be indicated in amperes and seconds respectively on a digital display.
(e) Earth-fault protection with an adjustable pick-up and time delay shall be provided if indicated on the appended single-line diagram.
3.3. Measurements
(a) An ammeter with a digital display shall indicate the true rms values of the currents for each phase.
(b) A LED bargraph shall simultaneously display the load level on the three phases.
(c) A maximeter shall store in memory and display the maximum current value observed since the last reset. The data shall continue to be stored and displayed even after opening of the circuit breaker.
3.3 Power measurements
(a) The control unit shall measure voltages and calculate power and energy values.
(b) These values shall be displayable on the screen and updated every second. The minimum and maximum values shall be stored in memory.
(c) Accuracy
Energy (kWh) 2.5%
Real power (kW) 2.5%
Apparent power (kVA) 2.5%
Demand power (kWh) 2.5%
3.4Measurement of power quality
The control unit shall offer functions allowing the analysis of the quality of AC distribution system power, including:
Measurement of the amplitude and phase of current and voltage harmonics up to the 50th order;
Measurement of the fundamental components of the voltage, current, active power, reactive power and apparent power;
Measurement of total current and voltage harmonic distortion.
3.5 Additional protection functions
The control unit shall offer the protection functions listed below.
Threshold Time delay
Minimum voltage
Maximum voltage
Voltage imbalance 25 to 690 V
100 to 931 V
10 to 90% Umean 0.5 to 3s
0.25 to 1 s
1 to 15 s
Minimum frequency
Maximum frequency 33 to 400 Hz
33 to 540 Hz 0.5 to 3 s
0.25 to 1 s
Current imbalance
Maximum current 5 to 90% Imax
0.4 In to Isd 1 to 15 s
0.5 to 1000 s
Phase sequence * 1/2/3
Instantaneous
Reverse power 2 to 20% of Pn 0 to 20 s
3.6 Communication
The circuit breaker shall be capable of communicating the following data via a bus:
Circuit-breaker status (open/closed, connected/disconnected/test, tripped on a fault, ready to close);
Control-unit settings;
Tripping causes;
The measurements processed by the control unit: current, voltage, frequency, power, power quality.
It shall be possible to remotely control the circuit breaker.
It shall be possible to remotely modify circuit-breaker settings:
Settings within the range defined by the switches on the front panel of the control unit;
Settings of the protection functions and the alarms.
Communications functions shall be independent of the control unit.
3.7Maintenance
The last ten trips and alarms shall be stored in two registers that may be consulted locally (date and time, type of fault or alarm).
Maintenance indicators shall be displayable on request on the front panel:
Percent wear of contacts;
Operations counter.
4.End of service life
The manufacturer shall provide instructions on the removal, dismantling and processing of circuit-breaker materials at the end of service life (material composition, weight, toxicity).
CAST RESIN MV/LV DISTRIBUTION TRANSFORMER
PART 1 - GENERAL
1.01 DESCRIPTION
A. This section cover the manufacturer, furnish, install and test all equipment, accessories and materials required for the installation of cast resin distribution transformer in accordance with specifications and drawings. Any material or equipment necessary for the proper operation not specified or described herein shall be deemed part of the specifications.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO Saudi Arabian Standards Organization.
2. IEC 60076-1 Power transformers
to 60076-5
3. IEC 60726 Dry type power transformers
4. IEC 60905 Loading guide for dry-type power transformers.
5. CENELEC Harmonisation Documents:
- HD 464 S1: 1988 + / A2: 1991 + / A3: 1992 for dry-type power transformers
- HD 538-1 S1: 1992 for three-phase dry-type distribution transformers 50 Hz, from 100 to 2500 KVA with highest voltage for equipment not exceeds 24 KV.
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed transformer.
C. If requested by the client, the supplier shall provide proof of application of a quality procedure complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
D. The manufacturer must have a sound experience in the field of transformers for not less than ten years, and should have a presentable reference list of the already supplied equipment of the same type and same make and that this equipment has been in satisfactory operation in Kingdom of Saudi Arabia for at least three years.
1.04 SUBMITTAL
A. Shop Drawings and Manufacturer's Data:
The contractor shall submit to the client/client representative for review, detailed dimensioned shop drawings and manufacturer's literature where deviations from the contract drawings or specification exist. Shop drawings and/or data sheets shall be based on information stated in the specifications and as shown on the contract drawings and shall show all pertinent deviations and data for the fabrication and complete installation.
Manufacturer's data sheets shall be submitted indicating the necessary installation dimensions, weights, materials and performance information. The above information may be provided by standard catalogue sheets marked to indicate the specific items provided.
B. Operation and Maintenance Instructions:
The contractor shall furnish data covering model, type and serial numbers, capacities, maintenance and operation of each major item of equipment or apparatus in accordance with the requirements of the contract documents. Operating instructions shall cover all phases of control.
C. Test Reports:
The contractor shall submit test reports to the client/client representative for review.
D. Recommended Spare Parts List:
The contractor shall submit recommended spare parts list to the client/client representative for review.
E. As Built Drawings:
The contractor shall submit the as built drawings to the client/client representative for review and approval.
1.05 COORDINATION
A. The contractor shall be held responsible for the proper coordination of all phases of the work under this contract.
B. It shall be the responsibility of the contractor to coordinate the work and equipment as specified herein with work to be performed and equipment to be furnished under other sections of the specifications in order to assure a complete and satisfactory installation.
1.06 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Deliver, store, protect and handle products to site as per manufacturer’s instructions.
B. Store transformers in clean and dry space. Inspect for damage. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect units from dirt, water, construction debris and traffic.
C. Lift only with lugs provided for the purpose. Handle carfully to avoid damage to transformers internal components, enclosure and finish.
PART 2 - PRODUCTION
2.01 GENERAL
A. The following specifications apply to three-phase transformers of cast resin type, class F insulation system with natural (AN) cooling for indoor installation, destined for use in three-phase MV/LV distribution systems.
B. If required, forced cooling (AF) can be used to increase the rated power up to 40%.
2.02 GENERAL REQUIREMENTS
A. General
1. The transformers shall be of climatic class C2 and of environmental class E2 as defined in appendix B of HD 464 S1: 1988 / A2: 1991. C2 and E2 classes shall be indicated on the rating plate.
2. The transformers shall be of fire behaviour class F1 as defined in article B3 of CENELEC HD 464 S1: 1988 / A2: 1991. F1 class shall be indicated on the rating plate.
B. Magnetic Core
1. This shall be made from laminations of grain oriented silicon steel, insulated with mineral oxide and shall be protected against corrosion with a coat of varnish.
C. LV Windings
1. These shall be made from aluminium or copper foil (according to the manufacturer's preference) with class F interlayer insulation by encapsulation (impregnation) with synthetic alkyd resin or equivalent.
2. At least the upper part of the LV coils shall be covered with a coat of epoxy resin or equivalent and the foil shall be protected everywhere with an insulation material even in the air ducts.
D. MV Windings
1. These shall be independent of the LV windings and shall be made of aluminium or copper wire or foil (according to the manufacturer's preference) with class F insulation.
2. The MV windings shall be vacuum cast in a class F fireproof epoxy resin casting system composed of:
- An epoxy resin
- An anhydride hardener with a flexibilising additive
- A flame-retardant filler.
3. The flame-retardant filler shall be thoroughly mixed with the resin and hardener. It shall be composed of trihydrated alumna powder (or aluminium hydroxide) or other flame-retardant products to be specified, either mixed with silica or not.
4. The casting system shall be of class F.
E. MV Connections
1. The MV connections shall be made from above on the top of the connection bars. Each bar shall be drilled with a 13-mm hole ready for connection of cable lugs on terminal plates.
2. The MV connection bars shall be in rigid copper bars protected by heat shrinkable tubing.
3. MV connections in cables are not allowed.
4. The MV connections shall be copper.
F. LV Connections
1. The LV connections shall be made from above onto bars located at the top of the coils on the opposite side to the MV connections.
2. Connection of the LV neutral shall be directly made to the LV terminals between the LV phase bars.
3. The LV connection bars shall be copper or tinned aluminium (according to preference of the manufacturer).
G. MV Tapping
1. The tapping which act on the highest voltage adapting the transformer to the real supply voltage value, shall be off-circuit bolted links.
2. Tapping with connection cables is not allowed.
3. These bolted links shall be attached to the MV coils.
2.03 METAL ENCLOSURE
A. If mentioned in the documents, the transformers shall be equipped with a metal enclosure for indoor installation comprising an integral IP 31 (except the base which may be IP 21) metal enclosure with:
1. An anti-corrosion protection in the manufacturer's standard colour.
2. Lifting lugs enabling the transformer and enclosure assembly to be handled.
3. A bolted access panel on the enclosure front to allow access to the MV connections and to the tapping. This shall be fitted with handles; it shall have one "Danger Electricity" warning label (T 10 warning), a rating plate and a visible braid for earthling.
4. Blanked off holes for fitting key locks on the bolted access panel to enable it to be locked.
5. 2 UN-drilled gland plates on the roof: one on the MV side, one on the LV side (drilling and cable gland not supplied).
6. 1 plate at the right MV side on the bottom of the enclosure for the MV cables for connections from the bottom.
2.04 ACCESSORIES AND STANDARD EQUIPMENT
A. The transformers shall be equipped with:
1. 4 flat bi-directional rollers
2. 2 lifting lugs
3. Haulage holes on the under base
4. 2 earthling terminals
5. 1 rating plate
6. 1 "Danger Electricity" warning label
7. 1 routine tests certificate
8. 1 instruction manual for installation, commissioning and maintenance in English.
B. Thermal protection
1. The transformers shall be equipped with a thermal protection device, which shall comprise:
- 2 sets of 3 PTC sensors, one sensor for "Alarm 1", one for "Alarm 2" per phase, installed in the coils of the transformer. They shall be placed in a tube to enable them to be replaced when ever necessary.
- An electronic converter with two independent monitoring circuits equipped with a changeover switch, one for "Alarm 1" and the other for "Alarm 2". The position of the relays shall be indicated by different coloured indicator lights. A third indicator light shall indicate the presence of voltage.
2. The three indicator lights shall be on the front of the converter. The electronic converter shall be installed away from the transformer.
3. A plug-in terminal block shall be provided for connection of the PTC sensors to the electronic converter.
4. The PTC sensors shall be supplied assembled and wired to the terminal block fixed on the upper part of the transformer. The converter shall be supplied loose with the transformer, packaged complete with its wiring diagram.
2.05 ROUTINE AND TYPE TESTS
A. Routine Tests
The following tests shall be carried out on all the transformers after the manufactu¬ring, enabling an official test certificate to be produced for each one:
1. Measurement of windings resistance.
2. Measurement of the transformation ratio and vector group
3. Measurement of impedance voltage and load loss
4. Measurement of no load loss and no load current
5. Applied voltage dielectric test
6. Induced voltage dielectric test
(All these tests shall be in accordance with Harmonisation Document HD 464 S1: 1988, the IEC 60726 and IEC 60076-1 to 60076-5 standards).
C. Type Tests and Special Tests
The following tests may be requested (if mentioned in the documents):
1. Temperature rise test carried out in accordance with the simulated loading method as defined by the IEC 60726 standard.
2. Lightning impulse test.
3. Short circuit test.
4. Noise level measurements in accordance with IEC 60551.
5. Measurement of partial discharges.
For measurement of the partial discharges, the acceptance criterion shall be:
- Partial discharges less than or equal to 10 pC at 1.10 Um.
If Um > 1.25 Un (Un = rated voltage, Um = system highest voltage), then the 10 pC are guaranteed at 1.375 Un.
(All these tests shall be in accordance with Harmonisation Document HD 464 S1: 1988, the IEC 60726 and IEC 60076-1 to 60076-5 standards).
6. The climate and environmental tests shall be performed in accordance with appendix ZA and ZB of CENELEC HD 464 S1: 1988 / A3: 1992.
7. The fire behaviour test shall be performed in accordance with appendix ZC of CENELEC HD 464 S1: 1988 / A3: 1992.
D. The manufacturer shall produce a test report from an official laboratory on a transformer of the same design as those produced.
Transformer Technical Data
For each requested transformer, the supplier shall give the following data :
Rated power As required KVA
Cooling AN or AF (as mentioned in the documents)
Rated frequency 60 Hz
Primary voltage 13.8 KV
Rated primary insulation level 17.5 KV
Power frequency withstand Voltage(rms) 38 KV
Basic Insulation Level (BIL) or impulse withstand voltage (peak) 95 KV
Off-circuit tapping +/- 2.5 %
Secondary voltage at no load between phases As required V
phase to neutral As required V
Vector group Dyn11
No load losses W
Load losses at 75° C W
Load losses at 120° C W
Rated impedance voltage at 120° C %
Acoustic power Lw(A) dB(A)
Acoustic pressure at 1 metre Lp(A) dB(A)
Maximum ambient temperature °C
Daily average ambient temperature °C
Yearly average ambient temperature °C
Maximum altitude m
MV winding temperature class F
LV winding temperature class F
Temperature of insulation system 155 °C
Climatic classification (HD 464 S1) C2
Environmental classification (HD 464 S1) E2
Fire behaviour classification (HD 464 S1) F1
Enclosure YES NO
Protection degree IP 31
Length mm
Width mm
Height mm
Total weight kg
Measurement circuit supply voltage for the thermal protection electronic
Converter DC AC V
PART 3 - EXECUTION
3.01 WORKMANSHIP
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
3.02 FOUNDATIONS AND SUPPORTS
A. The contractor shall provide concrete pedestals, anchor bolts, hangers, channels, saddles, etc., for installation of equipment and apparatus shown on the drawings and specified in the various sections.
3.03 EQUIPMENT ERECTION
A. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly. The connections shall be tightened with manual torque wrenches to the manufacturer's erection instructions.
3.04 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.
1.01 DESCRIPTION
A. This section cover the manufacturer, furnish, install and test all equipment, accessories and materials required for the installation of cast resin distribution transformer in accordance with specifications and drawings. Any material or equipment necessary for the proper operation not specified or described herein shall be deemed part of the specifications.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO Saudi Arabian Standards Organization.
2. IEC 60076-1 Power transformers
to 60076-5
3. IEC 60726 Dry type power transformers
4. IEC 60905 Loading guide for dry-type power transformers.
5. CENELEC Harmonisation Documents:
- HD 464 S1: 1988 + / A2: 1991 + / A3: 1992 for dry-type power transformers
- HD 538-1 S1: 1992 for three-phase dry-type distribution transformers 50 Hz, from 100 to 2500 KVA with highest voltage for equipment not exceeds 24 KV.
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed transformer.
C. If requested by the client, the supplier shall provide proof of application of a quality procedure complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
D. The manufacturer must have a sound experience in the field of transformers for not less than ten years, and should have a presentable reference list of the already supplied equipment of the same type and same make and that this equipment has been in satisfactory operation in Kingdom of Saudi Arabia for at least three years.
1.04 SUBMITTAL
A. Shop Drawings and Manufacturer's Data:
The contractor shall submit to the client/client representative for review, detailed dimensioned shop drawings and manufacturer's literature where deviations from the contract drawings or specification exist. Shop drawings and/or data sheets shall be based on information stated in the specifications and as shown on the contract drawings and shall show all pertinent deviations and data for the fabrication and complete installation.
Manufacturer's data sheets shall be submitted indicating the necessary installation dimensions, weights, materials and performance information. The above information may be provided by standard catalogue sheets marked to indicate the specific items provided.
B. Operation and Maintenance Instructions:
The contractor shall furnish data covering model, type and serial numbers, capacities, maintenance and operation of each major item of equipment or apparatus in accordance with the requirements of the contract documents. Operating instructions shall cover all phases of control.
C. Test Reports:
The contractor shall submit test reports to the client/client representative for review.
D. Recommended Spare Parts List:
The contractor shall submit recommended spare parts list to the client/client representative for review.
E. As Built Drawings:
The contractor shall submit the as built drawings to the client/client representative for review and approval.
1.05 COORDINATION
A. The contractor shall be held responsible for the proper coordination of all phases of the work under this contract.
B. It shall be the responsibility of the contractor to coordinate the work and equipment as specified herein with work to be performed and equipment to be furnished under other sections of the specifications in order to assure a complete and satisfactory installation.
1.06 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Deliver, store, protect and handle products to site as per manufacturer’s instructions.
B. Store transformers in clean and dry space. Inspect for damage. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect units from dirt, water, construction debris and traffic.
C. Lift only with lugs provided for the purpose. Handle carfully to avoid damage to transformers internal components, enclosure and finish.
PART 2 - PRODUCTION
2.01 GENERAL
A. The following specifications apply to three-phase transformers of cast resin type, class F insulation system with natural (AN) cooling for indoor installation, destined for use in three-phase MV/LV distribution systems.
B. If required, forced cooling (AF) can be used to increase the rated power up to 40%.
2.02 GENERAL REQUIREMENTS
A. General
1. The transformers shall be of climatic class C2 and of environmental class E2 as defined in appendix B of HD 464 S1: 1988 / A2: 1991. C2 and E2 classes shall be indicated on the rating plate.
2. The transformers shall be of fire behaviour class F1 as defined in article B3 of CENELEC HD 464 S1: 1988 / A2: 1991. F1 class shall be indicated on the rating plate.
B. Magnetic Core
1. This shall be made from laminations of grain oriented silicon steel, insulated with mineral oxide and shall be protected against corrosion with a coat of varnish.
C. LV Windings
1. These shall be made from aluminium or copper foil (according to the manufacturer's preference) with class F interlayer insulation by encapsulation (impregnation) with synthetic alkyd resin or equivalent.
2. At least the upper part of the LV coils shall be covered with a coat of epoxy resin or equivalent and the foil shall be protected everywhere with an insulation material even in the air ducts.
D. MV Windings
1. These shall be independent of the LV windings and shall be made of aluminium or copper wire or foil (according to the manufacturer's preference) with class F insulation.
2. The MV windings shall be vacuum cast in a class F fireproof epoxy resin casting system composed of:
- An epoxy resin
- An anhydride hardener with a flexibilising additive
- A flame-retardant filler.
3. The flame-retardant filler shall be thoroughly mixed with the resin and hardener. It shall be composed of trihydrated alumna powder (or aluminium hydroxide) or other flame-retardant products to be specified, either mixed with silica or not.
4. The casting system shall be of class F.
E. MV Connections
1. The MV connections shall be made from above on the top of the connection bars. Each bar shall be drilled with a 13-mm hole ready for connection of cable lugs on terminal plates.
2. The MV connection bars shall be in rigid copper bars protected by heat shrinkable tubing.
3. MV connections in cables are not allowed.
4. The MV connections shall be copper.
F. LV Connections
1. The LV connections shall be made from above onto bars located at the top of the coils on the opposite side to the MV connections.
2. Connection of the LV neutral shall be directly made to the LV terminals between the LV phase bars.
3. The LV connection bars shall be copper or tinned aluminium (according to preference of the manufacturer).
G. MV Tapping
1. The tapping which act on the highest voltage adapting the transformer to the real supply voltage value, shall be off-circuit bolted links.
2. Tapping with connection cables is not allowed.
3. These bolted links shall be attached to the MV coils.
2.03 METAL ENCLOSURE
A. If mentioned in the documents, the transformers shall be equipped with a metal enclosure for indoor installation comprising an integral IP 31 (except the base which may be IP 21) metal enclosure with:
1. An anti-corrosion protection in the manufacturer's standard colour.
2. Lifting lugs enabling the transformer and enclosure assembly to be handled.
3. A bolted access panel on the enclosure front to allow access to the MV connections and to the tapping. This shall be fitted with handles; it shall have one "Danger Electricity" warning label (T 10 warning), a rating plate and a visible braid for earthling.
4. Blanked off holes for fitting key locks on the bolted access panel to enable it to be locked.
5. 2 UN-drilled gland plates on the roof: one on the MV side, one on the LV side (drilling and cable gland not supplied).
6. 1 plate at the right MV side on the bottom of the enclosure for the MV cables for connections from the bottom.
2.04 ACCESSORIES AND STANDARD EQUIPMENT
A. The transformers shall be equipped with:
1. 4 flat bi-directional rollers
2. 2 lifting lugs
3. Haulage holes on the under base
4. 2 earthling terminals
5. 1 rating plate
6. 1 "Danger Electricity" warning label
7. 1 routine tests certificate
8. 1 instruction manual for installation, commissioning and maintenance in English.
B. Thermal protection
1. The transformers shall be equipped with a thermal protection device, which shall comprise:
- 2 sets of 3 PTC sensors, one sensor for "Alarm 1", one for "Alarm 2" per phase, installed in the coils of the transformer. They shall be placed in a tube to enable them to be replaced when ever necessary.
- An electronic converter with two independent monitoring circuits equipped with a changeover switch, one for "Alarm 1" and the other for "Alarm 2". The position of the relays shall be indicated by different coloured indicator lights. A third indicator light shall indicate the presence of voltage.
2. The three indicator lights shall be on the front of the converter. The electronic converter shall be installed away from the transformer.
3. A plug-in terminal block shall be provided for connection of the PTC sensors to the electronic converter.
4. The PTC sensors shall be supplied assembled and wired to the terminal block fixed on the upper part of the transformer. The converter shall be supplied loose with the transformer, packaged complete with its wiring diagram.
2.05 ROUTINE AND TYPE TESTS
A. Routine Tests
The following tests shall be carried out on all the transformers after the manufactu¬ring, enabling an official test certificate to be produced for each one:
1. Measurement of windings resistance.
2. Measurement of the transformation ratio and vector group
3. Measurement of impedance voltage and load loss
4. Measurement of no load loss and no load current
5. Applied voltage dielectric test
6. Induced voltage dielectric test
(All these tests shall be in accordance with Harmonisation Document HD 464 S1: 1988, the IEC 60726 and IEC 60076-1 to 60076-5 standards).
C. Type Tests and Special Tests
The following tests may be requested (if mentioned in the documents):
1. Temperature rise test carried out in accordance with the simulated loading method as defined by the IEC 60726 standard.
2. Lightning impulse test.
3. Short circuit test.
4. Noise level measurements in accordance with IEC 60551.
5. Measurement of partial discharges.
For measurement of the partial discharges, the acceptance criterion shall be:
- Partial discharges less than or equal to 10 pC at 1.10 Um.
If Um > 1.25 Un (Un = rated voltage, Um = system highest voltage), then the 10 pC are guaranteed at 1.375 Un.
(All these tests shall be in accordance with Harmonisation Document HD 464 S1: 1988, the IEC 60726 and IEC 60076-1 to 60076-5 standards).
6. The climate and environmental tests shall be performed in accordance with appendix ZA and ZB of CENELEC HD 464 S1: 1988 / A3: 1992.
7. The fire behaviour test shall be performed in accordance with appendix ZC of CENELEC HD 464 S1: 1988 / A3: 1992.
D. The manufacturer shall produce a test report from an official laboratory on a transformer of the same design as those produced.
Transformer Technical Data
For each requested transformer, the supplier shall give the following data :
Rated power As required KVA
Cooling AN or AF (as mentioned in the documents)
Rated frequency 60 Hz
Primary voltage 13.8 KV
Rated primary insulation level 17.5 KV
Power frequency withstand Voltage(rms) 38 KV
Basic Insulation Level (BIL) or impulse withstand voltage (peak) 95 KV
Off-circuit tapping +/- 2.5 %
Secondary voltage at no load between phases As required V
phase to neutral As required V
Vector group Dyn11
No load losses W
Load losses at 75° C W
Load losses at 120° C W
Rated impedance voltage at 120° C %
Acoustic power Lw(A) dB(A)
Acoustic pressure at 1 metre Lp(A) dB(A)
Maximum ambient temperature °C
Daily average ambient temperature °C
Yearly average ambient temperature °C
Maximum altitude m
MV winding temperature class F
LV winding temperature class F
Temperature of insulation system 155 °C
Climatic classification (HD 464 S1) C2
Environmental classification (HD 464 S1) E2
Fire behaviour classification (HD 464 S1) F1
Enclosure YES NO
Protection degree IP 31
Length mm
Width mm
Height mm
Total weight kg
Measurement circuit supply voltage for the thermal protection electronic
Converter DC AC V
PART 3 - EXECUTION
3.01 WORKMANSHIP
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
3.02 FOUNDATIONS AND SUPPORTS
A. The contractor shall provide concrete pedestals, anchor bolts, hangers, channels, saddles, etc., for installation of equipment and apparatus shown on the drawings and specified in the various sections.
3.03 EQUIPMENT ERECTION
A. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly. The connections shall be tightened with manual torque wrenches to the manufacturer's erection instructions.
3.04 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.
OUTDOOR PACKAGE SUBSTATION
PART 1 - GENERAL
1.01 DESCRIPTION
A. This section cover the manufacture, furnish, install and test all equipment, accessories and materials required for the installation of package substations in accordance with specifications and drawings. Any material or equipment necessary for the proper operation not specified or described herein shall be deemed part of the specifications.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO Saudi Arabian Standards Organization.
2. IEC 60076-1 Power transformers
to 60076-5
3. IEC 60354 Loading guide for oil-immersed type power transformers.
4. IEC 60439-1 Type Tested and Partially type tested Assemblies.
5. CENELEC Harmonisation Documents:
- HD 398-1 to 398-5: 1980 + A3 1986 for power transformers
- HD 428-1 S1: 1992 for three-phase oil-immersed type distribution transformers 50 HZ, from 100 to 2500 KVA with highest voltage for equipment not exceeding 24 KV.
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed package substations.
C. If requested by the client, the supplier shall provide proof of application of a quality procedure complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
D. The manufacturer must have a sound experience in the field of package substations transformers for not less than ten years, and should have a presentable reference list of the already supplied equipment of the same type and same make and that this equipment has been in satisfactory operation in Kingdom of Saudi Arabia for at least three years.
1.04 SUBMITTAL
A. Shop Drawings and Manufacturer's Data:
The contractor shall submit to the client/client representative for review, detailed dimensioned shop drawings and manufacturer's literature where deviations from the contract drawings or specification exist. Shop drawings and/or data sheets shall be based on information stated in the specifications and as shown on the contract drawings and shall show all pertinent deviations and data for the fabrication and complete installation.
Manufacturer's data sheets shall be submitted indicating the necessary installation dimensions, weights, materials and performance information. The above information may be provided by standard catalogue sheets marked to indicate the specific items provided.
B. Operation and Maintenance Instructions:
The contractor shall furnish data covering model, type and serial numbers, capacities, maintenance and operation of each major item of equipment or apparatus in accordance with the requirements of the contract documents. Operating instructions shall cover all phases of control.
C. Test Reports:
The contractor shall submit test reports to the client/client representative for review.
D. Recommended Spare Parts List:
The contractor shall submit recommended spare parts list to the client/client representative for review.
E. As Built Drawings:
The contractor shall submit the as built drawings to the client/client representative for review and approval.
1.05 COORDINATION
A. The contractor shall be held responsible for the proper coordination of all phases of the work under this contract.
B. It shall be the responsibility of the contractor to coordinate the work and equipment as specified herein with work to be performed and equipment to be furnished under other sections of the specifications in order to assure a complete and satisfactory installation.
1.06 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Deliver, store, protect and handle products to site as per manufacturer’s instructions.
B. Store package substations in clean and dry space. Inspect for damage. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect units from dirt, water, construction debris and traffic.
C. Lift only with lugs provided for the purpose. Handle carfully to avoid damage to package substation internal components, enclosure and finish.
PART 2 - PRODUCTION
2.01 GENERAL
A. The following specifications apply to outdoor package substations destined for use in three-phase MV/LV distribution systems.
B. Package Substation shall be a compact outdoor substation; factory assembled, metal enclosed type with galvanized steel sheet 2.0mm thick minimum. It should be designed, manufactured and tested in accordance with applicable IEC standards including IEC 60439-1.
C. The Substation should be composed of the following compartments, fully segregated by metal partitions and insulating materials with natural type ventilation:
1. A metallic enclosure for outdoor type.
2. Medium voltage compartment (SF6 Ring Main Unit – see related specification).
3. MV/LV Transformer compartment.
4. LV compartment (Main Distribution Board – see related specification).
2.02 TECHNICAL DATA
MV TR LV
1. Rated power (KVA) - as required -
2. Rated voltage (KV) 17.5 - 0.69
3. Service voltage (KV) 13.8 - 0.38
4. Rated frequency (HZ) 60 60 60
5. Rated insulation level (KV) 38 38 0.75
(Power-frequency for 1 minute withstand voltage)
6. Rated insulation level (KV peak) 95 95 8
(Impulse withstand voltage)
7. Short circuit withstand (sym.) at 20 - 30
Service voltage for 1 sec. (KA)
8. Busbar rated (A) 630 - As shown
9. Degree of protection for compartments IP43 IP23 IP43
10. HV bushings - Plug-in -
11. LV bushings - Flat bars -
12. Vector group - Dyn11 -
13. Maximum ambient temp.(Deg. C) 50 50 50
14. Altitude (m) Less than 1000 1000 1000
15. Daily average temperature between 5 Deg. C and 40 Deg. C and max. Of 50 Deg. C according to IEC.
2.03 METAL ENCLOSURE
A. The metallic enclosure shall comprises of 3 parts such as:
1. A skid base made of U-channel.
2. An external envelope made of 2-mm thickness galvanized steel sheet with
2 doors, one for MV compartment and one for the LV compartment.
3. Roof.
B. The external envelope and the roof are to be painted with two coat paints.
C. The cooling of the transformer compartment shall be natural type ventilation.
D. All the doors of the kiosk shall befitted with dust proof joints.
2.04 MV COMPARTMENT
A. It contains a SF6 Ring Main Unit (RMU) ensuring the MV outgoing and transformer
protection functions.
B. The RMU comprises of two 630A load-break switches and one 200A circuit breaker (for RMU specification, see related section)
2.05 TRANSFORMER
A. Technical Data
1. Type Mineral oil, hermetically sealed
2. Standard IEC 60076 and SASO
3. Cooling ONAN
4. Rating According to the drawing
5. Primary 13.8 KV or according to the drawing
6. HV Tapings ± 2.5% ± 5%
7. HV Insulation Level 17.5 KV
8. Impulse KV peak 95 KV
9. Power frequency 38 KV rms
10. Secondary According to the drawing
11. Vector Group Dyn 11
12. Ambient temp. 50 °C
13. Dielectric temp. rise 50 Degree C
14. Winding temp. rise 55 Degree C
15. Rated imp. voltage 4 to 6 %
16. Terminals - Flat bars for L.V
- Plug-in bushing for MV
B. Magnetic Core
1. This shall be made from laminations of grain oriented silicon steel, insulated with mineral oxide; the method of cutting and stacking shall be "step lap", so as to optimise the level of no-load losses.
C. LV Windings
1. These shall be made from copper profile wire or aluminium or copper foil (according to the manufacturer's preference).
D. MV Windings
1. These shall be made of copper profile wire or aluminium or copper round wire (according to the manufacturer's preference).
E. MV Connections
1. The standard MV connections shall use porcelain bushings on the top of the transformer.
2. Fixed MV plug-in bushings, with MV mobile plug-in bushings - straight or elbow according to the orientation of the incoming cables - may be provided if specified in the other documents.
F. LV Connections
1. The LV connections shall be made using porcelain bushings up to 200 KVA, and flat-bars from 250 KVA onwards.
2. A LV air-insulated terminal cover may be provided if specified in the documents.
G. MV Tapping
1. The tapping which act on the highest voltage adapting the transformer to the real supply voltage value, shall be provided with an off-circuit tap-changer switch with a padlocking facility on the top cover of the transformer.
H. Tank
1. The tank of the transformer shall be made with flexible cooling corrugations, in order to absorb the expansion of the dielectric due to temperature variations.
2. The cover shall be bolted on top of the tank.
3. The tank shall be built in such a way as to avoid any water accumulation.
I. Dielectric and Component Material
1. The dielectric shall be mineral oil, class I & II according to IEC 60296.
2. The concentration in PCB has to be lower than the minimum detection rate of 2 ppm (parts per million).
3. The components of the transformer such as insulation material, varnish, painting, etc. have to be new and PCB-free.
4. The filling of the transformer shall be made under vacuum, in order to guarantee the maximum preservation of dielectric properties.
5. The live part of the transformer shall be previously oven dried so as to remove all residual humidity.
J. Gaskets
1. All the gaskets shall be resistant against the action of the mineral oil, at the working temperature.
K. Protection against Corrosion
1. The anticorrosion treatment of the tank and the cover shall comprise:
- An external degreasing and rinsing
- A hot phosphating operation
- A powdering through application of a polyester resin with an electrostatic spray gun (minimum thickness 40 to 50 microns)
- Final colour green grey RAL 7033
2. The main characteristics of the coating guarantee:
- A gloss of 30 to 60 % for an angle of 60° (measured according to ASTM-D523)
- A salt spray resistance of 1000 hours (measured according to ASTM-B117)
- A UV resistance without losses more than 10% gloss according to the RAL scale 1 (measured according to NFT 30-057, over a 3 months period).
- An adherence of between 0 and 1 (measured according to ASTM-D3359)
L. Accessories and standard equipment
1. The transformers shall be equipped with:
- 4 bi-directional flat rollers
- 2 lifting and untanking lugs
- 2 earthling terminals
- 1 filling plug
- 1 draining device
- 1 rating plate
- 1 "Danger Electricity" warning label
- 1 routine tests certificate
- 1 instruction manual for installation, commissioning and maintenance in English.
2. Protection
- The transformers shall be equipped with a DGPT2 protection relay including:
a. 1 gas detector/flow level indicator with one contact (for gas discharge and drop
in liquid level)
b. 1 over pressure contact (for internal pressure increase)
c. 2 thermostats for alarm and tripping (for internal temperature increase)
d. 1 dial type thermometer without contact.
2.06 LV COMPARTMENT
A. LV Compartment shall comply with IEC 60439-1 recommendations. (See related specification).
B. The LV compartment shall be located on the opposite side of the MV compartment and is totally segregated from the transformer compartment.
C. The accessible shall be through a double, gasketted, lockable door.
D. All components shall be erected on a painted chassis, 5mm angular, fixed onto the skid of the kiosk.
2.07 MISCELLANEOUS
A. Internal lighting controlled by door operated switch shall be provided in HV and LV section.
B. Socket outlet, 2P+E shall be provided in the LV compartment.
C. MCB's or Fuse-carrier with fuses links for protection of socket & lighting shall be provided.
D. All MV and LV cables shall be handled through the bottom.
E. Labeling shall be white on black background, in English language. Texts should be approved.
2.08 ROUTINE AND TYPE TESTS
A. Routine Tests
1. The substation shall be tested in the factory according to applicable IEC standards against the following routine tests, and official test certificate shall be produced for each one:
- Mechanical operation tests and checking the interlocking.
- Power-frequency withstands voltage test for 1minute.
- Check MV and LV wiring.
- LV equipment operation test.
- Usual visual examination.
2. The following tests shall be carried out on all the transformers after the manufactu¬ring, enabling an official test certificate to be produced for each one:
- Measurement of windings resistance.
- Measurement of the transformation ratio and vector group
- Measurement of impedance voltage and load loss
- Measurement of no load loss and no load current
- Applied voltage dielectric test
- Induced voltage dielectric test
(All these tests shall be in accordance with IEC 60076-1 to 60076-5 standards).
B. Type Tests and Special Tests
1. The following tests may be requested for the transformers (if mentioned in the documents):
- Temperature rise test.
- Lightning impulse test.
- Short circuit test.
- Noise level measurements in accordance with IEC 60551.
- Measurement of partial discharges.
(All these tests shall be in accordance with IEC 60076-1 to 60076-5 standards).
2. The manufacturer shall produce a test report from an official laboratory on a transformer of the same design as those produced.
PART 3 - EXECUTION
3.01 WORKMANSHIP
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
3.02 FOUNDATIONS AND SUPPORTS
A. The contractor shall provide concrete pedestals, anchor bolts, hangers, channels, saddles, etc., for installation of equipment and apparatus shown on the drawings and specified in the various sections.
3.03 EQUIPMENT ERECTION
A. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly. The connections shall be tightened with manual torque wrenches to the manufacturer's erection instructions.
3.04 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.
1.01 DESCRIPTION
A. This section cover the manufacture, furnish, install and test all equipment, accessories and materials required for the installation of package substations in accordance with specifications and drawings. Any material or equipment necessary for the proper operation not specified or described herein shall be deemed part of the specifications.
1.02 APPLICABLE CODES AND STANDARDS
A. The work shall be carried out in accordance with this specification, the contract drawings and the standards listed hereunder.
The following codes and standards provide an acceptable level of quality for materials and products:
1. SASO Saudi Arabian Standards Organization.
2. IEC 60076-1 Power transformers
to 60076-5
3. IEC 60354 Loading guide for oil-immersed type power transformers.
4. IEC 60439-1 Type Tested and Partially type tested Assemblies.
5. CENELEC Harmonisation Documents:
- HD 398-1 to 398-5: 1980 + A3 1986 for power transformers
- HD 428-1 S1: 1992 for three-phase oil-immersed type distribution transformers 50 HZ, from 100 to 2500 KVA with highest voltage for equipment not exceeding 24 KV.
1.03 QUALITY ASSURANCE
A. All materials and products shall be new, sound and uniform in quality, size, shape, color and texture and shall be free from defects.
B. The contractor shall be responsible for ensuring that the required standards of quality control as mentioned in relative sections are maintained for the proposed package substations.
C. If requested by the client, the supplier shall provide proof of application of a quality procedure complying with standards. This means:
1. use of a quality manual approved and signed by a management representative,
2. regular updating of this manual so that it reflects the most recent applicable quality control procedures,
3. ISO 9002 certification.
D. The manufacturer must have a sound experience in the field of package substations transformers for not less than ten years, and should have a presentable reference list of the already supplied equipment of the same type and same make and that this equipment has been in satisfactory operation in Kingdom of Saudi Arabia for at least three years.
1.04 SUBMITTAL
A. Shop Drawings and Manufacturer's Data:
The contractor shall submit to the client/client representative for review, detailed dimensioned shop drawings and manufacturer's literature where deviations from the contract drawings or specification exist. Shop drawings and/or data sheets shall be based on information stated in the specifications and as shown on the contract drawings and shall show all pertinent deviations and data for the fabrication and complete installation.
Manufacturer's data sheets shall be submitted indicating the necessary installation dimensions, weights, materials and performance information. The above information may be provided by standard catalogue sheets marked to indicate the specific items provided.
B. Operation and Maintenance Instructions:
The contractor shall furnish data covering model, type and serial numbers, capacities, maintenance and operation of each major item of equipment or apparatus in accordance with the requirements of the contract documents. Operating instructions shall cover all phases of control.
C. Test Reports:
The contractor shall submit test reports to the client/client representative for review.
D. Recommended Spare Parts List:
The contractor shall submit recommended spare parts list to the client/client representative for review.
E. As Built Drawings:
The contractor shall submit the as built drawings to the client/client representative for review and approval.
1.05 COORDINATION
A. The contractor shall be held responsible for the proper coordination of all phases of the work under this contract.
B. It shall be the responsibility of the contractor to coordinate the work and equipment as specified herein with work to be performed and equipment to be furnished under other sections of the specifications in order to assure a complete and satisfactory installation.
1.06 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Deliver, store, protect and handle products to site as per manufacturer’s instructions.
B. Store package substations in clean and dry space. Inspect for damage. Maintain factory wrapping or provide an additional heavy canvas or heavy plastic cover to protect units from dirt, water, construction debris and traffic.
C. Lift only with lugs provided for the purpose. Handle carfully to avoid damage to package substation internal components, enclosure and finish.
PART 2 - PRODUCTION
2.01 GENERAL
A. The following specifications apply to outdoor package substations destined for use in three-phase MV/LV distribution systems.
B. Package Substation shall be a compact outdoor substation; factory assembled, metal enclosed type with galvanized steel sheet 2.0mm thick minimum. It should be designed, manufactured and tested in accordance with applicable IEC standards including IEC 60439-1.
C. The Substation should be composed of the following compartments, fully segregated by metal partitions and insulating materials with natural type ventilation:
1. A metallic enclosure for outdoor type.
2. Medium voltage compartment (SF6 Ring Main Unit – see related specification).
3. MV/LV Transformer compartment.
4. LV compartment (Main Distribution Board – see related specification).
2.02 TECHNICAL DATA
MV TR LV
1. Rated power (KVA) - as required -
2. Rated voltage (KV) 17.5 - 0.69
3. Service voltage (KV) 13.8 - 0.38
4. Rated frequency (HZ) 60 60 60
5. Rated insulation level (KV) 38 38 0.75
(Power-frequency for 1 minute withstand voltage)
6. Rated insulation level (KV peak) 95 95 8
(Impulse withstand voltage)
7. Short circuit withstand (sym.) at 20 - 30
Service voltage for 1 sec. (KA)
8. Busbar rated (A) 630 - As shown
9. Degree of protection for compartments IP43 IP23 IP43
10. HV bushings - Plug-in -
11. LV bushings - Flat bars -
12. Vector group - Dyn11 -
13. Maximum ambient temp.(Deg. C) 50 50 50
14. Altitude (m) Less than 1000 1000 1000
15. Daily average temperature between 5 Deg. C and 40 Deg. C and max. Of 50 Deg. C according to IEC.
2.03 METAL ENCLOSURE
A. The metallic enclosure shall comprises of 3 parts such as:
1. A skid base made of U-channel.
2. An external envelope made of 2-mm thickness galvanized steel sheet with
2 doors, one for MV compartment and one for the LV compartment.
3. Roof.
B. The external envelope and the roof are to be painted with two coat paints.
C. The cooling of the transformer compartment shall be natural type ventilation.
D. All the doors of the kiosk shall befitted with dust proof joints.
2.04 MV COMPARTMENT
A. It contains a SF6 Ring Main Unit (RMU) ensuring the MV outgoing and transformer
protection functions.
B. The RMU comprises of two 630A load-break switches and one 200A circuit breaker (for RMU specification, see related section)
2.05 TRANSFORMER
A. Technical Data
1. Type Mineral oil, hermetically sealed
2. Standard IEC 60076 and SASO
3. Cooling ONAN
4. Rating According to the drawing
5. Primary 13.8 KV or according to the drawing
6. HV Tapings ± 2.5% ± 5%
7. HV Insulation Level 17.5 KV
8. Impulse KV peak 95 KV
9. Power frequency 38 KV rms
10. Secondary According to the drawing
11. Vector Group Dyn 11
12. Ambient temp. 50 °C
13. Dielectric temp. rise 50 Degree C
14. Winding temp. rise 55 Degree C
15. Rated imp. voltage 4 to 6 %
16. Terminals - Flat bars for L.V
- Plug-in bushing for MV
B. Magnetic Core
1. This shall be made from laminations of grain oriented silicon steel, insulated with mineral oxide; the method of cutting and stacking shall be "step lap", so as to optimise the level of no-load losses.
C. LV Windings
1. These shall be made from copper profile wire or aluminium or copper foil (according to the manufacturer's preference).
D. MV Windings
1. These shall be made of copper profile wire or aluminium or copper round wire (according to the manufacturer's preference).
E. MV Connections
1. The standard MV connections shall use porcelain bushings on the top of the transformer.
2. Fixed MV plug-in bushings, with MV mobile plug-in bushings - straight or elbow according to the orientation of the incoming cables - may be provided if specified in the other documents.
F. LV Connections
1. The LV connections shall be made using porcelain bushings up to 200 KVA, and flat-bars from 250 KVA onwards.
2. A LV air-insulated terminal cover may be provided if specified in the documents.
G. MV Tapping
1. The tapping which act on the highest voltage adapting the transformer to the real supply voltage value, shall be provided with an off-circuit tap-changer switch with a padlocking facility on the top cover of the transformer.
H. Tank
1. The tank of the transformer shall be made with flexible cooling corrugations, in order to absorb the expansion of the dielectric due to temperature variations.
2. The cover shall be bolted on top of the tank.
3. The tank shall be built in such a way as to avoid any water accumulation.
I. Dielectric and Component Material
1. The dielectric shall be mineral oil, class I & II according to IEC 60296.
2. The concentration in PCB has to be lower than the minimum detection rate of 2 ppm (parts per million).
3. The components of the transformer such as insulation material, varnish, painting, etc. have to be new and PCB-free.
4. The filling of the transformer shall be made under vacuum, in order to guarantee the maximum preservation of dielectric properties.
5. The live part of the transformer shall be previously oven dried so as to remove all residual humidity.
J. Gaskets
1. All the gaskets shall be resistant against the action of the mineral oil, at the working temperature.
K. Protection against Corrosion
1. The anticorrosion treatment of the tank and the cover shall comprise:
- An external degreasing and rinsing
- A hot phosphating operation
- A powdering through application of a polyester resin with an electrostatic spray gun (minimum thickness 40 to 50 microns)
- Final colour green grey RAL 7033
2. The main characteristics of the coating guarantee:
- A gloss of 30 to 60 % for an angle of 60° (measured according to ASTM-D523)
- A salt spray resistance of 1000 hours (measured according to ASTM-B117)
- A UV resistance without losses more than 10% gloss according to the RAL scale 1 (measured according to NFT 30-057, over a 3 months period).
- An adherence of between 0 and 1 (measured according to ASTM-D3359)
L. Accessories and standard equipment
1. The transformers shall be equipped with:
- 4 bi-directional flat rollers
- 2 lifting and untanking lugs
- 2 earthling terminals
- 1 filling plug
- 1 draining device
- 1 rating plate
- 1 "Danger Electricity" warning label
- 1 routine tests certificate
- 1 instruction manual for installation, commissioning and maintenance in English.
2. Protection
- The transformers shall be equipped with a DGPT2 protection relay including:
a. 1 gas detector/flow level indicator with one contact (for gas discharge and drop
in liquid level)
b. 1 over pressure contact (for internal pressure increase)
c. 2 thermostats for alarm and tripping (for internal temperature increase)
d. 1 dial type thermometer without contact.
2.06 LV COMPARTMENT
A. LV Compartment shall comply with IEC 60439-1 recommendations. (See related specification).
B. The LV compartment shall be located on the opposite side of the MV compartment and is totally segregated from the transformer compartment.
C. The accessible shall be through a double, gasketted, lockable door.
D. All components shall be erected on a painted chassis, 5mm angular, fixed onto the skid of the kiosk.
2.07 MISCELLANEOUS
A. Internal lighting controlled by door operated switch shall be provided in HV and LV section.
B. Socket outlet, 2P+E shall be provided in the LV compartment.
C. MCB's or Fuse-carrier with fuses links for protection of socket & lighting shall be provided.
D. All MV and LV cables shall be handled through the bottom.
E. Labeling shall be white on black background, in English language. Texts should be approved.
2.08 ROUTINE AND TYPE TESTS
A. Routine Tests
1. The substation shall be tested in the factory according to applicable IEC standards against the following routine tests, and official test certificate shall be produced for each one:
- Mechanical operation tests and checking the interlocking.
- Power-frequency withstands voltage test for 1minute.
- Check MV and LV wiring.
- LV equipment operation test.
- Usual visual examination.
2. The following tests shall be carried out on all the transformers after the manufactu¬ring, enabling an official test certificate to be produced for each one:
- Measurement of windings resistance.
- Measurement of the transformation ratio and vector group
- Measurement of impedance voltage and load loss
- Measurement of no load loss and no load current
- Applied voltage dielectric test
- Induced voltage dielectric test
(All these tests shall be in accordance with IEC 60076-1 to 60076-5 standards).
B. Type Tests and Special Tests
1. The following tests may be requested for the transformers (if mentioned in the documents):
- Temperature rise test.
- Lightning impulse test.
- Short circuit test.
- Noise level measurements in accordance with IEC 60551.
- Measurement of partial discharges.
(All these tests shall be in accordance with IEC 60076-1 to 60076-5 standards).
2. The manufacturer shall produce a test report from an official laboratory on a transformer of the same design as those produced.
PART 3 - EXECUTION
3.01 WORKMANSHIP
A. Materials, products and equipment furnished by the contractor, shall be installed and all work shall be performed in a first-class workmanship manner, in conformity with the best trade practices and the printed directions of the applicable manufacturers; by skilled workers equipped to produce satisfactory results; in a safe, substantial manner so as to avoid undue stresses, rigid enough to prevent undue movement, so as to present a neat, orderly appearance and to facilitate operating, servicing, maintenance and repairing.
3.02 FOUNDATIONS AND SUPPORTS
A. The contractor shall provide concrete pedestals, anchor bolts, hangers, channels, saddles, etc., for installation of equipment and apparatus shown on the drawings and specified in the various sections.
3.03 EQUIPMENT ERECTION
A. All electrical equipment shall be installed in accordance with the manufacturer's recommendations, good electrical engineering practice, and the relevant drawings and specifications.
B. All metal surfaces to be bolted shall be thoroughly cleaned before assembly. The connections shall be tightened with manual torque wrenches to the manufacturer's erection instructions.
3.04 EQUIPMENT TESTING AND COMMISSIONING
A. After the installation is complete and properly adjusted, the contractor shall conduct operating tests. The various equipment and systems shall be demonstrated to operate in accordance with the requirements of the contract documents. Tests shall be performed in the presence of the client/client representative. The contractor shall provide electric power, instruments and personnel necessary for performing the various tests.
B. The testing of all electrical equipment shall include, but not be limited to, the items below. This shall be in addition to testing specified elsewhere in this specification.
1. General equipment check.
2. Field wiring and ground system verification.
3. Equipment adjustment.
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