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.
Monday, August 18, 2008
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.
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