1. Standard:
Capacitor shall be low-loss units , tested in accordance
with IEC 831-1 and 2 ‘’ shunt power capacitor for ac system having
a rated voltage up to and including 1000 V ‘’ .
2. Technology :
Capacitor shall be dry , three phases , metallised film , self-healing type,
with polypropylene or similar dielectric .
Thickness of polypropylene :
400 V range : 7 µm
470 V range : 8 µm
The use of polychlorinated biphenols ( PCB ) and oil as the capacitor impregnation is not
acceptable .
3. Power dissipated :
The capacitor losses in Watts shall not exceed 0.7 W/kvar discharge resistor
included .
4. Admissible overload :
The capacitor shall operate satisfactory under the following overload conditions :
· 110 % of nominal voltage ( as per IEC 831 part 1 and 2 )
· 130 % of nominal current at rated voltage and frequency .
5. Tolerance on capacitance :
The tolerance of the capacitor shall be :
· 0 % , + 10 % .
6. Temperature range :
The capacitor shall be designed to withstand temperature class - 25/D .
· Minimum : - 25°C
· Maximum : + 55°C
· Average over 24 hours : + 45°C
· Annual average : + 35°C
7. Insulation level :
The insulation level should be 6 kV withstand voltage ( 1 min 50 Hz ) .
The insulation level should be 11 kV impulse test withstand voltage ( 1.2/50 us )
8. Protection :
Each element forming the three phase capacitor shall be fitted with :
· One HRC cartridge fuse .
· One overpressure disconnect device .
· One built-in discharge resistor .
9. Enclosure and connection :
The group of elements forming a three phase capacitor unit shall be installed in
a plastic enclosure .
The capacitor shall be indoor type .
Each capacitor shall be provided with three terminal pads and shall
not required an earth connection .
10. Discharge resistor :
Each element forming the three phase capacitor shall be fitted with an internal
discharge resistor to ensure that the capacitor is discharged to a voltage not
exceeding 50 V measured at the capacitor terminals , one minute after
disconnection from the power supply .
11. Protection degree :
Three phases capacitor shall be IP 00 , but could be easily IP 42 by adding a three
phase cover .
12. Mounting :
The three phase capacitor shall be mounted on vertical plate .
Each element of the three phases capacitor shall be installed in horizontal position in order to
improve natural cooling .
All three phase capacitors shall have the same vertical dimensions between fixing points .
13. Modularity :
The three phases capacitor shall be modular designed in order to lower spare parts for maintenance purpose .
The three phases capacitor shall be designed to be assembled together without any
special tools or cables .
14. Type tests :
Type tests carried out on similar three phase capacitor , by independant and recognized
laboratory shall be supplied .
15. Documentations :
The supplier shall provide the folowing documentation :
Certificate of routine tests .
Certificate of type test on similar capacitor .
User manual .
16. Certification :
The three phase capacitor shall be designed and manufactured under ISO 9001 and
ISO 14000 .
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