The power factor correction capacitor (hereinafter referred to as “capacitor”) shall be of dry type and self-healing. The dielectric medium shall be metallised polypropylene film or foil. The elements shall be insulated with fire-proof material. The capacitor shall be environmentally-friendly.
The capacitor shall comply with IEC 60831 Part 1 and Part 2.
The losses of the capacitor shall be not more than 0.5 watt per kvar at the specified ambient temperature measured at the connecting terminals.
The capacitor shall be provided with overload disconnector which will interrupt the internal connection and disconnect the capacitor from the circuit in the event of pressure built-up within the capacitor.
2.5 DISCHARGE DEVICE
Each capacitor shall be provided with suitable means to discharge the capacitor to 50 volts or less within 60 seconds from an initial peak voltage of √2 times the rated voltage. No isolating device, fuse or otherwise shall be placed between the capacitor and the discharge device.
2.6 AMBIENT TEMPERATURE
The capacitor shall be Category C rated and suitable for operation under tropical ambient conditions with the highest mean temperature of 40 0C over a 24 hour period of continuous operation.
2.7 VOLTAGE RATING AND MAXIMUM PERMISSIBLE CURRENT
Capacitor shall be rated at 525 volts, 50 Hz. The capacitor shall be suitable for continuous operation at an r.m.s. line current of 1.3 times the rated current that occurs at the rated sinusoidal voltage and rated frequency of the supply source. The rated short time peak current of the capacitor shall be at least 140 times the rated current.
The capacitor shall be housed in container fabricated from heavy metal sheet steel coated with non-corrosive polyurethane resin enamel or in extrusion-processed aluminium container.
2.9 TEST RESULTS
Factory certified test results for routine test shall be provided for the capacitors supplied. The routine tests according to IEC 60831 shall include: –
(a) Test voltage between terminals – 1.75 times capacitor rated voltage for 2 seconds
(b) Measuring voltage – 525 V, 50 Hz
(c) Voltage test between terminals and container – 3000 V, 50 Hz for 10 seconds; or 3600 V,50 Hz for 2 seconds
(d) Capacitance measurement
(e) Loss measurement