PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

The capacitor bank may comprise of suitable number of single phase units in series
parallel combination. However, the number of parallel units in each of the series
racks shall be such that failure of one unit shall not create an over voltage on the
units in parallel with it, which will result in the failure of the parallel units.
The assembly of the banks shall be such that it provides sufficient ventilation for
each unit. Each capacitor case and the cubicle shall be earthed to a separate earth
bus.
Each capacitor unit/bank shall be fitted with directly connected continuously rated,
low loss discharge device to discharge the capacitors to reduce the voltage to
50 volts within one minute in accordance with the provisions of the latest edition of
IS :13585 Part 1.
Film dielectric, Aluminium foil conductor, impregnated with Non PCB, Non Toxic
biodegradable capacitor grade oil, under vacuum, two layers of biaxially oriented
propylene film shall be used.
Each unit shall satisfactorily operate at 135% of rated kVAR including factors of
over voltage, harmonic currents and manufacturing tolerance. The units shall be
capable of continuously withstanding satisfactorily any over voltage upto a
maximum of 10% above the rated voltage, excluding transients.
Unit Protection:
Each capacitor unit shall be individually protected by an MCCB/MCB fuse suitably
rated for load current and interrupting capacity, so that a faulty capacitor unit shall
be disconnected by the fuse without causing the bank to be disconnected. Thus, the
fuse shall disconnect only the faulty unit and shall leave the rest of the units
undisturbed. An operated fuse shall give visual indication so that it may be detected
during periodic inspection. The MCB breaking time shall co-ordinate with the
pressure built up within the unit to avoid explosion. Mounting of the individual
fuse may be internal or external to the capacitor case.
Capacitor Control Panel:
The control equipment shall be mounted in the MV panel made of 2.6mm/2.0mm
cold rolled sheet steel for the front and other sides respectively. The panel shall be
of indoor type and shall consist of :
- Isolating switch/MCB/MCCB
- Red and Green lamps for capacitors ON/OFF indication.
GTS : General Technical Specification. Page 135