DC Power Supply Battery charging equipment 48vdc and 220vdc

DC power supply Battery charging equipment is necessary for operation,signalings and protections of the substation as well as for substation emergency lighting , capacity (load) of battary shall be estimated on this basis,and shall have 5% at least reserve from the actual load.

Each battery is connected to the distribution board via a double pole changeover contactor to disconnect the battery from the distribution board when on boost change. Each battery charger is capable of float and boost charging the battery, from the ac supply voltage specified. The chargers are interlocked so only one battery can be boost charged at a time.

Chargers is capable of the automatic constant voltage output type designed for float and boost charge operation. They are suitable for operation from the alternating current supply under the ambient conditions specified. Charger can have two outputs : 48 VDC with power of 1000 W , and 220 VDC to feed the two types of the batteries 220 and 48.The charger is capable of fully charging the battery upon initial installation. It is capable of float charging a fully discharged battery to 95 per cent of its full capacity while supplying normal standing load. 

The charger boost charge feature provide an automatically controlled high charge rate sufficient to restore a fully discharged battery to the fully charged state within twelve hours without excessive gassing or any form of damage to the battery. Although it is not intended to operate the charger with the battery disconnected the charger shall, nevertheless, be capable, with the battery disconnected, of maintaining normal system voltage without damage to itself and with a ripple voltage no greater than 3 per cent rms of the nominal output voltage. Each charger shall also be capable of sustaining without damage to itself or continuous permanent short circuit at its output terminals. The float charge dc output of each main charger unit remain within the limits of ±1.5 per cent under any of the following conditions:

i. System frequency 50 Hz ±5 % per cent .

ii. Rated voltage input±10 % per cent.

iii. Output between 5-100 per cent of rated output continuously.

iv. Output between (100-110) % temporary.

v. Charger capacity must 10 % higher than the battary set capacity