Voltage Rating

Although the secondary side voltage rating of the transformer is fixed as 400 V, 3 phase along with neutral available along with the three phase wires in star configuration, the primary side voltage is decided through the voltage of incoming feeder(s). If there are more than one incoming feeders, the feeder for fixing the criterion for transformer selection can be decided on the basis of its proximity along with the substation, load delivering capability and availability of suitable voltage transformer. The number, steps and kind of tap changer that is on load or off load, is decided through operating requirements of voltage and current.