In spite of best efforts made by Electricity Board & various other factors the supply voltage at users location does fluctuate much beyond the required operating limits of Electrical/ Electronics equipments. This causes malfunctioning/ damage to these. Equipments, resulting into production losses, costly repair and wastage of power. In our Industrial units over 80% of load is of electric motors. These motors draw very high current at low and high input voltage. Due to these high currents, losses in the motor increases which lead to premature failure of winding. Due to these high current supply cable contactors & accessories also get heated & chances of failure increases.
Electrical equipments are designed for 230 volts or 400 volts (3 phase) supply voltage & operates with maximum efficiency at these voltage. Electrical motor draw very high current at high voltage & due to this energy consumption increases, also maximum demand increases & power factor get reduced. These leads to heading of motor & finally premature failure. Similarly in case of our lighting load, when voltage increases above 230 VAC the power consumption increases. For example the power consumption of 60-watt bulb increases by almost 30% if the voltage supplied to it increases from 230 volts to 270 volts. Also the life of bulb reduces from normal 1000 hours to just 100 hours only. The similar case in with CFL lamps . These lamps are designed for 220V operation & If supply voltage goes beyond 250 VAC continuous the lamps fail.
If the supply voltage variation is between 380 V to 440 VAC approx 8 to 10 & saving in electricity can be archived by supplying constant 400 VAC output.