Inspite of the best efforts by all the state electricity boards across the country , the voltage received at the end user is never constant. This erratic power supply is the main cause of breakdown of electrical equipment. Voltage varies in a fashion that generally it is low during day time and high during night hours. Moreover on the holidays, peak hours, rainy days and when agriculture load is switched off, the voltage rises sharply which is more dangerous. In India all the electrical equipment are rated at 400 / 415 Volts three phase and 220 / 230 Volts single phase