Which are the 3 wires? what is the potential difference in india?
Answers
Why is the potential difference between a live wire and a neutral wire 220V in India?
The secondary voltage of a 3 phase distribution transformer is 415 volt. There are four conductors coming out of the secondary of the distribution transformer. 3 of them are phase conductors and one is neutral conductor, which is earthed near the transformer. So the potential of neutral conductor is zero. The voltage or the potential difference between the other three conductors is 415 volt i.e. the secondary voltage of the transformer or the line voltage. Hence the potential difference between live wire or phase conductor and the neutral, which is called the phase voltage is (415/ 1.732 i.e. root3) 240 volt and not 220. However if the secondary voltage of transformer comes down to 380 volt or less due to over loading, then the line voltage becomes 220 volt or less.