If 1-Phase Power is 220V, why is 3-phase 440V and Not 660V?

April 21, 2020   photos  

When it comes to a question like that, the answer should be that in the three phases have 120 degree phase different at one time that one phase is zero and working a return path and number wise working for example and wave diagram we take degree in that time the R phase are zero S phase are positive and T are negative because S and T 220 + 220 = 440. So, that's why if 1-Phase Power is 220V, why is 3-phase 440V and Not 660V.