Power ratio between 3-phase and single-phase

Thread Starter


Joined Sep 23, 2016
"Calculate the ratio between the power that can be transported with a symmetrical three-phase system, and with a single-phase system. Both systems have the same phase voltage, the same power loss and similar conductors (both length and cross-sections)."

That's the question I have. I think the ratio is 1.732 (sqrt(3)) since that's also the ratio between phase and line voltage in a three-phase system. Could anyone tell me if I'm correct or not and if not where I'm wrong?


Joined Jun 17, 2014

Well if you have a wye system then you can have three independent loads and three independent line voltages so wouldnt that imply that you could have three times the power transfer?
That's if i understand your question correctly.
If you have a single phase system with 1000 watts, and systems A, B, and C each with 1000 watts, then the three phase system has 3000 watts which is 3 times the single phase system. Does that sound right to you?