mark thomas
Titanium
- Joined
- Dec 15, 2004
- Location
- SF Bay Area
I see it stated all the time that 3-phase motors are "more efficient" than single-phase motors. For example:
http://www.3phasepower.org/3phasemotors.htm
But it's never explained HOW they are more efficient.
I understand 3-phase motors are cheaper to buy and maintain, so total lifecycle economic efficiency is better. But is running a typical motor more efficient, in the sense of fewer watts consumed per work done? Suppose I power up two identical machines, but one with a 1 phase motor and the other with a 3 phase motor (same HP, same ), and I do the exact same work on each. Will the 3 phase motor consume fewer watts?
Is the answer simply in the efficiency rating of the motor itself? I looked on grainger for examples, and typical 3P motors are listed as 86% efficient, but 1P motors don't have a rating (or not the dozen or so I sampled) Isn't about 85% typical for 1P motors too?
Or is this one of those things that's way more complicated than it appears?
http://www.3phasepower.org/3phasemotors.htm
But it's never explained HOW they are more efficient.
I understand 3-phase motors are cheaper to buy and maintain, so total lifecycle economic efficiency is better. But is running a typical motor more efficient, in the sense of fewer watts consumed per work done? Suppose I power up two identical machines, but one with a 1 phase motor and the other with a 3 phase motor (same HP, same ), and I do the exact same work on each. Will the 3 phase motor consume fewer watts?
Is the answer simply in the efficiency rating of the motor itself? I looked on grainger for examples, and typical 3P motors are listed as 86% efficient, but 1P motors don't have a rating (or not the dozen or so I sampled) Isn't about 85% typical for 1P motors too?
Or is this one of those things that's way more complicated than it appears?