# Three phase question

Discussion in 'Homework Help' started by rmanach, Jan 21, 2009.

1. ### rmanach Thread Starter New Member

Jan 21, 2009
1
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Hello, I'm thoroughly confused by three phase right now and am working on a homework for my power class.

Is 480/277 always WYE? The 480 refers to phase to phase voltage, where as the 277 refers to phase to neutral, correct?

So if I have a 480/277 4 wire setup, then it has to be wye?

If it is wye, or if it is delta - what would be my line current if I had say a 10kW load?

I'm just confused by the notation since there is no Y in the middle (480Y277) Is that all there is to it?

Sorry if this is a dumb question, but I thought there was some sort of standard on this notation until I came across this.

Oct 29, 2008
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3. ### mik3 Senior Member

Feb 4, 2008
4,846
63
Maybe it is wye because a delta connection does not have a neutral wire. Or maybe is a delta with a ground wire.

I=P/(V*pf*sqrt3)

I=line current (A)
P=real power (W)
V=line voltage (V)
pf=power factor