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#6041 - 12/20/01 03:28 AM Wye or Delta?
Joe Carpenter Offline
Member

Registered: 12/19/01
Posts: 55
Loc: USA
A 4 wire 3phase system with 480 volts phase to phase and 277 volts phase to neutral. Is this always a wye system? What are the differences between 480 Wye systems and 480 Delta Systems?

Thanks

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#6042 - 12/20/01 03:44 AM Re: Wye or Delta?
Joe Tedesco Offline
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Registered: 10/07/00
Posts: 3325
Loc: Boston, Massachusetts USA
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Joe Tedesco, NEC Consultant

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#6043 - 12/20/01 04:00 AM Re: Wye or Delta?
George Corron Offline
Member

Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
Joe, The short answer is, a Delta system will produce phase to ground voltage that is 1/2 of the phase to phase voltage, Wye system the phase to ground voltage is phase to phase voltage X 1.732. In your question 480 X 1.732 = 277, therefore you have a Wye system. Let's make that 3 phase systems, single phase transformers can be wound in any danged way ya wanna.

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#6044 - 12/20/01 09:28 AM Re: Wye or Delta?
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
If the voltage to ground is 1/2 the phase to phase voltage, you would have a 4 wire delta with a high leg. If the delta is ungrounded the phase to ground voltage will float between 0 and the phase to phase voltage. If the delta is a grounded delta, one leg will be 0 volts to ground and the other 2 will have the phase to phase voltage to ground.
Don(resqcapt19)
_________________________
Don(resqcapt19)

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#6045 - 12/20/01 03:38 PM Re: Wye or Delta?
aphares Offline
Member

Registered: 12/17/01
Posts: 39
Loc: Indiana
The delta connection of the circuits in a three phase system in which the terminal connections are triangular like the greek letter DELTA. The delta connection will stand 1.732 as much current as the Y connection, but will give only .577 as much voltage. 480 X .577 = 276.96
(NOT) 480 X 1.732 = 831.36

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#6046 - 12/20/01 05:18 PM Re: Wye or Delta?
George Corron Offline
Member

Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
OOPS 480/1.732 = 277 fat fingered, non-proof reading rascal.

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#6047 - 12/20/01 08:55 PM Re: Wye or Delta?
Scott35 Offline

Broom Pusher and
Member

Registered: 10/19/00
Posts: 2724
Loc: Anaheim, CA. USA
Joe [Joe Carpenter],

Are you looking for Schematics, or technical differences between Deltas and Wyes?

If you would like to view some Schematics, look in either the Technical Reference area or the Electrical Theory area of this forum [ECN]. I'll post hyperlinks later if needed.

I'll add some tech data later on.

Scott SET

P.S. Does anyone manufacture a 480/277 4 wire Tee Transformer???

SET
_________________________
Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!

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