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#### owl

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Are the two legs the peak and trough of the same sine wave?

#### FrunkSlammer

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Yeeeeeah boooooyeeeeeee!

#### backstay

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owl said:
Are the two legs the peak and trough of the same sine wave?
They are the same phase but opposite ends of the same transformer secondary winding.

#### Going_Commando

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They are the same phase but opposite ends of the same transformer secondary winding.
I wonder if that is why they call it single phase? :whistling2:

There is a large group of amateur electrical engineers on the internet that think the 2 legs in a panel are 2 phases that are 180 degrees out of phase. They are the type that you can't try to confuse them with facts, as their minds are already made up. Even when you post transformer diagrams to show the winding taps, it don't make any difference. Really funny. :laughing:

#### FrunkSlammer

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So long as we're talking about 120/240 and not 120/208.

#### Going_Commando

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So long as we're talking about 120/240 and not 120/208.
Obviously different.

#### backstay

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Going_Commando said:
I wonder if that is why they call it single phase? :whistling2:

There is a large group of amateur electrical engineers on the internet that think the 2 legs in a panel are 2 phases that are 180 degrees out of phase. They are the type that you can't try to confuse them with facts, as their minds are already made up. Even when you post transformer diagrams to show the winding taps, it don't make any difference. Really funny. :laughing:
Well, if you sub feed a panel with two hots and a neutral from a 3 phase panel it would be two phases, but not 180 out of phase.

#### Going_Commando

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Well, if you sub feed a panel with two hots and a neutral from a 3 phase panel it would be two phases, but not 180 out of phase.
Obviously different. Jeeze you guys! :laughing:

#### FrunkSlammer

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Obviously different.
lol obvious to you! Not everyone on here has been edumacated on the ins and outs of electricity.

Many residences (condos & town homes) around here have 120/208.

#### Going_Commando

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lol obvious to you! Not everyone on here has been edumacated on the ins and outs of electricity.

Many residences (condos & town homes) around here have 120/208.
I apologize, I should have stated 120/240 single phase service in my reply. I'm not perfect okay! STOP YELLING AT ME!

#### FrunkSlammer

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I'M NOT YELLING. JUST TURN DOWN YOUR WHISPER 2000.

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#### boora2

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Single phase resi stuff is often 120-0-120 single phase,giving 240 between the legs in the US,120-0-120 in a wye circuit will be 208 tween the phases.

#### Aegis

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backstay said:
They are the same phase but opposite ends of the same transformer secondary winding.
So maybe you can clear this up, if they're from the same phase why would I get 240 between the two legs??

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:whistling2:~CS~

ce2two

#### owl

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Aegis said:
So maybe you can clear this up, if they're from the same phase why would I get 240 between the two legs??
I am guessing that one leg is the peak of the sine wave and the other is the trough

#### Big John

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So maybe you can clear this up, if they're from the same phase why would I get 240 between the two legs??
Because the transformer is wound that way. Putting 13,800V [or whatever] to the primary winding creates 240V in the secondary winding because the ratio is 57.5:1 so there are 57.5 turns on the primary for every one turn on the secondary.

The neutral is just a tap directly in the center of the secondary; the voltage measured to it is divided evenly in half because of its location. If you moved it, the voltage measured would also move. Put it 3/4 of the way down the winding and you'd get 180V to ground on leg, and 60V to ground on the other. Put it all the way at the end of the winding and you'd get 240V to ground on the other end.

#### A Little Short

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Because the transformer is wound that way. Putting 13,800V [or whatever] to the primary winding creates 240V in the secondary winding because the ratio is 57.5:1 so there are 57.5 turns on the primary for every one turn on the secondary.

The neutral is just a tap directly in the center of the secondary; the voltage measured to it is divided evenly in half because of its location. If you moved it, the voltage measured would also move. Put it 3/4 of the way down the winding and you'd get 180V to ground on leg, and 60V to ground on the other. Put it all the way at the end of the winding and you'd get 240V to ground on the other end.
Quit showing off. You just read that on the internet!:laughing:

#### RGH

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Owl good question ! you might want to get a book on commercial electric....transformer connections at this level are really interesting...208/240/277/460/480 "y"(s) & delta(s) are common and a little confusing at first....good diagrams and a little math and you'll been good to go:thumbsup:

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