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To: NicknamedBob; Cyber Liberty; GeronL
If you lose one phase of supplied power, the other phase can burn out motors

You betcha! That's why they make 'phase protection' circuits. Very important thingies to have in NYC because Con Ed has a nasty habit of flipping phases if they do some work out on the street where your feed comes from. Since phase protection has not always been in the code, a lot of old stuff, of which a lot is AC motored, has no protection from this. So elevators go up instead of down and ventilation equipment sucks instead of blows..

Now a quiz question. In your normal house service, you have 240 ac (or 220, or 208) coming into the house. If you go from one leg of that 240 vac feed to ground (neutral - which in most places is grounded, but not always..) you get your nominal 120 vac house voltage. Here's the quiz question: What is the voltage to ground/neutral from one leg of a 480 vac three phase supply?

Bonus question: Assuming the wiring follows code, how can you tell whether you are looking at a nominal 240 three phase or a nominal 480 three phase feed without a meter or looking at the name tags.. (and no, not by grabbing one of the hot wires and grounding yourself..)

3,617 posted on 10/12/2013 5:33:27 PM PDT by NoCmpromiz (John 14:6 is a non-pluralistic comment.)
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To: NoCmpromiz
Here's the quiz question: What is the voltage to ground/neutral from one leg of a 480 vac three phase supply?

277VAC. I'll take my Kewpie Doll.

3,619 posted on 10/12/2013 5:38:13 PM PDT by Cyber Liberty (It's hard to accept the truth when the lies were exactly what you wanted to hear.)
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To: NoCmpromiz

If you’re talking color coeds, that’s easy. Red, Black vs Yellow, Brown. “Ground and Yeller kills a Feller.”


3,620 posted on 10/12/2013 5:41:07 PM PDT by Cyber Liberty (It's hard to accept the truth when the lies were exactly what you wanted to hear.)
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To: NoCmpromiz

I hope your not asking me those questions. lol

Cuz my answer would be...

Albuquerque


3,629 posted on 10/12/2013 6:24:32 PM PDT by GeronL
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