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3 phase power question

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TheSiege said:
2a) A 3-pole breaker would be 3 phase 120. plain and simple.
2b) Would be 3 phase 480.

Look at a wye and a delta transformer and it makes more sense, like the other poster said, phase to ground/neutral produce a voltage and phase to phase creates a different voltage, the rest is just single or 3 phase

<--Electrician
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for 120/208v transformer, why is 3pole breaker= 120v 3phase, but 277/480v transformer, 3pole breaker = 480v 3phase?
 
JEDI said:
for 120/208v transformer, why is 3pole breaker= 120v 3phase, but 277/480v transformer, 3pole breaker = 480v 3phase?
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Well it depends on what kind of panel it is. It could be a 3 phase 277. Or it could be a 3 phase 480 panel, but most likely it is 3 phase 277 in commercial applications. Unless there are alot of motors for pumps and such, then it could be a 3 phase 480 panel.
 
Yeah, I know all about that whole "right gauge wire for the current needed thing." Whatever. You just cannot beat the fact that w/220v at the outlet you can plug in an OVEN or a DRYER with it's own normal plug. No special breaker, no special 4-prong-with-2-prongs-in-an-elipse-so-u-don't-fry-the-frickin'-east-coast-grid shape or whatever. You just plug it in. What a concept? Yeah, 50Hz can be a PITA when using a transformer; it changes voltage but not freq. But other than that "antiquated 220v" has 110v beat to heck, period. Bigass hammer drill? Plug it in! 2Kw power amp? Plug it in! 15K BTU air conditioner? Plug it in! US power sucks.
 
MichaelD said:
Yeah, I know all about that whole "right gauge wire for the current needed thing." Whatever. You just cannot beat the fact that w/220v at the outlet you can plug in an OVEN or a DRYER with it's own normal plug. No special breaker, no special 4-prong-with-2-prongs-in-an-elipse-so-u-don't-fry-the-frickin'-east-coast-grid shape or whatever. You just plug it in. What a concept? Yeah, 50Hz can be a PITA when using a transformer; it changes voltage but not freq. But other than that "antiquated 220v" has 110v beat to heck, period.
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its also alot more dangerous, the only benefit is have lower gauge wire needed. But id much rather have 3 or so 50 amp 2 pole breakers with specific plugs, then have 220 running trough my house. especially with kids.
 
TheSiege said:
its also alot more dangerous, the only benefit is have lower gauge wire needed. But id much rather have 3 or 50 amp 2 pole breakers with specific plugs, then have 220 running trough my house. especially with kids.
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I have kids too. Using "safer for kids" as an argument is like saying "I'd rather my kid gets run over by a bus instead of a cement mixer!" 😱 Sorry...not a good argument.

I've used a bigass hammer drill on a skinny 100-foot extension cord (on a 220v outlet). No perceptible difference in performance...and the cord didn't get warm. Unbelievable? NO! It's 220v!!!
 
MichaelD said:
I have kids too. Using "safer for kids" as an argument is like saying "I'd rather my kid gets run over by a bus instead of a cement mixer!" 😱 Sorry...not a good argument.

I've used a bigass hammer drill on a skinny 100-foot extension cord (on a 220v outlet). No perceptible difference in performance...and the cord didn't get warm. Unbelievable? NO! It's 220v!!!
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So have I, on 110v, It just takes more amps. And the argument is more like, My kid getting bit by a yorkie or a pitbull, I'll take the yorkie any day if the week.
 
MichaelD said:
Yeah, I know all about that whole "right gauge wire for the current needed thing." Whatever. You just cannot beat the fact that w/220v at the outlet you can plug in an OVEN or a DRYER with it's own normal plug. No special breaker, no special 4-prong-with-2-prongs-in-an-elipse-so-u-don't-fry-the-frickin'-east-coast-grid shape or whatever. You just plug it in. What a concept? Yeah, 50Hz can be a PITA when using a transformer; it changes voltage but not freq. But other than that "antiquated 220v" has 110v beat to heck, period. Bigass hammer drill? Plug it in! 2Kw power amp? Plug it in! 15K BTU air conditioner? Plug it in! US power sucks.
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The reason appliances have 4 prongs is because of safety for the person using them and similar plugs are required in foreign countries. You don't go around houses there plugging dryers and ovens into the same outlet as the tv. The only advantage is smaller wires but that doesn't matter in the short distances inside a home. 60hz vs 50hz give me 60hz any day over 220v vs 110v, I can design around the limitations of the voltage easily, but increasing the frequency, that takes work.
 
Rubycon said:
Stop posting 180 degrees out of phase! It's a real PIA to reverse the polarity of my display to read what you post! :hmm:
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Actually I'm pretty sure a full rotation is 540º in australia...disappointed you didn't know this :\
 
PM650 said:
Actually I'm pretty sure a full rotation is 540º in australia...disappointed you didn't know this :\
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1080 in Aussie. Someone hit their head on the toilet while counting revs before going down and realized 1080 would be a good number of lines for HDTV format! :hmm:
 
Ok, To clear things up, think of a triangle as delta, from one angle to another is 1 phase with 2 points. that is 240v, 1 phase but with 2 hots, cut it in the middle for a neutral and you have 2 120v sources still 1 phase. 277/480 is the same concept except it is in a Y transformation, its also the same for 120/208. because you cant exactly cut the Y in half where all the phases meet (middle). you dont get exactly half thats why you get 277 and not 240. you get 3 phase 480 when you take a hot from all points of the Y and you have no neutral. 3 phase 277 is when you take 3 hots and you tap the middle for a neutral. hope this helps a little more
 
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TheSiege said:
Ok, To clear things up, think of a triangle as delta, from one angle to another is 1 phase with 2 points. that is 240v, 1 phase but with 2 hots, cut it in the middle for a neutral and you have 2 120v sources still 1 phase. 277/480 is the same concept except it is in a Y transformation, its also the same for 120/208. because you cant exactly cut the Y in half where all the phases meet (middle). you dont get exactly half thats why you get 277 and not 240. you get 3 phase 480 when you take a hot from all points of the Y and you have no neutral. 3 phase 277 is when you take 3 hots and you tap the middle for a neutral. hope this helps a little more
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I was just about to say this!!! Really!
 
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