Re: 220V 3 phase => 60 HP, how many amps?

Oct 18, 2007 1 Replies


>


>> Eek. I've just gone and probed a panel, and it's 240 phase-to-phase,
>> and 208 to "neutral" on one phase, and about 120 to "neutral" on the
>> other two. Sounds like delta with one winding center-tapped, which
>> is why I say EEK!
>
> A common arrangement. For the purpose of calculating motor loads, you
> have a 240V 3 phase system.

Yeah, I've seen the setup before - apparently the delta is totally floating, and the CT winding gives 240 CT "lighting" power. The thing that kinda weirded me out is that the panel I looked at (actually, a sub-sub panel, right next to another machine) had Black, Red, and Blue going to 3 big fuses, and white going directly to the box frame, with green on the other side going to the machine.


You may also want to look around for nameplates and/or connection
> diagrams. Its possible that the M-G set might be dual voltage and be
> configurable for a 240V supply.

I saw a couple of very plausible answers today, and the PHB popped his head into the office and asked, "What did you pay these guys for these answers?" I said, "nothing, it's a public discussion group."


He grumbled a little, and said, "I guess I'm gonna have to get somebody in here." and I said, "Yeah - your best bet would be a real electrician - you're going to need somebody licensed to wire it up anyway." That at least got him off my back.


Thanks, Rich



[snip]

Hey, at least you'll have some good puns ready for him. ;-)

Paul Hovnanian mailto:Paul@Hovnanian.com ------------------------------------------------------------------ f u cn rd ths u r usng unx

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