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440v 3 phase and 220 v , for welder

Posted by id1scott (My Page) on
Tue, Feb 17, 09 at 14:25

Our whse is wired with 440v 3 phase. I am trying to put a 220v dryer plug in for a AC225 welder. There is 2 orange wires, 1 yellow, and 1 green. Does anyone know the correct way to wire the plug for the welder? Thanks


Follow-Up Postings:

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RE: 440v 3 phase and 220 v , for welder

Yes. The correct way is to hire en electrician who will know what to do.
I know I'll get flamed for this but from the sound of it someone is going to get hurt or killed at worst, or at least the magic smoke will be let out of your welder if you hook it up to this panel.

A 240v welder CANNOT Be wired to a 480V service!
I am amazed that you think it can.


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RE: 440v 3 phase and 220 v , for welder

I was told you could use one of the hot wires and it would be cut down to 220. Also the power is three phase but the welder is single phase. Just trying to use the power we have to run the welder.


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RE: 440v 3 phase and 220 v , for welder

You were told wrong.

If you had 120/208 Y service you could get 208, but not 240.

There's no way to get anything close to 240 from 480 service.

Screwing around with power in a commercial building if you aren't an electrician is illegal in most places and INADVISABLE if you haven't a clue.


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RE: 440v 3 phase and 220 v , for welder

I'll bet someone is thinking they can run the 240V welder off 277V (480Y = 277 phase-neutral)

It MAY work, but it's nowhere near legal, safe, or recommended.


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RE: 440v 3 phase and 220 v , for welder

"Yes. The correct way is to hire en electrician who will know what to do.
I know I'll get flamed for this but from the sound of it someone is going to get hurt or killed at worst, or at least the magic smoke will be let out of your welder if you hook it up to this panel."

Not sure why anyone would flame for this answer - to me it is really the ONLY correct answer to give under the circumstances.


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RE: 440v 3 phase and 220 v , for welder

I was actually able to do some welding of the fitting on the end of conduit that inadvertantly touched a 480V leg. I also managed to trip the breaker on the 13KV->480 stepdown in the basement.


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RE: 440v 3 phase and 220 v , for welder

A qualified electrician could install a buck boost transformer from 480 down to 240 to meet your needs. You must have some sort of transformer and panel in order to get 120v. for receptacles, so it may be easier to install a 208 to 240 transformer. However, if you have a delta/telta 480 to 240 (that would be a 120/240v panel with a hi-leg) transformer youre in luck. A Qualified electrician can have you up and going with minimal fuss.


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RE: 440v 3 phase and 220 v , for welder

If there is a small office in this warehouse with a receptacle, there HAS to be a 120V panel somewhere. Depending on the actual electrical specifications of the welder, it MAY be able to be connected to said panel, or as others have stated, a buck/boost transformer will need to be installed.


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RE: 440v 3 phase and 220 v , for welder

The other option is to by a 3-phase welder. Miller makes them and I presume others do as well.


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RE: 440v 3 phase and 220 v , for welder

To me it doesn't matter if there is a 120 volt panel somewhere in the building or not. This is all pure speculation on the part of people on this internet forum. The fact remains that if someone posts a question on how to hook up a welder to a three phase 480V service they are not capable of doing the work themselves.

There is nothing wrong with the OP asking the question, there is however in my opinion only one correct answer to it and that was already given in the first response.

I have no problem giving advice for residential work but three phase wiring is absolutley no place for a novice or DIY. Anyone who needs to ask how to connect something to a three phase service is not qualified to do it. There are way too many varibles in the situation - just look at what people are throwing around on this board right now - Delta's, Y's, high legs, buck transformers, step downs, step ups - heck why dont we just recommend that they install a phase converter while were at it...


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RE: 440v 3 phase and 220 v , for welder

I recommend anyone who wants to jump into any electrical DIY project to first spend some time in YouTube searching for 120v arcs and fires and then 220 and then jump to 480V. Spend some time looking up electrical burn photos and then really think about 'just winging it'. This stuff will separate your mind from your spirit almost instantaneously.

Here is a link that might be useful: 480v Arc Flash Demonstration


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RE: 440v 3 phase and 220 v , for welder

Yep, and as I pointed out, even if you have 120 power in the building, if it's three phase it's likely to only be 208volts between phases.

Of course it's possible (but unlikely) to have a stepdown transformer to provide 240.

JMVD is right. The poster has no business doing this unless he is an electrician. The very nature of his question indicates he is not one (or incompetent).


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