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Old 11-27-2011, 09:53 PM
Kerry Pinkerton's Avatar
Kerry Pinkerton Kerry Pinkerton is offline
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Default 380V 3 phase

I'm in the process of buying a metal shaping tool that is wired for 380 (50Hz) 3 phase. No other voltage is available with the machine.

I have obviously 220 single phase in my shop and normally run a rotary phase converter which also generates 330 3 phase.

The hertz issue isn't really a concern because the machine will just run a bit slower. The voltage however is something I'm in the dark about.

I know I can get a VFD that will take 220 input and produce 380V out with 0-100Hz. This WILL solve the problem but costs about $300. Plus it means I'd have to turn on something else before the machine. Not really a problem but it will be an irritation.

I have a big Westinghouse V30001 transformer that MAY have a 380 tap. I know I got enough to run a Canadian 550V bandsaw. I'll have to hook it up and measure the output taps.

However, I'm being told that it will run on 440 or 220V without an issue. This is an expensive machine and very expensive motor so I don't want to shorten it's life.

380V 3 phase is a common voltage in Europe.

Can someone school me in what the issues and solutions are?
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Old 11-28-2011, 07:45 AM
metal manny metal manny is offline
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Hi Kerry

I own a P21 Pullmax which is 380v 3-phase as this is the industrial norm here. I purchased the machine with the understanding that I'd have to swap out the motor for a 220 3-phase one, as I have a few 220v VFD's to control motors for my work, and only 220 single phase in the workshop.

Out of curiosity, I connected up the 220 VFD to see what would happen, with the understanding that the VFD would trip out before the motor blew due to its sophisticated management software for over-current etc.

Guess what - the machine runs beautifully, probably sucking a few more amps than before and will do the work intended. I've done this to a few motors since without any ill effect. If you already own a 220 VFD, perhaps try hooking it up and see...

Incidentally, all the motors I buy new to run on my VFD's come as 220/380 dual voltage units???

Best of luck - Manny
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Old 11-28-2011, 07:55 AM
metal manny metal manny is offline
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Default oops!

Sorry, forgot to add that you'll probably need to wire the motor in "delta" if it's hooked up in "star" mode to run at 220V

Manny
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Old 11-28-2011, 01:09 PM
kjc kjc is offline
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Quote:
Originally Posted by Kerry Pinkerton View Post

The hertz issue isn't really a concern because the machine will just run a bit slower. The voltage however is something I'm in the dark about.
It may be an issue.

I recollect that machines designed for 50HZ when run at 60Hz will run hot due to core saturation.....or maybe it's the other way around? You should check reliable internet sources to confirm which way around might be a problem 50Hz to 60 or 60Hz to 50.

Sorry my memory isn't better on the subject.
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Old 11-28-2011, 03:12 PM
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Kerry Pinkerton Kerry Pinkerton is offline
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Quote:
Originally Posted by kjc View Post
It may be an issue.

I recollect that machines designed for 50HZ when run at 60Hz will run hot due to core saturation.....or maybe it's the other way around? You should check reliable internet sources to confirm which way around might be a problem 50Hz to 60 or 60Hz to 50.

Sorry my memory isn't better on the subject.
It's a two speed motor....a little internet research tells:

Quote:
Looking at the case shifting a 50Hz motor to 60Hz duty.
a) It will turn 20% faster.
b) The cooling will increase dramatically.
c) The load's horsepower requirement will increase, possibly dramatically.
d) The V/f will drop which will not cause a current draw increase.
So other than running a bit faster, no harm from the overspeed. The additional cooling might help if heat is generated from over voltage situations....
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Old 11-28-2011, 07:26 PM
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OK, got some input from some people who understand this stuff. This is what I think I know:

380V 50hz is basically the same as 440V at 60hz.

My transformer has several taps in the mid/upper 400V range so I should have no problem getting 480ish volts.

As above, the motor will run a bit (20%) faster than designed but that's OK.

The one apparent potential issue is that the motor MAY pull a few more amps at startup. Don't think this will be an issue.

Long and short of it is that I should be good to go with this machine.
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Old 11-29-2011, 02:33 AM
robert robert is offline
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i am surprised i am the first to ask
when are you gone tell us what mistoury machine you are buying kerry
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Old 11-29-2011, 08:27 AM
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Kerry Pinkerton Kerry Pinkerton is offline
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...when are you going to tell us what mystery machine you are buying?
It's not quite a done deal yet and I don't want to bring bad luck into the deal. I'll post photos after I get it home and get it up and running, hopefully before Christmas.
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Old 11-29-2011, 10:23 AM
weldtoride weldtoride is offline
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Default Ask a rebuilder

I had a question recently re: a 208 3ph motor to run on my 240 3 phase, it was outside the 10% rule of thumb. The electrician I was conferring wth does a lot of industrial motor work, his advice was the best: take the motor to a motor rebuilder and ask. There is a company that has been in business for over 40 years in a nearby town. Instead of removing the motor, I took photographs of the motor data plates to the rebuilder. After asking me the use cycles intended for the motor, I got two opinions there and they were in agreement in my case: go for it, but watch amp draw under heavy load. They gave me a max where I would need a bump transformer, about a $100 in my case.

Good luck with your aquisition.

Mark
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