3 phase welder

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Disco
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3 phase welder

Post by Disco » Tue Jan 01, 2008 4:28 pm

I have a Hobart Model R400 3 phase welder (230 or 460 vac). Can I parallel all three transformers and run on single phase? Or can I just fed one transformer and run at reduced output? This is a 400 amp welder with a mag amp control. I don't need 400 amps, 150 would probably be plenty. Looks like I could just use the transformer that feds the control circuit. I would have to feed the cooling fan separately, but that would not be a problem. Any thoughts?

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dacflyer
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Post by dacflyer » Tue Jan 01, 2008 5:22 pm

we could tell you easier if you possibly had a schematic....

Disco
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Post by Disco » Tue Jan 01, 2008 7:19 pm

I have a schematic. I'm not sure how to attach it.

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dacflyer
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Post by dacflyer » Wed Jan 02, 2008 11:22 am

if you have the schematic as a file.. click the bottom that says
"ADD IMAGE TO POST"
try that....

Dean Huster
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Post by Dean Huster » Wed Jan 02, 2008 4:53 pm

Is it a DC welder, i.e., has a rectifier built in so that it's always a DC output? A three-phase welder, like the 3-phase alternator in a car, makes for some pretty smooth DC as far as ripple goes as compared to either standard half-wave or full-wave rectification.

Dean
Dean Huster, Electronics Curmudgeon
Contributing Editor emeritus, "Q & A", of the former "Poptronics" magazine (formerly "Popular Electronics" and "Electronics Now" magazines).

R.I.P.

Disco
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Post by Disco » Wed Jan 02, 2008 5:14 pm

Yes - it is a DC welder. You are right, the three phase is smoother. But if I run on single phase, I will have more ripple than on three phase.

dacflyer - I'm still trying to get a schematic in here some how. Not having much luck. I don't see an option to "add image to post". Sorry to be so dense. I haven't done much of this forum stuff. I'm still learning and I'm a little slow. Thanks for your help and patience.[/list][/list]

Disco
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Post by Disco » Wed Jan 02, 2008 6:33 pm

OK - Hope this works.
Link to the schematic:
http://www.flickr.com/photos/[email protected]/2159926133/

You can enlage it after it opens.

I think I can use just the "C" winding. Disconnect all of the primaries and secondaries of the "A" and "B" winding. This will cut down on the max current out, but I don't think that is a problem. This set up would allow the use of the high and low range outputs. The fan is 110 volts. I can feed it from a small transformer.

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dacflyer
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Post by dacflyer » Thu Jan 03, 2008 1:45 pm

i been looking at this schematic,,but i cannot see where the mains transformer primaries are..i see all the secondaries..

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jwax
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Post by jwax » Thu Jan 03, 2008 3:56 pm

How about playing it safe and giving Hobart a call?

Disco
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Post by Disco » Thu Jan 03, 2008 6:31 pm

Sorry - forgot to attach this page. This is the primary side. I will be using 240 vac.

http://www.flickr.com/photos/[email protected]/[/img]

Thanks

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dacflyer
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Post by dacflyer » Thu Jan 03, 2008 6:46 pm

ok, i looked at the schematic,, looking at the primary schematic you shown.. use fig. 1 to switch the welder over for 230 volt operation..
just change the jumpers as shown in fig.1 its that easy..

then your power connections should be as 120v - 0v - 120v = 240 volt

before it was 208v - 208v - 208v = 3phase

good luck

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