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208 volt welder on 240 volt

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Rob1969

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Discussion starter · #1 ·
Hello all,
Not directly job related but feel that all the knowledge on this forum can easily answer this question. I have the opportunity to get an older working ac/dc 208 volt Lincoln stick welder for free. My small garage turned fab shop has 240 volt single phase in it. The welder is currently wired to two legs from a 3 phase service. I understand that the sine waves in 3 phase are 120 degrees apart as opposed to 180 degrees apart on my single phase. My question is will the welder care about the increased voltage and 40 degree wave shift? I just don't want to go through all the trouble retrieving, moving, and wiring it up just to find out she won't run or even fry the unit. Thanks, Rob
 
#4 ·
Rob1969 said:
Hello all,
Not directly job related but feel that all the knowledge on this forum can easily answer this question. I have the opportunity to get an older working ac/dc 208 volt Lincoln stick welder for free. My small garage turned fab shop has 240 volt single phase in it. The welder is currently wired to two legs from a 3 phase service. I understand that the sine waves in 3 phase are 120 degrees apart as opposed to 180 degrees apart on my single phase. My question is will the welder care about the increased voltage and 40 degree wave shift? I just don't want to go through all the trouble retrieving, moving, and wiring it up just to find out she won't run or even fry the unit. Thanks, Rob
Click to expand...
It won’t work without a phase converter!
 
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#6 ·
valdelocc said:
It won’t work without a phase converter!
Click to expand...
Really??? I admittedly don't know anything welders, but I always thought single phase was single phase. Yes I get what the original poster is saying about the sine wave of true single phase being different than the sine wave of 2 legs of a 3 phase service, but I've never heard of it actually mattering for any piece of equipment.

This is interesting. What is the real correct answer?
 
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Discussion starter · #8 ·
It's a three phase system, but only connected to two legs not three. That's why I'm hoping it will work. The actual voltage across the two legs is 213.2 volts which make it even less of a jump to my garages 238 volts. A 11.59% jump doesn't seem that unreasonable.
 
#10 ·
I really don't know but I suspect the welder would run better with a phase converter. I know most wouldn't want to buy a converter when the welder was free. Maybe cheaper to sell it on Craig's List and buy a single phase welder.
There are YouTube videos on home made converters using, for example, a motor to create the missing phase. I wouldn't want to trash even a free welder. I might suspect the welder's output would suffer. I might peek inside and see if I could cipher a bit more. I know it's not like single phasing a motor.
 
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#12 ·
beenthere said:
Its a single phase welder currently wired to a 3 phase panel. But wired single phase. It will work fine on his 240 volt single phase service. Amp setting will be off slightly.
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This is how I'm understanding the question also. I believe when he says it's a "3 phase system" he is referring to the panel, not the welder.

Perhaps a simple confirmation on the 3 phase panel and single phase welder detail would help clear some confusion and develop a more concrete answer as to what needs to be done (or not done) to operate the welder.


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#13 · (Edited)
I think some of you guys that are confused are starting to confuse me. Can a phase converter convert 3 phase power (consisting of 2 hots that have a sine wave that is 120 degrees apart) into single phase that is 180 degrees apart? I've never actually heard of the need for this.

Also, what is pecmsg trying to get at in post number 7? What happens to the 3rd leg unused? I would guess nothing would happen to, but if it was just a transformer and not a "phase converter", the 2 output hot wires would be just as many degrees apart in the sine wave as the input hot wires would be. Did I solve the riddle, or were you going for something else?

I feel bad for Rob1969. I'm sure he didn't mean for his seemingly simple question to cause so much confusion.
 
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#14 ·
beenthere said:
Its a single phase welder currently wired to a 3 phase panel. But wired single phase. It will work fine on his 240 volt single phase service. Amp setting will be off slightly.
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Im with you here.

Its not different than a 3 phase building that has a single phase 208/240 a/c condensing unit. While the building main panel has 3 phases of power, you only run 2 legs to the disconnect and bada boom she is running. Now what I would imagine happened, is they ran the 3 legs to the disconnect, "in the event" they needed 3 legs in the future.
 
#15 ·
The way I read post #1, it is a single phase welder. Nowhere did he post that it is a 3 phase welder. Rob, what is the model number of your welder?
 
Discussion starter · #16 · (Edited)
Hello everyone. Thanks for responding. Yes, I am more confused now than I was before. The following is all the info from the welder:

Lincoln IDEALARC 250
Input- 208 volts
55 amps
60 cycle single phase

Output- 300 amp AC 250 amp DC

Model 250-250
Code 7056-C
Serial AC278-570
 
#19 ·
ammoniadog said:
I think some of you guys that are confused are starting to confuse me. Can a phase converter convert 3 phase power (consisting of 2 hots that have a sine wave that is 120 degrees apart) into single phase that is 180 degrees apart? I've never actually heard of the need for this.
Click to expand...
I am also confused by all this.

But I can say with certainty that 2 sine waves that are 120 degrees apart combine into 1 wave 180 degrees apart.


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Rob1969
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