220 outlet wiring question?

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I have a electrical question I need answered. The electrician that wired up my 50 amp 220 outlet for my welder used 8 guage two wire romex wire. Is it ok to use that wire even though the ground wire is only insulated with paper?Thanks for any info,John
Reply:Should be OK,  Check with electrical codes for your area.       The wire I used doesn't even have paper around the ground.       As long as the ground wire is connected to the box, and the receptacle,  and then also to the ground bar in you main panel.  Everything should be to code and safe.        If something were to give you a dead short... say a pinched hot wire, on a clamp.  (been there done that,)  and since the box is grounded along with the receptacle.  Your breaker will trip long before anything can get hot enough to cause a problem.Lincoln 225 AC/DC, Hobart 140 Mig. Oxy/propane Victor torch.(2) Makita 5" angle grinders  one with zip disk, 14" chop saw.  and just about every other tool you can think of. Whoever has the most toys when he die's ..... Wins!
Reply:I don't think it will pass inspection by the building inspectors because it is in violation of the NEC.  8-2 Romex is only rated to handle 40 Amps.  If your electrician would have used 8 THHN you would of been O.K. .  The Code calls for Romex wire to be rated by the 60 degree chart instead of the 90 degree chart used for THHN.
Reply:For a welding machine the 8 wire is fine.  For most of these mahines a 10 would be fine.  Its allowed to be derated as per the machines duty cycle as per Art 630 NECwww.urkafarms.com
Reply:SBerry,            Your correct as long as his machine has a 60% Duty Cycle or less. Ten gauge wire would work for 30% Duty Cycle or less.  I have never been a fan of using the minimum wire size allowed because of problems that can come about down the line (next owner of house sees a fifty amp outlet on one end and a fifty amp breaker on the other and assumes that it can be used for fifty amp anything.  Whats your interpretation of article 630.12? Reason I ask is that I received the manual for my Miller 330 A/B and it said that I should use a 175 Amp Breaker for it.  I thought it was a misprint, so I called Miller up.  They stated that the manual was correct , but damn, that seems  pretty high. I didn't catch what type of welder JohnV said he was going to use (data above is for an arc welder) or what the duty cycle is.  Most (actually all) the welders I have out in my shop are 60% Duty Cycle or higher, so I tend to go large on the wiring.  I am still hunting for data on my Wilson Hornet DC Generator welder (Duty Cycle,etc). I'm treating it as if it has a 80% Duty Cycle based on what I read in an old NEC book.  Also , just picked up a Powcon Model 300SS  and am interested in any feedback on it  (got it for $50 in our local newspaper).  I just got the manual in on it from Arc Products and it too is a 60% Duty Cycle 300 Amp machine.
Reply:What I understand of the code which applies to welding applications is that the wire is rate for continuous load. When the welder has a duty cycle it ensures that there will be time for the wires to cool because no welding will be performed. The breaker amp rating is designed to allow the welder to provide full output without popping the breaker on you. The wire will actually be carrying amps in excess of what you would figure is acceptable but it all comes back to the duty cycle. I have a Lincoln SW 175 and dug through all this stuff to make sure I wired my garage correctly. I'm glad I don't own a 100% duty cycle machine because it gets considerably more expensive to wire the garage for one of these. If you put a breaker of less than 175 amps in it and set the machine up for max output you'll probably pop the breaker during the initial arc strike. The running amps are not that high but the surge during start can get up there. I think it is like the start of a motor which draws about 6 times the running amps during start. Good luck.
Reply:I think thats the max allowable breaker for that machine. My synchro calls for 100A,,, provided you wire it with number 2 (and allowed to go up to 200).  I would be running on 100 unless it gave me problems with the machine you have. The code reads,,, if there is a problem you are allowed to upsize (I believe) John has a buzz box and I got that from another forum he was on. I agree with the principal about future use on wire size, especially if it is cable in wall. I always warn,, this is not a circuit for a kiln or other continious use device. I do tend to quote the allowables and generally reccomend 1 size up for home use. At home 10 for fairly short runs and limited use is fine I think. In the 50's and 60's they installed hundreds of thousands,, maybe millions of these 10/50 circuits for small welding machines, usually on fuse panels. I still see them in old farm buildings.www.urkafarms.com
Reply:I have TIG unit. Its a Thermal Arc 185 TSW that calls for a 40 amp breaker. I just happened to a 50amp breaker in there for a MM251 that I was considering purchasing.John
Reply:SBerry,           I lucked out and bought a lot of large gauge THHN wire when the prices were a lot lower than they are now (i.e. 1000 ft of 4 THHN at .19 a foot).  I had to put safety disconnects to each of the welders out in my shop to keep the inspectors happy.  I ran the Miller on a one hundred amp line at my old house and it ran fine.  I just wanted to hook it up according to the book. I would like to find out some info on the Wilson Hornet.  I fired it up on a three phase one hundred amp line and it welded beautifully.  I have an independent, 200 amp service run out to my shop and have been doing O.K. with it as long as I remember to just run one machine at a time.  Works alright as long as my son and his friends are not around. My shop is sort of like the elephant graveyard for old industrial machines, so the equipment seems to be on the large size.  The Wilson welder was so heavy I had to put four wheels on each axle to keep them from bending.  I just hate to see old iron sent to the scrapyard.Dog1