Help wiring for new MillerMatic 211

[isuhunter]

I received my new MillerMatic 211 and need to update my service receptacle and verify wiring in my garage.

With a 50 A breaker can I use #10 wire & NEMA 6-50R?

I currently have a 50 amp circuit service as pictured below but the incorrect receptacle and not sure what my wire is.

 

[ishiboo]

Being a welding receptacle, you can't use the derating from whatever else was planned to be on there to supply it. So if you have a 50A breaker on it, you will need to have #8 CU I believe offhand.

If you reduce that to the appropriate 25-30A breaker, no problem using the #10 wire that's already there since it is larger than the required #14.

 

[matt_i]

I'd take off the cover plate to ascertain wire size. The 50A circuit is just fine if its breakered properly for the wire size. Hopefully its hooked to a #6 awg wire.

 

[isuhunter]

I'd take off the cover plate to ascertain wire size. The 50A circuit is just fine if its breakered properly for the wire size. Hopefully its hooked to a #6 awg wire.

If its to a #6, would you keep the #6 and replace the receptacle only?

 

[pattenp]

Even though welder use only outlets can have smaller conductors than a general use outlet, I highly recommend wiring and over current protecting the circuit as a standard circuit. Which means 50A breaker using #6 NM or #8 THHN in conduit with a 6-50 receptacle.

 

[matt_i]

If its to a #6, would you keep the #6 and replace the receptacle only?

Yes, I'd make the receptacle a 6-50R, if that's what is supplied with your welder. If not I think you can find appropriate "appliance cord pigtails" at the box stores with that male end already molded onto a short cordset. Could possibly be near appliances as that would be a classic cord for an electric range/oven.

 

[sberry]

With that machine and all but 250 migs the 10/50 is fine. You need to reduce the breaker if you use 14 wire.

 

[isuhunter]

If I wanted to move the receptacle to the middle of my garage, what size wire would you replace with?

 

[sberry]

A 10/30 is a tailor made circuit for a 211 class machine. It won't trip a 30 but would be legal on a 50.