50 amp welder circuit

[dwp99]

Hello, I have a couple questions about the running of a dedicated circuit for a 200 amp welder.

The welder has a 3 prong plug 2 hot legs and a ground. The 3rd prong is grounded to the chassis of the welder. I want to run 6-2 with a ground from the breaker box to the outlet which is approximately 40 feet away as the romex is routed. I plan to run the romex overhead in the attic and then into 3/4" conduit as it comes out of the ceiling to the outlet.

1. Would this be the correct way to do this?

2. Is 6-2 heavy enough to carry the load of 50 amps?

Thanks

 

[Highbeam]

6 gauge is heavy enough for 50 amps. Note that your welder cord is very light gauge in comparison.

Running the 6 gauge romex through a conduit is legal but you need a big enough conduit. 3/4" pretty dinky.

 

[pattenp]

The #6 NM is good but you should use 1" conduit.

 

[theoldwizard1]

Running the 6 gauge romex through a conduit is legal but you need a big enough conduit. 3/4" pretty dinky.

Right on ! The issue with Romex® in conduit is "fill ratio" or how much air is left around the cable, Hopefully some one will chime in here what the proper size conduit is.

6 gauge Romex® is stranded, but it will be hard to bend. Depending on how many bends you have you might want to use THHN, which means conduit all the way from the box to the receptacle. THHN has more strands which means it is more flexible and easier to pull.

 

[DesertSparky57]

You could choose to use 8Awg as well. 8/2 is a bit smaller than 6/2. I'd have to check to be sure, I think conduit fill is 4 6awg or 6 8awg in 3/4" EMT, but that is for single THHN. A piece of one inch conduit would be your friend in this case. A nice deep box for the receptacle to go in would be a good idea too. I have always disliked stuffing big dryer or appliance plugs in standard size boxes, just a personal preference though.

 

[dwp99]

Thanks for all the help. I'm going to use about 3.5' - 4 ' of conduit the only bend will be at the outlet and it will be in an offset bend. It should slide in with no problem.

I'll use 1" conduit.

Thanks again

 

[pattenp]

Be sure to use a plastic press on bushing on the cut end of the conduit where the NM enters up in the attic.

 

[DesertSparky57]

I was just about to mention the bushing where you transition into the pipe. Good call pattenp. Little press on bushings work very well.

 

[dwp99]

Be sure to use a plastic press on bushing on the cut end of the conduit where the NM enters up in the attic.

That was going to be my next question. what type of bushing do I use on the raw end of the conduit?

Thanks.

I went back out in the garage and had another look at the cord coming out of the welder. It's 8-2 10-1.

 

[DesertSparky57]

Yup. That sounds right for the cord on a 50A machine. The bushings are a press on type. Wherever you are getting your electrical supplies from should have them.

 

[dwp99]

Yup. That sounds right for the cord on a 50A machine. The bushings are a press on type. Wherever you are getting your electrical supplies from should have them.

Thanks