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Looking into stick welding at home, but do not have a 240v 50 amp outlet in the garage to run the machine. I know a square D 50 amp 2 pole circuit breaker, some 6 gauge wire and an 240v outlet are required to install an outlet. The question is can I install such an outlet in the sub panel in the garage?


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Looking into stick welding at home, but do not have a 240v 50 amp outlet in the garage to run the machine.
You’re in amazingly good shape to do that upgrade, by sheer luck of the draw. The key thing is conduit back to the main panel.

Though this would be easier if you tore out that too-small panel and fit a nice 18-space.

I know a square D 50 amp 2 pole circuit breaker
Who said Square D?? That’s a Westinghouse panel.

That’s not how you pick breaker types. The breaker has to be correct for the panel. Every panel type is different, the clips the breaker goes on are different shapes. Square pegs, round hole, the wrong breaker will “snap in” but it won’t engage properly, and will damage the bus bar - especially for a high current draw like a welder. And potentially start a fire.

Your Westinghouse panel is semi-obsolete, but fortunately it fell into the Bryant/CH/Eaton lineage, and so it has bus stabs that are compatible with Eaton BR type. That is the only correct breaker for that panel.

To belabor the point, do not put Square D anything in that panel. Square D breakers are for Square D panels.

some 6 gauge wire
Sometimes, you can use #8.

and an 240v outlet are required...
That’s a NEMA 6 or a NEMA 14. Some knuckleheads install a NEMA 10 which is illegal and unsafe. Avoid that error :)

The question is can I install such an outlet in the sub panel in the garage?
You are one lucky son-of-a-gun! It can be done but not without some rework.

Re-run the feeder

Here’s the lucky part: You appear to have 3/4” metal conduit between your main panel and your subpanel! You need to follow that back to the main panel and find every bend and access point. We’ll be pulling *much better* wire in there that’s the right color. But you’ll need to find every access point, because you’ll need access to all of them to pull the new wires. Typically access points are at 90 degree corners.

The new wires from main to subpanel will be:

- 1 x 6 AWG copper THHN - white or gray. (For neutral)
- 1 x 8 AWG copper THHN - green. (For ground)
- 2 x 6 AWG copper THHN - any other colors

This will allow more than twice the current you can handle now.

Change the breaker in the main panel to 70A

The #6 THHN wire, since it is in conduit, is good to 65A. They don’t make 65A breakers, so you can round up to the next size of breaker which is 70A.

However, this breaker must match the main panel. If the panel is Square D, use Square D breakers. If GE, use GE breakers. Anything else, shoot us a photo of the main panel’s labeling and we’ll tell you the proper breaker to fit.

Rework the panel

The panel has issues - notice the grounds on the neutral bar (very wrong) and the clump of grounds nutted together (legal but sloppy). I’d rather mount a proper accessory ground bar in there, or at least add a ground screw into the panel chassis for each ground screw. But if that can’t be done, look for better splicing options.

But get the grounds off the neutral bar and spliced to the grounds and panel chassis. Somehow!

Move existing breakers onto double-stuffs

For this you’ll need two Eaton “twin/duplex/tandem” breakers like a BRD1515. These take 1 breaker space but support 2 circuits. You’ll need fit 2 of them on either the top or the bottom and move all your existing circuits to these.

That will free up 2 whole spaces. Into those 2 spaces you stick a 50A breaker. You need a full-size breaker because I fully expect the inspector will at some point tap you on the shoulder and require a GFCI breaker there, unless you got it permitted prior to NEC 2020 taking effect.

Run conduit to your new recep location

You can’t run bare cable because the wire needs physical protection, being in a garage. I recommend you stay with EMT metal conduit, even though it’s a bit awkward to learn to work with, because EMT provides the ground “wire” and that’s one less wire to fish, which may mean smaller conduit.

If you’re installing a NEMA 6-50 recep, you need 2 hot-color wires (any color but white gray or green). Both THHN #8 since which is good for 50A because it’s THHN/conduit. 1/2” conduit is fine.

If you’re installing a NEMA 14-50 recep, you need a third #8 white or gray wire. That will fit in 1/2” EMT conduit; any other kind will need 3/4”.

And that’s it, hook the wires to the breaker and recep and you’re all good. Your subpanel is now 70A and it can support the 50A breaker for the welder and the 4 existing circuits (the assumption is they won’t all be maxed out at the same time).
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