Garage welder wiring questions

How far is the new outlet from the main service entrance panel? When in doubt, you can't use wire that's too heavy.

50 amps at 50' = 6ga. 100 amps = 4ga. 50 amps at 100' = 4 ga. 100 amps = 1ga. 50 amps at 150' = 2 ga. 100 amps = 00ga.

I'm sure that better electrical people will respond. Is the garage attached? Are you running wire overhead? Is the outlet the only load you're questioning or is the whole garage on it's own circuit?

Reply to
Tom Gardner
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I noticed that no one has mentioned that it depends on the type of welder you end up with.

For example, a Lincoln AC 225 or AC/DC 225/125 takes a 50 amp outlet. I think my SP-170T (an excellent Lincoln MIG welder) calls for 30 amps but I'm not sure because I plugged it into the outlet that was already there for my old AC 225.

But now I also have an old IdealArc 250/250 which we use for arc and TIG welding and it calls for 90 Amps! We're able to use it in the 50 Amp outlet but only at about half capacity. You probably think it unlikely that you would ever have anything this large (I certainly did!) but at $500 it was a lot cheaper than a newer inverter-based TIG welder that uses less current so it's worth considering. :-) You'd be surprised what kind of deals you can get if you go to a few auctions.

In all likelihood though, a 50 amp outlet should do for just about anything you'll ever want and even with the large unit we can TIG 1/8" steel and aluminum without any trouble. I'll let someone else tell you the proper wire size.

Best Regards, Keith Marshall

"I'm not grown up enough to be so old!"

Reply to
Keith Marshall

A common welder is the red Lincoln "tombstone" design. It takes 50 amps at 220 volts, which is quite a bit more than the 30 amps used by an electric dryer. Here are some considerations:

  1. The receptacle for a welder is unique - the plug on the welder will not fit a dryer receptacle - must have a welder receptacle.
  2. You should probably run gray PVC conduit from the breaker box to the receptacle location. Leave a pull string in it so that whatever wire you need can be added later.
  3. 10 guage will be too small. That's about right for a 30 amp dryer though. An electrically heated hot tub needs 60 amps, so the wiring for it would be adequate for a welder.
  4. Consider that most houses are supplied with 200 amp service. With the welder running, the lights may dim a bit. Other appliances may be affected as well.
  5. An electrician should be at least consulted regarding wire sizes, etc. For my hot tub, I set everything up - drilled holes, dug trenches, etc. Paid 0 (several years ago) for the electrician to run the wire and connect it up.
  6. I recommend that you pay a bit more and get an AC/DC welder. DC is so much smoother and there are rods which are DC-only.
  7. Invest in a fire extinguisher. You will eventually set something on fire which is not supposed to be burning. At least have a small bucket of water available.

Good luck.

I am wiring up my new garage. I will mostly use this for working on > cars and motorcycles, some occasional woodwork, and I have had the > need to use a welder before. I do not own a welder now, I usually > borrow one or use one at a different location. > > So, 10 gauge? 10-2 or 10-3? Larger? What is the common welder size? > (in amps?) > > Thanks for any input. > > -Ryan
Reply to
Tom Kendrick

Good advice. I've purchased several TIG welders at auction over the past 25 years and have never paid more than $400 or so. The latest is an Airco square wave that was only a few years old when I got it.

These machines typically require a 100A circuit to run at full capacity. As Keith says, you can do most things with a smaller feed, but if you want to weld 1/4"+ aluminum you'll want the 100A circuit.

I'd at least run wire large enough to upgrade to 100A in the future, even if you install a smaller breaker now. (Make sure the breaker lugs will handle the larger wire.) There are special exceptions that allow the use of smaller than normal conductors for welders, but the actual selection depends on the duty cycle of the welder. Unless the length of the run is very long, I'd just run wire with

100A ampacity.

Ned Simmons

Reply to
Ned Simmons

Hopefully not on an electrical fire!

. You will eventually set something on

Reply to

The garage is unattached. It has it's own 60 amp subpanel (I tried to talk to the electrician about a larger one, but he convinced me I would never need more than 60 amps). The welder outlet will be about

4 feet from the subpanel, using probably 6 feet of wire.

So 6 ga. would be ok for a 50 amp outlet, and maybe even 8 ga if my local code allows it for a welder.

Thanks for the tips.


Reply to

Pity. The next size up would have allowed for a 60 amp welder outlet plus lighting, etc. As it is, you may wish to install only a 50A breaker for your welder. If you have a 60A main and a 60A welder, it's questionable which will trip if the welder pulls a bit much. This could leave you in the dark.


Reply to
Ted Edwards

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