I have a 220 arc welder designed to run on a 50 amp circuit. I have an existing 30 amp drier circuit. I am wondering if I used a rod no bigger than 1/16" if I could get away with using my drier circuit. Mostly just running beads no longer than about 1".
Does the welder have different current settings?
It’s done. You don’t need the welder’s full current for 1/16" rod. Your duty cycle may be shortened. You can probably get 1" beads. But don’t come running to me if your welder breaks before the last weld is finished 
More seriously, depends on the breaker. If it’s a rapid trip you probably can’t harm your welder. But if it takes a few seconds that thing might get really hot.
You won’t hurt the welder, but you could trip the breaker on the dryer circuit. Depending on the breaker, you could wear our your breaker in short order (they don’t like blowing repeatedly, and certainly not without fully cooling off after blowing).
Keeping a short duty cycle will help, but it can be hard to only weld for 5 seconds and then let it cool for 30 seconds. It’s slow going. Also, do not run a long cord between the dryer socket and the welder.
I believe with a 1/16 rod I can set the welder at about 70 amps. Most the jobs I do are pretty small and not that frequent, a little waiting in-between would be too bad.
I don't think I would use it anymore if it ever blew the breaker. I was more worried about the slow draw heating up the wires before it blew the breaker, I believe my wires are 8 gauge. I need to double check though. The receptacle has about 12 feet of wire to the breaker box.If you’re dealing with an AC-225 welder, it’s drawing 50 AMPS input with a 225 AMP output. If you set it at 70 AMPS, your current draw should be 50*70/225=15.6 AMPS. Now, things aren’t going to be exact, but you would nominally be running at half the rating of the dryer circuit, so you should be OK. The run from the receptacle to the breaker box is bound to be adequate, it’s the run between the receptacle and the welder that, if not a heavier gauge, could increase the current draw.
Breakers are specifically designed to prevent wires from overheating, assuming that the correct gauge was used (and 8 is correct for a 50A).
If the breaker box has space available, can you move the weld shop close to the box?
And put in a separate 50 amp breaker/ receptacle?
No its the turn on current … its got capacitors and so on there designed for the larger circuit … sure you are setting the output current, but the turn on “get ready” current drawn may not be reduced…
What kind of welder is this? An AC model will be a little more complicated than a big old tombstone type DC welder. I still think you’ll be ok with low enough current, but I hesitate to suggest plugging anything into an underrated line.
It is a 15 year old a/c welder, they weigh about 40#. I have used them at job sights for years. They work pretty good. The small amount of welding I do anymore I don’t feel very motivated to do any rewiring although it would be convenient to be able to do something here and there. Presently I take things over to a local muffler shop and they usually charge me between $10.00 and $20.00 for small jobs. I think I would have to beef up my sub panel in the garage if I upgraded to a 50 amp.
You’ll know if it’s too much for the circuit because it’ll pop the breaker. I have a 110V, 20A machine, and it’ll run on low power settings just fine, but turn it up all the way and the lights go out in the garage as soon as it makes a spark. (The lights and power plugs in the add-on garage are a single 15A run.)
If your dryer circuit is only 30 amps you should probably get it beefed up even without the welder, my turn-of-the-century dryer plug has a 60A breaker.
Your post made me go double check my breaker, I have two 30 amp breakers. Is that the same as 60 for one breaker? If so I am good to go.
That welder is worth around 50 bucks. I’m using something like that right now. Not too much of risk to try it out. I was lucky, there was already a 50AMP breaker and wiring for the stove, so I tapped into that line a while back for my old Tombstone. And it’s there for my little piece of crap MIG also. I gotta get me a TIG and a plasma cutter.
That is 30 amps each leg or 30 amps total at 240 VAC.
Each 120v leg has a 30 amp breaker.
Is this a duplex breaker, with the handles tied together? If not, that’s a code violation and a potentially serious safety issue.
It is a duplex breaker yes
Then yeah, you’re golden. Well, more likely to set yourself on fire than your house, at least. Don’t use it indoors and get the beefiest extension cord you can find with the right plugs, of course. And remember that the workpiece is still hotter than the pan you use to cook a steak for a sold minute after it stops glowing.
LOL, the welding part I have been doing for many years, the wiring not so much.