Electrical question

I am going to buy a sp-135 mig welder soon and have learned that it draws 25 amps at max output. The breakers in the garage are only 20 amps. If I replace the existing ones with 25 amp breakers, will there be much of a danger? I am unsure of which gauge the wires going to the breaker are, but they are roughly 1/8 of an inch in diameter.
Thanks, Matt

Yes. The breakers in there now are 20 amps because the wiring is only safe for a maximum of 20 amps. Just replacing the breakers, without also replacing the wires, is an invitation to disaster. You should install a new circuit for the welder, and while you're at it you might as well make it a 30 amp circuit.

what i did is tap into the 60amp breaker that controled the oven..it has been wired like that for about 2 yrs now..just dont be cooking and welding at the same time..||charles||

OK, Do not ever install a bigger breaker for a piece of equipment than needed. If it has a problem you might create even more when the breaker doesn't blow. It's not all just shorting out, overheating circuits is a big issue with welders.

Find the rating for that equipment and use, if possible, a dedicated circuit for it. This is the safest way especially for a house where you don't always know what else is on that circuit.

The paperwork with the machine should have all the info need of the correct breaker sizes.

BTW, all circuits have certain size wire to go along with the size of the breaker and installing bigger breakers on small wires is dangerous!

hinkley

MinotJeep said:

I am going to buy a sp-135 mig welder soon and have learned that it draws 25 amps at max output. The breakers in the garage are only 20 amps. If I replace the existing ones with 25 amp breakers, will there be much of a danger? I am unsure of which gauge the wires going to the breaker are, but they are roughly 1/8 of an inch in diameter.
Thanks, Matt

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You should follow the advice offered here ... or call an electrician and rewire per local building codes.

Wouldn't want to see you, the family, or the house catch fire. Not to mention if it's not to code and something happens your homeowners insurance may be voided.

Do it right ... play it safe.

Thanks for all the advice. I won't be replacing the breaker. As it turns out, I may not have to do anything. I bought the welder this afternoon and have been using it to just fine with the existing breakers. I think I might run into trouble if I run the settings all the way up, but I have a torch to weld thicker if it comes to that.
Thanks again for the advice, Matt

As everyone else notes, don't up the breakers. If this is a garage, and you have ready access to the breaker box, it's really easy and cheap either to add a circuit with bigger wire and the right breaker, or if the panel is full, it's not that hard to add a sub-feed box for the same thing. A dedicated 30-amp line would be very handy anyway.

It really is nice to have a 30 amp circuit in the garage. When I got my welder I had to add a 50 amp, 240 volt circuit. I figured while I was at it I might as well add a 30 amp, 120 volt circuit also. It has been WELL worth the minor additional effort. I now have plenty of power in the garage to run anything I want.

MinotJeep said:

I am going to buy a sp-135 mig welder soon and have learned that it draws 25 amps at max output. The breakers in the garage are only 20 amps. If I replace the existing ones with 25 amp breakers, will there be much of a danger? I am unsure of which gauge the wires going to the breaker are, but they are roughly 1/8 of an inch in diameter.
Thanks, Matt

Click to expand...

you should be fine with a 20 amp circuit.

I doubt you will blow any breakers if you run the welder at its rated output.

I used to have a miller 135 and NEVER blew a 20 amp breaker.....

I reallly think you should buy a 220 welder, but sounds like your mind is made up.

"SP-135 Plus K1874-2
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The SP-135 Plus combines a wire feeder and welder with features that allow anyone to make great welds! It is one of the few portable, MIG & flux-cored packages on the market to feature continuous voltage adjustment for tight procedure control. With a convenient 115V input and 135 amps of welding power you can weld a multitude of applications from home and farm repair projects to body work in automotive shops. Also great for welding stainless steel and aluminum.

Advantage Lincoln For welding steel, stainless steel and aluminum. Package includes gun and cable, work clamp and cable, input power cord, guide tubes and drive rolls, gas solenoid valve, gas regulator, and spool of wire. 115V operation-no special wiring required. Solid state output control for long life and repetitive welding applications. Designed for .023"-.030" solid MIG wire and .035" flux-cored wire. For welding 24 gauge through 5/16" mild steel plate. Suitable for welding with .023"-.035" stainless steel and .035" aluminum."