Home electrical help needed - fab'ing a welder extension cord

Leland Pate · 07-10-2011, 11:33 AM

So, I'm all but ready to fire up my Lincoln 175 Square Wave TIG. I've got the bottle filled and new consumables for the torch. I've got a pile of 1/4" mild steel to practice on... Now I just need to get power to the welder.

I am currently renting so upgrading my garage service is not possible. Since I am not going to use this welder at it's peak power, I've been told by some reliable guys that I can get away using my dryer's 30A service in the laundry room, which is adjacent to the garage. I bought a NEMA 6-50R receptacle for the welder and a 30A plug for the dryer outlet.

Now, my only confusion is what wire type and how should it be wired? The welder only uses three wires while the dryer outlet uses a fourth.

What's the safest way of making a cord to do the job?

1990C4S · 07-10-2011, 02:49 PM

You should have two hot lines on the dryer (red, black, 220V between them), a neutral to run the motor (either hot line to the neutral white wire is 120 V), and a ground.

That's your four dryer wires.

Your welder likely only needs the two hot lines and the ground, probably no neutral required. Buy a dryer extension cord, or just a male connector and get a #8 or #10 three wire extension cord cable and connect it yourself. There should be a wiring diagram on the connector. If you buy a pre-wired cable it should be the four colors I mentioned above, white doesn't have to be connected to the welder.

rusnak · 07-10-2011, 03:06 PM

You might find a spider box too, which would be a relay, cord, and outlet all in one. I have no idea how much they cost, but it can't be more than doing a permanent job, only this you can take with you.

John Rogers · 07-10-2011, 03:16 PM

Here is an old link that might help. When I made the cord for my 220v MIG welder years ago, Home Depot carried a nice bright orange 8ga wire and it was EXPENSIVE! I bought enough to go from my garage outlet to the street so I could weld on my race car trailer and I think I bought 60 feet. I paid about $5 a foot I think in that was 10 or 12 years ago. Industrial places are probably cheaper? It never got warm even running at full load a few times welding thick aluminum.

230v extension cord [Archive] - WeldingWeb™ - Welding forum for pros and enthusiasts

Leland Pate · 07-10-2011, 10:40 PM

Thanks guys... I've already bought a 20ft length of 10ga 4 strand wire. So, I should just cap off the white wire and use the bare copper wire as the ground?

Sounds easy enough...

joeydeangel · joeydeangel's Garage

Hey I am CA Certified Industrial Journeyman Electrician an long time Chula Vista resident if you need any help more then happy to help ya out!

Zeke · 09-25-2011, 08:25 AM

Leland, that sounds fine. 2 of my welders run on 220 and they have 3 wires. The 3rd wire is an equipment ground, not a neutral. Make sure you pick the ground at the dryer outlet for your welder ground.

Rufblackbird · 09-30-2011, 06:10 PM

Lee,

I realize this is a bit late, but I just saw the thread :/

I made my own a while back, basically read the following DIY and did something very similar, except I wired an additional outlet for my plasma cutter. Using it for a Miller 211 Autoset MIG right now without any problems at all, wiring didn't even get warm after welding some heavy duty D rings on a trailer.

DIY:
HOW TO - make a 220V extension cord - WeldingWeb™ - Welding forum for pros and enthusiasts

which I got through this thread on a search:
220v Extension Cord - WeldingWeb™ - Welding forum for pros and enthusiasts

and mine: