Need 240V wiring advice

[HOWDY69]

I have an old (1960's) 120/240V clothes dryer outlet in the garage. Can it be replaced with a new outlet to run a 240V comprressor or MIG welder?

[fordman]

wire size will be your problem with reusing an old outlet. it depends on amperage of the dryer vs mig welder or compressor. i dont know the size of line you would need for that either. i just know you have to match the line size to what you are running.

[Thunderfoot]

Depending on the "AMP" rating of the circuit on the wall and the compressor or welder. But that is what we did for years before we built a shop... The air compressor we have is like 2 or 3 hp and it was ok... for a big welder we used the Stove outlet as it was rated heaver, but for a small MIG the drier one should be ok also...
But do check the circuit breaker size as it should be rated for the wire that was used.

[HOWDY69]

I pulled the cover off the old 3 prong dryer outlet and to my surprise there were 4 wires inside, black, red, white, and bare. So I just replaced it with a new 4 prong dryer outlet, Line 1, Line 2, neutral, and equipment ground. I then made a cord for the compressor using a 4 prong dryer plug without the neutral prong. I was ecstatic to find the 4 wires in the outlet because I found conflicting opinions on whether the equipment ground could be connected to neutral. I know several people that run their compressors and welders that way but based on web research it does not appear to protect a person who touches a tank that is charged by a short. I feel better having a true equipment ground and I didn't have to have new wire run to the panel to get it. I have no idea why the electrician who wired the wash room during a remodel 20 years ago ran 10-4 to a 3-prong dryer outlet but if I could find him I would kiss him...Ok maybe I would just give him a nice box of chocolates.

[fordman]

the name of that wire would be called 10-3 with ground. you can buy 10-3 with no ground in it too.

[flyboy2610]

if I could find him I would kiss him...Ok maybe I would just give him a nice box of chocolates.

I'm guessing he would rather have the chocolates.

[HOWDY69]

the name of that wire would be called 10-3 with ground. you can buy 10-3 with no ground in it too.

10-4

[MaxKlinger]

I have no idea why the electrician who wired the wash room during a remodel 20 years ago ran 10-4 to a 3-prong dryer outlet

I believe the 3-prong dryer/range outlets were legal until the 1996 revision of the NEC (National Electrical Code).

By the way, what is your welder rated for, in terms of current draw? 10-3 is only good for 30 Amps, and should have a double-pole 30-Amp breaker. If you're running a welder, you should look at the current that your equipment draws. You might be better off with a 50-Amp circuit, which would require larger wire (8-3, I believe).

[thebannister8]

my understanding from what i'm told is the many types of 220 plugs correspond to amp rating....i have 10 guage from an old 220 dryer....running on a 30 amp curcuit...i made a 40ft extension cord out of 8 guage and run my welder with it.....

[fordman]

usually dryer require 30 amp circuts i think electric stoves reqiure 50 amp circuts and welders shoul dhave 50 amp circuts. the style of plug on your appliance usually tells what size of plug to buy and dictates what size circut you should run for that type of plug.

[thebannister8]

my welder is a cheepo from sears 20 years ago that pulls about 20 amps.....i can only weld little stuff...which is good because my welding is scary

[FordHam]

I'm wiring now for a new Millermatic 180. The owner of the welding shop said the welder needed a fifty amp breaker, and if I wanted to run a drop cord for it, it should be an 8-3 with a ground. Was going to run it off the current plug for my compressor, 60 gallon, 8 hp, but that only has a 30 amp circuit breaker. Electrician said it would be better to run an 8 guage off a new 50 amp circuit.