Electrical Receptacle Question

[Erik_O]

I am looking at getting into a MillerMatic 180 and don't know if I can power it in my shop. Right now I have a 3 wire receptacle (NEMA 1030R) that has two slots in a "V" configuration with a "L" shaped slot above the "V". My impression is that this is a 2 hot wire and 1 return wire config with no ground.

Can I rewire for a NEMA 6-50R receptacle? Would I just throw in a separate ground wire and use the existing three wire to power it (at 230 volt, 30 A).

Thanks,
Erik

[AnotherDano]

That third wire is the ground, not a neutral.
You'll need a neutral only if the appliance requires 110v for controls/displays, like a dish washer, dryer etc.

[Wacko Welder]

First of all . . .

Lets start at your breaker panel. Does ONE breaker control only that receptacle. If so, what is the amp value of that breaker. It is probably a double breaker.

If yes to above, proceed . . .

Next, what gauge is the wire connected to this breaker. . .

As to the actual receptacle used that will match your welders plug,
the 6-50R (receptacle) & the 6-50P (plug) shown in your manual is somewhat "overkill" for your welder, but this is Millers & Lincolns industry standard way of protecting us & "them".

The only thing that is important is that you have a large enough wire/conductor to support your welder (12 gauge in your case) and a breaker sized to "protect it". 20 amp would be appropriate .

All you need in the way of a 220 is two (2) hots and a ground. Sounds like you have that already. What was there before. If your current plug has 4 wires (2 hots, a neutral & a ground) . You only need to connect to the two hots (the two vertical blades on the receptacle) and the green to ground ( the one that is round) if there is a fourth wire in there (a neutral) wire nut and tape it and push it aside.

[Erik_O]

Thanks for the help

Thanks for the help, WackoWelder.

"Lets start at your breaker panel. Does ONE breaker control only that receptacle. If so, what is the amp value of that breaker. It is probably a double breaker."

-The breaker is a double, with 30 A showing on both levers. The Millermatic 180 is rated at 21.7 A input, so this should be sufficient, right?

"Next, what gauge is the wire connected to this breaker. . ."

- The cable reads: "_____ Aluminum A Type SS Cable Type _____ _____ 6 AWG AL 3 CDRS 500 Volts (UL) Sun Light Resistant".
The ___ indicates an unreadable word. So, this is 3 conductor 6 gauge aluminum cable, correct? I understand aluminum is bad, will this be a problem?


"All you need in the way of a 220 is two (2) hots and a ground. Sounds like you have that already. What was there before. If your current plug has 4 wires (2 hots, a neutral & a ground) . You only need to connect to the two hots (the two vertical blades on the receptacle) and the green to ground ( the one that is round) if there is a fourth wire in there (a neutral) wire nut and tape it and push it aside."

-Inside the existing cable there is a black wire, black wire with red stripe, and a bare wire (no insulation). So, are the two black wires the 2 hot wires (120 v each?) and the bare is the ground? To install the 6-50R receptacle, the two black wires get connected to the two blades and the bare wire gets connected to the ground on the 6-50R?


Thanks for the help,
Erik

[Wacko Welder]

Yes

You are correct . . . buy a good quality receptacle, preferably at an electrical supply house. Tell them what you are attaching to. ie the 6 gauge aluminum.

[linas58]

Do some more research!

If its actually aluminum wire, I would rip it out and throw it away. I think there are some other posts here that speak to aluminum wire. Replace it with copper. I believe electrical code states 10ga is required.

Secondly, do some research into 220V 30A. I believe the electrical code has changed and for this type of circuit it is required to have 2 hots (black, red), a neutral (white) and a ground (bare wire).

The NEMA 6-50R is a 50amp. Not sure what that will get you. The breaker will trip at 30 amps.

Good luck

[Wacko Welder]

If its actually aluminum wire, I would rip it out and throw it away. I think there are some other posts here that speak to aluminum wire. Replace it with copper. I believe electrical code states 10ga is required.

Secondly, do some research into 220V 30A. I believe the electrical code has changed and for this type of circuit it is required to have 2 hots (black, red), a neutral (white) and a ground (bare wire).

The NEMA 6-50R is a 50amp. Not sure what that will get you. The breaker will trip at 30 amps.

Good luck

You only need a neutral if you have an appliance that will need 110vac also. The breaker is there to protect the wire. It does not matter if you have a higher rated receptacle. Most quality 6-50R will be rated for aluminum. See link

http://www.doityourself.com/invt/u189548