240v outlet wiring

[aj2n]

I'm buying a welder and need to wire in an outlet for it. It'd be great if some of yall could give me some brief how to info.

thanks guys.

 

[glkingar]

First of all, if you aren't comfortable around electricity don't do it. Find someone who is. Having said that you will need 2 open slots next to each other in your breaker box. You will need to know the amperage required for the welder. Your welder manual should provide that information. Don't connect it to an existing circuit. Don't overload your panel either. If all of this is ok then buy a dual breaker that is rated for your welder. It should have a bar that ties the two legs or breaker switches together as well. You probably have one or two of these already in your panel. Your AC and electric stove for example. Depending on the connector you will have 3 pins or possibly 4 pins. Again your welder manual should have some info on this. There will be 2 hot wires 1 from each side of the dual breaker. There will a neutral wire that goes to a neutral bus bar. That will be the one with all of the white wires going to it. That will be all you need for a 3 pin connector. A 4 pin will have a ground wire that will go to the ground bus bar. The one with all of the bare wires. Make sure you use heavy enough wire for the connections to the plug which will be determined by amperage required and distance from the panel to the plug. Longer distances will require a larger gauge wire. Again be very careful and if you aren't comfortable with this DON'T TRY IT. Turn off the main breaker before you take off the panel face. I know a lot of electricians that work on live panels but it doesn't appear that is the case here.

Good luck and BE CAREFUL

Gerry

 

[mjncad]

Gerry:

Thanks for posting good general advice to the O.P. :thumbsup:

 

[Martian]

What welder did you get? I'm about to undertake the same project (for a welder too), except I'm replacing an old 220 that will need heavier wire, a different plug and a different breaker to account for the more amps of the welder than what I'd had previously. Pretty much everything you have to do + ripping everything out.

 

[pat32rf]

I try to never rip the old out if it is just undersized. (unsafe is different) Sooner or later that old run of wire will be just what I need for my next piece of equipment...saw, compressor, heater etc.

 

[big bubba]

you'll need also to determine the gauge of the wire for the circuit. the distance from panel to the welder will also determine gauge of wire to use.
why not put your welder specs & circuit distance on the welding part of this forum for that input. the size circuit breaker is also important, think i put a 50 amp breaker, but yours may require different.

 

[Martian]

I try to never rip the old out if it is just undersized. (unsafe is different) Sooner or later that old run of wire will be just what I need for my next piece of equipment...saw, compressor, heater etc.

My barn is all open, no drywall or such, so if I need to put it back in I can. With the price of copper, I don't know if it'll stick around, though.

you'll need also to determine the gauge of the wire for the circuit. the distance from panel to the welder will also determine gauge of wire to use.
why not put your welder specs & circuit distance on the welding part of this forum for that input. the size circuit breaker is also important, think i put a 50 amp breaker, but yours may require different.

I was recommended to put a 50 amp breaker in and an 8/3 wire. So that's what I'm doing!:thumbsup: I'd recommend you do the same. But, if you have a different welder than I'm getting (I'm getting the Millermatic 211), then your needs may be different.

 

[crazyal]

I think a 50 amp breaker for a 211 is over kill. It could come in handy for a larger welder in the future. For a 50 amp circuit I would use 6 gauge copper, not 8. 8 may not even be to code for a 50 amp circuit but I'm not an electrician so others can better tell you.

 

[murphy1244]

I think a 50 amp breaker for a 211 is over kill. It could come in handy for a larger welder in the future. For a 50 amp circuit I would use 6 gauge copper, not 8. 8 may not even be to code for a 50 amp circuit but I'm not an electrician so others can better tell you.

All depends on how long of line you need.

 

[Canada_CT230]

I put 8 wire in. My electrician said that was fine for hobby welding and for the 50 ft run.

I will caution the O.P on the instructions for wiring a 240v plug.

There is more to it than just 2 open spaces in the breaker box and some wire. You need to straddle both sides of the buss in the breaker box to get 240v.

If you don't know what I am talking about then you don't have enough knowledge to do the install of a 240v plug safely.

Remember...it only takes a few milliamps to kill you....never mind the 100A or 200A that is in your breaker box.

 

[Martian]

I think a 50 amp breaker for a 211 is over kill. It could come in handy for a larger welder in the future. For a 50 amp circuit I would use 6 gauge copper, not 8. 8 may not even be to code for a 50 amp circuit but I'm not an electrician so others can better tell you.

That's just what I was recommended for my 20' run. Maybe I'll have to call a buddy who's an electrician and have it done properly or at least know for sure what I need and what will make code. 50 Amp breaker is overkill, but I'd like to future proof myself. The 211 is only a 25 amp machine.

 

[murphy1244]

That's just what I was recommended for my 20' run. Maybe I'll have to call a buddy who's an electrician and have it done properly or at least know for sure what I need and what will make code. 50 Amp breaker is overkill, but I'd like to future proof myself. The 211 is only a 25 amp machine.

Martian, Have your buddy do it, The job will turn out much better. The voltage is nothing to play with if its not your thing.

 

[Martian]

Martian, Have your buddy do it, The job will turn out much better. The voltage is nothing to play with if its not your thing.

That's what I'm starting to think will be the best idea. Thanks Murph.

 

[Mickey_Fx]

Before you get too raped up in this project, take a look at the plug on the cord that came with the welder. Recently purchased a Lincoln 180C and went through the same thought. Shop was already wired for 220V/50A for a large welder the previous owner had. Only needed to handle 30A for my welder but when I looked, the cable that came with the welder was a 50A plug. No change in wiring which was good fo me.

Ya don't want to jump the gun if max power consumption is within 30A range then find out that's not what the welder cord was made for.

 

[grsthegreat]

There are about 5 different posts here about welders ... and all have ended with people yelling at each other and calling names. its amazing

Per NEC regs..... a single welder CANNOT be derated off of its nameplate rating. Thats the small metal engraved plate that comes on the unit.

If it says 50 amps..than it has to be wired for 50 amps. it doesnt matter if it has a #10 wire coming off of the welder or a #6 wire. If the plate says 50 amps, wire for 50 amps.

Romex wire has to follow the 60C set of tables in the electrical NEC code book. Section 310:15 of the code book rates #8 copper wire for 40 amps, and rates #6 copper ROMEX for 55 amps.

Will said welder work om #8 wire. more than likely. Will it work legally....NO.

 

[crazyal]

The welder in question requires only 25 amps at 240v. If it's the one I'm thinking about the plug on the welder is one where the legs can easily be turned at will to work with either 120v or 240v and the machine will auto adjust for the incoming voltage.

For this application 8 gauge wire would be over kill. However, and this is why unless you are very sure you are following the code, if you wire a 50 amp outlet with a 50 amp breaker then at some point in time somebody may try to plug something into it that will draw the full rated power.

Because the code is very complicated (like grsthegreat said romex needs to use the 60c, not the 75C tables) it's best to err on the side of caution and have an electrician do the work. It sounded like you wanted to do it yourself so that's why I suggested 6 awg vs 8 awg, again erring on the side of safety. Another suggestion I'll make is to wire a 50 amp receptacle, not one that will fit the plug on your welder's cord.

 

[murphy1244]

The welder in question requires only 25 amps at 240v. If it's the one I'm thinking about the plug on the welder is one where the legs can easily be turned at will to work with either 120v or 240v and the machine will auto adjust for the incoming voltage.

For this application 8 gauge wire would be over kill. However, and this is why unless you are very sure you are following the code, if you wire a 50 amp outlet with a 50 amp breaker then at some point in time somebody may try to plug something into it that will draw the full rated power.

Because the code is very complicated (like grsthegreat said romex needs to use the 60c, not the 75C tables) it's best to err on the side of caution and have an electrician do the work. It sounded like you wanted to do it yourself so that's why I suggested 6 awg vs 8 awg, again erring on the side of safety. Another suggestion I'll make is to wire a 50 amp receptacle, not one that will fit the plug on your welder's cord.

Always a good idea to use bigger wire.

 

[Groo]

welders can generally get by with smaller wire since they don't have a 100% duty cycle and a 211 needs no where close to 50 amps.

leaving undersized wire just hanging out in the walls is not to code, and it causes headaches in the future.

When planning this out, think about the future. Do you think you will ever need another plug? were would you put it? Think you will ever pick up any other 220v equipment? Think you might want a 4 wire plug for anything down the road?

I ran 6 gauge 4 wire for my welder plug. I have 2 plugs off the same wire. 1 is a 4 wire 50amp RV plug going into the garage, and a standard 50 amp welder plug going into the work shop. I was able to find a 50amp RV extension cord for less than a welder extension cord, and then I made up an adapter using a range cord and a welder receptacle. I also like the option of using a breakout box down the line.

 

[CJONE]

I guess without starting a pissing match you have to run the correct wire for the breaker size. Please don't use a 50 amp breaker with 10 gage wire just because the machine will not draw more than 30 amps. Downsize the breaker to 30 amps. heavier wire is fine just don't do the oppsite. Like murphy said heavier is better. Like was stated also I would not use 8ga. on a 50 amp circuit, 6ga. for me. CJ

 

[murphy1244]

I guess without starting a pissing match you have to run the correct wire for the breaker size. Please don't use a 50 amp breaker with 10 gage wire just because the machine will not draw more than 30 amps. Downsize the breaker to 30 amps. heavier wire is fine just don't do the oppsite. Like murphy said heavier is better. Like was stated also I would not use 8ga. on a 50 amp circuit, 6ga. for me. CJ

As CJ said you can't run a 50 amp breaker and use smaller wire cause its a welder. You must size the wire for the circut.