Welder(s) wiring questions

[jproaster]

Hey all. Wondering what is safe for welders for operating at my home hobby shop- both wall sockets and extension cords.

Lincoln AC225 and Millermatic 215

I've installed a wall socket for the Lincoln with 50 amp breaker.
Do I need to install another socket for the MM 215?

Second issue is the extention cord. My distance from indoor socket to outside area to weld would require about 20' cord.

Since the MM215 is multiprocessing, I'm not as concerned about a cord to for the Lincoln. But, could both units share same cord?

Thanks
John

 

[sberry]

Yes, a number 10 cord is ideal for both of them. 10 cable or better to the outlet and 50A breaker. The cord is a size better than the Multimatic needs. The blue one is allowed on a 50A circuit. Circuit is good for both machines.
The owners manuals are confusing for these at best. They need a lat version with a lay recommendation which could be a step above minimum wire size which would make it easier.
I like 10 for them for cords as the connection is so much better and a quite a bit less performance drop with the Lincoln than a 12.

 

[ekimneirbo]

You simply have to make sure the plugs on the welder cords are the same configuretion and that they match the receptacle you plug them in to. So if the machines have removable plugs, and they don't match.....change one of them to match the other...then buy the correct receptacle.
If both machines have molded on plugs, you can cut one off and change it...........or leave them alone and put in two different receptacles.

 

[matt_i]

There's some weirdness in the NEC when it comes to sizing welder circuits. Typically the "duty cycle" or percent of 10 minutes it can weld is important when minimally sizing wire.

I have a #6 awg in my head for wiring a 50A circuit but a #10 is fine for welding. You have to be careful because of same if you ever intend to plug something else into the circuit.

 

[dledinger]

Matt is correct that derating of the branch circuit conductors is allowed for a welder, based upon the duty cycle of said machine.

What size conductors did you install on your 50amp branch circuit?

The 20’ cord is inconsequential. Worry about the branch circuit size, for now. Neither the National Electrical Code, or the metal you’re welding, know the first thing about the process behind it. Don’t worry about that.

 

[dr_clyde]

You simply have to make sure the plugs on the welder cords are the same configuretion and that they match the receptacle you plug them in to. So if the machines have removable plugs, and they don't match.....change one of them to match the other...then buy the correct receptacle.
If both machines have molded on plugs, you can cut one off and change it...........or leave them alone and put in two different receptacles.

Wire size is far more important than receptacle shape.

 

[jproaster]

Matt is correct that derating of the branch circuit conductors is allowed for a welder, based upon the duty cycle of said machine.

What size conductors did you install on your 50amp branch circuit?

The 20’ cord is inconsequential. Worry about the branch circuit size, for now. Neither the National Electrical Code, or the metal you’re welding, know the first thing about the process behind it. Don’t worry about that.

Pretty sure I put 6 wire to the receptacle. Mm. Maybe 8 awg. Don't remember for sure.

 

[sberry]

6 or 8 is plenty for those machines and any others that come 50A end. Don't cut the plugs off the machine. The manufact urea has went to great deliberate effort to send it with the correct plug. Welder plugs are 6 50. Many of the new machines can be served by 30A, they still use a 50 plug and are allowed on 50 circuits.
I am willing to run a wire and add an outlet, machines find a home but really not sure why a guy buys a Multi, expensive machine to use a buzz box. You can turn the buzzer in to a cinder on a number 10 wire to the power pole, done it, built a whole semi tanker with one.
I don't know of any other equipment comes factory with a welder plug.

 

[sberry]

Anyway, the new mvp come 14 cord and a 50 adapter. The 240v only units come with a 12 cord which allow it to be used on 50. The adapter is a short circuit,, like a reset in a power strip that allows the lighter cord on 50,, when it's used on 120v it relies on the 20A breaker on the circuit.

 

[sberry]

They can use the same roll of cord for all the machines on the same assembly lines, the 120 migs, the mvp and when they are 240 you use the 12 cord and 50 plug, both feeders and buzz boxes. Only machines use different are the 250 migs with high duty cycles.
More and more come of the same 14 spool , Hobart and Miller get it supplied thru ITW company. Share lots parts.

 

[sberry]

A 225 buzzer comes with a 12 cord and allows 85 ft of 12 on single circuit in pipe with 50 breaker. 48A at rated output. The multi is 1/2 that. They allow about 50 ft 14 provided it's on a 30 breaker. I just wired for 1, the guy has it and a 175. I used 50 ft of 12. Wasn't my shop, with limited outlets would have used 10/50 but have other machines. My own homes for small machines is 10/30 but the cost of the wire is irrelevent and have about 6 circuits at their home. 100, about 3 at 50 and a couple 30 for smaller machines.
I had 4 other in rest of the shop, abandoned 2 in a rewire as I never used them.

 

[jproaster]

Thanks for the help.
It seems I should install a 30 amp circuit and make a cord with 10 wire for the Miller 215.

 

[sberry]

The cord can work for either machine. The 215 requires a 12 but I like 10 for other welders and the connection at the recept is so much better with a little heavier wire. Ready made welder cords come 8 and was a standard before the inverter generation and was intended to allow for any 50A machine.
The 250 class migs,, 252 for example puts out near 300 and I forget what it's rated is at 60% duty cycle. In a shop like dr clyde has may have changed guns, larger welding wire and special gas to allow it to run hot and long. Would melt the factory gun off. While the machine calls for 8 wire 10 isn't an issue in a home shop with 035 and c25, cant run it hard enough to warm the wire. Same for my shop,, one wire, one gas, I use 10 for all my welder cords

 

[sberry]

10 also gives them all the help they can get. I am not sure what the larger cord does for inverters but for buzzers and trans migs , especially buzzers where a bit over 40A draw is normal it keeps v drop to a minimum vs the 12, about 3 vs 10 or 12.

 

[sberry]

Some of the machines, the AC225 was designed when nominal voltage was 220. They worked on 208,,, I don't recall if they changed and call for 10 wire for that but now voltage is over 20 higher that when they designed the machines, lowered the amps in 10%. They now draw 40, maybe even less for the work they are commonly used for.
I see for the 215 they allow for 14 circuit wire and call for 12 on the cords with limited distance. I think some of it is accumulative,,, the cords could be longer from a primary circuit with heavier wire. I have ran my Maxstar out to 150 ft on 120v where it started to have problems and trip breakers above 75A settings. It will run 100 ft of cord from a panel. I have ran buzzers 100 ft 10 no problem.

 

[sberry]

Thanks for the help.
It seems I should install a 30 amp circuit and make a cord with 10 wire for the Miller 215.

You can use the 215 and 10 cord from the 50 you have also.

 

[dledinger]

Unless you’re dead set on running two welders at once, there’s no need to instal an additional circuit.

 

[ekimneirbo]

Wire size is far more important than receptacle shape.

They are both important. If you don't have the correct configuretion plug, you can't connect it to the wall plug.....

The OP said: I've installed a wall socket for the Lincoln with 50 amp breaker.
Do I need to install another socket for the MM 215?

Then he asked if both machines could share the same extension cord

I took that to mean that he didn't have cord plugs on the machines that fit in the same female plug. The 50 amp breaker to the plug should supply either of those machines easily. Hopefully the wire from the electric panel to the wall plug is sized properly. At that point he wants to hook up an extension cord. If the machines don't have the same type of male plug, he could only use the cord with one of them. So the answer is to change one of the machines plugs to match the other machines plug. Thats what I did on my welders.

I didn't even mention wire size. I always use larger wire than needed as I remember what happened in a lot of older houses with minimal wiring. Very expensive to upgrade later. I bought a pallet full of used large industrial wire at an auction. Been using it for years to add plugs and panels and make long extension cords. I have three different welders (Miller 350P and Dynasty 200 Tig and ESAB) along with a Plasma Cutter. All have the same plug that I bought from Lowes. Works great and never any problems.

Note: The first coiled cord is about 35 ft long while the second somewhat lighter duty cable on the floor is about 20 ft long.

 

[jproaster]

10/3 with correct plug and receptacle. No second circuit. Got it.

Thanks.

Nema 6-50 connectors - correct for 50 amp 240v?

 

[dr_clyde]

They are both important. If you don't have the correct configuretion plug, you can't connect it to the wall plug.....

The OP said: I've installed a wall socket for the Lincoln with 50 amp breaker.
Do I need to install another socket for the MM 215?

Then he asked if both machines could share the same extension cord

I took that to mean that he didn't have cord plugs on the machines that fit in the same female plug. The 50 amp breaker to the plug should supply either of those machines easily. Hopefully the wire from the electric panel to the wall plug is sized properly. At that point he wants to hook up an extension cord. If the machines don't have the same type of male plug, he could only use the cord with one of them. So the answer is to change one of the machines plugs to match the other machines plug. Thats what I did on my welders.

I didn't even mention wire size. The thing always comes up seems to be "how cheaply can I install the most minimal whatever because I'm afraid if I spend a few more dollars to overbuild for the worst condition.....the world will come to an end" Instead of worrying about minimum acceptable size, the OP should oversize the wiring in the extension cord and then never have to worry about not only ruining the wire, but whether his welder might not function as well if a few of those copper strands should break and current capacity to the welder decreases. Everybody is always looking for Cheap but still expecting great results.I learned a long time ago that every time I skimp to save a dollar I end up paying for it later.Better to buy more capacity than you need than to find out what you bought isn't satisfactory. What good does it do to have a 50 amp breaker if it won't trip till your extension cord is melting ?

I agree, it’s better to oversize just a bit and not worry.

It’s very easy to put a plug end or receptacle on too small of wire and have a problem. That’s all I was pointing out.

 

[anndel]

For my Hobart Handler 140, I use a 10 ga extension cord into a 20A outlet.

 

[dledinger]

10/3 with correct plug and receptacle. No second circuit. Got it.

Thanks.

Nema 6-50 connectors - correct for 50 amp 240v?

A 6-50 is correct for 240 and 50 amps. You won’t be able to run anything requiring a neutral.

You would need 10/2, not 10/3.

Correction, if you’re making a cord, you’d need 10/3. 10/2 with ground for the branch circuit.

 

[sberry]

What good does it do to have a 50 amp breaker if it won't trip till your extension cord is melting ?

It wont if its not overloaded. On a welder circuit the breaker doesn't protect any part of it from thermal, the applied load does.
As for too small of a wire,,,, this would be below code. I am not a fan of some of the minimums, a size better is good but there is no additional safety gained by going 2 or more sizes above it. It doesn't hurt anything but its not a gain in most cases.

 

[ekimneirbo]

It wont if its not overloaded. On a welder circuit the breaker doesn't protect any part of it from thermal, the applied load does.
As for too small of a wire,,,, this would be below code. I am not a fan of some of the minimums, a size better is good but there is no additional safety gained by going 2 or more sizes above it. It doesn't hurt anything but its not a gain in most cases.

You are right of course.....I'm just **** about oversizing electrical circuits. I always consider how much its gonna cost if I have to redo it later, and I know that even wires that don't fail quickly from getting hot, can fail gradually over time when they operate near their maximum for long periods of time. But, what you said is correct.

 

[sberry]

The minimums are based on what is safe and what is acceptable voltage drop and they don't always include all the details. I don't have a recept in front of me and a couple may list different but 1 I had recently lists 10 thru 2 wire, seems I have seen them list 12. Legally the 14 can feed it but would need pigtails at the outlet of larger wire.
I will agree that despite what I say about it to some extent and what I do is different. (I am not immune from over kill either, I have wire 2 sizes larger on some of mine, it helps the machine, the connections are soooo much better, both recept and breaker. and 10 ft of wire I stock is irrelevant.
I got some 6 circuits, short and free scraps of wire, I got some 10/50 but 2 or 3 ft of wire, losses irrelevant. And 10/30 for small machines. A size bigger than the cord on them.
Only reason I harp on this is that I didn't know what I didn't know and there is a lot of assumptions about wiring that are simply untrue. In accurate at best. The forums have really helped about grounding. Over and over the same questions. Stickies are ok but working on someone till they get it is another.
I started on Elect Tool box and survived they weretalking to a dummy and they tolerate me then I went to DIY for about a year and repeat what I read and remember installing something and went to find the right answer from the head inspector and it kind of hit me as to what I was studying. The fundamental understanding can begin to improve from there and while I don't know squat about the math it has become instinct to consider the ground and related equipment, method and size to make a legal install that would pass inspection ruling out human error.
I really don't care why so much as a science as some do,,, I wanna hook it up and use. Took me a long time due to some poor mentorship in some degree, coupled with the fact I can copy and my design is good, the fastening I take a little time on, not scared to use a right size bolt.
In my early years was schooled in the worry of loss. Everything I built was too heavy, too big, in a lot of cases correct would have been better. I will fix something if it doesn't work or change fittings. Aint the end of the world to do some things twice.
Digging is that way. I could have put spare pipe in some spots but when I really wanted to run the last wires 20 years later things had changed and wanted it in a different spot. Only places I want to run new wire are places havnt been done yet.

 

[dledinger]

A new Lincoln AC 225 comes with a 12awg cord, an requires a 50amp circuit.

We would never consider that an appropriate load for a 12awg conductors, but things are different when duty cycle is take into account.

I have a 50amp circuit I’ve used for years for welding, which is wired with 10/2. That was the appropriate size for my largest piece of equipment based on duty cycle.

If I wanted to use that circuit for any other load, I’d have to swap in a 30 amp breaker.

 

[jproaster]

It's interesting, what I imagined a simple question requiring a simple answer, what one can learn.

Thanks all.
John

 

[dledinger]

Let’s talk about hot water heaters next time...the opposite scenario!