wire size for welder

[poorboy]

My Uncle gave me a lincoln AC stick welder. My brother inlaw dragged in some 8/3 SO wire. I thought about running about 5 ft. from the breaker box in the barn using the 8/3 and installing a plug and using the remaining 50 ft as a movable line with a male and a female end. That way I could have the same set up and move to the shop and other barn when I needed to.
Question one: Is 8/3 so large enough for the 50 amp welder?
Question two: What size breaker would be the best ?

Thanks in advance,
Patrick

 

[Anonymous Poster]

Unless you are going to be running the welder at max capacity, the 8/3 will work out fine.

 

[poorboy]

Franz thanks for the reply. I wasn't sure about the setup myself so I thought I would ask. I'm still not sure about the breaker size though. Should I use a double 30, 40 or a 50?

Patrick

 

[justractors]

A double 50 amp breaker works for me.
I use a 10/2 cable 25" long as an extension cord for both the Lincoln 225 and the Millermatic 250, but not at the same time.

 

[poorboy]

Justractors, I guess thats what I'll go with. Thanks for the info!

Patrick

 

[patrickg]

I bought a used extension cord about a hundred feet long with 4 conductors. I think it was #6 wire but I don't recall for sure. I cut it into two pieces. One is about 30 something feet long and the other 60 something feet long. I wired up 250 volt 50 amp plugs and sockets. I can run my 50 amp 240 volt welder on either or both (in series) and weld a hundred feet from a dryer type outlet anywhere one can be found. I don't recall the gauge but it does not heat up and the welder works fine at full power. I included 2 duplex 120 volt 20 amp outlets in the box I put the socket/outlet to have power for my 120 volt welder or for grinder, lights, fan, whatever... I paralleled two of the conductors on one leg of the 240 to reduce overall line loss a bit because I wanted to get something out of lugging its weight.

In my shop bld I have a 25 foot coil of two conductor + gnd #4 with a dryer outlet on the end. This lets me have some mobility before I have to drag out the BIG extension cord. I have this circuit on a dual 50 amp breaker.

Happy welding!

Patrick

 

[poorboy]

I did end up going with a double fifty and 5 ft of the eight 3 and a female. I also had the guy run 12/2 of a 20 amp breaker in the box that my fencer was connected to. We went into the box and back out into the fencer outlet that was clamped there. This left me with enough wire to attach it to it's own breaker if the ground fault outlet the fencer was plugged into caused any problem in the future. I used all the spare electrical parts I had laying around. This was because the electrician was a good friend that I conned into coming over on a saturday night for a freebee. But my wife has trouble getting excatly what I send her after, she does well though most times and it did save me from a trip into town. I haven't got back to that barn though since I've been finishing the lot fence and baling some second cutting this week after school. Patrick sounds like a good setup for some future projects, have fun.

Patrick

 

[KWentling]

8 gauge wire has a max. load rating of 40 amps, so you need to use a 40 amp breaker. That should work fine for you.

 

[ddl]

what you mean is that you can use this wire up to 40 amps, you can use less current and fuse lighter, say 30 amp if that is the load. You can not fuse let say for 41 amps. But you can underfuse to match the load. The real question is why would you select wire much larger than neede if you mdid not have it on hand.

Dan L

 

[cisco]

As stated by others, 8/3 and a 40 amp breaker should be fine - you can go to 6 gauge and 50 amps if your unit requires such, but most don't. BTW, what is the line going to your barn/garage? I had a friend who put in great wiring - 6 gauge - for his new welder, and then discovered the line from his house, a couple of hundred feet away, to his (added on by a previous owner) garage fuse box was 8 gauge (inside a conduit coming up from the floor, so he couldn't easily ascertain such).

 

[Ken Kegris]

Here we go 10 gauge = 30 amps 8 gauge = 40 amps 6 gauge = 50 amps. I have used a dryer plug on a 30 amp circuit but could not weld long on the higher amps. I use 6 gauge wire and the standard welder plug and receptacle. I would assume you have a Lincoln tombstone welder. They were 50 amp at least mine is.

Kenny kkegris@yahoo.com

 

[schoppy]

Ken is correct. Always size breakers or fuses to the conductor size not the load. Also the appropriate receptacle is important as lower amperage rated connectors will heat up especially as you increase welding amperage. The longer the cable the larger the conductor to account for voltage drop. There are charts for all these calculations. My Lincoln calls for a 50 amp breaker and rated receptacle.

 

[LD1]

This was 15 years ago, I am pretty sure he has it figured out.

In any case, welders have their own section in the code.

There is a derating factor based on the duty cycle of the welder. In some cases, it may be perfectly ok to run 12 ga on that 50a breaker. Just depends on the welder duty cycle. Most welder owners manual has this info.

8ga /50a for a welder.....most likely not a problem at all.

 

[Ken Kegris]

When working for a school district I tried to weld up desk legs just tacking, on a 10 gauge circuit dryer plug I could do about 3 legs then the breaker would pop then after that 2 legs was about all I could do and that was with a tombstone Lincoln 225 This was a 20% DUTY CYCLE welder. At home on the 6 gauge wire I often exceed that duty cycle. those welder have a fan in them so that helps. If I have buckets or heavy duty stuff I usually use the mig or the portable the mig is 60% and the portable is 100% so no danger there. I often use my portable for thawing pipes, CAREFULLY and usually in the industrial setting.

Kenny kkegris@yahoo.com

 

[LD1]

Yep, 30 amp breaker was too small. Thought we were talking about wire size. 12ga or 10ga on a 50a breaker would solve your problem.

 

[buickanddeere]

Ken is correct. Always size breakers or fuses to the conductor size not the load. Also the appropriate receptacle is important as lower amperage rated connectors will heat up especially as you increase welding amperage. The longer the cable the larger the conductor to account for voltage drop. There are charts for all these calculations. My Lincoln calls for a 50 amp breaker and rated receptacle.

. There is thermal protection and there is short circuit protection, don't confuse the them with each other . What about motor loads ? A 50 amp breaker on a 30 amp conductor is specified in the code book.

 

[hr3]

Yep, 30 amp breaker was too small. Thought we were talking about wire size. 12ga or 10ga on a 50a breaker would solve your problem.

Are you sure about that..???

 

[LD1]

Are you sure about that..???

If I wasn't sure, I wouldn't have posted it

 

[medic0648]

Yes. Motor loads tend to size the wire by the running amps and the breaker or fuse by a significant multiplier depending on the type.