Extension Cord for welder

[Sublifer]

All of this sounds interesting and, at times, confusing. I still don;t see the point of extending the welder power cords and having to lug a welder in and out of the garage when you can extend the welding cables much easier and leave the welder where it sits - unless you are using a wire welder.

The power cord that came with the welder is all of 6 feet long, not enough to even get into the garage. Why not get really long leads? Because 50 feet of 1/0 cable is $200 and that would only make me two 25 foot leads. I do still want longer leads but I will wait for a good price on craigslist.

 

[grsthegreat]

This is like the 4th post in this site that has debated welder circuits.
I am an electrical contractor and all i can say is were required to provide a #6 cord for a 50 amp rated draw per NEC requirements. For 100 foot run you dont need to worry about voltage drop.

Where the problem lies in on the manufacturers end. They arnt burdened by the NEC. Why else do you find lamp cord wire used on a light fixture that has 20 - 60 watt light bulbs burning. the manufacturers can care less. Same with welders. Ive seen new units with 50 amp rated nameplates that have #10 pigtail wires on them. A #10 wire is rated at 30 amp continuous load. The thing about a 50 amp welder, it will peak at 50 amps for 1/10 of a second during ark start...then it drops off drastically as welding continues. The NEC has entire sections allocated to derating factors on welders. Its a real mess. All i know is i have to ... by law.. wire welder circuits & welder extension cords RATED to the nameplate... not to what the pigtail is.

 

[crazyal]

Everyone is entitled to an opinion but lets not suggest the OP violate the NEC.

If you are feeding a circuit with a 50 amp breaker the wire needs to be sized for at least 50 amps and within reasonable limits bigger wire is better (no more than a few gauges bigger.) Otherwise the wire will burn up and set the house on fire before the breaker gets close to tripping.

Pat

The question was why could a welder use a smaller gauge cord than what the national electrical code requires for wiring a house. For that the NEC doesn't apply.

 

[rsewill]

This is like the 4th post in this site that has debated welder circuits.
I am an electrical contractor and all i can say is were required to provide a #6 cord for a 50 amp rated draw per NEC requirements. For 100 foot run you dont need to worry about voltage drop.

Where the problem lies in on the manufacturers end. They arnt burdened by the NEC. Why else do you find lamp cord wire used on a light fixture that has 20 - 60 watt light bulbs burning. the manufacturers can care less. Same with welders. Ive seen new units with 50 amp rated nameplates that have #10 pigtail wires on them. A #10 wire is rated at 30 amp continuous load. The thing about a 50 amp welder, it will peak at 50 amps for 1/10 of a second during ark start...then it drops off drastically as welding continues. The NEC has entire sections allocated to derating factors on welders. Its a real mess. All i know is i have to ... by law.. wire welder circuits & welder extension cords RATED to the nameplate... not to what the pigtail is.

Thanks!

 

[Freakingstang]

Where the problem lies in on the manufacturers end. They arnt burdened by the NEC. Why else do you find lamp cord wire used on a light fixture that has 20 - 60 watt light bulbs burning. the manufacturers can care less. Same with welders. Ive seen new units with 50 amp rated nameplates that have #10 pigtail wires on them. A #10 wire is rated at 30 amp continuous load. The thing about a 50 amp welder, it will peak at 50 amps for 1/10 of a second during ark start...then it drops off drastically as welding continues. The NEC has entire sections allocated to derating factors on welders. Its a real mess. All i know is i have to ... by law.. wire welder circuits & welder extension cords RATED to the nameplate... not to what the pigtail is.

I agree with everything except the #10 at a continous 30 amps. For romex cable, sure. Not so much with 3 or 4 strand SO cable. 30 amps continous will burn the neutral.

I work for a generator company that provides distro along with cabling. We use 10/5 SO (90c) with our 21-20 plugs (20amps) even at a full 20 amps you can see the neutral cable charred inside the insulation.

Another thing to remember (for all the guys not electrical savy) is that a breaker has two purposes. It will trip when it heats up. A 50 amp breaker is a thermal breaker and is only good for 80% for a continuous load. It will only trip once it exceeds that 80% for an extended period. The other purpose is to provide a break point in case of a direct short (phase to phase or phase to ground). If you are using cable inadequate for the load, the breaker doesn't know, doesn't care.. So if the cable is on fire from over amperage, the breaker isn't going to trip until the insulation melts and two lines cross... We see it on a lot larger scale with our 400 amp rated 4/0 cable. The weak link is in the connection points (cam lock ends similar to stick lead extensions). If we are pulling 350-380 amps (digital breakers rated for 100% continous) and there is a weak connection point heat is created. We had a couple cam lock catch fire (just smoldering) at this years super bowl with only 200-220 amps on cable rated for 400...

Just keep that in mind.. Don't cut corners when it comes to electricity. No one here wants to see anything happen to anyones shop, house or barn

 

[CJONE]

I agree with everything except the #10 at a continous 30 amps. For romex cable, sure. Not so much with 3 or 4 strand SO cable. 30 amps continous will burn the neutral.

I work for a generator company that provides distro along with cabling. We use 10/5 SO (90c) with our 21-20 plugs (20amps) even at a full 20 amps you can see the neutral cable charred inside the insulation.

Another thing to remember (for all the guys not electrical savy) is that a breaker has two purposes. It will trip when it heats up. A 50 amp breaker is a thermal breaker and is only good for 80% for a continuous load. It will only trip once it exceeds that 80% for an extended period. The other purpose is to provide a break point in case of a direct short (phase to phase or phase to ground). If you are using cable inadequate for the load, the breaker doesn't know, doesn't care.. So if the cable is on fire from over amperage, the breaker isn't going to trip until the insulation melts and two lines cross... We see it on a lot larger scale with our 400 amp rated 4/0 cable. The weak link is in the connection points (cam lock ends similar to stick lead extensions). If we are pulling 350-380 amps (digital breakers rated for 100% continous) and there is a weak connection point heat is created. We had a couple cam lock catch fire (just smoldering) at this years super bowl with only 200-220 amps on cable rated for 400...

Just keep that in mind.. Don't cut corners when it comes to electricity. No one here wants to see anything happen to anyones shop, house or barn

???? For a 220-240v welder? If you are cooking the neutral you have got major problems. Something is trying to run on 120. CJ

 

[patrick_g]

???? For a 220-240v welder? If you are cooking the neutral you have got major problems. Something is trying to run on 120. CJ

Amen, brother, just what was going to say. If the welder is powered by 220-240 then why is there any current in the neutral conductor? I suppose it is possible a panel lamp or maybe a fan could run on 120 but not take enough power to heat the neutral.

I think the poster related his experience and his observations are valid but they are for a different situation where 120VAC was being supplied so don't apply here.

Pat

 

[crazyal]

Here's what my manual for my Lincoln 255 MIG welder recommends. The 255 is about as big of a mig welder that I think you'll ever need. But I wouldn't rule out finding a Lincoln tombstone 250 or 300 amp stick welder for cheap.

I think you'll be safe with 8 gauge wire, even for a large stick welder. I went with 6 because it's not that much more, the only draw back to larger wire is weight and stiffness, and if I ever need to make a second cord in the future so I can weld something further way (maybe can't get close enough to my garage) I can just plug it into the extension cord I already have. I'm sure it's over kill 99% of the time.

 

[crazyal]

Here's what my manual for my Lincoln 255 MIG welder recommends. The 255 is about as big of a mig welder that I think you'll ever need. But I wouldn't rule out finding a Lincoln tombstone 250 or 300 amp stick welder for cheap.

I think you'll be safe with 8 gauge wire, even for a large stick welder. I went with 6 because it's not that much more, the only draw back to larger wire is weight and stiffness, and if I ever need to make a second cord in the future so I can weld something further way (maybe can't get close enough to my garage) I can just plug it into the extension cord I already have. I'm sure it's over kill 99% of the time.

 

[Freakingstang]

Amen, brother, just what was going to say. If the welder is powered by 220-240 then why is there any current in the neutral conductor? I suppose it is possible a panel lamp or maybe a fan could run on 120 but not take enough power to heat the neutral.

I think the poster related his experience and his observations are valid but they are for a different situation where 120VAC was being supplied so don't apply here.

Pat

Sorry, yes... On a typical 208-240 single phase welder, you should not even have a neutral, just normally two hots and a ground.

Since the thread was welder ext cords...I threw in some personal experiece as there are plenty of 110 buzz boxes and plasma cutters out there and DIY people don't always know the hazzards...

I should have been more clear with what I meant