Welder Extension Cord

[Travelover]

he could plug that thing into a 115v 15 amp circuit if he wanted to, you can always use a wire thicker then needed, but never thinner. I used to have my welder plugged into a 30 amp circuit, with a 25 foot 4/3 cord, thats way better than the 10/3 needed, much less voltage drop.

I think this is correct. The critical thing is that the fuse blows before the wire glows.

 

[deereman75]

Mine is 8/3 wire. I am assuming in my situation I should be fine. What is your opinion?

I am sure you will be fine. My outdated code book says 8 gauge is for up to 60 amps. I was actually going to get 20 feet of 6 or 8 gauge for my welders cord, but because of a mistake by the new guy at the cable store, we got 25 feet of 4 gauge for like $40-$50. If I had to pay the full price for the cable, no way would I use 4 gauge, 6 at the most. (this thing is HEAVY)

 

[grsthegreat]

I am sure you will be fine. My outdated code book says 8 gauge is for up to 60 amps. I was actually going to get 20 feet of 6 or 8 gauge for my welders cord, but because of a mistake by the new guy at the cable store, we got 25 feet of 4 gauge for like $40-$50. If I had to pay the full price for the cable, no way would I use 4 gauge, 6 at the most. (this thing is HEAVY)

60 amp Canadian is 40 amps US . THHN wire #8 is rated 40 amps @ 60C (140F) which is how they rate extension cords. If you use the 90C tables, it goes to 59 amps, but no one recognizes that temp range for cables.

 

[deereman75]

60 amp Canadian is 40 amps US . THHN wire #8 is rated 40 amps @ 60C (140F) which is how they rate extension cords. If you use the 90C tables, it goes to 59 amps, but no one recognizes that temp range for cables.

I am sure you know far more about this then I do, and I am sure you are right. I was looking at the table some more, and it is for loomex cable, and is based on a spec sheet from 1982. (this isnt the offical code book, just a simplified version, based on the offical version)

 

[grsthegreat]

I am sure you know far more about this then I do, and I am sure you are right. I was looking at the table some more, and it is for loomex cable, and is based on a spec sheet from 1982. (this isnt the offical code book, just a simplified version, based on the offical version)

i wish they would bring back the old 1970's code books . they were like 1/4" thick hehe. My new code book is about 2" thick..all of it useless garbage :laughing: :laughing: :laughing: :laughing: :laughing: :laughing:. Its amazing how the 1950 houses are running just fine thank you

 

[kennyd]

Welder circuits and extension cords can be Derated a little bit due to the duty cycle of welders, meaning they are not drawing current constantly. Your #8 cord is perfect. Just look at the Cord that came attached to the welder, it's probably #10.

 

[J_J]

ToolBoxTavern,

You only have 33 A input current at 208 V with a 40 A cutting ability.

http://www.hobartwelders.com/pdf/spec_sheets/AirForce_700i.pdf

Wire Size Calculator

This calculator says that if using a 50 ft cord, and 33 input amps at 208 V, the wire size required computes at #14, single phase , copper wire.

 

[J_J]

60 amp Canadian is 40 amps US . THHN wire #8 is rated 40 amps @ 60C (140F) which is how they rate extension cords. If you use the 90C tables, it goes to 59 amps, but no one recognizes that temp range for cables.

Please explain how your amps are different.

40 A US, should be 40 A Canadian.

 

[J_J]

Yes, required by code to ground all metal bits, plus a very good idea.

JJ, #8 is used for ~50A circuits, not 80A. This is a standard welder extension cord. I can buy the exact cord with the 50A M&F plug ends on it from Hobart at the Fleet Farm store here. For home use, it is hard to get something that really needs more than 50A, and even harder to drive a welder hard enough to max that out. Home welders just don't run that hot and heavy. Not many interstate bridges built in home garages...

Use this calculator and tell me what it calculates for a 50 ft wire, and 80 amps. Should compute at #8 wire

Wire Size Calculator

This is what Lincoln says, 230VAC Single Phase 70 Amps #8




120V/40A = #10 wire.

208V/40A = #12


Pro Cut-80

K1581-1 98

208/230/460/ 1-ph: 96/87/48A (44.5)

 

[deereman75]

well that calculator is clearly wrong.