Weld cable sizing

[ATCOEnt]

MAC702, Amy702,

I have read that the welding cable size recommended to run 300 amps a distance of 100 feet is 1/0 and to run the same amperage 150 feet you will need 2/0. This is based on direct current (DC), 60% duty cycle and a voltage drop of 4 volts or less. May I use 2/0 cable the first 50 feet from the machine and 1/0 the last 100 feet or will I have to use 2/0 the entire 150 feet? I hope I do not have to buy 150 feet of 2/0 to go another 50 feet!

[Coalsmoke]

Nope, although ideal to have 2/0 straight through, if you make sure you have good connections and use 2/0 for the first 50' and 1/0 for the next 100' will be just fine.

[ATCOEnt]

Thanks Coalsmoke.

[J hall]

According to a 1982 Lincoln owners manual, 300amp 60% combined length of both cables. Up to 150ft #1 ga 150to 200ft #1/0 200 to 250ft #2/0
I run 150' 1/0 with a 25' #1 whip lead.
Jeff

[ATCOEnt]

Thanks Jeff. I plan to run 100' with a 50' stinger & ground (combined lengths) normally but when I need to add length I will add it at the machine with larger cable.

[90blackcrx]

Kind of off topic, but if I needed two 50feet extension cords to connect together, would I have to up the gauge wire ? This is the cord I'm looking at.

http://www.brwelder.com/indextemplate.cfm?file=shop/detail.cfm&ID=799&SubCategory=155