Wire size for welder AC supply

I just picked up an old Ac/DC Dayton welder (230/180 amps). The label says "Pri
Amps 65.7" at 230 volts. Can anyone help me determine what size wire I need to
run to an outlet to feed this thing. I will probably want 20-25 feet or so.
Dayton 3Z563
$75
Pri Volts 230-O.C.V. 78-Arc Volts 25-Pri Amps 65.7-Sec Amps 230
It'll be a big step up from my ancient 130 amp AC buzz-box. Finally, I get tp
play with DC.
Reply to
Bob F
Loading thread data ...
Go to Home Depot and look up table next to the wire spools. I believe #4 will cover you nicely, according to my table.
Reply to
Ignoramus31588
Did you take into account the duty cycle derating the NEC allows? NEC article 630.11 and table 630.11(A), multipliers range from 1.00 for 100% duty cycle welders down to 0.45 for 20% duty cycle or less. If the welder in question were rated at say 50% duty cycle, the multiplier would be 0.71 so you'd size the wire for a 46.647A load (rounded up to 50A) or 6ga copper conductors.
Reply to
Pete C.
More to think about. The welder says 100% duty cycle, tapering to 20% at full output current.
Would that mean I could go to 8ga. ?
Reply to
Bob F
(AT 90 amps AC)
Reply to
Bob F
Probably depends on how you plan to use the machine, and the wire type you choose.
Most suppliers, including Lowe's and Home Depot, sell type THHN wire. Copper #8 is good for 55 amps, #6 is 75 amps.
formatting link
I would bet you could wire this machine with #8, and run 3/32 rods all day long. But if you think you might want to push the upper limits of the machine very often, or very long - #6 might be your best bet.
You might also want a bigger machine some day, but maybe not.
In either case, you can down size your neutral one size and save a little. Like 8,8,10 or 6,6,8.
Reply to
Maxwell
Yes, but is it a good idea? I do not think so. He may want to use the outlet for other things too. Much better to go to #4 and have a full powered outlet.
Reply to
Ignoramus4856
It's a 240V welder, it doesn't use a neutral connection at all, just two hots and a ground.
Reply to
Pete C.
Certainly a possibility. It's one of the places where the NEC allows things that may not be the best idea outside of an industrial environment. If the SWMBO want's to use the outlet for a pottery kiln or other non-welder use as well, then a normally rated feed would be more appropriate. Of course with the price of copper these days, if the run from the panel is significant the cost difference may be surprisingly high.
Reply to
Pete C.
Agreed, but that's just terminology. Grounds and neutrals all connect back to the same place on a 240V system, and can be downsized one wire size.
Reply to
Maxwell
Ummm, not entirely true. Equipment grounding conductor sizes are determined by the size of the overcurrent device (circuit breaker ) that protects the circuit. See NEC Table 250-122 . In the case of a 60 amp circuit ( #6 THWN wire) one could use a # 10 copper grounding conductor. In this case you're down 2 wire sizes, but a 20 amp circuit ( #12 copper ) requires a # 12 grounding conductor. Paul
Reply to
Paul in Lapine
And they don't necessarily "connect back to the same place" either.
In a subpanel, the grounding and grounded conductors are _not_ bonded.
scott
Reply to
Scott Lurndal
You're either nit picking or you missed the point.
His application will require either a #8 or #6 circuit, both of which will allow you to save money on wire by dropping at least one wire size on the third conductor.
Reply to
Maxwell
And you are either nit picking or you missed the point. A sub-panel was not mentioned.
Reply to
Maxwell
I simply didn't want someone reading this thread to assume that it is always OK to drop a size for the neutral or grounding conductor in a 240v circuit. That certainly isn't the case. Paul
Reply to
Paul in Lapine
Your welder needs 66 amps when welding at 230 amps. I never need to weld at 230 amps. Usually I run about half that. My welder runs fine on a 30 amp breaker with 10/2 wire with ground. Much of the time I run it on a 25 amp generator without problems. My way isn't proper or to code. Works fine.
Reply to
Pat
I would match the wire to the circuit breaker. If you put in a 60 amp breaker then I would wire it with 60 amp wire.
Reply to
Pat
What size rod do you usually run? I have significant problems with the rod sticking at lower currents.
Reply to
Bob F

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.