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smoothy
Jul 27, 2014, 07:38 PM
Got a question for the ELectricians here. I am wiring in a welder into my main panel (200 amp service) (5 foot run) 60 amp dual pole breaker (if I can't do it with that I don't NEED to do it) using 6 gauge copper high temperature teflon double insulated wire to a dedicated dual pole breaker (the welder is a 220v 295amp transformer based a/c stick welder so I need everything I can give it). Problem is my common bar won't accept 6 gauge wire, since I understand the common and ground are bonded in the main panel, is it acceptable, safe and legal. To use a copper grounding lug to terminate this on the ground, or what alternative means do I have to do this.

hfcarson
Jul 28, 2014, 03:39 AM
for a 60 ampere branch circuit you are permitted to use a #10 awg ground...
NEC table 250.122

hkstroud
Jul 28, 2014, 05:00 AM
By "common" I assume that you mean neutral. For a 240V circuit there should be no neutral, only 2 hots and a ground..

smoothy
Jul 28, 2014, 05:26 AM
Yes... thats what I mean. I'm an Electronic Engineer, not an Electrical engineer or Electrician the terminology is not the same in my field.

I'm a bit confused because the charts I looked at say 10 gauge is insufficient for 60 amps at 240v (what I calculate is the maximum I could use when I need to turn it up all the way, and what the manufacturer recommend it be wired for) and 10 gauge is the max size that fits the ground bar. But thats why I'm asking you guys, maybe I'm looking at it wrong and paranoid about undersizing anything. (I've seen far too many melted wires over the years on too many things)

I need far more than I could draw off the 30 amp dryer circuit I've used this on since 1975 (at much lower welding currents). In a year or so I plan to put a 100 amp subpanel in my garage and move it out there at that time.(using this same breaker position to feed it).. but I have to weld and gusset a set of I-Beams this week and this is the only welder I have with the capacity to do it. Both my MIG and my TIG are outclassed on stuff that thick. And scratch the TIG because I'm doing this outdoors.

My panel happens to be three feet from my side basement door that opens into my driveway. I'll just run my welding cables out the door when I use it.

hkstroud
Jul 28, 2014, 07:34 AM
10 gauge is the max size that fits the ground bar

I guess I'm confused. You say you are running a cable for a 240V welder. I assume you are running that cable to a receptacle or to a disconnect and then to a receptacle. Logically that cable would be a two conductor cable with a ground. Your connections would be to a double pole breaker and to the ground buss. Depending on the type of cable the hot conductors would be #6 (larger if you are using Romex). The ground would be # 10. Your ground buss should accommodate a #10 ground wire.

The neutral buss should accommodate at least a #6 conductor. However, there should not be a connection to the neutral buss.


the welder is a 220v 295amp transformer

Does welder specify input amperage. Any welder pulling 60 amps is pretty big, especially for a home owner.

smoothy
Jul 28, 2014, 03:44 PM
This is a big welder... it will do 295 amps. THey actually did call for a 60 amp connection. I looked inside of the panel another time. The ground isn't an issue after all. There was a free lug on very top of the buss I didn't notice before because I was working on the lower right side and it was up on the upper left side. Right next to the ground that went out to the copper rod and right above the tie bar that ties the busses on the left and right side together. The busses themselves won't accept anthing larger than 10 gauge, but the lug would accept stuff up to the size of the servce entry cable.

THese are pictures of one just like mine.






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