OT: 230v welder wiring, using a dryer circuit Options

[bondo]

I just got a millermatic 175 welder. 230v, 19.5 amps. I'm going to make an extension cord for it and was wondering what guage wire I should use. Is 12ga enough? (going about 30 feet, just enough to get all the way around the garage, and into the driveway a bit)


Also, the dryer outlet is neutral grounded. Should I use it as is or add a second outlet with a real ground?

[914GT]

QUOTE (jonwatts @ Jan 16 2006, 12:51 AM)

(IMG:http://www.914world.com/bbs2/html/emoticons/icon_bump.gif) All hail the god of archives (IMG:http://www.914world.com/bbs2/html/emoticons/pray.gif) I searched before asking and found some good threads on this subject, including this one. But I still have a few questions. 1. What's the upper limit on how long a 220V extension cord can be before it becomes a problem? 2. If the welder is rated at 20 amps why did they put a 50 amp plug on it? Don't they know that most of their customers are guys trying to repair rusty cars in their garages?

1. Depends on the minimum voltage the device with correctly operate under peak and continuous operating current. Generally you want less than a 10% voltage drop, but for a welder I'd keep it under 5% so you don't have problems with the wire feed motor at max. peak amps. Use a wire gauge chart such as this one to size the wire.

2. Possibly because 25-30 amp single-phase receptacles are not as common for household use. More people probably have dryer outlets close to the garage. You could go down to a smaller amp plug rated higher than the max. input amps on the welder, but you'd still have to buy the matching receptacle. And it shouldn't be a standard plug used for 115V equipment even though they exist with 20 amp ratings.