Wiring, 230v extension chord
 

I want to make a 230v extension chord for my welder that runs off my dryer circuit. My welder draws 25A @ 230v at full load, max duty cycle 30%. I don't plan on welding anything on that high of setting, maybe 50% load.

I have a 50 ft 12/3 chord and a dryer plug.

Will this work?

Chart here: Extension cord - Wikipedia, the free encyclopedia

12/3 should be fine for 50', although I wouldn't go any further than that.

its not smart, the welder draws more at full power then the wire is rated for.

im sure you'll be fine. its intermittent and you'll keep it on a lower setting then full load.

12/3 is not going to work, you'll just burn the wires cause it not rated for that kind of amperage. you must you 10/3 to make it work safely.

i believe table 2 in the canadian electrical code shows for copper that #12 is rated up to 20 amps and #10 is rated up to 30 amps.

i think think you'd need #10 as pocha stated to be safe.