In my shop I have two general purpose electrical circuits that I connect everything to except the big machines. They are 20 amp (120VAC)circuits with 12 gauge wire. Each circuit starts with a GFCI outlet and then a chain of normal outlets. All outlets are 20 amp.

On one circuit I have my Yorkcraft 6" jointer plugged in. I've had this a few years. It's been lightly used with no prior problems.

This evening I was jointing a piece of 1 x 6 maple set to take off less that 1/64 per pass. After a bit, the GFI would pop. Thinking this might be the GFCI outlet, I connected the jointer to the second circuit. Same problem. The only other piece of equipment running was the DC which is on a separate 240VAC circuit.

The circuit breaker (20 amp)never pops. The GFCI outlet is maybe 6' from the panel and the second outlet (jointer) is about 8-10' from that.

The jointer has a 1 hp motor (running at 120VAC)and, when I pulled the cover off, the motor was barely warm. No dust buildup either since I have this connected to my DC.

I have done a baby crib's worth of (soft)maple and 2 large bookcase's worth of cherry without incident. The piece I was working on was a piece of the leftover maple.

Any thought why this would cause the GFCI to pop and not the circuit breaker? Also, what would I look for with respect to the cause. I bought the jointer new 8 or 9 years ago and it has been lightly used.

Thanks,

Bill Leonhardt