On Monday, October 14, 2013 7:50:23 PM UTC-4, Bill Leonhardt wrote:
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

Follow-up

I have my lights (fluorescent) coming off the main house panel and all else coming off a sub panel for the shop. That way I can lock out all machines and outlets when I have grand kids working in the shop.

The shop is in my basement and I believe that general circuits (those not dedicated to a specific use) are required have a GFCI.

All my outlets and plugs are in good shape but the GFCIs are 9 or 10 years old. Still, it's hard to imagine they both failed at the same time.

I will see if I can get compressed air into the motor (although I think it's sealed)to further blow it out. My 13" Rigid planer ran OK on one of the circuits since I got enough of the board flattened before the jointer quit to plane both sides.

I'll report back after the air trial.

Bill