On Aug 24, 8:43*am, "john" wrote:
It is odd that the GFI trip 10 seconds after the fan is on. Perhaps it has
become unbalanced, and when it is up to speed it vibrates so much something
gets shorted?

To answer a couple of your questions...
My fan has no plug on it. It's wired from a wall switch. I have
other things running on the same circuit (a few outlets and an 8'
fluorescent shop light). My fan trips the GFI whether there are
additional loads on the circuit or not. It doesn't seem to make a
difference. I used my compressed air to blow out the motor and it
didn't help. When I first posted, I mentioned that the fan would run
for ten seconds and then trip the GFI. The 'ten seconds' only
happened the first couple of times I tried it. Since then, it trips
immediately. I think I've successfully ruled out the GFI (replaced),
the wall switch (replaced), and the wiring from the GFI to the switch
to the fan (all closely inspected). I suppose it's time to have the
motor serviced. If anyone is interested, I'll post the outcome later.

Thanks for everyone's help.

unklerichie