On Dec 24, 11:34 am, "HeyBub" wrote:
BobK207 wrote:

I have had trouble with motor loads tripping GFI's.

The fact that it trips when the fan is turned "off" leads me to
believe what you're seeing is not a true ground fault (current leakage
to ground) but "merely" a difference between the instantaneous
currents on the hot & neutral wires.

I'm an ME but I did study some motor & circuit stuff in
school.......here's my best attempt at an explanation, when the fan
is turned off, the magnetic field of the windings of the motor
collapses & induces a current back thru the neutral (since the hot
lead is switched & therefore open).

The field collapses 60 times a second when running...

yeah but BOTH the hot & the neutral are still connected when the fan
is running.....

I believe it is the "collapse" with the hot open & the neutral still
connected that causes the problem for the GFI current sensing circuit.

My comments were meant to provide a plausible reason for the behavior
"GFI trip on fan shutdown"

& your theory is?

Sounds like Doug's comment that its ok to switch both should solve the
issue.


OP-

Is the fan / switch wiring such that you can easily install a DPST
switch and switch the hot & the neutral to the fan?

cheers
Bob