A GFI Outlet Problem FAQ

Overcurrent doesn't trip a GFCI. A current inbalance between the line and neutral trips a GFCI. A "current leakage" to ground - either the safety ground or something bonded to it. - Or something that LOOKS LIKE a current inballance - possibly a current lag - or lead - (phase shift) could fool an over sensitive GFCI processor? I'l bet the fan only has a single pole switch on it. Is it a 3 wire plug? or only a 2?

Does it trip if you pull the plug instead of shutting off the switch (fan only) - this would be equavalent to a 2 pole switch - more or less - Many "dual insulated" devices (2 prong plug un-grounded - like many heaters - have a 2 pole switch that disconnects both line and neautral at the same time. If the plug is not polarized perhaps reversing it would change things?? The GFCI is sensing current flow on one side (likely line) and no current flow on the other (likely neutral) convincing the circuit there is a leakage to ground -(possively capacitive - more likely inducive ? - capacitive phase shift causes current to lead voltage - up to 90 degrees in a purely capacitive circuit while a purely inductive circuit current lags voltage. The capacitance or inductance of the #16 extention cord (twisted or parallell?) combined with inductive kick or whatever of the shaded pole? fan motor - a shaded pole motor has very low resistance compared to it's inductance due to the pole shading - all combined COULD fool a marginal GFCI.

I'm not an EE, so not saying I'm right - but these are things "I" would investigate - -

I don't know about others but on a Square D QO GFCI a ground fault trips the little yellow button while an overload/short trips the lever

- if we are talking a breaker (panel mounted) device. A GFCI outlet does not trip on overload

I found this thread while looking for another post of yours. Several people have said this about not being warm, and I could put this reply after any of them but you are he lucky oen. Last week a tree fell into my yard and while using an electric chain saw rated at only 11.5 amps, I found that my 75 or 100 foot extension cord was slightly but detectably warm. I'll admit I don't know the gauge but it's the same one I use for and it's intended for mowing the lawn.

Posted and mailed. Did I find the right email address?

I'm following that rule, even though the label on the cords says it'll handle 13A. I know someone tried it with a heater that used 12.5A (the usual rating for 120V heaters). The cord was getting warm and soft all over and seemed unsafe.