Any other response is stupid.
Any other advice is blather.


I beg to differ. Other responses are not necessarily stupid nor blather. There are additional valuable points to be made that you did not include.

A GFCI is also an ultra-fast circuit breaker. Meaning that older motors that commonly will not trip a regular breaker will often trip a GFCI, yet not be defective - this due to the momentary turn-on surge.


Again, I beg to differ. A GFCI is is not by design a circuit breaker. It does not respond to sustained circuit overload conditions in a manner that protects house wiring -- which is exactly what a breaker is intended to do. Prevent fires.

A friend recently called me, mystified, asking why the GFCI he'd just installed was not tripping under a 30+ amp load, it was a 15 amp GFCI. I told him..... it's not a breaker. It's designed to protect humans from shocks, not fires. In this case, I expect the eventual failure mode would have been overheated wiring resulting in a fire somewhere in the circuit.... not necessarily the GFCI.

My friend was trying to create a protected sub circuit in a garage, where there was no access to the breaker, because it was in the house. I instructed him to install a sub panel with breakers and GFCIs in the outlets -- or use GFCI breakers. An expensive option.

Will some GFCIs trip (as per this thread) from momentary overloads? Yes, because switching inductive loads create a brief imbalance in the neutral. Signals out of phase, so to speak. Not from over current. Most will happily supply excess current if the rest of the house circuit allows.

Typically, a long wire run to a motor, an extension cord for example, will aggravate the imbalance, adding inductance.

Some devices will trip a GFCI pretty much most of the time. However, that this happens DOES NOT make the GFCI device faulty. It makes the device faulty


Again, I beg to differ. Nuisance trips are NOT necessarily indicative of a defective device. There are various motor start and stop conditions that can cause an imbalance (loading, inductance, stalls, voltage drop, even temperature).

GFCIs do fail in-elegantly. Some will refuse to trip. Others will trip too often, even under non imbalanced conditions. Better quality GFCIs will hold up longer and fail to safety -- tripping too often rather than not at all..

Terry