Ingo Electricians, why does this happen?

[jkaetz]

Our kids' bathroom has two switches (light and exhaust fan) + a GFI outlet with a nightlight in a three gang wall box. If the fan is switched on and then off quickly the GFI will trip. The fan still works after this so I know the fan is not on the load side of the GFI. I doubt I would have ever noticed this but the kids like to play with the switches and thus I usually find the night light off and GFI tripped.

 

[actaeon277]

Our kids' bathroom has two switches (light and exhaust fan) + a GFI outlet with a nightlight in a three gang wall box. If the fan is switched on and then off quickly the GFI will trip. The fan still works after this so I know the fan is not on the load side of the GFI. I doubt I would have ever noticed this but the kids like to play with the switches and thus I usually find the night light off and GFI tripped.

Fan is probably fed from the same branch as the GFCI, just not fed from the same GFCI.
GFCIs do NOT like motors.
Turning on a motor, then turning it right off can cause a surge, which the GFCI senses, and trips.


Circuit breakers in the house, sense current, usually in the amp range, and trip on overcurrent.
This protects the HOUSE, not the person, since milliamps kill.

Ground Fault Circuit Interrupters don't look at the current. Or at least, the overall current.
GFCIs look at the DIFFERENCE in CURRENT.
Current going in the hot leg, and the current going out the return leg.
It looks at the difference between them.
A difference of a certain amount of milliamps (I forget how much) will cause it to trip.
A difference between the "going in" and the "going out" implies the current is going somewhere, maybe your body, so it trips.

 

[jwamplerusa]

Fan is probably fed from the same branch as the GFCI, just not fed from the same GFCI.
GFCIs do NOT like motors.
Turning on a motor, then turning it right off can cause a surge, which the GFCI senses, and trips.


Circuit breakers in the house, sense current, usually in the amp range, and trip on overcurrent.
This protects the HOUSE, not the person, since milliamps kill.

Ground Fault Circuit Interrupters don't look at the current. Or at least, the overall current.
GFCIs look at the DIFFERENCE in CURRENT.
Current going in the hot leg, and the current going out the return leg.
It looks at the difference between them.
A difference of a certain amount of milliamps (I forget how much) will cause it to trip.
A difference between the "going in" and the "going out" implies the current is going somewhere, maybe your body, so it trips.

What @actaeon277 said. You can try to mitigate the issue by verifying all grounds and connections in the circuits. Minor resistance can result in a differential current sensed by the GFCI and a trip. GFCIs are amazingly sensitive and fast.

Observing proper electrical safety precautions, check and clean the ground, neutral, and hot wires from the breaker box to the problem location. If the current connection is via poke home installation convert to the screw clamped connections. I have had this work to reduce trips from once a week or two, to a fairly rare event.

 

[Frosty]

This also explains why my GFI I installed in the living room trips on occasion, seems I wired the ceiling fan down from that outlet.

 

[Rookie]

It could also be the gfci is going bad. When they're going bad, they get more sensitive. Everything in my house is on a gfci circuit. I never have issues until they're going bad, then I replace them.

 

[femurphy77]

It could also be the gfci is going bad. When they're going bad, they get more sensitive. Everything in my house is on a gfci circuit. I never have issues until they're going bad, then I replace them.

Don't you know in today's brave new world there is no such thing as a bad gfci? It's just a gfci with a different point of view and you must accept it or youre a white racist supremacist misogynistic poopie head!

 

[Frosty]

Don't you know in today's brave new world there is no such thing as a bad gfci? It's just a gfci with a different point of view and you must accept it or youre a white racist supremacist misogynistic poopie head!

What if the GFI is also white?

 

[Creedmoor]

What if the GFI is also white?

 

[femurphy77]

What if the GFI is also white?