GFCI receptacle fed from GFCI breaker

[Dmoe]

Our new house has been decorated for Christmas this year and the outdoor lights keep tripping the GFCI breaker. I think there may have been some moisture in the extension cord. It got me looking into what's going on. When I reset the breaker it holds for the night and is typically tripped on the morning. The extension cords are all off the ground. Looks like the Romex leaves the GFCI breaker and feeds the outdoor receptacle on the back deck. From there it feeds a switched GFCI receptacle at the front door.

I have one set of lights plugged into the front receptacle and one set of lights plugged into the back receptacle. This morning I unplugged the front receptacle to see if it trips overnight so I can possibly isolate whether the issue is in the rear light stringers it the front.

Any ideas here? Why the double protection (GFCI receptacle fed from a GFCI breaker) and the receptacle isn't tripping.

 

[Little Bill]

I'm allowing this thread but please keep all responses to explain GFCI protection and not any "how to" type replies.

 

[480sparky]

There's no rule against multiple GFCIs on a circuit.

There's also nothing to say the GFCI closest to the ground fault must trip first.

 

[rnatalie]

I agree with 480. We just had this discussion in another thread.

 

[LarryFine]

I have one set of lights plugged into the front receptacle and one set of lights plugged into the back receptacle. This morning I unplugged the front receptacle to see if it trips overnight so I can possibly isolate whether the issue is in the rear light stringers it the front.

Results?

Any ideas here? Why the double protection (GFCI receptacle fed from a GFCI breaker) and the receptacle isn't tripping.

I might violate forum rules by making a recommendation.

 

[kwired]

So one outdoor receptacle is a GFCI type and the other isn't? but both fed from same GFCI breaker? that is how I interpret OP. If that is correct and the GFCI receptacle does trip when pressing test button, chances are greater the offending fault is plugged into the other receptacle if the GFCI receptacle is not also tripping. If not there could be something intermittent elsewhere in the wiring that causes trip, or if it could even be tripping on overload and not GFCI function.

 

[synchro]

So one outdoor receptacle is a GFCI type and the other isn't? but both fed from same GFCI breaker? that is how I interpret OP. If that is correct and the GFCI receptacle does trip when pressing test button, chances are greater the offending fault is plugged into the other receptacle if the GFCI receptacle is not also tripping.

That is a likely cause of the tripping if this is the scenario for the OP.
Another less likely possibility is that there's some ground fault leakage current from both sets of lights, but each current by itself is less than the Class-A GFCI trip threshold. In this case the GFCI receptacle wouldn't trip, but the breaker would be sourcing both fault currents and together they might be enough to exceed the threshold and trip the breaker.

 

[GeorgeB]

I've personally had 2 GFCI devices semi-randomly trip because of failing (or not?) surge protection MOVs in power strips ... hot to EGC current. Before I called the electrician the 2nd time, I took them all out and resolved the issue. Seasonal lighting may have power strips ...