[Mr. Michael]

Hey all,
So I've got about 10 strings of LED Christmas lights strung together. They claim to be stable to having up to 25 strings, low wattage. I've had this setup for 3-4 years now, and they've been hooked up this year for over a month.


There's an outlet in my garage (not GFCI) where I run an outdoor extension cord, to the outside of my house, where I split the power between one tree and my house (so it splits in two, also with outdoor rated equipment).

The other day when I came home the lights were all off. The outlet was dead, and so were several GFCI outlets in my home. Upon further investigation, whenever I plug my lights in to the outlet, it shorts all 5 outlets (4 are GFCI) until I reset the outlet in my basement.

I can plug other things into the garage outlet, so I don't think the problem is with the outlet itself. I also plugged the lights into a different circuit, and it shorted that circuit.
Any idea why this would suddenly happen? And any ideas on how to fix this? Thanks,
Michael

 

[AllanJ]

A ground fault or maybe a short circuit has developed somewhere in your strings of lights. Maybe the insulation wore away where you have a clip to hold the lights on the house or on a tree. Even moisture getting into one of the lamp socket can form a conductive path over to some metal object like a gutter can cause this.

Try unplugging some of the strings of lights (with the entire group unplugged) and then plug in what is left to see which string of lights has the problem.

 

[oh'mike]

Obviously one or more strands is defective-----unplug them all---and the plug them back in,,one at a time, until you find the bad one.

Your GFCI's are wired wrong---not a big deal .but irritating that one will cause the others to trip also.

 

[curiousB]

Upon further investigation, whenever I plug my lights in to the outlet, it shorts all 5 outlets (4 are GFCI) until I reset the outlet in my basement.

You should NEVER cascade GFCI outlets. A ground fault downstream will trigger one of the GFCIs but which one is unclear. This is known as a race condition and it could vary from time to time and be unpredictable. Generally people just put one GFCI as a logical point in the circuit and then everything downstream is protected by that GFCI. If you wanted separate GFCIs in multiple locations (so the tripping and testing is just done on each outlet) then you cascade the line side to the downstream GFCIs and pigtail a hot and neutral to the GFCI line side in the box leaving the load side not connected to anything.

 

[dmxtothemax]

You should NEVER cascade GFCI outlets. A ground fault downstream will trigger one of the GFCIs but which one is unclear. This is known as a race condition and it could vary from time to time and be unpredictable. Generally people just put one GFCI as a logical point in the circuit and then everything downstream is protected by that GFCI. If you wanted separate GFCIs in multiple locations (so the tripping and testing is just done on each outlet) then you cascade the line side to the downstream GFCIs and pigtail a hot and neutral to the GFCI line side in the box leaving the load side not connected to anything.

It all depends on weather the downstream ones are hooked up
to the feed side or load side of the first gfci.
If they are all daisy chained on the feed side they will work !
I dont know if this is code compliant thou !
But it will work !

 

[AllanJ]

No problem putting individual ground fault circuit interrupter receptacles all along a circuit with a regular breaker, wiring them all up using their line side terminals. Their load side terminals are left empty or connected to additional receptacles without GFCI units, or to other items such as lights. This costs more than having one GFCI unit protect other receptacles downstream but you might want the convenience of not having to go to another room or down to the breaker panel to reset the GFCI.

I never heard of unpredictable things happening with putting a GFCI unit on a circuit or subcircuit that already has GFCI protection other than it is also a waste of a GFCI unit (and money).