The GFCI that protects outside lights continually trips off. There are three lights plus receptacle. Basically the wiring is- Fuse box to Torx timer to GFCI to outside lights. How do I begin to diagnose where the problem lies. I replaced the GFCI but it still trips. Any ideas?

 

Some background would help. When you say "continually," do you mean within a half-second of resetting it, or do you mean overnight, or do you mean once in a while? If anything except the first answer, is there a pattern -- such as it trips in humid or rainy weather? When did this start happening, and did anything change around that time?

 

In addition to John's comment about patterns, is its trip matched with the operation of the timer?

 

Thanks for the reply. The trip is immediate upon reset. Push in pops out. It began about a week ago. Preliminary inspections show no water or broken lines that are visible within outside electrical boxes, lamp post, etc.

 

Do you try to reset with the circuit energized (timer on)? If the circuit is off while trying to rest, most GFCI's will not reset.

 

Thanks for the reply. Of course the GFCI only resets if power is on. Here is another test I just tried. If I remove the GFCI the lights works and NO circuit breaker tripping.

Any other ideas?

 

You have ground fault. The GFCI is doing its job.

Disconnect the wires from the load side of the GFCI. Does it reset now? If it does, reconnect them and go to the next box and disconnect the wires there. Does the GFCI reset now? If it does, ...

You can either work from the GFCI downstream, or from the last outlet upstream, or from the middle (binary search). In any event, this diagnostic procedure will tell you what box the ground fault is in. Then post back and tell us.

You may have moisture in one of the outside boxes. If that is the case, then try to seal it up better.

 

Another possibility is the gfci is wired incorrectly. Check it carefully. The words "line" and "load" mean different things to different people.