I notice the CFCI in the Orbit 57095 timer box tripping every few days. The only thing plugged into the CFCI is the transformer going to OpenSprinkler. Even if there was a ground fault, it would be on the secondary circuit of this transformer. Besides, it is very dry here. The only think wet is near the sprinklers that are far from the GFCI. My main thoughts go to the magnetic fields of the transfomer messing with the GFCI. Any other thoughts?
I don’t have enough knowledge about GFCI. But I did some Google search and my understanding is that it trips when the difference between the supplied current and returned current is more than, say 6mA. This is often due to leakage current, unexpected shorting to ground, or anything that causes the current to leak out without returning. I can’t think of an obvious reason for your case, but I suspect if there is a wire that is worn out or exposed, it can result in leakage which trips the GFCI.
Thx. The leak would be on the secondary winding. This has been a while for me, but I don’t think something on the secondary can trip a GFCI. The only other pointers that I can find hint at transient voltage, or ground connected to neutral. I will check the latter when it is light outside tomorrow.
I found that the hot/neutral were reversed at the panel. The GFCI from the Orbit box should have locked-out on this condition. Oh well, I should have started with the 3 light tester anyway. Condition corrected. Will post the results in a few days.