I believe the recent rain tripped my outside outlet which is on the same line as the GFI in my garage. I have all outdoor Christmas lights on outdoor extension cords, but I forgot to unplug them in the rain and I think it tripped. The problem is, I cleared all my outlets and went to reset the GFI...nothing. I can get it to "click" in, but it doesn't even stay for a second. I checked the circuit breaker...no tripped circuit. There are no other GFEs on that line. My home was built in 2007 in the U.S..
Can an overload on a GFI cause the actual box to malfunction? Should I replace the box? Can this overload cause any of the wiring to burn or does the tripped GFI prevent that from coming close to occuring. Thanks in advance!
Re: Tripped GFI
The most likely explanation is that water has infiltrated the junction box and it causing the GFCI to trip. It's also possible that moisture has penetrated the GFCI itself. If you are going to leave something plugged into an outdoor outlet, it needs to be covered with a rain-tight box. It is also possible that you overloaded the GFCI with your Christmas light display and the device was damaged.
Originally Posted by TRice
How many amps are you running on your Christmas light display? You mentioned extension cords... are they sized appropriately for the attached load? If you are using LED or minilights, you're probably not drawing to much unless it's a HUGE display, but incandescent lighting (C7/C9 bulbs, floodlights, etc.) draws a lot of current. The maximum continuous load on a typical 15A GFCI receptacle is 1440W or 12A (keep in mind that's the maximum load for the single receptacle on a circuit, the entire 20A circuit itself maxes out at 1920W or 16A). A couple of hundred C7 bulbs with a single floodlight will use all of the GFCI's capacity.
A GFCI functions differently than a standard circuit breaker. A circuit breaker is designed to measure current through the hot leg of a circuit. If the amount of current exceeds the capacity of the breaker, the breaker trips and shuts off current. By pairing the breaker rating with the appropriate gauge of wire, this prevents overloads from resulting in overheated wiring and possibly fires.
On the other hand, a GFCI functions by comparing variances in the amount of current between the hot and neutral legs of a circuit. If a device plugged into an GFCI is operating correctly, the current between those two legs will be equal. If there an imbalance, this means that current is faulting to ground somewhere, and the GFCI trips to prevent and electric shock hazard. A GFCI does *not* provide overload protection. It is possible to overload a GFCI and it will not trip, as long as the load does not fault to ground.
My suggestion is: turn off the breaker for the branch circuit and remove the GFCI from the junction box. Check all wiring to ensure that nothing is loose, has come disconnected or faulting to ground. See if there is any water inside the junction box, and dry it out if necessary. If the connections are good and tight, and the box is dry, the GFCI itself may have failed. If that case, you would need to replace it, making sure to completely seal the junction box from moisture when you do. I recommend using a raintight cover.
Re: Tripped GFI
Excellent response. Thank you. As a side note, I do have a raintight outlet. No junction boxes are exposed to the elements. The only thing that got wet were the extension cords and lights. I guess some water may have gotten into the outlet, but the cover was on. My lights are all LED and its a small display...no more than 1000w.
Howver, taking into account what you said, I must have had a groundfault somewhere since the line was not overloaded.
Re: Tripped GFI
I would also unplug and allow to dry completely all the junctions between extension cords and lights, and between light strings. GFI can be quite sensitive, as they need to be, and any cross current down the line may be enough.