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jwar 07-07-2007 10:40 PM

GFI Tripping and troubleshooting
One of my kitchen gfi circuits just started tripping. I have power to the GFI outlet, but it won't reset unless I unwire the electrical ground on the load end. I've unplugged everything I can think of that is down stream from the GFI, but it still trips. I also tried a new GFI outlet. Right now I have bypassed the GFI and just wired the incoming and outgoing wires together. The circuit breaker isn't tripping, and all the downstream outlets read as correctly wired according to my socket tester. SO: How do I troubleshoot this? Is there a tool that I can work down the load path to see where the problem is? My next thought is to install a GFI in each outlet to see how far I get before it start tripping. But that sounds like a real pain.

Square Eye 07-08-2007 09:37 PM

When some electricians peel back the sheath on romex wire, they are not very careful. The black or white insulation can end up with nicks that can arc occasionally. The thing about arcing is that it gets worse over time as the insulation burns away or melts. This arcing can blow a GFI circuit quickly. So that's what I generally search for after replacing the old unit. No meter can measure the arc. It's typically never noticed until you hit an on switch somewhere in the circuit.
Other potential problems, a ground wire crammed into a box that's close enough to a hot wire lug to have the same arcing effect.
Trip the breaker and pull one device at a time out of it's box starting at the GFI and carefully inspect everything. After all boxes are opened and the devices pulled out. You can remove them one at a time and ohm meter each wire to ground in each box and black to white. There is a possibility that there could be a bad device in the circuit or a problem with a wire between boxes. If you don't find anything, wire them back one at a time starting at the GFI. Plug something typical in like a toaster and turn it on. If after a minute, the GFI does not trip, turn the breaker off and re-install the next device. Repeat until it trips again.

Let us know if it still trips and you can't find a problem. There were certain manufacturers having a hard time with the GFIs tripping a few years ago. Those GFIs should not be available now though.
What brand is your GFI?

jwar 07-09-2007 12:32 AM

Thanks "I" sq.
I do have some tight boxes. Tried to shove the grounds in firts and deepest, but, I'll try pulling them one by one and see where the problem ends. Arigato

liteaswitch 07-12-2007 10:57 AM

Some GFI triggering maybe caused by INDUCTIVE loads or static discharge
Inductive load false triggering would activate only when the switch was turned on or turned off (which would typically be attached to a device with a Motor/Fan ) If this is the case then check out
If you have a STATIC issue then the device (which is unusual) maybe triggering when your STATIC elevated Body discharges into the connected appliance. to confirm this simply slide/rub across your carpet while apppliance is running and then touch appliance and see if it triggers GFI. Try this 3-4 time if you suspect this type of mechanism. If none of this things seem to profile your situation then
YOU MOST LIKELY HAVE A WIRING PROBLEM and need to closely look at your wiring, and /or connected appliances

maine845 02-08-2008 09:14 AM

If you are comfortable with a screwdriver, and a volt/ohm meter, find out what outlets are on the circuit, turn the breaker off. Pull all of the outlets out of the boxes. Disconnect the black and whites from the GFCI outlet. Using the continuity setting on your electrical test meter, see if there is any "continuity" between the bare ground and any white or black conductor. If you get "continuity" I'd recommend that you remove the outlets black and white wires and do the same scenario. It is possible that the bare wire is touching or coming in contact with the white wire with in the device box. If the bare was coming in contact with a black wire, the circuit would trip. What nobody has advised you about is how a GFCI device works. Think of it as a sink if your faucet fills the sink up with a gallon of water, the drain should see a gallon leaving. This works the same way with electricity. The current has to enter the circuit and leave the circuit equally. If some current "leaks" to ground, there is an imbalance in the circuit and the GFCI device is doing it's job correctly by tripping.

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