GFCI Problems

1611 Views 4 Replies 4 Participants Last post by richardcaffrey, Jul 13, 2009

richardcaffrey

Discussion Starter · Jul 13, 2009

I have a GFCI Outlet in my garage that is tied to two outlets within the garage and two outlets external (front porch and back porch) and lastly to a front yard "lamp" Two or three times a year the GFCI "breaks" and then it takes two to three weeks before it will "hold" the load again. This is very frustrating

I think I know how I cause it. I recently thoroughly cleaned my house spraying down the porches, so I figured that the outlets got wet. But that was 11 days ago and the GFCI still trips immediatly after I try to reset it. I do not have anything plugged into any of the outlets in the GFCI circuit and it still wont hold.........I'm wondering if anyone has any "tricks of the trade" that might get me back on track. Should I try to "air" out the outlets on the porches? I replaced the GFCI Circuit a couple of years ago when the electrician told me later that there was nothing wrong with the old one. Does the fact that the "circuit" extends totally around the circumference of my home (full 360) have anything to do with it? Thanks.

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HouseHelper

· #2 · Jul 13, 2009

I would suspect the line leading to the yard lamp has been nicked and is letting moisture in. Disconnect that line from the circuit if you can , then see if the GFCI will hold.

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Yoyizit

· #3 · Jul 13, 2009 (Edited)

HouseHelper said:
I would suspect the line leading to the yard lamp has been nicked and is letting moisture in. Disconnect that line from the circuit if you can , then see if the GFCI will hold.

Yes.

Courtesy of 220/221:
Disconnect the neutral wire from the load side of the GFCI and check for no continuity between it and the ground wire.
Reconnect the neutral.

Or, to test at full voltage,
put a 7-1/2w incand. lamp in series with the ground wire that serves the cable downstream of your GFCI.
If the voltage across the bulb reads from 0.6 vac and up you've found your leakage path to ground. A normal reading would be less than 15 mVac.

If it is moisture I guess you could bypass the GFCI and pass ~10A through the cable for several hours/days until it "bakes out", but that may be just curing the symptom.

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PaliBob

· #4 · Jul 13, 2009 (Edited)

richardcaffrey said:
......... the "circuit" extends totally around the circumference of my home (full 360) have anything to do with it? Thanks.

Yes it does. Leviton customer service says a maximum total run of 90 feet. I have heard that other suppliers say 100 feet.

The reason this distance recommendation (not a code rule) applies is that despite the name GFCI these are dumb devices that only trip on Differential current. When the total differential current gets up to 5mA ±1mA the device will trip. The device can only trip on the differential current> It cannot tell if that is due to a Fault or that the circuit leakage gets up to >5mA.

The longer the Run, the more the leakage, especially when wet.
Recommendations:
1) Breakup that long GFCI run into two or more GFCI circuits

One GFCI for the garage only
One GFCI for the Porch & maybe the light (depending on distance)

Don't daisychain the Porch GFI off the Garage GFCI. That won't do any good

2) Weatherproof the lamp post as much as possible to prevent water intrusion

3) Install wet location covers on the Porch. One for the new GFCI and the second for the downstream receptacle.

Note: make sure you keep GFCI protection on the front yard lamp,. especially if it is on a metal post.
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