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tripping gfci receptacle #68019
07/27/06 02:32 PM
07/27/06 02:32 PM
M
mahlere  Offline OP
Member
Joined: Nov 2005
Posts: 507
New Jersey
this one is new to me. i have a situation where there is a GFCI receptacle protecting an underground feed to a flood light. Light is a simple 500W quartz.

Installation was done about 1.5 yrs ago, no problems. Now in the past month, the following as begun to occur.

when the light gets turned on, it will work for about 30-45 mins then trip the gfi.

the line from the gfi to the light is fine. i'm guessing a bad fixture. But why will it work for 30-45 mins?

anyone seen this before?

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Re: tripping gfci receptacle #68020
07/27/06 02:59 PM
07/27/06 02:59 PM
L
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
Winchester, NH, US
Possible ground fault as the fixture heats up and something expands. If the fixture is deenergized for 20 minutes, does it run for another 30 minutes or so, and then trip again?

LarryC

Re: tripping gfci receptacle #68021
07/27/06 03:03 PM
07/27/06 03:03 PM
E
earlydean  Offline
Member
Joined: Dec 2003
Posts: 751
Griswold, CT, USA
I have run into this before.

Aboveground NM, the box behind the luminaire had a little water in the splices. Dried it out, sealed the back of the fixture to the building, problem solved.
In another case, the UG feed had a little slice on one conductor in the UG part. Only tripped when the tide came in.

If your run is totally dry, try to isolate the problem by bypassing the UG feed with a temporary aboveground feed.

What type insulation is on the wire you used to feed the UG to the luminaire? THHN or THWN? or did you use UF?

Do you have a hi-pot? Some part of the circuit has a "slow leak".


Earl

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