why would a gfi trip? i just replaced service in a home & replaced some of wiring. everything was working fine for the last 3 months until we had a storm a week ago. gfi plug i placed under panel trips. it had line & load wired correctly. replaced it with another gfi & it tripped. replaced that gfi with a 20A plug and it didn't trip breaker. 3 prong tester showed it to be wired correctly. garage door opener acted weird after i was able to keep power on with 20A plug. it took overhead door up ok but only brought door half way down before garage door opener stopped. lights on opener went out and led on opener door button went out. i unplugged door opener & fiddled with other wires on opener for a little bit. after around 5 minutes, lights on opener came on, door operated properly. i don't think i did anything to fix opener.
gfi tripping
- Thread starter ronson
- Start date
- Status
bphgravity
Senior Member
- Location
- Florida
Re: gfi tripping
I am supposing you have had a neutral to ground connection develop maybe due to vibration from the garage door or relaxing conductors. That or the garage door motor itself is the problem.
I am supposing you have had a neutral to ground connection develop maybe due to vibration from the garage door or relaxing conductors. That or the garage door motor itself is the problem.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: gfi tripping
is best to avoid motors on gfci but they should work.
is best to avoid motors on gfci but they should work.
al hildenbrand
Senior Member
- Location
- Minnesota
- Occupation
- Electrical Contractor, Electrical Consultant, Electrical Engineer
Re: gfi tripping
Ronson,
Is the opener plugged into the receptacle under the panel, or is there a branch circuit extension off the Load side of the receptacle?
If there is a branch circuit extension, disconnect it from the GFI, and see if the GFI holds. Break apart the GFI protected part of the branch circuit and then reconnect it to the load side of the GFI starting at the GFI load terminals.
Since you mention a storm. . .there is always the chance that the circuit board in the opener is damaged in a manner that is creating the 5 milliamp ground fault.
Ronson,
Is the opener plugged into the receptacle under the panel, or is there a branch circuit extension off the Load side of the receptacle?
If there is a branch circuit extension, disconnect it from the GFI, and see if the GFI holds. Break apart the GFI protected part of the branch circuit and then reconnect it to the load side of the GFI starting at the GFI load terminals.
Since you mention a storm. . .there is always the chance that the circuit board in the opener is damaged in a manner that is creating the 5 milliamp ground fault.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: gfi tripping
start by un plugging GDO.Sorta like a flow chart.If it still trips problem is further downstream on gfci circuit.If it trips only with GDO plugged in then replace GDO or get it off the gfci as it is not required to be on gfci.
start by un plugging GDO.Sorta like a flow chart.If it still trips problem is further downstream on gfci circuit.If it trips only with GDO plugged in then replace GDO or get it off the gfci as it is not required to be on gfci.
Re: gfi tripping
jim, you know what, i do recall going around the first time i tried to solve this by unplugging everything on the circuit but that didn't help. the gfi would still trip. i will try that again just in case i missed unplugging something. then i guess the next best thing to do would be to disconnect one receptacle at a time from 12/2 romex coming from gfi. perhaps ground wire is touching a neutral somewhere? or a screw has come loose?
jim, you know what, i do recall going around the first time i tried to solve this by unplugging everything on the circuit but that didn't help. the gfi would still trip. i will try that again just in case i missed unplugging something. then i guess the next best thing to do would be to disconnect one receptacle at a time from 12/2 romex coming from gfi. perhaps ground wire is touching a neutral somewhere? or a screw has come loose?
jeff43222
Senior Member
- Location
- Minneapolis, Minnesota
Re: gfi tripping
I agree that it's likely a neutral-ground short. Is the opener on a dedicated circuit, or are there other outlets? Does anything else on the circuit act weird?
As for having the opener on a GFCI-protected circuit, I haven't found any problems with doing this. I put the opener in my own garage on a 20A circuit protected with a Siemens GFCI breaker, and I haven't had any problems.
-Jeff
I agree that it's likely a neutral-ground short. Is the opener on a dedicated circuit, or are there other outlets? Does anything else on the circuit act weird?
As for having the opener on a GFCI-protected circuit, I haven't found any problems with doing this. I put the opener in my own garage on a 20A circuit protected with a Siemens GFCI breaker, and I haven't had any problems.
-Jeff
Re: gfi tripping
the opener is on a ckt alongwith a wall clock, tv, table lamp, cordless phone base and garage ceiling lights. everything was fine until we had a storm a couple of weeks ago when the homeowner called me and said the garage lights would not work. that is the first time when i found that another gfi (to the tv and garage closet lights) on the same ckt had tripped. (I was going to split up the ckt further) nothing else on the ckt acts strange. replaced gfi under panel with 20A receptacle for now. when you say neutral/ground short, do you mean that the neutral & ground wires could be touching somewhere along ckt?
the opener is on a ckt alongwith a wall clock, tv, table lamp, cordless phone base and garage ceiling lights. everything was fine until we had a storm a couple of weeks ago when the homeowner called me and said the garage lights would not work. that is the first time when i found that another gfi (to the tv and garage closet lights) on the same ckt had tripped. (I was going to split up the ckt further) nothing else on the ckt acts strange. replaced gfi under panel with 20A receptacle for now. when you say neutral/ground short, do you mean that the neutral & ground wires could be touching somewhere along ckt?
jeff43222
Senior Member
- Location
- Minneapolis, Minnesota
Re: gfi tripping
Yes. GFCIs are sensitive enough that a short between those two wires can trip it. I've tested receptacles by shorting the neutral and ground, and it always trips the GFCI, whether it is a receptacle GFCI or the breaker style.
Re: gfi tripping
The reason a GFCI will trip when the "EGC" contacts the "Grounded Conductor" is you have provided a parallel path for the current to flow in. The reduced current in the "Grounded Conductor" is not balanced with the "Ungrounded Conductor" and is seen by the GFCI, in otherwords what it's supposed to do.
Roger
The reason a GFCI will trip when the "EGC" contacts the "Grounded Conductor" is you have provided a parallel path for the current to flow in. The reduced current in the "Grounded Conductor" is not balanced with the "Ungrounded Conductor" and is seen by the GFCI, in otherwords what it's supposed to do.
Roger
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: gfi tripping
how about this theory.The lightning damaged a duplex receptacle while seeking a ground.Maybe a carbon tract from neutral to ground.Might be hard to see,but remove load as needed till you find it
how about this theory.The lightning damaged a duplex receptacle while seeking a ground.Maybe a carbon tract from neutral to ground.Might be hard to see,but remove load as needed till you find it
Re: gfi tripping
i didn't get to go over there today but maybe tomorrow. like i said, i unplugged all the devices i knew from the ckt. the gfi still tripped. when i get back over there, the first thing i will do, is unplug the load wires off the back of the gfi. if that doesn't trip it out, then i will reland the load wires & proceed to the next receptacle, which will be the one in the ceiling to the garage door opener. i pulled the recpt out of the box the last time i was there. i tried to be careful & place the recpt back into the box so the neutral & grd wires wouldn't touch. maybe this next time, before i disconnect the other branch romexes from this box i will leave the recpt out of the box so i can visually make certain that the neutral & grd wires don't touch while i flip breaker back on. if that doesn't trip gfi, then i will disconnect the branch romexes from that box, perhaps one at a time. now that i think about it, i might ought to go around & check every recpt with my 3 prong tester first & see if it shows anything wrong. that might save me having to undo everything.
[ June 16, 2004, 10:46 PM: Message edited by: ronson ]
i didn't get to go over there today but maybe tomorrow. like i said, i unplugged all the devices i knew from the ckt. the gfi still tripped. when i get back over there, the first thing i will do, is unplug the load wires off the back of the gfi. if that doesn't trip it out, then i will reland the load wires & proceed to the next receptacle, which will be the one in the ceiling to the garage door opener. i pulled the recpt out of the box the last time i was there. i tried to be careful & place the recpt back into the box so the neutral & grd wires wouldn't touch. maybe this next time, before i disconnect the other branch romexes from this box i will leave the recpt out of the box so i can visually make certain that the neutral & grd wires don't touch while i flip breaker back on. if that doesn't trip gfi, then i will disconnect the branch romexes from that box, perhaps one at a time. now that i think about it, i might ought to go around & check every recpt with my 3 prong tester first & see if it shows anything wrong. that might save me having to undo everything.
[ June 16, 2004, 10:46 PM: Message edited by: ronson ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: gfi tripping
Is there any outside underground feeds that might be on this circuit? Post light, shed, pool pump, Etc... also if you have a continuty tester test the load wires, between the neutral and ground and hot to ground. there should not be any load on these. Also check if there is any plug in surge suppressor's plug in as these have a MOV between the hot and ground and neutral and ground and if they are bad it will trip the GFCI plug.
Is there any outside underground feeds that might be on this circuit? Post light, shed, pool pump, Etc... also if you have a continuty tester test the load wires, between the neutral and ground and hot to ground. there should not be any load on these. Also check if there is any plug in surge suppressor's plug in as these have a MOV between the hot and ground and neutral and ground and if they are bad it will trip the GFCI plug.
Re: gfi tripping
well, i finally got back to this job & finally got time to get on this computer. the HO is a maintenance electrician at a local chemical plant. he decided to go to Walmart & put up some florescent lights in garage. he cut into the ckt for garage & installed himself a switch to these florescents. i followed the ckt from the gfi below the panel to the plug for garage door opener, then to lighting & plug in garage closet, then to switch HO cut in. on second light, neutral from light popped out of wire nut when i checked to see if it was tight! voila! that could explain 5 mA difference that gfi detected.
well, i finally got back to this job & finally got time to get on this computer. the HO is a maintenance electrician at a local chemical plant. he decided to go to Walmart & put up some florescent lights in garage. he cut into the ckt for garage & installed himself a switch to these florescents. i followed the ckt from the gfi below the panel to the plug for garage door opener, then to lighting & plug in garage closet, then to switch HO cut in. on second light, neutral from light popped out of wire nut when i checked to see if it was tight! voila! that could explain 5 mA difference that gfi detected.
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