# GFCI Receptacle Trippng



## RIVETER (Sep 26, 2009)

czars said:


> I was wondering if you all would share reasons that you have seen GFCI receptacles tripping other than the following: 1) something that was plugged in was defective, 2) an old or defective GFCI was causing the tripping, 3) one of the insulated conductors accidently or momentarily touching the ground wire or the metal receptacle box or 4) a floating ground wire in the cable.
> 
> I presently have two clients with "mystery" tripping GFCI's and I'm out of ideas.


Clue me in ...how did you determine the FLOATING GROUND?


----------



## Dennis Alwon (May 9, 2009)

There are many reasons a GFCI will trip. More info will be helpful. Is there outside wiring connected to this circuit? Is it periodically tripping or all the time ?


----------



## czars (Aug 20, 2008)

*GFCI Tripping*

Floating ground: I finally used my ohmmeter between the suspected floating ground and a known good ground connection.

Location: GFCI receptacle is in a bathroom, near the sink. No apparent moisture problems. I changed the receptacle several weeks ago thinking that it might be old and tired. The receptacle trips at odd times. Sometimes it trips when a hair dryer is used in the vicinity but not on the same circuit. Sometimes it trips during the night when nothing is connected or being used. The HO reported that it has tripped 5 times in the past week with no obvious correlation to anything.


----------



## RIVETER (Sep 26, 2009)

czars said:


> Floating ground: I finally used my ohmmeter between the suspected floating ground and a known good ground connection.
> 
> Location: GFCI receptacle is in a bathroom, near the sink. No apparent moisture problems. I changed the receptacle several weeks ago thinking that it might be old and tired. The receptacle trips at odd times. Sometimes it trips when a hair dryer is used in the vicinity but not on the same circuit. Sometimes it trips during the night when nothing is connected or being used. The HO reported that it has tripped 5 times in the past week with no obvious correlation to anything.


Bear with me. A floating ground, to me, indicates something other than a GOOD ground, Hence, something wrong. If a FLOATING ground is insignificant enough to ignore it in regards to the GFCI tripping,why even bring it up? I am not trying to be smart...others know I'm not, but FLOATING gets thrown out there so much I think it needs to be explained.


----------



## Magnettica (Jan 23, 2007)

Maybe supplied from a 3-wire branch circuit, perhaps a loose neutral connection..


----------



## czars (Aug 20, 2008)

*GFCI Receptacle Tripping*

A MWBC might be involved. I need to check that out. However, I don't see how a loose neutral connection could cause a GFCI receptacle to trip with no loads on the receptacle or downstream of the receptacle.


----------



## MDShunk (Jan 7, 2007)

Does this person, or a neighbor operate a ham radio or is there a very closeby FM repeater? I can trip a GFCI with my two-way radio. It's pretty dramatic when you stand next to a panel full of GFCI breakers and key up the radio. They'll all start to trip off like a bunch of firecrackers during Chinese New Year. 

You say there's nothing on the load side, eh? Hmmm.... I'd probably set up a power quality recorder and see if the neutral might be dropping out from time to time.


----------



## 480sparky (Sep 20, 2007)

czars said:


> .....I presently have two clients with "mystery" tripping GFCI's and I'm out of ideas.


Take what they say with a grain of salt. Many HOs don't understand line-load protection and 'downstream' outlets.

"There's nothing plugged into it"............. that we know of.

"There are no outlets 'downstream' of it"..........that we can find.

"It's never tripped before". And my roof was just fine until it started leaking, too.


----------



## czars (Aug 20, 2008)

*GFCI Receptacle Tripping*

Thanks for the info. I'll let you know what I discover.


----------



## frank (Feb 6, 2007)

My next door neighbour had a trip problem. I asked all the usual questions. What were you using at the time. Iron, she said. Check the iron but this is fine, Oh but the washing machine was on too, Check the washing machine, Tests fine. Well I don't know she said. I did not have anything else in the hoiuse switched on - except the fridge. the freezer, the conditioning, the Tv. The satelite receiver. The computor and the WiFI unit. Etc etc. I finally narrowed it down to the central heating boiler pump.Job done and of course for free. HO are hard work.

Frank


----------



## Magnettica (Jan 23, 2007)

czars said:


> A MWBC might be involved. I need to check that out. However, I don't see how a loose neutral connection could cause a GFCI receptacle to trip with no loads on the receptacle or downstream of the receptacle.


I musta missed the part where u said no load.


----------



## Mike_586 (Mar 24, 2009)

MDShunk said:


> Does this person, or a neighbor operate a ham radio or is there a very closeby FM repeater? I can trip a GFCI with my two-way radio. It's pretty dramatic when you stand next to a panel full of GFCI breakers and key up the radio. They'll all start to trip off like a bunch of firecrackers during Chinese New Year.
> 
> You say there's nothing on the load side, eh? Hmmm.... I'd probably set up a power quality recorder and see if the neutral might be dropping out from time to time.


I've gotta try that....

If were talking about a receptacle wired up only on the line side, a MWBC isn't even a consideration in this, losing ground should have no effect at all either. Its more likely there's a loose joint or connection somewhere upstream of the receptacle that momentarily loses power or neutral. A lot of GFCI receptacles will trip on loss of power or neutral, I've never seen a GFCI receptacle that wouldn't function just fine weather there was a ground or not.

EDIT:



czars said:


> A MWBC might be involved. I need to check that out. However, I don't see how a loose neutral connection could cause a GFCI receptacle to trip with no loads on the receptacle or downstream of the receptacle.


I just noticed your wording here. I was thinking this was a single GFCI wired to the line side of the receptacle not feeding anything downstream but you never actually specified weather there was nothing plugged in downstream but it was wired on the load side, or if it everything downstream was wired line side or if this was the last receptacle in the run. The only thing this will change is that you might have to look for a neutral to ground fault downstream of the receptacle on the protected side if everything downstream is wired of the load side of the receptacle. Being an intermittent problem, hooking it up to the line side for a week and seeing if it holds will tell you weather the problem is on the line side or the load side.

BTW: If its been working fine for a long time and only recently developed problems, I highly doubt a MWBC is the cause here.


----------

