I have encountered a problem with some GFCI's in a customers home. I have seperated line and load and installed three new GFI receptacles, I've even pigtailed all the hots together to the line side and all the neutrials to the line neutral side and the GFI will still not trip out when testing hot to ground. The test and reset buttons work but the device does not trip out hot to ground. The kicker is that that is not the only GFI receptacle in the home doing this. I thought that maybe some how the neutrals of two different circuits were some how tied together. When testing for voltage I have a good hot, neutral, and ground. I hope someone may have some advice pertaining to this. I've been an electrician for a long time and have never seen anything like this, but maybe I am not seeing something and need a fresh set of eyes!!
GFI Receptacles
- Thread starter lachance
- Start date
- Status
bphgravity
Senior Member
- Location
- Florida
Re: GFI Receptacles
What do you mean by "testing hot to ground"? If the gfci unit trips and resets using the buttons on the device itself, then it is working properly. Are you using a plug-in tester with a test button? No other method that I know is a correct method for testing gfci's.
What do you mean by "testing hot to ground"? If the gfci unit trips and resets using the buttons on the device itself, then it is working properly. Are you using a plug-in tester with a test button? No other method that I know is a correct method for testing gfci's.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: GFI Receptacles
Only the button on the GFCI will properly test it. If it won't test with a plug in test then you do not have a connection to the equipment grounding conductor somewhere. The button inserts a resistor between the neutral and hot creating a 5 mA unbalance.
Only the button on the GFCI will properly test it. If it won't test with a plug in test then you do not have a connection to the equipment grounding conductor somewhere. The button inserts a resistor between the neutral and hot creating a 5 mA unbalance.
charlie
Senior Member
- Location
- Indianapolis
Re: GFI Receptacles
Your grounding conductor is not continuous from the panelboard to the GFCIs. Without a return grounding conductor, the GFCI can not be tested with an external GFCI tester.
Your grounding conductor is not continuous from the panelboard to the GFCIs. Without a return grounding conductor, the GFCI can not be tested with an external GFCI tester.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: GFI Receptacles
I agree with "The Other Charlie." The GFI looks at current flowing through the hot and current flowing through the neutral. If they are not the same, it trips. If you have a device that puts a resistor between hot and ground, that should establish a complete path for current to flow. The path would be from hot, through the test resistor, to the ground pin of the GFI receptacle, then via the EGC to the ground bus of the panelboard, then via the bonding jumper to the neutral bus, and thus back to its source. Thus, the hot has current that the neutral does not see. If that is the intended test method (and I?ll not comment on that method, without getting more information), then the GFI should trip. Therefore, I would suspect a problem with continuity of the EGC.
I agree with "The Other Charlie." The GFI looks at current flowing through the hot and current flowing through the neutral. If they are not the same, it trips. If you have a device that puts a resistor between hot and ground, that should establish a complete path for current to flow. The path would be from hot, through the test resistor, to the ground pin of the GFI receptacle, then via the EGC to the ground bus of the panelboard, then via the bonding jumper to the neutral bus, and thus back to its source. Thus, the hot has current that the neutral does not see. If that is the intended test method (and I?ll not comment on that method, without getting more information), then the GFI should trip. Therefore, I would suspect a problem with continuity of the EGC.
physis
Senior Member
Re: GFI Receptacles
I don't know weather my personal experience with Green Lee recently has anything to do your situation but I stopped buying their products because of low quality and failures.
I'm not trying to knock Green Lee, it's only my experience.
I just through away a receptacle tester that did not work. These things are too simple to not work. I'm thinking it may be possible that your tool is the problem.
Edit: that tester didn't work out of the package.
[ December 18, 2004, 04:05 PM: Message edited by: physis ]
I don't know weather my personal experience with Green Lee recently has anything to do your situation but I stopped buying their products because of low quality and failures.
I'm not trying to knock Green Lee, it's only my experience.
I just through away a receptacle tester that did not work. These things are too simple to not work. I'm thinking it may be possible that your tool is the problem.
Edit: that tester didn't work out of the package.
[ December 18, 2004, 04:05 PM: Message edited by: physis ]
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: GFI Receptacles
See my reply in the third post.
See my reply in the third post.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: GFI Receptacles
Tom I have to add (to your third post)
I know that most here would have known this but there are a few here that I thought maybe wouldn't.
Tom I have to add (to your third post)
The bold is added to allow the understanding that since the line neutral is on the line side of the current coil there will be no current in the load neutral, this creats the unbalance on the load side of the GFCI.
I know that most here would have known this but there are a few here that I thought maybe wouldn't.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: GFI Receptacles
You're right--I didn't get that until you restated and bolded it. Thanks, Wayne!
So, the proper way to test a GFI would be to plug test and in-device-button test the actual GFI, and then ensure all the loads trip the GFI with a plug tester, checking polarity along the way, right?
(I never really tested with the button on the GFI. Never was taught how it worked! )
You're right--I didn't get that until you restated and bolded it. Thanks, Wayne!
So, the proper way to test a GFI would be to plug test and in-device-button test the actual GFI, and then ensure all the loads trip the GFI with a plug tester, checking polarity along the way, right?
(I never really tested with the button on the GFI. Never was taught how it worked!
)
- Location
- Illinois
- Occupation
- retired electrician
Re: GFI Receptacles
Don
It only works if you have an EGC and its load is more than the 4 to 6 mA required to trip a GFCI so you really don't have a true test. The built-in tester and plug in testers provide a test current of about 8mA at 120 volts. While this value is sligtly higher than the maximum 6mA trip, it was selected to provide a proper test with nominal voltages that are less than 120.
Don
friebel
Senior Member
- Location
- Pennsville, N.J.
Re: GFI Receptacles
Follow-up message concerning GFCI's
There was a message put out on Mike' Holts Code Forum, and it stated that nation wide, the failure rate was about 20 percent for GFCI's.
Stop and think about that, for every 100 GFCI receptacles that we install, 20 of them fail.
That is why in the manufacturers instructions they recommend that we should test the circuit breaker or the receptacle test button.
At my home, I have a plug in GFCI tester that I plug into the receptacle, and then I can adjust the amount of fault current the receptacle will see. The receptacle has always tripped out at between 4 to 6 mA. I have never had a breaker or receptacles fail. But with the statistics that have been put out, we cannot take a chance. We need to check our receptacles and/or breakers on a regular schedule.
When I worked for the DuPont Co. we would always document the testing of the GFCI breakers and/or receptacles.
Follow-up message concerning GFCI's
There was a message put out on Mike' Holts Code Forum, and it stated that nation wide, the failure rate was about 20 percent for GFCI's.
Stop and think about that, for every 100 GFCI receptacles that we install, 20 of them fail.
That is why in the manufacturers instructions they recommend that we should test the circuit breaker or the receptacle test button.
At my home, I have a plug in GFCI tester that I plug into the receptacle, and then I can adjust the amount of fault current the receptacle will see. The receptacle has always tripped out at between 4 to 6 mA. I have never had a breaker or receptacles fail. But with the statistics that have been put out, we cannot take a chance. We need to check our receptacles and/or breakers on a regular schedule.
When I worked for the DuPont Co. we would always document the testing of the GFCI breakers and/or receptacles.
charlie
Senior Member
- Location
- Indianapolis
Re: GFI Receptacles
Friebel, you are going to too much effort to test your receptacles. The test button will do just fine but test them you should. I imagine that most of the GFCIs will fail over time and they all should be checked. In my opinion, all electromechanical devices will eventually fail. It is all a matter of how much time and how many operations until failure.
Friebel, you are going to too much effort to test your receptacles. The test button will do just fine but test them you should. I imagine that most of the GFCIs will fail over time and they all should be checked. In my opinion, all electromechanical devices will eventually fail. It is all a matter of how much time and how many operations until failure.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: GFI Receptacles
At least all new GFCI receptacles now when they fail they fail safe and will not provide any power through them. So now when they fail we get a call.
But at least there more safe. as most home owners would just keep using the older types.
[ December 28, 2004, 12:37 AM: Message edited by: hurk27 ]
At least all new GFCI receptacles now when they fail they fail safe and will not provide any power through them. So now when they fail we get a call.
But at least there more safe. as most home owners would just keep using the older types.
[ December 28, 2004, 12:37 AM: Message edited by: hurk27 ]
charlie
Senior Member
- Location
- Indianapolis
Re: GFI Receptacles
I have been told that most of the problems occur in areas like Florida (the lightning capital of the universe) and outside of buildings where GFCI receptacles have been installed in weatherproof boxes.
I have been told that most of the problems occur in areas like Florida (the lightning capital of the universe) and outside of buildings where GFCI receptacles have been installed in weatherproof boxes.
- Location
- Illinois
- Occupation
- retired electrician
Re: GFI Receptacles
Wayne,
Don
Wayne,
As I understand this, these new "lockout" GFCIs only lock out in the event that they fail a test initiated by pushing the build in test button. The don't "self-test" and if no one ever pushes the test button, they won't "lock-out".
Don
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