What could it be?

[480sparky]

Went and looked at a problem this morning that I thought I'd get everyone's take on.

Backstory: Couple bought an existing home a year ago and completely remodeled it down to the bones. New everything. After moving back in, they were plagued with breakers tripping. Last fall, they started keeping track of what tripped, and when.





Mostly, it's the GFCI breakers feeding the kitchen. My first thought was it just might be a bad batch of breakers, but apparently the original EC replaced them. My second guess is that, somehow, there's actual ground faults in the laundry, dishwasher, disposal, microwave AND gas stove. The vast majority of tripping issues seem to be the dish/disposal circuit, the microwave circuit, and the two SABCs. All five are on Siemens GFCI breakers. But the HO states that occasionally other circuits would trip.

I didn't have the time today to tear into all this and investigate much, including megging the appliances and circuits nor put an ammeter on each circuit to see what each one draws. But it seems odd that this many GFCI breakers trip so often. So I thought I'd post it here to get a passel of second opinions.

 

[K8MHZ]

My SWAG would be that they have a ground touching a neutral somewhere.

 

[480sparky]

My SWAG would be that they have a ground touching a neutral somewhere.

All five circuits?

 

[growler]

Backstory: Couple bought an existing home a year ago and completely remodeled it down to the bones. New everything.

Is that a complete gut down to the studs and rewire? I'm talking all new wire?

 

[JFletcher]

All five circuits?

If the same green newbie trimmed them all out, the wires on the receptacles could have too much wire stripped, or the ground pushed back haphazardly, causing it to touch the neutral when there is a just a bit of vibrating. Could also be loose terminations in the panel.

There is absolutely no way all of those appliances have true or even phantom ground faults. I would check the panel first, then the receptacles. It's possible there are loose wires in both places.

 

[steve66]

Is that a complete gut down to the studs and rewire? I'm talking all new wire?

I can see how older wire (cloth covered, or wire that has had moisture in it) could cause GFCI's to trip. That probably is the first thing to ask about.

A few other things to look for: Excessive wire lengths or washers or dryers with 3 wire feeds, or shared neutrals. These are from page 10,

http://ecatalog.squared.com/pubs/Ci...rs/QO-QOB Circuit Breakers/0730CT9801R108.pdf

Other things to check: Do they have appliances on dedicated circuits? Are the breaker connections to the buss good, or are those creating excessive heat causing the breakers to trip?

Heck, without seeing it, they could have the panel mounted right by a space heater, so its hard to guess.

If you can't find anything obvious, would it be possible to put GFCI outlets at the microwave and disposal (since those seem to be the worst), and see if a regular breaker also trips?

 

[al hildenbrand]

Interesting set of symptoms, Ken. The contemporaneous documentation over a couple months is compelling. Too many diverse symptoms to be just one thing. . . and they lead me to wonder if the installing electrician was worth his/er salt. Did you ask after who did the remodel wiring? Was it the carpenter?

 

[texie]

I would want to be sure that every circuit has the correct neutral associated with that circuit and only that circuit. Open every thing up and meter it all to be sure.

 

[electricguy61]

1) If it is a gas stove, the igniter for the gas will trip a GFCI for sure. (think about it: the stove sends a spark to the grounded burner plate). We now catch the igniter circuit with something like the refrigerator.

2) Are they GFI breakers, AFCI/GFI breakers or GFCI receptacles? Makes a big difference in troubleshooting

3) Did someone pull a fast one and wire another outlet(s) that your not aware of into these circuit/circuits?

4) New home? Passed inspection? Try removing the AFCI protection (temporarily of course ) See what happens. I’ve had to do this on Panasonic Bath Fans. The AFCI’s just didn’t like them. (I should state these were Homeline AFCI breakers, which are by far the most troublesome for us. I will no longer install Homeline panels for this reason.)

 

[480sparky]

Is that a complete gut down to the studs and rewire? I'm talking all new wire?

Yep.

If the same green newbie trimmed them all out, the wires on the receptacles could have too much wire stripped, or the ground pushed back haphazardly, causing it to touch the neutral when there is a just a bit of vibrating. Could also be loose terminations in the panel.

There is absolutely no way all of those appliances have true or even phantom ground faults. I would check the panel first, then the receptacles. It's possible there are loose wires in both places.

I find it hard to believe that 5 circuits have intermittent N-G shorts. If that's a common error in this installation, then all the AFCI breakers would be randomly tripping as well.

I would want to be sure that every circuit has the correct neutral associated with that circuit and only that circuit. Open every thing up and meter it all to be sure.

If that was the case, the breaker would trip with any load as soon as it was turned on. That's not the case, however.

.........2) Are they GFI breakers, AFCI/GFI breakers or GFCI receptacles? ............

4) New home? Passed inspection? Try removing the AFCI protection (temporarily of course ) See what happens. I’ve had to do this on Panasonic Bath Fans. The AFCI’s just didn’t like them. (I should state these were Homeline AFCI breakers, which are by far the most troublesome for us. I will no longer install Homeline panels for this reason.)

GFCI breakers.

The original EC did temporarily install non-GFCI breakers, and the HO said they didn't trip. But the GFCI breakers were reinstalled on the original ECs demands. Whether there was an inspection or not I haven't determined, but I'm assuming there was. But the inspection may have been done before the appliances were hooked up.


As stated, my first thought is a batch of bad breakers. But I'm not really convinced that's the case and am reluctant to just spend the HO's money and install all new GFCI breakers and not have that solve the issue. I'm wondering if there's some far-fetched cause lurking outside the box. Like an intermittent loose neutral. Or a phantom electrical pulse caused by an old X-10 system still in use here.

 

[growler]

As stated, my first thought is a batch of bad breakers. But I'm not really convinced that's the case and am reluctant to just spend the HO's money and install all new GFCI breakers and not have that solve the issue. I'm wondering if there's some far-fetched cause lurking outside the box. Like an intermittent loose neutral. Or a phantom electrical pulse caused by an old X-10 system still in use here.

I'm not sure anyone should be spending the homeowner's money for anything. If this was a complete rewire then it should fall under the rules for new construction. Here it would be required that the original EC ( company that was paid to do the work and obtain the permit) provide a one year warranty.

This problem has me thinking of a house I worked on about 15 years ago. The house was less than a year old and a high end home. When I went in the attic the wired was all completely chewed by squirrels. I got them to contact an exteriminator. He found about 8 areas where small varmits could enter. Since the home was still under warranty they could at least try to go after the builder for repair cost. I don't know if they ever got any money from the builder but I got paid for the repairs.

Something simple to check out if they have had circuits other than GFCI protected one's that tripped. I have seen cables chewed down to bare copper that would work most of the time.

 

[K8MHZ]

This may be a silly question but, are the breakers all wired correctly?

 

[K8MHZ]

1) If it is a gas stove, the igniter for the gas will trip a GFCI for sure. (think about it: the stove sends a spark to the grounded burner plate). We now catch the igniter circuit with something like the refrigerator.

Not necessarily. The spark is on the output side of a transformer and the current returns back to that side of the transformer, not back to the panel. The 120 volt side's load is line to neutral, not line to ground.

 

[K8MHZ]

All five circuits?

Theoretically, it could be possible that the installer did a crappy job stuffing receptacles in and the bare ground is touching a neutral connector or wire in several places.

Or, the neutrals could be connected together, two in one box and three in another would do it.

I would start with one circuit and check every outlet all the way back to the panel and see what that reveals.

 

[480sparky]

Theoretically, it could be possible that the installer did a crappy job stuffing receptacles in and the bare ground is touching a neutral connector or wire in several places.

Or, the neutrals could be connected together, two in one box and three in another would do it.

I would start with one circuit and check every outlet all the way back to the panel and see what that reveals.

If it's a solid N-G short, the circuit would never work. Same with multiple GFCI-protected circuits having their neutrals tied together. The instant a load is turned on it WILL trip. But these are intermittent trips.

 

[growler]

The vast majority of tripping issues seem to be the dish/disposal circuit, the microwave circuit, and the two SABCs.

I would start with one circuit and check every outlet all the way back to the panel and see what that reveals.

These are normally circuits that would run all the way back to the panel (new rewire) without splices or taps and should be easy to check.

In the last 30 years or so I haven't had that much of a problem with GFCIs tripping but that could have been because we normally go for the less expensvie receptacles and not breakers.

If it were me I would like to talk to the electrician that did the rewire and see if he/she normally wires houses. Get an idea if they did pull homeruns with no splices.

I also wonder if they use metal boxes. some people don't get the romex connectors installed right but a pinched wire normally trips right off.

 

[growler]

If it's a solid N-G short, the circuit would never work. Same with multiple GFCI-protected circuits having their neutrals tied together. The instant a load is turned on it WILL trip. But these are intermittent trips.

That's what makes it interesting. Intermittent problems can be a bear to solve.

 

[kwired]

Yep.



I find it hard to believe that 5 circuits have intermittent N-G shorts. If that's a common error in this installation, then all the AFCI breakers would be randomly tripping as well.




If that was the case, the breaker would trip with any load as soon as it was turned on. That's not the case, however.




GFCI breakers.

The original EC did temporarily install non-GFCI breakers, and the HO said they didn't trip. But the GFCI breakers were reinstalled on the original ECs demands. Whether there was an inspection or not I haven't determined, but I'm assuming there was. But the inspection may have been done before the appliances were hooked up.


As stated, my first thought is a batch of bad breakers. But I'm not really convinced that's the case and am reluctant to just spend the HO's money and install all new GFCI breakers and not have that solve the issue. I'm wondering if there's some far-fetched cause lurking outside the box. Like an intermittent loose neutral. Or a phantom electrical pulse caused by an old X-10 system still in use here.

AFCI not required for some reason?

Or are they dual function devices?

I wouldn't rule out RF interference, seems to pop up here and there and is hard to track down where the source of the problem is.

Might not even be related to the load of circuits involved.

Tried to put an occupancy sensor (wall switch style) a few years ago in my shop, on existing T8 fluorescent luminaire. Every time it turned the light on, it tripped a GFCI receptacle that was completely isolated from the lighting circuit back to the panel. Still have no idea why it did this, I just removed it and put regular switch back in.

 

[480sparky]

AFCI not required for some reason?

No.

Or are they dual function devices?

No

I wouldn't rule out RF interference, seems to pop up here and there and is hard to track down where the source of the problem is.

Might not even be related to the load of circuits involved.

Tried to put an occupancy sensor (wall switch style) a few years ago in my shop, on existing T8 fluorescent luminaire. Every time it turned the light on, it tripped a GFCI receptacle that was completely isolated from the lighting circuit back to the panel. Still have no idea why it did this, I just removed it and put regular switch back in.

I know RF can trip GFCI breakers. It's something weird like that that I suspect is the culprit.

 

[480sparky]

Just a thought:

Install a GFCI breaker. Terminate some NM to it, run it across the basement, then dead-end it in a plastic box. Wire nut the ends. Do not connect a load to it. Megger it to confirm there's no ground faults.

Besides a strong RF signal, what else could cause this to trip?