Nuisance tripping GFI breakers

[Electrical1234567]

Were all the breakers bought at the same time?

Yes. Same supplier. 1 large gear order. It’s all Eaton gear. Breakers, panels, meter stacks. All Eaton gear.

 

[hillbilly1]

main service is 208/120. No step down transformers or anything like that. Pretty straight forward service really. The fact that they trip then moving the breakers down 1 bussed space and don’t trip is what’s really throwing me for a loop.

Maybe the service bond? Usually poco has their end bonded at the transformer too, you would think. The transformer would be the common denominator since it appears widespread.

 

[Electrical1234567]

Maybe the service bond? Usually poco has their end bonded at the transformer too, you would think. The transformer would be the common denominator since it appears widespread.

That’s what we think too either something in the main 4,000 amp service or the transformer. The main bonding jumper was factory installed so you don’t ever really look too much into it. We scheduled a shut down for next week so we can check all our connections again. We mark all our torques so I find it hard to believe something was missed, but human error is human error.

I just wish I could find an explanation for why the breakers trip with no load, then you move them down a bussed space and they hold. I hate when you’re trying to trouble shoot and something just doesn’t make any sense. I’m losing sleep over this thing. And I’m not the type of electrician that’ll just move the breakers down have them hold and wash my hands of it. Obviously something is not right.

 

[tortuga]

Are all the dwelling units wired with 4-wire 208 3 phase or did you run open wye (3-wire) to the units?
Is that transformer utility owned? I suspect your issue is on the utility side.

 

[Electrical1234567]

Are all the dwelling units wired with 4-wire 208 3 phase or did you run open wye (3-wire) to the units?
Is that transformer utility owned? I suspect your issue is on the utility side.

Units are all 3 wire. No 3 phase in the units.

 

[jim dungar]

Have you asked the manufacturer?
I once had a project where the was a manufacturing problem for one shift. Everyone of my problem items came from that single production run. Lucky me.

 

[Electrical1234567]

Have you asked the manufacturer?
I once had a project where the was a manufacturing problem for one shift. Everyone of my problem items came from that single production run. Lucky me.

We have a call with an Eaton rep scheduled for Monday. It’s really just the moving the breaker and them holding that’s the confusion.

 

[hillbilly1]

That’s what we think too either something in the main 4,000 amp service or the transformer. The main bonding jumper was factory installed so you don’t ever really look too much into it. We scheduled a shut down for next week so we can check all our connections again. We mark all our torques so I find it hard to believe something was missed, but human error is human error.

I just wish I could find an explanation for why the breakers trip with no load, then you move them down a bussed space and they hold. I hate when you’re trying to trouble shoot and something just doesn’t make any sense. I’m losing sleep over this thing. And I’m not the type of electrician that’ll just move the breakers down have them hold and wash my hands of it. Obviously something is not right.

It appears moving them to a different phase would indicate that one phase is being odd to the other two. Check voltage from each phase to ground, and each phase to neutral, and neutral to ground. Should be very close to the same other than a little voltage drop, if any. I would not think anything other than bonding on the service at the switchgear would affect the gfi’s.

 

[tortuga]

Yeah really sounds like its a utility issue, call the utility 24/hr number and report it as an 'partial outage / outage' as it could be a urgent safety issue. Ask them to load test the service.
Be sure to go meet the person they send out and put your meter on the main breaker also, around here they use a giant box of what looks to be hair dryers and can put at least 100A load on the system.
Also take a few breakers back to your shop and load test them off a known working panel/system.

 

[jim dungar]

I know of no GFCI that is voltage sensing. I don't think they even have 'neutral loss' sensing like receptacles have. But this seems to be your problem.
Moving the breaker from the top to bottom positions is changing which system leg is on which pole of the breaker.

Have you tried them someplace in the middle?
Are these 1-phase panels, even though the system is 3-phase? If so, it appears the problem exists regardless which two phases feed the panels.

 

[tortuga]

OP says

the tripping seems to get worse the more units we energize. If we energize 1 floor we have almost no tripping but as we energize more units it get worse.

Makes me think POCO is missing a primary phase or a neutral.

 

[Gene B]

What is the trip reason?

 

[hillbilly1]

I know of no GFCI that is voltage sensing. I don't think they even have 'neutral loss' sensing like receptacles have. But this seems to be your problem.
Moving the breaker from the top to bottom positions is changing which system leg is on which pole of the breaker.

Have you tried them someplace in the middle?
Are these 1-phase panels, even though the system is 3-phase? If so, it appears the problem exists regardless which two phases feed the panels.

Yes, but the electronics is powered off the line, a high line to neutral voltage may affect the electronics. It appears with this case, it may be the reason the problem seems to go away when the breaker is moved. Only voltage testing could verify. But it could also be a defective batch of breakers. Hard to troubleshoot over the internet! LOL!

 

[kwired]

Some sort of interference introduced to say A phase that makes then trip but connect between B and C phase and they are fine? Or something similar to that scenario?

These are straight GFCI's and not Dual function? I think some AFCI don't work so well on 208/120, two wire 120 volt circuits is still fine but can't use a two pole for supplying a MWBC on 120/208.

 

[Electrical1234567]

Some sort of interference introduced to say A phase that makes then trip but connect between B and C phase and they are fine? Or something similar to that scenario?

These are straight GFCI's and not Dual function? I think some AFCI don't work so well on 208/120, two wire 120 volt circuits is still fine but can't use a two pole for supplying a MWBC on 120/208.

That’s what’s tripping us up. Is it’s a 208 3 phase system but single phase in the units. So either A-B A-C or B-C. And it’s doing it across all them. But again if we move the breakers down one phase they are fine. Also, they are straigh GFCI no arc. Dryer, Range, PTAC. So PTAC circuit doesn’t have a neutral and we have the same result.

 

[Electrical1234567]

I know of no GFCI that is voltage sensing. I don't think they even have 'neutral loss' sensing like receptacles have. But this seems to be your problem.
Moving the breaker from the top to bottom positions is changing which system leg is on which pole of the breaker.

Have you tried them someplace in the middle?
Are these 1-phase panels, even though the system is 3-phase? If so, it appears the problem exists regardless which two phases feed the panels.

Yes single phase panels with a 3 phase system. And the problem exists regardless which phases feed the panel. I just can’t understand how changing the system leg on the pole of the breaker fixes the nuisance trip.

 

[Electrical1234567]

Yes, but the electronics is powered off the line, a high line to neutral voltage may affect the electronics. It appears with this case, it may be the reason the problem seems to go away when the breaker is moved. Only voltage testing could verify. But it could also be a defective batch of breakers. Hard to troubleshoot over the internet! LOL!

Ya troubleshooting is bad enough when ur looking at the shit let alone from a vague post lol I was more curious if anyone’s ran into changing the leg feeding a pole of a 2 pole gfi fixing a nuisance trip and why if there is an explanation it would be happening. Still landing the same 2 phases just in a different sequence and all of a sudden we are good to go. And how long will it hold before it happens again.

 

[kwired]

That’s what’s tripping us up. Is it’s a 208 3 phase system but single phase in the units. So either A-B A-C or B-C. And it’s doing it across all them. But again if we move the breakers down one phase they are fine. Also, they are straigh GFCI no arc. Dryer, Range, PTAC. So PTAC circuit doesn’t have a neutral and we have the same result.

Doesn't solve your problem but NEC has gone too far with most the GFCI requirements that have been added ever since maybe 2005 or so and for most part the justification is more so "because we can" rather than because of real world statistics to back up the new rules.

 

[kwired]

Yes single phase panels with a 3 phase system. And the problem exists regardless which phases feed the panel. I just can’t understand how changing the system leg on the pole of the breaker fixes the nuisance trip.

Does it temporarily fix it and it eventually has problems again?

 

[Electrical1234567]

Doesn't solve your problem but NEC has gone too far with most the GFCI requirements that have been added ever since maybe 2005 or so and for most part the justification is more so "because we can" rather than because of real world statistics to back up the new rules.

I completely agree. Add more rules every 3 years to make everything worse.