Service w/ approx 70 GFCI's tripping; need help thinking through.

[synchro]

I made the utility pedestal taps myself. After we were energized, which was maybe 7-10 days later, the job foreman told me the lineman came to tell him the connections were wrong.

Duke left me four 750’s in a pedestal, one unmarked black, and the other three had a colored zip tie in red, blue, white.

Now I’m having flashbacks to the time another utility energized my neutral on a job once because they use white, red & blue as phase conductors.

So now I’m willing to bet they energized my neutral bus on this job. If so, then it’s highly likely all of these breakers are damaged.

If I understand this correctly, initially the white conductor (which is actually a phase conductor in this case) was connected to the panels' neutral busses and then the panels were energized. This would apply 208V from the line bus to the neutral bus on breakers fed by the utility's red and blue conductors, which could lead to damage. But there still would've been a proper 120V line-to-neutral bus voltage on breakers that were fed with the utility's white conductor, because the white and black were effectively exchanged from the "viewpoint" of those breakers. So there might be hope that 1-pole breakers that were connected to the white and black conductors both before and after the exchange might still be OK. Not that this is much consolation even if true.

 

[hillbilly1]

If the 50/3’s aren’t tripping, I’m almost certain the 20/3’s won’t trip either.

If I had a constant grounded neutral downstream, the breaker wouldn’t hold. It’s for that reason I haven’t pulled every grounded conductor and checked continuity back to the neutral bar.

But......

I just had what may be a giant light bulb moment.


I made the utility pedestal taps myself. After we were energized, which was maybe 7-10 days later, the job foreman told me the lineman came to tell him the connections were wrong.

Duke left me four 750’s in a pedestal, one unmarked black, and the other three had a colored zip tie in red, blue, white.

Now I’m having flashbacks to the time another utility energized my neutral on a job once because they use white, red & blue as phase conductors.

So now I’m willing to bet they energized my neutral bus on this job. If so, then it’s highly likely all of these breakers are damaged.

#%$@


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A possibility, I stopped a utility from screwing up a service I had done many years ago, I had four parallel conduits, four 750 mcm each. Marked yellow, brown, purple and grey in each pipe, the lineman started to take all of the wires in one pipe and terminate to phase A on the transformer! Don't know what he was thinking!

 

[texie]

If I understand this correctly, initially the white conductor (which is actually a phase conductor in this case) was connected to the panels' neutral busses and then the panels were energized. This would apply 208V from the line bus to the neutral bus on breakers fed by the utility's red and blue conductors, which could lead to damage. But there still would've been a proper 120V line-to-neutral bus voltage on breakers that were fed with the utility's white conductor, because the white and black were effectively exchanged from the "viewpoint" of those breakers. So there might be hope that 1-pole breakers that were connected to the white and black conductors both before and after the exchange might still be OK. Not that this is much consolation even if true.

Depending on the GES and intersystem bonding it would seem to me that this would have appeared as a dead short and other damage would have been seen. It would also assume that the main was on and all the branch breakers were off or the equipment connected to the branch circuits would have shown damage.

 

[brantmacga]

If they energized the neutral bus, it was before the main was ever turned on. We do our own voltage checks before any breakers are turned on.

Also, no equipment was installed when the service was energized. .


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[texie]

If they energized the neutral bus, it was before the main was ever turned on. We do our own voltage checks before any breakers are turned on.

Also, no equipment was installed when the service was energized. .


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You may be onto something then. Wish you the best as I know this must be a painful problem.

 

[swwright]

Have you resolved this? Curious if it was just defective breakers or not.

 

[brantmacga]

Have you resolved this? Curious if it was just defective breakers or not.

Last Monday, 4/13/20, I sent someone to replace (4)x QOB120GFCI’s and (1)x QOB230GFCI.

The 30/2 and two is the 20/1’s that were replaced no longer would reset.

As of Thursday, none of the breakers that had been replaced have tripped.

I’m giving it another week at least to see if they hold before moving forward with replacing all of them.

It’s a large account for Square D (and for us) and they’ve offered to provide replacements at no cost. I don’t think the breakers were defective to begin with. I think it was something on the utility side that caused the issue.


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[Jefflayton71]

Had a similar problem years ago, it turned out to be water getting into the receptacles during cleaning at night. They were hosing everything down while cleaning the floor. Most would dry out before morning shift and reset, we finally pulled out devices and found water inside the metal boxes. We had to install in use covers on receptacles below 48".

 

[brantmacga]

Update: as of 4/13, no breakers have tripped since we replaced the GFCI’s that stopped resetting mentioned above.


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[hbiss]

It’s a large account for Square D (and for us) and they’ve offered to provide replacements at no cost.

Square D account manager: "hey Frank, send them those GFCI breakers we made special that are really regular breakers".

Update: as of 4/13, no breakers have tripped since we replaced the GFCI’s that stopped resetting mentioned above.

-Hal

 

[Another C10]

There are approximately 60+ 20/1 GFCI circuit breakers, 10+ 20/2 & 30/2 GFCI circuit breakers, and 14x 50/3 GFCI circuit breakers. This store has been open for maybe 8-10/wks. I've been told that "almost" every GFCI circuit breaker within the AP panels except for the 50/3 breakers has tripped. There is no pattern; some days they might have no breaker trip, some days 4-5, and days like today where 12 breakers tripped.

My tactic would be follow the pattern, identify the breakers involved, document the time frames of occurrence, isolate the equipment involved until the problem can be narrowed down or possibly even eliminated. then proceed to correct" I'm the type that likes narrow the problem down to the point when the last connection is made and bang the problem occurs. The difficult part is keeping the business active while dismantling their electrical systems. Sounds like a great challenge. Unfortunately the client may not like the cost. I would contact the manufacturer though to make sure they don't have a bad batch of product reported by others.