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

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The trip control is electronic, so if it is wore out, it would have to be the electromechanical solenoid and any moving parts associated with it...........Years ago, Eaton had a problem with their 2000 amp transferswitches. They used motorized breakers, and after 10 or 20 transfers, they would quit working. Turned out, they used a plastic or nylon limit switches that wore out quickly. They replaced them with metal, luckily they were still under warranty.
 
brantmacga said:
Between 6pm yesterday and noon today, five GFCI’s tripped, and two will not reset.
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The equipment on the breakers that won’t reset has been plugged in elsewhere and is working .
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You might check whether the breakers that won't reset will do so if the load wires are disconnected. Obviously if it still won't reset then the breaker is likely faulty.
Is it possible to transfer the wires of the branch circuit for a GFCI that won't reset to another GFCI breaker in the panel to see if that breaker will hold with this circuit? Or exchange breakers themselves if that works out better. If the tripping breaker now holds then that specific branch circuit might have an issue.

I haven't used it but Fluke has a high sensitivity "Leakage Current" clamp meter that could be used to see what level of leakage (i.e., unbalanced current} is present on the load wires of the GFCIs.

www.fluke.com

Fluke 369 FC Leakage Current Clamp Meter | Fluke

The Fluke 369 FC leakage current clamp meter offers wireless data recording and trending for preventive maintenance, without taking equipment offline.
www.fluke.com www.fluke.com
 
synchro said:
You might check whether the breakers that won't reset will do so if the load wires are disconnected. Obviously if it still won't reset then the breaker is likely faulty.
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That’s the plan, whenever I can get down. The problem is this job is 3 hours away, so that has compounded the difficulty. I asked them to leave the breaker alone for now.

I’m likely going to replace just a few GFCI’s to monitor and see if square D rep is correct in thinking that the problem is now fixed but the breakers are now faulty. I don’t have any hopes for that, but I have to try it.


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brantmacga said:
That’s the plan, whenever I can get down. The problem is this job is 3 hours away, so that has compounded the difficulty. I asked them to leave the breaker alone for now.

I’m likely going to replace just a few GFCI’s to monitor and see if square D rep is correct in thinking that the problem is now fixed but the breakers are now faulty. I don’t have any hopes for that, but I have to try it.


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Click to expand...


If the breakers get faulty with such ease, we as humans have bigger problems. I truly despise the code making process. Why can't they just come out with a table on the maximum length each gauge can be run instead of "solution" which will only create more problems.
 
mbrooke said:
Can you give us the spec, name and general model number of the equipment popping them?
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its everything in the kitchen.... every piece of equipment has tripped. And most of these are things we've been working with for years. Plug-in coolers, freezers, heating cabinets, coffee makers, egg cookers, beverage dispensers, frappe machine, ice cream machine, computers, etc.... Only the fryers and grill elements have not tripped, although the control circuits have. I've lost count of how many of these stores we've built, but I can tell you this is extremely abnormal. There are 2-3 certain pieces of equipment that always give us trouble with GFCI's, but nothing like this before.

Again its about 70 circuit breakers that are tripping. I got a text this morning from store manager that its becoming more frequent now; some are tripping every few minutes whereas it used to be every other day.
 
brantmacga said:
its everything in the kitchen.... every piece of equipment has tripped. And most of these are things we've been working with for years. Plug-in coolers, freezers, heating cabinets, coffee makers, egg cookers, beverage dispensers, frappe machine, ice cream machine, computers, etc.... Only the fryers and grill elements have not tripped, although the control circuits have. I've lost count of how many of these stores we've built, but I can tell you this is extremely abnormal. There are 2-3 certain pieces of equipment that always give us trouble with GFCI's, but nothing like this before.

Again its about 70 circuit breakers that are tripping. I got a text this morning from store manager that its becoming more frequent now; some are tripping every few minutes whereas it used to be every other day.
Click to expand...

What a nighmare!! You are in a No Win. We've all had one, but jeesh.
 
brantmacga said:
its everything in the kitchen.... every piece of equipment has tripped. And most of these are things we've been working with for years. Plug-in coolers, freezers, heating cabinets, coffee makers, egg cookers, beverage dispensers, frappe machine, ice cream machine, computers, etc.... Only the fryers and grill elements have not tripped, although the control circuits have. I've lost count of how many of these stores we've built, but I can tell you this is extremely abnormal. There are 2-3 certain pieces of equipment that always give us trouble with GFCI's, but nothing like this before.

Again its about 70 circuit breakers that are tripping. I got a text this morning from store manager that its becoming more frequent now; some are tripping every few minutes whereas it used to be every other day.
Click to expand...

If this the first store with GFCIs on these circuits?
 
brantmacga said:
Some of the 20/2 breakers that have tripped are 208v circuits. The 50/3 are all 208v circuits, and as I said none of those breakers have ever tripped, but I wanted to mention that the 50/3 breakers have no connection point for a load neutral wire. They are rated at 208v only.
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I'm having a lot of trouble wrapping my head around why the 20/2 208v circuits are also tripping.... where is that current going and why isn't it causing a dead-short? Why is it NOT affecting the 50/3 breakers? The only difference between these CB's and the 20/2 - 30/2's is the lack of a load-neutral connection.
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Is there room in the panel to put in a 3-pole 20A breaker to power a 20/2 208V circuit that's tripping? Just like the 50/3 breaker you mentioned above, the 20A 3-pole breakers don't have a load neutral connection. So as I mentioned earlier these 3-pole breakers would not need a "grounded neutral" detection function. So if you substitute in a 20A 3-pole breaker and it doesn't trip then that would lend credence to the hypothesis that the grounded neutral detection function in the 20/2 breaker is falsing and causing it to trip, and it's not caused by ground fault leakage on the load side.
 
synchro said:
Is there room in the panel to put in a 3-pole 20A breaker to power a 20/2 208V circuit that's tripping? Just like the 50/3 breaker you mentioned above, the 20A 3-pole breakers don't have a load neutral connection. So as I mentioned earlier these 3-pole breakers would not need a "grounded neutral" detection function. So if you substitute in a 20A 3-pole breaker and it doesn't trip then that would lend credence to the hypothesis that the grounded neutral detection function in the 20/2 breaker is falsing and causing it to trip, and it's not caused by ground fault leakage on the load side.
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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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For the sake of solving the mystery. I hope that's the case. I've kinda lost track but have you installed any new GFCIs since that occurrence ? If sdo, are they holding ?
 
augie47 said:
For the sake of solving the mystery. I hope that's the case. I've kinda lost track but have you installed any new GFCIs since that occurrence ? If sdo, are they holding ?
Click to expand...

No, I’m sending a guy down there Monday with a couple of 20/2’s and four 20/1’s. There are some of each in this size that will no longer reset. The equipment is connected elsewhere and working. Store manager will monitor for a week. If these hold and never trip, I will likely move forward with replacing all of the breakers. Square D has offered to send a replacement for all of them.


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