Eaton 1000 amp breaker nuisance tripping

S

Scott K

Member
Location
Boynton Beach, FL USA
Hello Everyone,
Has anyone else experienced this issue? I've been struggling with this issue of Eaton 1000 amp main breakers nuisance tripping. These are Double pole main breakers for apartment buildings on the East Coast of South Florida. This apt. complex has 19 buildings with 11 units each plus a house panel for each. The buildings are about 35 years old and Each building had the service replaced about 3 years ago. So far 3 of the buildings are having issues with the main breakers tripping for what seems to be no reason starting back in October of last year. Started with one building, then a couple months later the second building started and now a third started a couple weeks ago. We replaced 2 of the breakers with refurbished ones since we were told there is a 6 month lead time for new ones due to backorders. The refurbished worked fine for about 6 weeks and then started tripping like the others. We sent the 2 that we removed to Eaton for testing and just got back the results. The Breakers tested normal and no indication of nuisance tripping was discovered. Needless to say, the occupants of the buildings are irate! As the breakers are tripping at least once a day now. Seems mostly in the middle of the night but also happens in the daytime. FPL says it's not they're problem. If anyone can shed some light on this problem I would be so grateful.

Thank you in advance.
 
240 volt single phase? If it was 480, and only happened at night, I would say a fault in the parking lot or security lights, but that usually doesn’t happen that often in 208 or 240 volt lights. Shouldn’t be a ground fault type breaker, but if it is for some reason such as availability, settings, missing external CT, service neutral wires bypassing the external ct, or a backwards ct is just a few of possibilities.
 
I would start by double checking the math for each service from 3 years ago. I would also verify the breakers aren't configured at a lower setting. Like the trip unit is actually 800A installed or 600A.

At night, I am guessing majority of people are home sleeping and running either the AC or heaters + whatever other electronics. I would also verify car charger installations if the units have garages. If they have their own parking garages.

I would also verify wire sizes and torque to the main breaker.

Lastly, I would start tracking the times when the tripping occurs. 6pm vs 4am says a lot in terms of probability of people using power and the equipment having time to cool off at night. It will help narrow down causes.
 
The EV chargers would be a good starting point, as they would increase the load by a greater amount, existing heat and A/C if changed, would have been upgraded to more efficient units, so not as likely.
 
At 1000A and up, main breakers are required to have ground fault protection. If nothing else does, these breakers can be the only thing that trips from GF current, which can happen for a number of reasons.
 
Jraef said:
At 1000A and up, main breakers are required to have ground fault protection. If nothing else does, these breakers can be the only thing that trips from GF current, which can happen for a number of reasons.
Click to expand...
I believe it is if it’s over 250 to ground, if I remember correctly? OP hasn’t came back to verify voltage.
 
Scott K said:
FPL says it's not they're problem. If anyone can shed some light on this problem I would be so grateful.
Click to expand...
Dont take their word for it. Put your own power quality data logger on for at least several days, including a trip. Recording just amps or volts is not sufficient.

Edited to clarify logging.
 
Last edited:
petersonra said:
Why would an apartment building be anything other than 208 3 phase, or 240/120????
Click to expand...

It is possible that a large enough building would take service and distribute at 480V and then step down say on individual floors. But I very much doubt this is the case. The OP says 11 units per building, and a double pole breaker, so my nickel is on 120/240V single phase service.

-Jonathan
 
hillbilly1 said:
Been there, done that! Busted a pharmacist!
Click to expand...
Busted a crane maintenance tech once. We kept coming in to work on commissioning some overhead bridge cranes, only to find the VFD DC bus fuses blown. The incongruous part was that we were not using the drives yet, because we were still troubleshooting the control and safety systems. So we set up a spy cam on each control cabinet that triggered when the door opened. A a graveyard shift maintenance tech was putting a screwdriver across the DC bus terminals. He was apparently pissed because their crew was supposed to do that work, but after 6 months they didn’t have even one of them running (out of 62 bridge cranes and carriers), mostly because they would keep getting interrupted to fix the working cranes. So we were brought in by the GC to take over.
 
You must log in or register to reply here.
Top