I earned my degree in college and spent seven years in the computer business in San Jose, CA. I maintained the Cray 1S computer system at NASA Ames Research Center and was a back up engineer for Lawrence Livermore Labs. I left electrical engineering and became a pilot which is how I make a living today. I’m a resident in the building talked about in the post and I noticed very different settings on the main breaker. My building trips multiple times per day and from my conversations with the property manager resetting the breaker is the current solution - (which is not a great option). I would like to assist in any data collection needed to rectify this issue. It’s gone on now since October.
Eaton 1000 amp breaker nuisance tripping
- Thread starter Scott K
- Start date
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Since you are not an electrician, you won't get any help on anything that involves actually working on this equipment, changing things out, or measurements that involve contact with the wiring itself. But there is still lots that we can help you with.
First thing I'd suggest is that you get a picture of the switchgear and the front of the breaker, and after it trips get another picture before it gets reset. Post the pictures here for feedback. If you can figure out if the system is 120/240V or 208/120V, that would be helpful.
The point that @Jraef made in post #8 is important: large breakers often have 'ground fault' sensing built in. This is the big brother of the sort of sensing used in GFCIs, but is intended for protecting electrical systems from large faults rather than protecting people from shocks. This generally isn't required for a residential building, but _might_ be present anyway. The problem is this: often the ground fault system of the main breaker is often more sensitive than the overcurrent tripping of a branch circuit, so the main trips instead of the branch circuit. IMHO this is the first issue to rule out.
Next check with the power company to see if you can get any 'demand' readings for the service. It might be that for short periods of time your apartment buildings are actually drawing excess power, and the main breaker is tripping exactly as it should.
You may need to get your electrician to install some sort of power monitor; something that measures current, voltage, and ground fault current, and records what is going on. Also get a video camera pointed at the breaker!
-Jonathan
First thing I'd suggest is that you get a picture of the switchgear and the front of the breaker, and after it trips get another picture before it gets reset. Post the pictures here for feedback. If you can figure out if the system is 120/240V or 208/120V, that would be helpful.
The point that @Jraef made in post #8 is important: large breakers often have 'ground fault' sensing built in. This is the big brother of the sort of sensing used in GFCIs, but is intended for protecting electrical systems from large faults rather than protecting people from shocks. This generally isn't required for a residential building, but _might_ be present anyway. The problem is this: often the ground fault system of the main breaker is often more sensitive than the overcurrent tripping of a branch circuit, so the main trips instead of the branch circuit. IMHO this is the first issue to rule out.
Next check with the power company to see if you can get any 'demand' readings for the service. It might be that for short periods of time your apartment buildings are actually drawing excess power, and the main breaker is tripping exactly as it should.
You may need to get your electrician to install some sort of power monitor; something that measures current, voltage, and ground fault current, and records what is going on. Also get a video camera pointed at the breaker!
-Jonathan
Elect117
Senior Member
- Location
- California
- Occupation
- Engineer E.E. P.E.
This.
And you or the building owner should call a licensed electrician to come and put a power monitor on the main for a couple of weeks. But one week at a minimum. All three phases, plus the neutral.
Start rattling off details. What is the bus rating, the voltage, the main breaker size, and trip settings. etc. Is it outside, inside, in the sun, in the shade, etc.
Start keeping track of times and weather. Journal it.
You are trying to narrow down possible causes. And there are quiet a lot of possible causes at this point.
It’s not fixed- since 6-22 the power has tripped 34 times. We were without power last night from midnight to 7:30 am - the breaker was reset and it tripped again around 11:50 -all attempts to reset the breaker failed until 14:30. I just got back from the office and the “ plan “ is to continue to reset this breaker. I’m thinking there should be some sort of troubleshooting / monitoring elimination of possible components to move this towards a solution. At this time I would just like to have reliable power. I did notice the settings on the breaker differ significantly from those buildings not experiencing a loss of power. Possibly this is contributing to the tripping of the breaker?
I wasn't talking about the electrical issue.
Thank you sooooooooo much - what our HOA is doing is just passing the buck spending thousands of $$ with different engineers getting nowhere. We changed the main breaker a couple weeks ago and now the problem is happening more frequently. The “plan” is to continue to reset the breaker!! Someone please help us !!
Thank you!! I”ll pass this on
It is still tripping - 34 times since 6/22. In the past 24 hours out of power from midnight to 7:30 am, then again from 11:50 am to 14:30 pm. We still need some help.
I fixed your profile since you didn't
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Very possibly. Can you please post a picture of the breaker and a close-up of the settings? And perhaps a photo of the breaker in a building not having problems?
As I noted previously, we will not support you in doing actual electrical work; do not change any settings but have a qualified electrician do that. But a photo (or your notes about what the settings are) might help us give you advice about what the electrician should be looking at. It sounds like money has been invested in electricians who didn't solve the problem.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
One thing for your electrician to check, does the main have phase loss protection? Since you have several buildings doing the same thing, it’s possible the utility is losing a leg ( never take the utilities word it’s not on their end) a recorder will verify this.