mike93lx
ALLIANCE MEMBER
If it fits, it ships
Main breaker tripped but one circuit stayed on
- Thread starter teknikfrog
- Start date
sparky 1971
Well-known member
As long as it works. Put a little effort in next time.
mike93lx
ALLIANCE MEMBER
Got it, boss
.One more reason for hose clamps!
Jim greengo
Well-known member
Battery backup?
The meter/load combo that was installed on my shop in 2001 had a meter socket, a 200a main with maybe 6 breaker slots and feed through lugs going to the house. It also had another two pole spot above the 200a main that was fed separately from the meter and not protected by the the 200a main. This breaker was used to power my well pump and remained on when the 200a main was off.
Maybe the OP has a similar combo panel with two main feeds from the meter, one 200a and another smaller. I don't know if that is a currently used panel though, lots of NEC changes since 2001. A picture would be helpful.
This pic is upside down but you can see the two separate feeds from the meter. I replaced the panel 5 years ago with a 380A in order to have additional bus capacity for the solar inverters. I don't know why I still have it laying around. Can't get rid of anything I guess.
Maybe the OP has a similar combo panel with two main feeds from the meter, one 200a and another smaller. I don't know if that is a currently used panel though, lots of NEC changes since 2001. A picture would be helpful.
This pic is upside down but you can see the two separate feeds from the meter. I replaced the panel 5 years ago with a 380A in order to have additional bus capacity for the solar inverters. I don't know why I still have it laying around. Can't get rid of anything I guess.
Last edited:
dcg9381
Well-known member
This is like electrical mystery theater with no actors. Where are the darn photos? 
justsam
Well-known member
Are you certain it was a live camera image you saw after the brown out? I am not familiar with Ubiquiti cameras but with my camera system, if there is a connection loss, or power loss, it will retain the last captured image. Do you store images on any local device, cloud storage or on your phone?
Innovate1
Well-known member
The OP said it would be a couple days before they could get pics...
dcg9381
Well-known member
Ubiquiti will notify you when the camera goes offline. There is also a live feed function that it will default to.
OP
teknikfrog
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Yeah it's been freezing cold and we have ten inches of snow on the ground and my garage is a hike uphill from my house. Forgive me.
Here is a pic:
I've only been inside a handful of panels in my lifetime but everything here looks completely normal to me. Side note I love all the extra space in here.
BTW this garage is new construction, around five years old.
I did test turning off the main breaker and my cameras shut off.
So it looks to me like what happened is when the main breaker tripped it failed to trip fully and I'm guessing one leg stayed on which would explain why most items were out but the cameras remained on. They actually did drop out for 12 seconds or so (it keeps logs) but came back on and remained on for half a day or so until I noticed the main breaker trip and re-set it.
Question; how big of a deal is this? Do I need to explore the issue further or just let it go?
Yeah it's been freezing cold and we have ten inches of snow on the ground and my garage is a hike uphill from my house. Forgive me.
Here is a pic:
Man I would have flipped that panel over....
I don't see any blatantly incorrect or dangerous.
OP
teknikfrog
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All my lights and garage door opener were out.
So I opened the panel and noticed the main breaker was in the 'tripped' position.
wyliesdiesels
Well-known member
Cameras would have to be on the upper right breaker seeing as how the 2 bottom breakers are on the same bus stab.
Theres only 3 120v branch breakers so not hard to determine
Yeah, I know. I asked OP for a reason.
OP
teknikfrog
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justsam
Well-known member
Not that it would explain the issue, but are grounds and neutrals from your branch circuits tied to a common buss as it appears?
Why would that matter?
Not the case. Top row is different than the bottom row.
sparky 1971
Well-known member
If the main didn't open, then whatever is on the bottom left wouldn't have worked either.
I assume this is a main panel as OP indicated garage has seperate meter.
If the main didn't fully open (both poles), and the lower right cb had power, then so would the lower left cb.
sparky 1971
Well-known member
Right, but he said the cameras didn't shut off when the main tripped. He also said in post #59 that the cameras are on the bottom right breaker. Thus, if the main didn't open fully and the cameras really were still on, whatever is fed from the bottom left breaker would have had to also be on.
Agree, but post 63 says it would NOT have been on.
Higgins
Well-known member
Some security systems have an internal battery to provide battery power during disturbances….
sparky 1971
Well-known member
Oops. I'm bass ackwards on everything today.
At least I knew what I meant even if you didn't.
Herzog
Member
Pretty odd that your lights were out if one leg was still live, since all your 20 amp breakers are all on the same leg.
edit, nm. The top breaker is on the left leg.
edit, nm. The top breaker is on the left leg.
wyliesdiesels
Well-known member
no they arent. count the bus stabs. they alternate.
2 are on the same bus (bottom). the one at the top is on the opposite bus
dcg9381
Well-known member
Unifi cameras do not.
wyliesdiesels
Well-known member
what is on bottom left breaker? that shouldve still had power since its on the same bus as the cameras
OP
teknikfrog
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Would be random outlets.
I can offer this. I have a SquareD 200A panel.
Quite a few years ago I turned off the main breaker in my new panel which should have killed power to the entire house and was about to dig in and add more circuits when I heard music coming from upstairs. I did not own a battery powered radio. Went upstairs and with the main breaker off, the outlets in that room were still powered. Went back to the panel and with a meter found that with the main breaker off one buss was powered, one was not powered. huh.
Contacted SquareD, the person I spoke with "knew of the problem". Didn't seem to happen often, but it was a mode of failure they knew did happen. They recommended changing out the panel as a whole, I bought a new panel, went outside and pulled the meter, popped the breakers off the busses and folded them back out of the way, then just swapped out the buss and main breaker assemblies between the new and old cabinets. Then snapped the breakers back on the new buss assembly. They sent me a check for a few hundred dollars.
justsam
Well-known member
What is on the 240VAC feed on the upper left? Perchance did you try to use it during this "outage", as it would have only one side of 240 and should have been dead.
That is interesting! I wonder if Square D ever issued some bulletin or advisory on the issue. They are no small player I am surprised those in the business have not ran into this, like some of the Federal Pacific or Zinsco issues.
OP
teknikfrog
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Air compressor. Did not try to use it.
wyliesdiesels
Well-known member
those outlets shouldve still had power as well then
wyliesdiesels
Well-known member
I remember hearing something about an issue with SQ D but dont recall what it was
which model line? homeline or QO?
sparky 1971
Well-known member
If it's the one I'm thinking of, it had something to do with an improperly torqued neutral lug on the plug on neutral QO panels. I don't remember if Homeline was included or not.
Homeline and QO single phase have the same main breakers if that's what you are trying to figure out. That one is a QOM200.