Tripping Gateway Breaker

[Cudaman340]

Hello,

I had a 11.2KW with a power wall 2+ installed about a year ago. About 4 months in my main old breaker panel fried due to suspected water instrusion.

I had a company come out last minute and they were a little sketchy but did a good job I thought. Sketchy as in not only suggesting to file an insurance claim (I did no regrets), but as soon as they heard it was approved they wanted to push to change out all the aluminum wiring in the house and such for even more money. It seemed odd my problem was fine being fixed with a new main panel, but as soon as my insurance said they’d pay they wanted to do more.

Long story short, I got a new 200 amp main panel with a 125 breaker, and a new sub panel limited to 100amps. When asked about why not 200 amps and a 100 amp sub he said it was due to the aluminum wiring.

Life was good for about 4 months up until recently. I’ve got a wall charger set at 48A I had installed prior with new wiring on its own dedicated circuit. Lately the sub 100A main breaker has been popping when the car decides to charge and there’s additional load like ac. It even popped the other night at 1am with hardly any load on the house (ac off).

I’ve set the wall charger to 24 amps in the mean time, but this seems off. Is there a reason I couldn’t have at least a 125amp breaker on the sub to match the main? I’d like to explore getting my main panel to 200, and what my limit is on my sub, I’m guessing I have to see what the wiring is between the main and sub and go off that.

Is there a max the gateway can handle? Many electricians run when they hear it has Tesla solar/power wall. If I could get educated some perhaps I can be prepared enough to spell out to an electrician exactly what the situation is and what needs to be changed to where they won’t be scared off by “Tesla hardware.”

 

[Vines]

Hello,

I had a 11.2KW with a power wall 2+ installed about a year ago. About 4 months in my main old breaker panel fried due to suspected water instrusion.

I had a company come out last minute and they were a little sketchy but did a good job I thought. Sketchy as in not only suggesting to file an insurance claim (I did no regrets), but as soon as they heard it was approved they wanted to push to change out all the aluminum wiring in the house and such for even more money. It seemed odd my problem was fine being fixed with a new main panel, but as soon as my insurance said they’d pay they wanted to do more.

Long story short, I got a new 200 amp main panel with a 125 breaker, and a new sub panel limited to 100amps. When asked about why not 200 amps and a 100 amp sub he said it was due to the aluminum wiring.

Life was good for about 4 months up until recently. I’ve got a wall charger set at 48A I had installed prior with new wiring on its own dedicated circuit. Lately the sub 100A main breaker has been popping when the car decides to charge and there’s additional load like ac. It even popped the other night at 1am with hardly any load on the house (ac off).

I’ve set the wall charger to 24 amps in the mean time, but this seems off. Is there a reason I couldn’t have at least a 125amp breaker on the sub to match the main? I’d like to explore getting my main panel to 200, and what my limit is on my sub, I’m guessing I have to see what the wiring is between the main and sub and go off that.

Is there a max the gateway can handle? Many electricians run when they hear it has Tesla solar/power wall. If I could get educated some perhaps I can be prepared enough to spell out to an electrician exactly what the situation is and what needs to be changed to where they won’t be scared off by “Tesla hardware.”

Main breakers do not trip randomly when properly designed. I would have an electrician out with a thermal camera and see if there are any hot spots from a loose connection or measure with a multimeter if this is truly an overload situation. The cameras aren't even that expensive if you are handy and are comfortable opening your electrical panel while it is energized.

The only times I have heard of a main breaker tripping there was an electrical issue with a wire improperly landed and it was arcing.

 

[Cudaman340]

Thanks for the reply!

Yea it seems odd for sure, it seems like a good option to investigate for hot spots or arching. For clarity, the sub panel mail breaker labeled “Gateway” is the one that trips, the main panel feeding it doesn’t.

I will say the breaker that does trip is pretty hot to the touch. Ironically the breaker for the EV circuit and the main breaker aren’t as hot so maybe a loose connection there.

Having helped my father finish a basement (he’s retired and was in building hvac and retro’s), I’m comfortable doing some of this on my own to see if there’s anything obvious.

 

[h2ofun]

Thanks for the reply!

Yea it seems odd for sure, it seems like a good option to investigate for hot spots or arching. For clarity, the sub panel mail breaker labeled “Gateway” is the one that trips, the main panel feeding it doesn’t.

I will say the breaker that does trip is pretty hot to the touch. Ironically the breaker for the EV circuit and the main breaker aren’t as hot so maybe a loose connection there.

Having helped my father finish a basement (he’s retired and was in building hvac and retro’s), I’m comfortable doing some of this on my own to see if there’s anything obvious.

My first question is has all this stuff been done with permits?

 

[cali8484]

I had a breaker go bad after only a couple years on an EV charger circuit that started to trip under rated load. One check you could do is to charge at max current and then go listen to breaker closely. If you hear any buzzing sound then it could be bad and should be replaced. Improperly seated magnet in breakers is one main cause of the failure.

 

[Vines]

I had a breaker go bad after only a couple years on an EV charger circuit that started to trip under rated load. One check you could do is to charge at max current and then go listen to breaker closely. If you hear any buzzing sound then it could be bad and should be replaced. Improperly seated magnet in breakers is one main cause of the failure.

Branch breakers go bad often enough that they are a common replacement. I am just saying that if the MAIN breaker trips (usually a 100A or larger, large frame breaker) that is the time to look at something a bit more carefully than just an average breaker tripping. It might just be a replacement time, but in my experience, you need to take a good look at things if you are tripping a main breaker at 3 AM without HVAC load, especially if you just had a bunch of work done.

Maybe you have one of those giant on-demand electric water heaters and someone took a shower while the car was charging?

Main breakers don't easily trip at or very near the rating on the breaker, it will usually take a sustained overage of amperage to trip a main breaker, or a more significant issue.

 

[yblaser]

Branch breakers go bad often enough that they are a common replacement. I am just saying that if the MAIN breaker trips (usually a 100A or larger, large frame breaker) that is the time to look at something a bit more carefully than just an average breaker tripping. It might just be a replacement time, but in my experience, you need to take a good look at things if you are tripping a main breaker at 3 AM without HVAC load, especially if you just had a bunch of work done.

Maybe you have one of those giant on-demand electric water heaters and someone took a shower while the car was charging?

Main breakers don't easily trip at or very near the rating on the breaker, it will usually take a sustained overage of amperage to trip a main breaker, or a more significant issue.

In this case though isn't the "main breaker" that the OP is talking about just really a locked down branch breaker used to back-feed into the subpanel?

If the breaker is getting warm to the touch I would also make sure that the appropriate length of stripped wire was inserted into the breaker and fasteners appropriately torqued.

 

[Vines]

In this case though isn't the "main breaker" that the OP is talking about just really a locked down branch breaker used to back-feed into the subpanel?

If the breaker is getting warm to the touch I would also make sure that the appropriate length of stripped wire was inserted into the breaker and fasteners appropriately torqued.

Correct, my advice was also meant for another observer with a similar issue. This is a normal frame size breaker, so subject to the same failure as other small frame breakers.

Also, the 125A breaker in your service panel where it is supposed to be a 100A max feeding the backup system. See the 4th paragraph under "For overhead and underground service" In this case since its bottom fed, they mean the top spot of the bus should have 80-100A breakers only, and the rest are limited to 70A or less.

As to the limitation with aluminum wires this seems like BS to me. They should have installed a nice combo service panel with room for a 200A branch breaker, or other 200A connection. The 100A maximum connection (with an wrong 125A breaker) is not serving you at all. This is basically throttling your whole service to 125A, so you get little benefit from the service swap.

The wire they used could be aluminum but there is no issue with 200A aluminum wire. If the branch breakers currently use aluminum wire, then this isn't changing.

I would never have a company that seemed sketchy work on my wiring but that's just me.

In looking more at your loads your pool may be programmed to run at night, so that was maybe another load running. EDIT This doesn't explain the tripping of the 100A breaker though.

 

[Cudaman340]

Hi all, thanks for the replies!

Been busy so just getting around to following up. I ended up taking off the panel covers to see what’s going on. What I found I feel is an issue. To recap, the main panel has a 125amp breaking feeding nothing but the sub panel.

The sub panel has a 100amp breaker on the top right powering all the circuits including my WC that’s on a 60 amp breaker ran with 4 AWG. The sub panel main is the one that trips and feels warm when I go out and reset it.

As far as other loads, most of my lighting is LED bulbs, a couple tv’s, a surround sound, 2 fridges, an electric powered ignition for the gas water heater, and pool(only runs from 730-3pm).

The car was set to charge off peak and would trip sometimes in the evening afrer 8PM. I’ve backed down the max charge to 24A on the WC for now and haven’t had issues.

The issue I’ve discovered is the main and sub (100A) connect to the Tesla Gateway with copper 4 AWG. The main, Tesla interface, and the sub all permit 200A service per the labeling.

The wiring looks like it’s 4 AWG based on the wiring label and size. 4 AWG is rated at 85 amps @75c, not close to 100 or 125!

I think the corrective action is to replace the wiring with 3/0 AWG copper wire from the main/sub connecting to the Tesla gateway, chance the neutral to copper 3/0 AWG, and verify the ground going to the grounding rod is adequately sized (4 AWG?). Also replace main and sub with 200 Amp breakers so they are adequately sized.

As much as I’d like to have the electrician come back and fix the 4 to 3/0 as shady as he seems after doing the main repair (and wanting to do more after he found out insurance was involved), I’m going to work on a different option as he seems shady and I don’t trust him finding this.

 

[BGbreeder]

Thanks for the update. I'm glad that you didn't burn anything down!

Out of curiosity, what size wire is going into that tandem 50A breaker in your gateway?

Personally, I would not send more work to someone who did less than desirable work the first time through. I'm a little surprised that your inspector did not catch that the wire gauge not being up to the breakers, and loads.

Good luck in getting things shipshape.
All the best,

BG