Tesla Gateway (V2) Breaker Tripped Last Night

[SteveO332]

Installed November 2023. 4 x PW3s, Backup Gateway V2, 23.49kw system.

This morning, I woke to find that the power was out of my home. Neighbors weren't out. I checked the breaker in the Tesla Backup Gateway, and it was tripped, so I've been on batteries all night and ran out at about 5am. That's when my alarm (kids) told me the power was out.

What could cause that, and how do you prevent it?

 

[Vines]

Installed November 2023. 4 x PW3s, Backup Gateway V2, 23.49kw system.

This morning, I woke to find that the power was out of my home. Neighbors weren't out. I checked the breaker in the Tesla Backup Gateway, and it was tripped, so I've been on batteries all night and ran out at about 5am. That's when my alarm (kids) told me the power was out.

What could cause that, and how do you prevent it?

Usually it takes a significant electrical fault to trip the main breaker, so be careful. What size is the breaker? Have you had any recent construction or landscaping between the installation and now?

I would have an electrician come to inspect your breaker panels for signs of arcing or damage. If there seems to be no obvious damage I would turn the breaker back on. If the problem persists you can pay an electrician to do an insulation test on the existing subfeed wires from Gateway to the rest of the home.

It might be safe to turn the main breaker back on, but if there is any noise, smell or sound associated with turning it back on then immediately turn it back off. I would certainly not be touching anything else when I turned the main breaker back on.

 

[jgleigh]

Did you get an alert in the app that the grid was down? Very unusual for the Gateway breaker to trip.

Breakers do go bad sometimes, so also something to have Tesla (or an electrician) check out.

 

[SteveO332]

I missed it (sleep focus mode), but the grid actually never went down. The only thing I can think of is maybe it was drawing too much at once?

Free nights, so everything starts at the same time. 2 vehicles + powerwalls recharging + house usage spiked it right before it tripped.

Free nights start at 9pm, so I moved both vehicles to start charging at midnight instead, so the usage is spread out.

Looking at the V2 gateway specs, it's a 200 amp current rating, so 200 x 240 = 48,000...maybe it did trip the breaker?

 

[BGbreeder]

Yes, adding a tiny bit of surge to your 42kW load, and I could easily see how your breaker could trip. Even as a sustained load, 42kW, aka 175A is asking a lot of everything, breakers, wiring, bus bars, etc. Isn't the overcurrent rating normally 125% of the sustained load, and 125% of 175A would be above 200A? I defer to folks like @Vines and @wwhitney who know the NEC electrical code.

All the best,

BG

 

[wwhitney]

Yes, adding a tiny bit of surge to your 42kW load, and I could easily see how your breaker could trip. Even as a sustained load, 42kW, aka 175A is asking a lot of everything, breakers, wiring, bus bars, etc. Isn't the overcurrent rating normally 125% of the sustained load, and 125% of 175A would be above 200A? I defer to folks like @Vines and @wwhitney who know the NEC electrical code.

A 200A breaker should hold at 200A for a while, more than an house I would think. The NEC requirement to upsize a breaker to 125% of the load kicks in for normal breakers (not 100%-rated) and for continuous loads (which draw their maximum current for 3 hours or more).

So if the breaker trips at under 200A and an hour or less, I would be looking for a source of excess heat that could be causing premature tripping. E.g. a poor (high resistance) connection on the breaker or nearby.

Cheers, Wayne

P.S. The breaker is tested under the listing standard to hold indefinitely in free air at 40C ambient. The issue is that breakers are not used in free air but inside cabinet, where heat will dissipate more slowly, and there are other sources of heat (busbars and other breakers). The 125% factor is to provide additional headroom against nuisance tripping like this. But absent other problems, for such a nuisance trip to occur, the air temperature immediately adjacent to the breaker within the cabinet would need to climb above 40C.

 

[SteveO332]

Yes, adding a tiny bit of surge to your 42kW load, and I could easily see how your breaker could trip. Even as a sustained load, 42kW, aka 175A is asking a lot of everything, breakers, wiring, bus bars, etc. Isn't the overcurrent rating normally 125% of the sustained load, and 125% of 175A would be above 200A? I defer to folks like @Vines and @wwhitney who know the NEC electrical code.

All the best,

BG

Thank you. I just noticed as well that the breaker is actually rated for 150 amps, so the limit is technically 36kw. No wonder it tripped!

 

[CrazyRabbit]

Have Tesla adjust your current limit in the software. This way the powerwalls will adjust the Powerwall draw to no trip your main breaker. You might think about EVSE that can PowerShare a single circuit too.

 

[SteveO332]

Have Tesla adjust your current limit in the software. This way the powerwalls will adjust the Powerwall draw to no trip your main breaker. You might think about EVSE that can PowerShare a single circuit too.

Does that have to do with PCS settings in the TeslaOne app?

 

[Vines]

Have Tesla adjust your current limit in the software. This way the powerwalls will adjust the Powerwall draw to no trip your main breaker. You might think about EVSE that can PowerShare a single circuit too.

This is your best solution really to have panel limits set so that you do not trip the main breaker. If your house went into sustained load such that the limit was exceeded, the limit is not set.

Have your installer set panel limits so in the future the Powerwalls would stop charging to meet the set limit and you can charge your cars whenever.

I am glad your 150A breaker tripped for sure if you were drawing a constant 42 kW! This is working as intended.

 

[offandonagain]

After getting solar/battery, I'm much more aware of my peak load and always try to keep it as low as possible. It avoids pulling from the grid during the day, plays nicer on Powerwalls at night, and plays nicer on the grid when you need it. In this case, staggering your two EVs to charge at different times would go a step further.

Of course, Powerwalls and EVs should also be smarter about the rate and time of charging. They only get away with it now because adoption is still relatively low, but once this 9pm bump starts showing up on the ERCOT demand chart (or 12am on CAISO's), we'll have a problem

 

[wwhitney]

I am glad your 150A breaker tripped for sure if you were drawing a constant 42 kW! This is working as intended.

That's not something we can rely on happening. A 150A breaker is allowed to hold indefinitely at 175A, or it may trip.

Cheers, Wayne

 

[Vines]

That's not something we can rely on happening. A 150A breaker is allowed to hold indefinitely at 175A, or it may trip.

Cheers, Wayne

Agreed, I see the 42 kW sustained then the reported spike in home usage. I was intending on reassurance compared with my initial email where I thought things were more serious.

 

[CrazyRabbit]

Does that have to do with PCS settings in the TeslaOne app?

YES

 

[CrazyRabbit]

After getting solar/battery, I'm much more aware of my peak load and always try to keep it as low as possible. It avoids pulling from the grid during the day, plays nicer on Powerwalls at night, and plays nicer on the grid when you need it. In this case, staggering your two EVs to charge at different times would go a step further.

Of course, Powerwalls and EVs should also be smarter about the rate and time of charging. They only get away with it now because adoption is still relatively low, but once this 9pm bump starts showing up on the ERCOT demand chart (or 12am on CAISO's), we'll have a problem

Tesla’s EVSE equipment is capable of load sharing. Even tho you have two charger circuits you could set the chargers to load share to play nicer to the grid, if that would work for your vehicle usage.
Because of the amount of utility scale solar on the grid, the rate is really low during the day. Utilities should start to incentivize charging during the day.

 

[SteveO332]

Tesla’s EVSE equipment is capable of load sharing. Even tho you have two charger circuits you could set the chargers to load share to play nicer to the grid, if that would work for your vehicle usage.
Because of the amount of utility scale solar on the grid, the rate is really low during the day. Utilities should start to incentivize charging during the day.

Agreed - when I was with Tesla Electric with realtime buyback rates, I noticed it often was either zero or negative during the day. Negative sellback rates even appeared on my bill. It didn't amount to much, but still, it was there.

Tesla Powerwall support did update my PCS settings not too long ago to match my plan set. I only have one wall connector, the other vehicle is plugged in to the wall via a 14-50. If I put another Tesla UWC there, I think that enables the load sharing.

Right now, I just limited both vehicles to charge at 20amps - I don't drive much so the recharge speed isn't a major issue.

 

[OCJeff]

You can also set the maximum import rate yourself via the Tesla One app. You can set it to limit import to xx,xxx watts.

Once you log in, you should be able to connect to your backup gateway TEG-XXX SSID and password which is in the cabinet on a sticker (last 5 digits of the serial # iirc). For more details on logging into the app I'll refer you to this thread:

How to Use Tesla Pro App as End User?

I am no longer able to access the gateway through my IP address. I get the message to download the pros app. I downloaded the app. How do we use it as a homeowner similarly to how we logged into the gateway through the IP?

teslamotorsclub.com

 

[SteveO332]

I have Powerwall 3s, so I actually have to log into a Powerwall directly (network starts with TeslaPW-XXXXXX).

But check this - Powerwall support told me that using the TeslaOne app as a homeowner could VOID MY WARRANTY on the power walls and asked me not to use it anymore.

Anyone else heard this?!

 

[jjrandorin]

I have Powerwall 3s, so I actually have to log into a Powerwall directly (network starts with TeslaPW-XXXXXX).

But check this - Powerwall support told me that using the TeslaOne app as a homeowner could VOID MY WARRANTY on the power walls and asked me not to use it anymore.

Anyone else heard this?!

The app description of the Tesla One app says its for "employees and external partners". I would expect that any settings changes on a powerwall would be logged somewhere. If a homeowner changes something that then requires Tesla to "do something" to fix, thats not something any company would cover under warranty.

Personally, I am surprised that the app is visible in the regular app store, or not gated behind some requirements to download it or something. I personally would not be telling tesla support on the phone I was logging into it, and I would be careful with changing any options using it that are available to change.

Thats just me though, and my own opinions. I dont work for Tesla or anything (I feel compelled to remind people of this when I have opinions on stuff since for some reason people will see I am a mod here and think that has something to do with being a part of Tesla or working there, etc).

 

[SteveO332]

They asked me how I knew one of my units failed a firmware update, so I spilled the beans. I could have also just said it's in the settings in the app; it shows the lowest firmware of all 4 units.