Good question from building inspector.

[BIC1]

The building inspector was reviewing my PW interior basement install yesterday. Code requires a fire dept warning plaque on the electrical/PV panels outside. The inspector asked, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?"

Since PWs have been around for a few years, I'm guessing this question has been answered. How does the interior PW get turned off from outside the burning house? Thanks.

 

[wwhitney]

It doesn't get turned off from outside the burning house. That's what the placards are for, to notify people there's an interior source of power, and where its shutoff is. So that people will know to treat the house as still energized, until such time as they can reach the interior shutoff to disconnect the Powerwalls.

Cheers, Wayne

PS An exterior mechanism to activate the interior shutoff could be installed, but to my knowledge is not required.

 

[gpez]

The building inspector was reviewing my PW interior basement install yesterday. Code requires a fire dept warning plaque on the electrical/PV panels outside. The inspector asked, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?"

Since PWs have been around for a few years, I'm guessing this question has been answered. How does the interior PW get turned off from outside the burning house? Thanks.

https://www.tesla.com/sites/default/files/pdfs/powerwall/powerwall_2_ac_owners_manual.pdf, Section 5: "What to Do in Case of an Emergency"

Essentially it says to turn off the Powerwall, open the AC breakers, and don't use type D fire extinguishers.

 

[boaterva]

As a comment this is the same as they would do normally (kill AC breakers) as the fire department would normally have no external power shutoff.

If they want to kill the power to the house, they always kill the main breakers on the main panel, I assume (that’s easier/safer than taking an ax to the meter, right?).

With a PW/solar install, then you have the external shutdowns added for quick disconnect of the PWs and gateway.

That makes sense? EE here, but not FD of course.

 

[brur]

kind of think

As a comment this is the same as they would do normally (kill AC breakers) as the fire department would normally have no external power shutoff.

If they want to kill the power to the house, they always kill the main breakers on the main panel, I assume (that’s easier/safer than taking an ax to the meter, right?).

With a PW/solar install, then you have the external shutdowns added for quick disconnect of the PWs and gateway.

That makes sense? EE here, but not FD of course.

kind of think the firemen can pull the meter pretty easy. Just clip the puny little wire lock, or pry till it stretches out.
As for the breakers themselves, it's up to the fifty states, here in AZ the meter box is outside.

 

[Ampster]

The inspector asked, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?"

The important issue maybe not the power to the house, but the 400 to 500 volts of DC on the roof if the PowerWall is continuing to cause the Grid Tie inverter to operate as if there was a power outage. The firemen are more likely to be shocked by that DC because they often go on the roof before entering a flame engulfed home.

 

[boaterva]

The important issue maybe not the power to the house, but the 400 to 500 volts of DC on the roof if the PowerWall is continuing to cause the Grid Tie inverter to operate as if there was a power outage. The firemen are more likely to be shocked by that DC because they often go on the roof before entering a flame engulfed home.

If you shut down the inverter it kills the solar automatically on any recent (years) install.

 

[Ampster]

If you shut down the inverter it kills the solar automatically on any recent (years) install.

Yes, that is correct. Pulling the meter or turning off the main breaker won't turn off the Grid Tie inverter if the PowerWall is powering it as if there was a power outage. The question asked by the inspector was, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?" Earlier, @wwhitney explained the scenerio I was alluding to.

Unless there is a way to turn off the PowerWall and/or the Grid tie inverter then the solar panels will be energized. The three PowerWall installations that I have seen installed in the interior of garages do have the gateway on the exterior and perhaps there is a placard that lets the firemen know to turn off the PowerWall and or the GT inverter. I don't know if that was how the OP's system was designed or if his gateways is even on the outside.

 

[BIC1]

I have new construction with the PV installed during the build. One year later now, the Powerwall is going in. Wish I had done it during the build; would have made a little bit of interior wiring easier. Outside is the net-meter, PV shutoff & main breaker shutoff. Everything else is in the center of the basement: main circuit breaker panel, battery, gateway & another breaker box (generation panel?) between gateway & battery.

Apparently, can only turn the Powerwall off in the center of the basement. But, as @boaterva mentioned, most everybody's main panel shutoff is inside anyway. Mine is in the small minority outside (at least around these parts).

 

[cwied]

Yes, that is correct. Pulling the meter or turning off the main breaker won't turn off the Grid Tie inverter if the PowerWall is powering it as if there was a power outage. The question asked by the inspector was, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?" Earlier, @wwhitney explained the scenerio I was alluding to.

Actually, if they turn of the PV switch outside, it should de-energize the solar panels. At least that's the way it is for me, because the inverter is outside. In any case, when the Powerwalls were installed, they added a bunch of information for firefighters on the cover of my main panel, which is on the outside wall of my garage. This documents the three places where the power needs to be turned off:

 

[Ampster]

Actually, if they turn of the PV switch outside, it should de-energize the solar panels. At least that's the way it is for me, because the inverter is outside.

Yes, turning off the PV switch outside would prevent your PowerWall from energizing your GT inverter. Do you have another panel outside, where they can turn off the PowerWall, or do they have to go inside to do that? It is not clear to me from the lables without knowing if the Battery Backup Load Panel is outside.

 

[1100MCM]

For my install, the city inspector (on behalf of the city fire department) made Tesla install two disconnect switches (one for each Powerwall) outside of the house near the main breaker panel. This on top of the two disconnect switches that the electric utility had made the solar installers put on the system. So now I have four switches, two meters, and a whole mess of red warning placards outside the house.

 

[Ampster]

This on top of the two disconnect switches that the electric utility had made the solar installers put on the system.

Who is your electric utility?

 

[Dan123]

The building inspector was reviewing my PW interior basement install yesterday. Code requires a fire dept warning plaque on the electrical/PV panels outside. The inspector asked, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?"

Since PWs have been around for a few years, I'm guessing this question has been answered. How does the interior PW get turned off from outside the burning house? Thanks.

In my case, there are two circuit breakers outside that disconnect and turn off the powerwalls.

 

[cwied]

Yes, turning off the PV switch outside would prevent your PowerWall from energizing your GT inverter. Do you have another panel outside, where they can turn off the PowerWall, or do they have to go inside to do that? It is not clear to me from the lables without knowing if the Battery Backup Load Panel is outside.

The switches for the Powerwalls are inside the garage (on the other side of the wall the main panel is on). The bottom label has a map of the house showing the location.

 

[Watts_Up]

The building inspector was reviewing my PW interior basement install yesterday. Code requires a fire dept warning plaque on the electrical/PV panels outside. The inspector asked, "what happens after the fire dept turns off all the electrical/PV switches outside and the PW is still powering the house?"

Since PWs have been around for a few years, I'm guessing this question has been answered. How does the interior PW get turned off from outside the burning house? Thanks.

This explain why in some counties, like Australia, the Powerwalls must be installed outside of an house, so they can easily be disconnected .

 

[bob_p]

For our installation (Dec 2019), there are 3 panels with disconnect switches:

• Tesla Gateway panel - this switch disconnects the system from the grid (the system can still run off solar/PowerWalls)
• Generation panel - a breaker panel with individual breakers for each PowerWall and each block of solar panels/microinverters (allowing individual PowerWalls or blocks of solar panels to be disconnected)
• Generation disconnect panel - a large throw switch (the big handle on the far right) that disconnects all generation equipment from the Tesla Gateway (the system then can run only off the grid)

For our house, all of these panels are in same location on the outside of the house. The PowerWalls are inside the garage, and each have their own switch to turn them off - though in a fire, even with the switch off, the PowerWalls can be storing a lot of energy, creating increased risk if they are exposed to high heat.

 

[JayClark]

In my case, there are two circuit breakers outside that disconnect and turn off the powerwalls.

My utility in AZ required separate master blade style cut-off switches, one for solar, one for PW, and One master for cutting-off the grid. So the PW goes through an outside cutoff switch, before coming back into the house to the gateway. The side of my house looks like somebody played a joke on us and just installed a line of cut-offs and meters (3 meters, at each cutoff point too).

 

[1100MCM]

Who is your electric utility?

Smaller public utility, TID.

 

[Ampster]

Smaller public utility, TID.

That would probably explain why they were able to require a shutoff switch behind the meter. The IOUs have no authority to tell us what we have to do behind the meter in California.
There is a different relationship with public (municipal) utilities which are owned by governmental entities that also adopt the building and fire codes.