Do you need fire suppression for 3x Powerwalls in Northern California?

[Vines]

There are several non interconnected ones available for conditioned garages (135F max) The one specified by Wayne is allowed by SCC fire, for a conditioned space.

If your garage is not conditioned, and the construction is such that the interior temperature could reach 100 degrees (not in a basement or with living space above it), then you would need a heat detector rated for 194F degrees. So far I cannot find any non-interconnected versions rated for 194F degrees. Our only solution is to install an interconnected system.

I cannot speak to the others, but the Nest is not listed as a heat detector, though it can sense heat. SCC fire specifically said no to the Nest and I talked to the tech support at Nest trying to convince them to list it. Happy to hear the other interpretations of the code, but the one that matters is the Fire Marshall's. When the language required interconnected heat detectors it was even worse, at least they don't need to be interconnected now.

As for the update from Wayne, its all accurate but a couple items to add:
Engraved plaques are pretty universally accepted per the NEC, made with special plastic designed for laser engraving. They have never required aluminum backed signs to my knowledge.

I don't know of any cell on the market today that would pass the 9540A test with the "For use in residential dwelling units" Unless the cell is absolutely impossible to send into thermal runaway, through any means of destruction (heading, crushing, puncturing etc.) Literally the test is that if the cell cannot be sent into any measured thermal run away then it will pass, pretty high bar.

R327.4 If you are within the building envelope (batteries under or in a living space) its 5/8" Type X sheetrock required, and a fire rated door.

R327.3 To get closer than 3' spacing requires 9540A testing, its a whole series of tests.

 

[wwhitney]

I don't know of any cell on the market today that would pass the 9540A test with the "For use in residential dwelling units" . . . Literally the test is that if the cell cannot be sent into any measured thermal run away then it will pass, pretty high bar.

Good to know, I didn't get to looking up what level of performance was required.

R327.4 If you are within the building envelope (batteries under or in a living space) its 5/8" Type X sheetrock required, and a fire rated door.

While that's a reasonable requirement, and within the spirit of R327.4, and may be the intention, the way it's written does not require that. What it says is that the room should have walls or ceilings that are finished or non-combustible; if they are unfinished wood construction, provide 5/8" Type X drywall. And there's no mention of a fire door.

So if the AHJ is requiring 5/8" drywall in all cases on the basis of the text of 2019 interim CRC R327.4, that's a slight stretch. A fire door requirement would be a bigger stretch.

Of course, if the installation is in a garage, other parts of the CRC require a 15 minute (I think) finish and door on walls/ceilings between the dwelling unit and the garage; and if there is living space above the garage, 5/8" Type X drywall is required on the ceiling.

R327.3 To get closer than 3' spacing requires 9540A testing, its a whole series of tests.

Do you know what performance level is required on those test for a less than 3' spacing? [To be clear to the casual reader, these would be a different set of tests under 9540A than the previously mentioned cell level test for the "For use in residential dwelling units" label.]

Cheers, Wayne

 

[wwhitney]

If your garage is not conditioned, and the construction is such that the interior temperature could reach 100 degrees (not in a basement or with living space above it), then you would need a heat detector rated for 194F degrees.

FWIW, in UL539, the standard to which the random heat alarm I posted is listed to, Table 7.1 lists three categories of temperature rating of heat alarms, Low (115-134 F), Ordinary (135-174 F), and Intermediate (175-225 F), with associated maximum ceiling temperatures of 90F, 100F, and 150F, respectively.

So if the requirement is for operation with a maximum ceiling temperature of only 100F, UL539 says an ordinary temperature heat alarm , like the one I linked to, would be enough.

You can view all the UL standards for free at ul.com with a free account. You just have to opt-in to receiving emails from them, then on the purchase page for the standard you can use the "digital view" button to get a no-copy/paste view of the standard, watermarked with your account info.

Cheers, Wayne

 

[Vines]

FWIW, in UL539, the standard to which the random heat alarm I posted is listed to, Table 7.1 lists three categories of temperature rating of heat alarms, Low (115-134 F), Ordinary (135-174 F), and Intermediate (175-225 F), with associated maximum ceiling temperatures of 90F, 100F, and 150F, respectively.

So if the requirement is for operation with a maximum ceiling temperature of only 100F, UL539 says an ordinary temperature heat alarm , like the one I linked to, would be enough.

You can view all the UL standards for free at ul.com with a free account. You just have to opt-in to receiving emails from them, then on the purchase page for the standard you can use the "digital view" button to get a no-copy/paste view of the standard, watermarked with your account info.

Cheers, Wayne

According to the SCC FD, the issue is that alarm is listed only up to 100 F. I have a STP membership now, so I don't need the free viewer.

Good to know, I didn't get to looking up what level of performance was required.


While that's a reasonable requirement, and within the spirit of R327.4, and may be the intention, the way it's written does not require that. What it says is that the room should have walls or ceilings that are finished or non-combustible; if they are unfinished wood construction, provide 5/8" Type X drywall. And there's no mention of a fire door.

So if the AHJ is requiring 5/8" drywall in all cases on the basis of the text of 2019 interim CRC R327.4, that's a slight stretch. A fire door requirement would be a bigger stretch.

Of course, if the installation is in a garage, other parts of the CRC require a 15 minute (I think) finish and door on walls/ceilings between the dwelling unit and the garage; and if there is living space above the garage, 5/8" Type X drywall is required on the ceiling.


Do you know what performance level is required on those test for a less than 3' spacing? [To be clear to the casual reader, these would be a different set of tests under 9540A than the previously mentioned cell level test for the "For use in residential dwelling units" label.]

Cheers, Wayne

Good catch on the fire performance required for utility spaces. I see that the new language does not include requirements for the fire door in basements and utility rooms. I had some confusion between the attached garage and utility space requirements.

The garage must have fire separation per R302.6 , which requires doors per R302.5.1 (a Solid wood or 20 minute fire rated door.) If there is living space above the garage then the Sheetrock shall be 5/8" Type X. Interestingly a finished basement would not require any of that.

The performance required for less than 3' spacing is pretty specific. Its basically saying that once thermal runaway is initiated, the flames that result need to not start a larger fire.

 

[miimura]

Holy smokes - thanks for this info Wayne! I don't know where you're researching this stuff, but I'm glad you've been able to make some sense out of this. I guess even if Contra Costa County early-adopts R327 I should be able to comply.

The Garage wall is 268 inches from the garage door aperture itself to a side-door leading to the side of my house. This wall has no windows. I should be able to fit 3x Powerwalls even with 3 foot gaps between them and 3 feet away from each opening. I just hope they don't require bollards since it's the side of the garage.

If you are planning on installing on the inside of a garage wall, I don't think that clearance to a door leading to the outside matters. The 3' clearance to doors and windows applies to exterior installations where the doors and windows lead to the interior living space.

 

[SMAlset]

....But now there's a chance may need Sunrun to have access to 0.080 aluminum plate, 3M reflective lettering, and a CNC machine to make a new plaque design.

Sunrun, Tesla Energy, etc are all large companies and doubt they would have a problem finding a shop to produce an aluminum sign for their customers as required. Easy enough to email design files to printing companies and have the product shipped to them. Chances are with Tesla being vertically integrated the sign making is all done in house already.

In any event glad our PWs were permitted and installed already. Guess we’ll be hearing more from new installs running up against this in the future.

 

[SMAlset]

Would be interesting if Tesla Gateway2 could monitor for heat and give audibles and send notifications to your app if a temperature rise is detected as it monitors flow.

 

[miimura]

Would be interesting if Tesla Gateway2 could monitor for heat and give audibles and send notifications to your app if a temperature rise is detected as it monitors flow.

Placement of heat detectors matters. In addition, the Gateway may not be near the batteries at all.

 

[SMAlset]

Placement of heat detectors matters. In addition, the Gateway may not be near the batteries at all.

But if the Gateway is tracking info from the PWs regardless of where they are in the setup and could see that the PW was registering a high temp out of normal operating range, would it matter where the unit was? As it happens ours is above our PWs in the garage.

 

[miimura]

But if the Gateway is tracking info from the PWs regardless of where they are in the setup and could see that the PW was registering a high temp out of normal operating range, would it matter where the unit was? As it happens ours is above our PWs in the garage.

When code requires heat detectors, you have to use a UL listed product for that purpose, as discussed up-thread. The PWs reporting their own temperature would not satisfy that requirement.

 

[BGbreeder]

If your garage is not conditioned, and the construction is such that the interior temperature could reach 100 degrees (not in a basement or with living space above it), then you would need a heat detector rated for 194F degrees. So far I cannot find any non-interconnected versions rated for 194F degrees. Our only solution is to install an interconnected system.

@Vines: could you get by your temperature limit by installing ventilation fans in the garage to keep the temperature below the required limit?

All the best,

BG

 

[Vines]

Possibly, I haven't tried to solve the issue that way, was hoping to just install some Powerwalls.

 

[SVDNN]

Hoping anyone could comment on the spacing between bollard(s) required for side wall on ground garage install for PWs??

I was planning on stacking 3 PWs together near the exterior garage door pillar that is 27" in depth, but now being told bollard required by city in mid peninsula SF Bay. The stacked PWs should be 18.5" depth to wall, if can make bollard within the 27" it will acceptable to not impede entry into garage (...have custom cabinets thru most of garage and do not want exchange the wall space to PWs).

 

[Sam123]

OK, I had a chance to read through the 2019 Interim California Code Cycle requirements that will take effect July 1, 2021 (and for which jurisdictions may elect to permit work currently).
...
R327.3.1 Spacing of 3 feet between individual units is required, but the ridiculous "3 feet from walls" is gone. Large scale fire testing results by the manufacturer can allow a reduction in the 3 feet separation requirement (haven't looked at the details of this).

Does this mean that the 'stacking' of two Powerwalls is no longer allowed in jurisdictions that enforce CRC R327?

R327.4 Powerwalls may only be installed in (A) garages, detached accessory structures, outdoors 3 feet from windows and doors "directly entering the dwelling unit"

Any idea if this means horizontal distance? Or just 3' distance period? My best logical placement for the Powerwalls would be on side yard concrete walkway against the outside wall, next to the main electrical panel, outside our master bedroom directly below high clerestory windows (bottom of window would be 3' above the top of Powerwall); would this be allowed?

 

[holeydonut]

Does this mean that the 'stacking' of two Powerwalls is no longer allowed in jurisdictions that enforce CRC R327?

I'm probably the only person ever to have 3x Powerwalls on my garage that aren't connected to anything lol.

The Power Ranger who mounted them on the wall said that he was told stacking was no longer allowed in Contra Costa county. I can't tell if this is just because Sunrun is being ultra-careful, but he basically said that extra thickness of two PW's stacked was causing headaches with getting permits and final inspection/approval. He also said he's seen a bunch of requests for bollards in recent months.

He was very happy to learn garage wall was a great candidate for Powerwall placement. That's about the only good news I've had out of this terrible ordeal.

 

[Vines]

Does this mean that the 'stacking' of two Powerwalls is no longer allowed in jurisdictions that enforce CRC R327?

Any idea if this means horizontal distance? Or just 3' distance period? My best logical placement for the Powerwalls would be on side yard concrete walkway against the outside wall, next to the main electrical panel, outside our master bedroom directly below high clerestory windows (bottom of window would be 3' above the top of Powerwall); would this be allowed?

To my knowledge its 36", not 36" horizontal distance, then upwards to infinity. To be clear though R327 in its current form has no such provisions. Only those jurisdictions that adopted it early are using the new R327.

This does preclude stacking kits until Tesla completes the 9540A testing, assuming it performs as well as they suspect. Bollards are a pain too, especially if they need to withstand the 6k force at 24" high. CALSSA is actively pursuing some code language that would define exactly what is subject to damage, but at best that would be a year out from any kind of wide adoption.

 

[jboy210]

I'm probably the only person ever to have 3x Powerwalls on my garage that aren't connected to anything lol.

The Power Ranger who mounted them on the wall said that he was told stacking was no longer allowed in Contra Costa county. I can't tell if this is just because Sunrun is being ultra-careful, but he basically said that extra thickness of two PW's stacked was causing headaches with getting permits and final inspection/approval. He also said he's seen a bunch of requests for bollards in recent months.

He was very happy to learn garage wall was a great candidate for Powerwall placement. That's about the only good news I've had out of this terrible ordeal.

So is he saying that if you cann wall-mount the PWs you don't need to mess with the bollards and such for 3 Powerwalls?

 

[holeydonut]

So is he saying that if you cann wall-mount the PWs you don't need to mess with the bollards and such for 3 Powerwalls?

He said since I was mounting on the side wall instead of the wall the headlights shine on, I didn't need bollards. But he said I wouldn't be allowed to double-stack Powerwalls on the side of the garage. Luckily everything fit for me since my garage has no windows.

So now I get to see Powerwalls when I enter my garage but they're not doing anything. Sad.

 

[jboy210]

He said since I was mounting on the side wall instead of the wall the headlights shine on, I didn't need bollards. But he said I wouldn't be allowed to double-stack Powerwalls on the side of the garage. Luckily everything fit for me since my garage has no windows.

So now I get to see Powerwalls when I enter my garage but they're not doing anything. Sad.

OK thanks. We have ours single mounted on the walls a couple of feet of the ground. If we get a 3rd we would likely do the same. The only way to hit one of our PW with a car would be to do a very terrible job of parking and open a door into it.

 

[holeydonut]

OK thanks. We have ours single mounted on the walls a couple of feet of the ground. If we get a 3rd we would likely do the same. The only way to hit one of our PW with a car would be to do a very terrible job of parking and open a door into it.

Yeah the guy basically said the reason you can't stack them on the side of the garage (like where the car won't ram it) is because then you'll have two Powerwalls that are too close to each other. The PWs need some inches between them in California even if Tesla designed them to be stackable. I don't understand any of this, but nothing about this process makes sense to me any more.

I think it's funny that outside of California where the houses get way bigger, the rules are more lax. But in California where garage space is at a premium, it's all "space them a football field apart please." And the number of reported incidents of residential ESS catching fire in California is zero. I can't find one single example of a thermal event documented anywhere.