Heat Detection for Energy Storage Systems

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inspector23

Senior Member
Location
Temecula, CA
I have been volunteered to canvas and (hopefully) find out how other California jurisdictions are handling this wide-open-to-interpretation “reasonable alternatives”. Storage System operating conditions for ambient temperature are usually well above the 100-degree F mentioned in the bulletin. Hoping I can get some input on how various jurisdictions in California are handling this situation. Thanks in advance for your time and input.


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tallgirl

Senior Member
Location
Glendale, WI
Occupation
Controls Systems firmware engineer
I have been volunteered to canvas and (hopefully) find out how other California jurisdictions are handling this wide-open-to-interpretation “reasonable alternatives”. Storage System operating conditions for ambient temperature are usually well above the 100-degree F mentioned in the bulletin. Hoping I can get some input on how various jurisdictions in California are handling this situation. Thanks in advance for your time and input.


View attachment 2558827
Replying to watch for replies.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
I have been volunteered to canvas and (hopefully) find out how other California jurisdictions are handling this wide-open-to-interpretation “reasonable alternatives”.
Here's a discussion of this from the installer's point of view, with a fair amount of chaff mixed in, but still some references to how some jurisdictions have been behaving: https://teslamotorsclub.com/tmc/threads/santa-clara-county-retroactively-changing-ess-rules.189387/

One of the issues is that heat alarms listed to the smoke alarm standard are all 135F alarms (e.g. First Alert HD6135FB). There are plenty of purely mechanical (bimetal) heat sensors rated at 194F (e.g. System Sensor 5604), but they just close a pair of dry contacts when heat is detected. So without an alarm panel, I don't think they can be used; I haven't found a smoke alarm product that supports a remote sensor or provides a pair of contacts that could be used to initiate the alarm. Perhaps allowing a simple standalone circuit of power supply, horn, and mechanical heat sensor would be "reasonable."

The First Alert HD6135 FB manual says not to install it "where temperatures are regularly below –20º F (–29º C) or above 115º F
(46º C)". So if one could log the temperature in the proposed alarm location to provide some confidence that the temperature would be within the above range, that would be "reasonable" in my opinion, even if the listing standard mentions 100F (I haven't checked the standard). Some flexibility in mounting location would help with that, e.g. if the ESS is wall mounted, putting the heat alarm on that wall, but lower than the typical 12" maximum height below the ceiling, where temperatures may be cooler than near the ceiling.

Another option would be to condition the garage with a small through wall heat pump. Obviously that's a potentially heavy requirement for a project, but should eliminate the concerns.

Cheers, Wayne
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Here's a discussion of this from the installer's point of view, with a fair amount of chaff mixed in, but still some references to how some jurisdictions have been behaving: https://teslamotorsclub.com/tmc/threads/santa-clara-county-retroactively-changing-ess-rules.189387/

One of the issues is that heat alarms listed to the smoke alarm standard are all 135F alarms (e.g. First Alert HD6135FB). There are plenty of purely mechanical (bimetal) heat sensors rated at 194F (e.g. System Sensor 5604), but they just close a pair of dry contacts when heat is detected. So without an alarm panel, I don't think they can be used; I haven't found a smoke alarm product that supports a remote sensor or provides a pair of contacts that could be used to initiate the alarm. Perhaps allowing a simple standalone circuit of power supply, horn, and mechanical heat sensor would be "reasonable."

The First Alert HD6135 FB manual says not to install it "where temperatures are regularly below –20º F (–29º C) or above 115º F
(46º C)". So if one could log the temperature in the proposed alarm location to provide some confidence that the temperature would be within the above range, that would be "reasonable" in my opinion, even if the listing standard mentions 100F (I haven't checked the standard). Some flexibility in mounting location would help with that, e.g. if the ESS is wall mounted, putting the heat alarm on that wall, but lower than the typical 12" maximum height below the ceiling, where temperatures may be cooler than near the ceiling.

Another option would be to condition the garage with a small through wall heat pump. Obviously that's a potentially heavy requirement for a project, but should eliminate the concerns.

Cheers, Wayne
I think you've identified the most important issue, which is how do you get a signal from a foreign component to trigger a residential smoke alarm system (not smoke detector system)? On the other hand, anyone who can afford an ESS is not likely to be put in the poor house by the cost of a fire alarm control unit and 24 volt detectors.

I also did a quick look at the System Sensor line of conventional heats. Those rated for 135 have a max install temp of 100, those rated for 194 have a max ambient of 150.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
I think you've identified the most important issue, which is how do you get a signal from a foreign component to trigger a residential smoke alarm system (not smoke detector system)? On the other hand, anyone who can afford an ESS is not likely to be put in the poor house by the cost of a fire alarm control unit and 24 volt detectors.
So since you know a lot about these issues, are you aware of any UL 217 products that would support an external trigger or remote sensor?

If not, can you suggest the simplest/cheapest products to support a fire alarm system that has just one heat sensor as its input? Obviously that wouldn't be able to trigger existing smoke alarms, but perhaps that would be a "reasonable" alternative per the bulletin.

Cheers, Wayne
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
So since you know a lot about these issues, are you aware of any UL 217 products that would support an external trigger or remote sensor?

If not, can you suggest the simplest/cheapest products to support a fire alarm system that has just one heat sensor as its input? Obviously that wouldn't be able to trigger existing smoke alarms, but perhaps that would be a "reasonable" alternative per the bulletin.

Cheers, Wayne
I am not personally aware of any UL217 listed detectors or accessories that will take an external trigger, which is not to say there are none.

I'd suggest a FireLite MS-2 panel. It's a 2-zone conventional panel. You can put 135°F or 194°F conventional rate-of-rise heat detectors on it, although if you're looking for compatibility with 100°F ambient, it will have to be the 194°F detectors. It has one notification appliance circuit, so you can drop a horn strobe in the garage/ESS shed and another one inside the residence to alert occupants. The panel is about $450, the detectors are about $25 each and the System Sensor P2RL horn strobes are about $53 each. The panel does not come with central station capability, it's going to be strictly local.

If you wanted to get geeky, you could try a Fike Detect-A-Fire which can be had as low as 140°F, but they recommend using a unit rated at 100°F above the expected ambient to reduce nuisance trips, but otherwise its fine for the ambient. The advantage of the Detect-A-Fire is faster response on the rate-of-rise portion of the detector. They are not cheap. From a brief look, they clock in at about $270 a pop.

The detectors should be mounted on the ceiling above the ESS units.
 

tallgirl

Senior Member
Location
Glendale, WI
Occupation
Controls Systems firmware engineer
Code makers stimulating the economy. Hey, if we put this in the code someone will have to manufacture it, right? ;)
This sounds like someone who went crazy with requirements without thinking. A 100F temperature limit isn't going to prevent combustion, and it isn't going to keep batteries from going crazy if the battery has a proper thermal management system. It's just a dumb requirement.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
This sounds like someone who went crazy with requirements without thinking. A 100F temperature limit isn't going to prevent combustion, and it isn't going to keep batteries from going crazy if the battery has a proper thermal management system. It's just a dumb requirement.
The 100°F stipulation is for the ambient temperature of the ESS location. I imagine CA and AZ can easily get there in the summer. Heck, a few days at 90+ and you could do that in NJ. The issue is that heat alarms, of the sort that are compatible with smoke alarms generally installed in homes, aren't listed for installation in locations that will regularly go over 100°F. Now, this isn't to say they won't work, but you shouldn't depend on that, and they may exhibit unexpected behavior, ie, going off when they shouldn't, or not going off when they should.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
This sounds like someone who went crazy with requirements without thinking. A 100F temperature limit isn't going to prevent combustion, and it isn't going to keep batteries from going crazy if the battery has a proper thermal management system. It's just a dumb requirement.
I think the requirement is purely to give sleeping occupants of a house a better chance of getting out on time.

The same requirement should be applied when EV chargers are installed in garages. ;)

Install LiFePo ESSs.
 

tallgirl

Senior Member
Location
Glendale, WI
Occupation
Controls Systems firmware engineer
I think the requirement is purely to give sleeping occupants of a house a better chance of getting out on time.

The same requirement should be applied when EV chargers are installed in garages. ;)

Install LiFePo ESSs.
Well ... having lived in Austin, where my garage with an EV inside it, routinely exceeded 100F, I'm just not seeing the need.

There are UL 214 listed 135F sensors which should work in Austin (I think the temperature range is probably just what was tested, not what they are actually functional at). I just don't see where 100F is safe in the sense that it won't just be removed. The risk of nuisance trips ... every day in July and August ... seems too high.
 

analog8484

Senior Member
Location
CA
Occupation
Tech
Well ... having lived in Austin, where my garage with an EV inside it, routinely exceeded 100F, I'm just not seeing the need.

There are UL 214 listed 135F sensors which should work in Austin (I think the temperature range is probably just what was tested, not what they are actually functional at). I just don't see where 100F is safe in the sense that it won't just be removed. The risk of nuisance trips ... every day in July and August ... seems too high.
Just curious, is ESS installation in garages generally allowed in Austin?
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Consulting Electrical Engineer - Photovoltaic Systems
Just curious, is ESS installation in garages generally allowed in Austin?
For a while they were not per the fire chief, but later he rescinded the order, so now they are. The people whose PowerWalls had had to be installed on an outside wall during the time the order was in force had their equipment fail to keep them in power during the Snowpocalypse outage because the batteries got too cold to operate.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Well ... having lived in Austin, where my garage with an EV inside it, routinely exceeded 100F, I'm just not seeing the need.

There are UL 214 listed 135F sensors which should work in Austin (I think the temperature range is probably just what was tested, not what they are actually functional at). I just don't see where 100F is safe in the sense that it won't just be removed. The risk of nuisance trips ... every day in July and August ... seems too high.

I'm confused why you're citing 100F. 100F has nothing to do with the requirement.

What ESS installers want is a higher than 100F ambient rated unit that contains a heat detector and which comes with an integrated alarm. And in the case where the home already has interconnected smoke alarms, we'd want a unit that is compatible. That is what is apparently not available. The fact that listed 135F sensors exist isn't much help (nothwithstanding gadfly's contention that anybody who can afford an ESS can afford to have a fire alarm panel installed, which is something of an exaggeration). Because a sensor is not an alarm.
 

tallgirl

Senior Member
Location
Glendale, WI
Occupation
Controls Systems firmware engineer
I'm confused why you're citing 100F. 100F has nothing to do with the requirement.

What ESS installers want is a higher than 100F ambient rated unit that contains a heat detector and which comes with an integrated alarm. And in the case where the home already has interconnected smoke alarms, we'd want a unit that is compatible. That is what is apparently not available. The fact that listed 135F sensors exist isn't much help (nothwithstanding gadfly's contention that anybody who can afford an ESS can afford to have a fire alarm panel installed, which is something of an exaggeration). Because a sensor is not an alarm.
Then I'm confused why they are calling it a "heat alarm" and what's supposed to be done in environments where 100F ambient isn't even remotely hot.

That said, I'm with Gadfly. A fire alarm panel, which 2-path reporting and a single fire zone and sensor, is cheaper than just about everything having anything to do with battery storage, stationary or mobile.
 

tallgirl

Senior Member
Location
Glendale, WI
Occupation
Controls Systems firmware engineer
Then I'm confused why they are calling it a "heat alarm" and what's supposed to be done in environments where 100F ambient isn't even remotely hot.

That said, I'm with Gadfly. A fire alarm panel, which 2-path reporting and a single fire zone and sensor, is cheaper than just about everything having anything to do with battery storage, stationary or mobile.
NOW I understand. That notice was confusing because it didn't list the temperature to be sensed, only the fact there are no sensors rated for above a 100F ambient.

Duh.

I did go looking for the actual code, and had to dig the find the actual language without 100F being mentioned.
 
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