Smoke detectors and the M1G

[lugnut]

Reading through the search results I got on smoke detectors, one thing that isn't clear is how you guys that have integrated DC-powered smoke detectors (regardless of whether 2 or 4 wire) are meeting building codes which in most municipalities seem to require 120VAC powered SD's from the house main supply, and all linked together, and with battery back-up?

Are you leaving those original builder-installed detectors untouched (and unmonitored by the ELK), and the DC powered detectors are a supplement to that so building codes don't directly come in to play?

Another interesting thing I've come across, and I had never heard/read before, is that the National Fire Protection Ass'n recommends all smoke detectors be replaced at 10 years, regardless of whether they still appear to be working, because their data shows those old detectors have a 30% chance of failure going forward from there, due to various aging effects.

30% failure probability is pretty high for such an important device, so I plan to replace my 120V powered detectors too. Or maybe there is a way to cover it all with new DC powered and monitored detectors?
I wonder how many other people are unaware of that recommendation to replace after 10 years. Probably a lot, I would guess.

EDIT: How do you modify the title of your post? I'm not seeing a way to do that.

 

[ctay]

To my knowledge there is no requirement in the national building code (which is followed by many municipalities) that smokes be 120V. They have to be powered off the electric grid or something to that effect but no requirement for 120V. On most systems the (4 wire) smokes are powered off the SAUX power on the M1 which is battery backed up. The M1 is UL listed so it has been tested every bit as much as the 120V smokes.

The electrical and building inspectors didn't flinch at my 12v smokes. Just asked to see the battery and the UL sticker on the elk and tested them just like they would with 120V.

 

[JonR]

I initially ran into resistance from the electrician and the city inspector when I explained that I wanted to use low-voltage smokes INSTEAD of line voltage in our new house. I read the code and got some pointers from the forums here, and after a few phone calls and providing some information to the inspector he eventually came around and sent me a letter asserting that my setup would meet code. The UL sticker and having all of the sounders go off on any alarm were the critical items. We're close to final inspections so hopefully we'll have smooth sailing.

JonR

 

[lugnut]

I initially ran into resistance from the electrician and the city inspector when I explained that I wanted to use low-voltage smokes INSTEAD of line voltage in our new house. I read the code and got some pointers from the forums here, and after a few phone calls and providing some information to the inspector he eventually came around and sent me a letter asserting that my setup would meet code. The UL sticker and having all of the sounders go off on any alarm were the critical items. We're close to final inspections so hopefully we'll have smooth sailing.

JonR

The response I got when I talked to the local inspector yesterday was that the requirements reads that the smoke alarms must be directly hard wired to the electrical supply of the house, to which I replied, yeahbut, they'd have battery back-up, to which he replied, that doesn't matter because that is required of the AC smoke detectors too. They also have to be interconnected but that was beside the point.

There wasn't much I could say at that point, so I browsed around the internet, where you can find lots of city codes for various cities, and there are a lot that read the way he described. A strict interpretation considers the conversion the panel makes from AC to DC which powers the detectors as an indirect powering, subject to failure of the power conversion device, and it's kinda hard to argue with that.

I'm not so sure this means there is no way I can use the ELK with smoke detectors, for monitoring and reporting purposes, it just means the ELK can't be the power source. It does reduce the field of detectors I can use though. Unless I take the approach I mentioned, and have the Elk essentially service "redundant" detectors.

 

[Digger]

To my knowledge there is no requirement in the national building code (which is followed by many municipalities) that smokes be 120V. They have to be powered off the electric grid or something to that effect but no requirement for 120V. On most systems the (4 wire) smokes are powered off the SAUX power on the M1 which is battery backed up. The M1 is UL listed so it has been tested every bit as much as the 120V smokes.

The electrical and building inspectors didn't flinch at my 12v smokes. Just asked to see the battery and the UL sticker on the elk and tested them just like they would with 120V.

Many states adn localities are starting to adopt the International Residency Code which I believe refers to the International Fire Code. That specifies the detectors should be powered by the main building source supply (120 V feed) and have a battery backup. In addition they must operate independant of a Fire Alarm Control Panel or Central Station communication device.

I dont have a copy of the code. The above is from memory.

 

[BraveSirRobbin]

I'm not so sure this means there is no way I can use the ELK with smoke detectors, for monitoring and reporting purposes, it just means the ELK can't be the power source.

There is always the GE 120 Volt smoke detectors which have a relay on board. You need only one to replace just one of your 120 VAC smoke detectors, then wire the relay into the Elk. Search for "smoke" and my handle and you will see some posts on them. This is what I did because when I moved into my home I already had six of these in place.

 

[lugnut]

I'm not so sure this means there is no way I can use the ELK with smoke detectors, for monitoring and reporting purposes, it just means the ELK can't be the power source.

There is always the GE 120 Volt smoke detectors which have a relay on board. You need only one to replace just one of your 120 VAC smoke detectors, then wire the relay into the Elk. Search for "smoke" and my handle and you will see some posts on them. This is what I did because when I moved into my home I already had six of these in place.

Thanks for that. Looks like quite a few folks here have used those GE ESL 350 and the CC or CX suffix with the relay. I have 6 Firex ionization smoke alarms that were installed by the builder. They are 13 years old, so I think I'll just replace all those with the GE's for now, with the monitor zone back to the ELK. Probably add some more later, separately, and powered by the ELK.

 

[me2]

We ran into this same thing while building. The inspector didnt want to hear anything about any smokes but the 120v ones. Wouldnt discuss it. I had them put one detector right at the Elk location. Then I added a relay to that smoke. The relay is attached to the Elk. I have also added more smokes and heat detectors that are dc and hooked directly to the Elk.

 

[videocam]

I used the GE AC smokes ... they are all tied together via AC and the smoke on the end has a relay that I tie in to the Elk-M1G.
-Cam

 

[lugnut]

I used the GE AC smokes ... they are all tied together via AC and the smoke on the end has a relay that I tie in to the Elk-M1G.
-Cam

On the GE ESL350 smoke alarms, one thing that isn't clear to me is how the relay on the ESL350 CX and CC models operates in the event of AC power lost. It doesn't show anywhere (that I can find) in the GE literature how the relay trigger operates (i.e. from AC or DC voltage, and how much), and whether it is independent of the smoke alarm itself operating from 120VAC or from 9VDC battery. Has anyone simulated an alarm condition and positively confirmed that the relay operates the same, regardless of AC or DC power?

I know it would make sense that it would operate the same regardless of AC or DC, but to leave out such an important operational detail from the data sheet makes me wonder. I guess the document I have is actually more of a marketing sheet, since GE requires you to be an alarm professional before they will let you download data sheets.

 

[Madcodger]

I like BSR's idea of connecting to the Elk with the GE relay, but suggest you check with your insurer if you take a discount on your premium b/c you have a monitored system. They may be just fine with it, but better to check before a problem happens, rather than try to argue the case after. As for codes, you're pretty much stuck with whatever you and your local inspector can negotiate, I think.

For our house, I just installed the GE wireless (CADDX) detectors as a redundant system for the Elk. Probably overkill, but you likely don't need as many as you would for the interconnected system. For example, we have interconnects in each bedroom (for the fastest possible alerting to get someone outside) but only one wireless detector on that level, outside most of the bedrooms, in the hall. Also, you might want to consider heat-rise detectors in the attic, utility room, garage, and kitchen - where most people don't put smoke detectors but where a fire is most likely to start in many cases.

Hmmm... As I think about it, perhaps the best system is a combination of both the interconnects with the GE relay, and the CADDX wireless detectors. Probably no reason both can't be used, together.

 

[Carlton Bale]

For this type of application, wouldn't the GE 350CX be the correct model, as opposed to the GE 350CC? The way I read the specification sheet, the 350CC trips the relay only if it detects smoke, not if another alarm on the circuit detects smoke. the 350 CX trips the relay if any detector on the circuit detects smoke.

Here is the spec sheet that I found: http://www.gesecurity.com/portal/GESDownlo...pe=Data%20Sheet

Shouldn't the 350CX be used when replacing 1 existing alarm and connecting the smoke system to the security system?

 

[BraveSirRobbin]

Yes, there are two types of GE smoke detectors. One that trips its relay when it receives smoke, and another that trips its relay when it or any of the existing smokes trip. I used the later so I could incorporate my existing six smoke detectors into my HA system by replacing only one smoke detector.

I will not know exactly which one tripped, but will know that "something" tripped.

Here are a couple more posts with additional details.

http://www.cocoontech.com/index.php?showto...=smoke+detector

http://www.cocoontech.com/index.php?showto...amp;#entry56297

I also believe the ideal monitoring is with conventional "security" smoke detectors with line relays, but I wanted to use my existing detectors and opted for this methodology.

 

[aehusted]

I think the 10 year rule of thumb that you are talking about is true for ionization and optical type detectors. The ionization type use tiny bits of radioactive americium that decay over time. The optical type use an IR LED which also has a finite useful lifetime.
My own detectors (forget what brand) have an even more limited aesthetic lifetime. The white plastic turns to a nasty yellow-brown color long before the functionality degrades. This eyesore variety of planned obsolescence really annoys the hell out of me....

Another interesting thing I've come across, and I had never heard/read before, is that the National Fire Protection Ass'n recommends all smoke detectors be replaced at 10 years, regardless of whether they still appear to be working, because their data shows those old detectors have a 30% chance of failure going forward from there, due to various aging effects.

 

[Digger]

I think the 10 year rule of thumb that you are talking about is true for ionization and optical type detectors. The ionization type use tiny bits of radioactive americium that decay over time. The optical type use an IR LED which also has a finite useful lifetime.
My own detectors (forget what brand) have an even more limited aesthetic lifetime. The white plastic turns to a nasty yellow-brown color long before the functionality degrades. This eyesore variety of planned obsolescence really annoys the hell out of me....

Another interesting thing I've come across, and I had never heard/read before, is that the National Fire Protection Ass'n recommends all smoke detectors be replaced at 10 years, regardless of whether they still appear to be working, because their data shows those old detectors have a 30% chance of failure going forward from there, due to various aging effects.

Some mfg's do not use UV protection in the plastics (or not enough). As the detectors age they turn yellow then brown many times. I have a few of my older detectors (4 or 5 years) that one side that faces a window is yellowing and the opposite is still white. I hate to spend the money on a new detector just yet as they are only half way through their lifespan.

Even though the product is for indoor use and mounting on a ceiling it can still be exposed to UV rays.