Of the shelft device to tie HV smokes into ELK

felixrosbergen

Senior Member
Hi All,

About 6 months ago i saw a post about a device that you tie into the interconnect between your HV smokes sensors, it then had a relay or something from where you could tie it into an alarm panel.

I've seen schematics posted on how to make your own before, but this seemed to be an off the shelf products.

I've searched the forums, but have not been able to locate it again. Anybody know what i'm talking about?

Trying to tie my 'First Alert' smokes (HV, about 6 of them on an interconnect) into my ELK.

Any assistance is much appreciated.
 
BRK RM4 is the relay only device. I think I paid $15 for mine. You do have interconnected smokes right? If not, it won't work.

Also, another thing to be aware of is that it won't trip if the power is out as it requires 120V to operate the relay. I use it anyway because it's better than nothing. Maybe at some point I'll put in 4-wire smokes. But I had better things to do, and this is a good stopgap measure.
 
BRK RM4 is the relay only device. I think I paid $15 for mine. You do have interconnected smokes right? If not, it won't work.

Also, another thing to be aware of is that it won't trip if the power is out as it requires 120V to operate the relay. I use it anyway because it's better than nothing. Maybe at some point I'll put in 4-wire smokes. But I had better things to do, and this is a good stopgap measure.


I might be wrong but, I think that there is a "trigger" type wire that signals the rest of the detectors to sound. Someone explained to me that in the wire run to my alarm panel contained white, black, ground and red. white, black and ground are 110 and the red was 9volts (signal or interlink) we ended up ordering a module from Kidde (same as smokes) that has a relay in it. I was wondering if the 9volts changed state when in alarm, (energized to de-energized) couldn't I just put a cheap relay to trigger of the voltage and change the state of my dry contacts from the relay... I haven't gotten to try yet as we are ordering the part for it. When I put it in I will try playing with it.
 
My understanding is that the signal on the interconnect either does not have enough power, or it does some weird stuff to signal the other smokes which makes it incompatible with using a relay directly with it.

Of course, I have not tested it.
 
This is not a good idea for many reasons. Those relay adapters you speak of are not designed to do what you are asking. They are designed to turn on ventilation fans or close fire doors. Read ALL the instructions on these relays before using them for that.

Second, HV smokes generally are ionization alarms, designed for a fast response but they are prone to false alarms. Not a problem until the fire department gets involved. For this reason, in some areas, ionization alarms can't be used on a monitored panel.

Third, of course the ever popular, what happens when the power goes out, like it often does during a fire?

There are really even more reasons but I'll stop here. Follow the codes, leave your HV smokes in place, and add in smokes designed for a panel, and do it correctly.
 
This is not a good idea for many reasons. Those relay adapters you speak of are not designed to do what you are asking. They are designed to turn on ventilation fans or close fire doors. Read ALL the instructions on these relays before using them for that.

Second, HV smokes generally are ionization alarms, designed for a fast response but they are prone to false alarms. Not a problem until the fire department gets involved. For this reason, in some areas, ionization alarms can't be used on a monitored panel.

Third, of course the ever popular, what happens when the power goes out, like it often does during a fire?

There are really even more reasons but I'll stop here. Follow the codes, leave your HV smokes in place, and add in smokes designed for a panel, and do it correctly.

First, I whole heartedly agree that when it comes to life safety, NO CORNERS should be cut at all. Jerry rigging should NOT be done for an alarm system where much is at stake (lives and such) In the context of the system I was working on, there are smokes made for and powered by the system as well. The client wanted also to monitor the status of his KIDDE smokes (over and above requirement) The KIDDE unit also supervises the power. The alarm panel is also programmed to shut down hvac if either our smokes or theirs go off. (ok'ed by AHJ and sign off by inspector.) Our application (not designed by me) was not to cut corners but to add to the system. All work is to code and done correctly.

just sayin.

Dan :)
 
http://www.brkelectronics.com/product/RM4


After signal15 mentioned the name i found the unit.

Should this work? It mentions CO alarms rather than smokes... If you test a smoke with the button does that test the interconnected ones as well?

With regards to false alarm so far in 1 year i haven't had any even though they are ionizing.. i assume you can get NextAlarm to call me first before sending the fire dept.
 
http://www.brkelectronics.com/product/RM4


After signal15 mentioned the name i found the unit.

Should this work? It mentions CO alarms rather than smokes... If you test a smoke with the button does that test the interconnected ones as well?

The NFPA 72 2007 does not allow this. Its your house and you are welcome to do as you please, but you also have other stake holders such as your insurance company that insures your house from lose (with your associated discount for a monitored alarm) and potentially the people you may eventually sell your house to. At least I'd get a building inspector to sign-off on this to protect yourself now that you've publicly stated your wiring it this way.

With regards to false alarm so far in 1 year i haven't had any even though they are ionizing..
You can probably find valid reason not to follow just about every building code or alarm code, and there are even many that vary based on where you live. In some areas it may be required that smoke alarms confirm an alarm by resetting and waiting for a second alarm, were in other areas it may be illegal to use that same verify feature. I never said the rules were 100% logical or even the best, just that they are the rules. I'm also NOT saying that these rules apply to everywhere, because many DO vary with location, but you should check. In the end you either follow the rules or you don't. These isn't an in-between.
 
http://www.brkelectronics.com/product/RM4


After signal15 mentioned the name i found the unit.

Should this work? It mentions CO alarms rather than smokes... If you test a smoke with the button does that test the interconnected ones as well?

Hah, funny. When I bought it, it said it was for fire alarms, and it said it was for triggering an alarm monitoring panel. They removed the alarm trigger part, and changed it to CO. Maybe their legal dept made them change it to avoid lawsuits.
 
Hah, funny. When I bought it, it said it was for fire alarms, and it said it was for triggering an alarm monitoring panel. They removed the alarm trigger part, and changed it to CO. Maybe their legal dept made them change it to avoid lawsuits.

So you have this installed and working? What smokes sensors do you have? I have First Alerts (6 of them i think).

So i guess i wire into into the box of the one in the basement and then run a loop from the alarm panel through it.
 
First Alert and BRK are the same company. I just put mine in the box to the smoke in the basement, wired it in according to the documentation, and ran a wire to my ELK. There are 5 connections:
- neutral
- hot
- traveler between smokes
- the two contacts that go to the panel

I know this isn't the best solution as it doesn't work when the power is out. A better solution would be smokes that were meant to tie into the alarm system, each into their own zone. But, I wanted something connected so I could get alerts to my phone if I was away, and this was the quickest/cheapest option. At some point, I'll put in 4 wire smokes, but I have other things to worry about now. The reality of it is, I'm in a better situation than I was before, even if it isn't ideal.
 
I too have HV smokes. They are BRK SC9120B.

If a BRK RM4 relay were attached to the line, can this be run to an Ademco Vista 20P? If so, how? It seems as though the output of the RM4 is full 120V AC. Am I wrong? Is it a low voltage output? Just wondering how to interface this.

Also, how easy (or difficult) would it be to change to 2-wire or 4-wire LV smokes, given that there's only wiring for HV smokes in place?

Thanks again for all your help.
 
First of all, don't post to a two year old thread.

The output of the RM4 is a Form C (SPDT) contact set. Connect it to a Vista 20P zone just like a door or window contact. Most likely you will want to connect the brown and gray wires. Be sure to identify the zone as a smoke zone so you get full time protection.
Do not remove your 120 VAC smoke detectors. They are required by code if you live in the United States.
 
First of all, don't post to a two year old thread.

The output of the RM4 is a Form C (SPDT) contact set. Connect it to a Vista 20P zone just like a door or window contact. Most likely you will want to connect the brown and gray wires. Be sure to identify the zone as a smoke zone so you get full time protection.
Do not remove your 120 VAC smoke detectors. They are required by code if you live in the United States.

The 120 VAC units are not smoke detectors, they are smoke alarms, there is a difference.

You can replace the 120 VAC alarms with a fire alarm system if it is installed in accordance with NFPA 72. Your area may fall under a different code body so it is important to check with a licensed installer and/or authority having jurisdiction.

The relay that is shown is not listed to connect 110V smoke alarms to a system and therefore doesn't meet code for this purpose.

With all the code stuff out of the way, if your going to do this anyway and call the fire department or central station. You will regret it when a alarm malfunctions, and they will.
Sent from my Galaxy Nexus
 
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