Adding a Relay Module to Security panel for System Sensor 2112i3

[TomM]

Last year I replaced several old smoke detectors in my home with newer System Sensor 2112i3 units previously used as part of a Brinks security system at another home. I wired them as follows:
 
* From security panel: AUX+ (red wire) to Sensor V+; AUX- (black wire) to Sensor SYNC; Zone2 (yellow wire) to Z+ IN; Zone G (green ground) to Z- IN.
 
These smoke detectors are connected in series and have a resistor installed in the last unit and use 12v power from the security panel. Everything tested fine. However, the alarm beeper in each unit would not reset/stop after testing until I powered down the security board. I was told that I needed to install a relay module at the security panel side and use an virtual switch to briefly interrupt power to the smoke detectors. This was supposed to reset the smoke detectors and, therefore, stop the smoke alarm beeping.
 
Here's my problem... I installed the 5V relay module on the panel and the virtual switch for it works fine. But, the 12V to the smoke detectors is not being interrupted as expected. I wired the AUX - wire from the panel to the COM point on the relay and then connected the black wire leading to the smoke detectors to the NO point on the relay module. When I turn the virtual switch on or off that black wire connection is interrupted as it's supposed to be. After some testing I determined that the smoke detectors were still getting 12V power even without the AUX- black connection from the panel. However, when I removed the Zone G connection from the panel to the smoke detectors, and removed the black wire connection from the panel, then the 12V power to the smoke detectors was off. In other words, BOTH wires needed to be disconnected in order to interrupt 12V power to the smoke detectors.
 
Can anybody help me figure this out?
 
 

 

[RAL]

It would help to have some more information.
 
1. What brand/model is your alarm panel?
 
2. Where is your virtual switch signal coming from?
 
3. Why are you using a 5V relay?  Most alarm panels operate on 12VDC, and usually you would use a 12V relay. Unless your virtual switch only produces a 5V output?  
 
You mention a SYNC terminal on the smoke detector.  I'm puzzled by that.  The System Sensor 4-wire units I'm familiar with don't have such as terminal.
 
I would wire the relay so that it controls the +AUX (+12V) wire.  Connect +AUX to the COM terminal of the relay.  Assuming the relay is unpowered by your virtual switch during normal operation, connect the NC terminal of the relay to the smoke detector V+ (+IN) terminal.

 

[TomM]

It would help to have some more information.
 
1. What brand/model is your alarm panel? *** It's a Konnected Alarm Panel V2 from www.Konnected.io
 
2. Where is your virtual switch signal coming from? *** It is created in the SmartThings app after the relay module is installed on the Konnected Alarm Panel.
 
3. Why are you using a 5V relay?  Most alarm panels operate on 12VDC, and usually you would use a 12V relay. Unless your virtual switch only produces a 5V output?  *** The relay module only requires 5V to operate and there is a place on the Konnected board when installed that gives it 5V.
 
You mention a SYNC terminal on the smoke detector.  I'm puzzled by that.  The System Sensor 4-wire units I'm familiar with don't have such as terminal.*** Wish I knew how to provide a picture. This System Sensor does have a SYNC terminal where the 12V AUX- from the panel connects to the smoke detector. I believe that this model 2112i3 is slightly different because it was provided through a 3rd party Security company like Brinks later to be bought by ADT.
 
I would wire the relay so that it controls the +AUX (+12V) wire.  Connect +AUX to the COM terminal of the relay.  Assuming the relay is unpowered by your virtual switch during normal operation, connect the NC terminal of the relay to the smoke detector V+ (+IN) terminal.

 

[RAL]

1. What brand/model is your alarm panel? *** It's a Konnected Alarm Panel V2 from www.Konnected.io

Ok, the fact that it's a konnected panel explains a lot about why you're doing things the way you are.  Not really a true alarm panel in my opinion.
 
 

You mention a SYNC terminal on the smoke detector.  I'm puzzled by that.  The System Sensor 4-wire units I'm familiar with don't have such as terminal.*** Wish I knew how to provide a picture. This System Sensor does have a SYNC terminal where the 12V AUX- from the panel connects to the smoke detector. I believe that this model 2112i3 is slightly different because it was provided through a 3rd party Security company like Brinks later to be bought by ADT.

I think once you get up to 5 posts, you'll be able to post a picture.  In the meantime, you can place your picture on a web site like imgur.com and place a link to it in your post.
 
Brinks and ADT did some strange things by having proprietary smoke detectors for use with their proprietary panels.  There are a few discussions in various forums that say the 2112i3 will not work with anything but a Brinks panel.  What exactly that means isn't clear.
 
Standard smokes are designed to handle tandem ring, where all the detectors will sound their internal sounders in a synchronized  fashion (usually required by code).  This is accomplished through the use of a reversing relay which reverses the polarity of the power, causing them all to start sounding.  Brinks chose to do it differently, and that might have something to do with the Sync terminal you have on your detectors.  You probably can get them to trigger an alarm, but whether or not you can get them to do tandem ring, I can't say.
 
Use the 5V relay that you have, and wire it up to drop the +12V from your +AUX power and see if that works. 
 
A couple of other things...
 
4-wire smokes should have an end-of-line resistor after the last detector in the daisy chain, connected across the sensor terminals, which you say you have.  This allows the alarm panel to detect a break in the wiring.  
 
4-wire smokes should also have an end-of-line relay after the last smoke detector in the daisy chain to supervise power.  If power is lost due to a break in the wiring, the relay will trigger an alarm.  Without the relay, the smokes could be getting no power at all and you'd never know it.
 
The konnected web site makes no mention of these things in their instructions on how to wire up a smoke detector.  It's not at all clear to me whether it would work with an EOL resistor.  If it can't handle that, that's bad news.
 
In fact, the example they show of an ESL smoke detector shows it being wired to the release relay terminals which some detectors have which are meant for releasing electric door locks and such, and not the proper sensor terminals.  No wonder they warn you not to depend on the konnected for life safety!

 

[TomM]

Ok, the fact that it's a konnected panel explains a lot about why you're doing things the way you are.  Not really a true alarm panel in my opinion.
 
 

I think once you get up to 5 posts, you'll be able to post a picture.  In the meantime, you can place your picture on a web site like imgur.com and place a link to it in your post.
 
Brinks and ADT did some strange things by having proprietary smoke detectors for use with their proprietary panels.  There are a few discussions in various forums that say the 2112i3 will not work with anything but a Brinks panel.  What exactly that means isn't clear.
 
Standard smokes are designed to handle tandem ring, where all the detectors will sound their internal sounders in a synchronized  fashion (usually required by code).  This is accomplished through the use of a reversing relay which reverses the polarity of the power, causing them all to start sounding.  Brinks chose to do it differently, and that might have something to do with the Sync terminal you have on your detectors.  You probably can get them to trigger an alarm, but whether or not you can get them to do tandem ring, I can't say.
 
Use the 5V relay that you have, and wire it up to drop the +12V from your +AUX power and see if that works. **This is what worked!
 
A couple of other things...
 
4-wire smokes should have an end-of-line resistor after the last detector in the daisy chain, connected across the sensor terminals, which you say you have.  This allows the alarm panel to detect a break in the wiring.  
 
4-wire smokes should also have an end-of-line relay after the last smoke detector in the daisy chain to supervise power.  If power is lost due to a break in the wiring, the relay will trigger an alarm.  Without the relay, the smokes could be getting no power at all and you'd never know it.
 
The konnected web site makes no mention of these things in their instructions on how to wire up a smoke detector.  It's not at all clear to me whether it would work with an EOL resistor.  If it can't handle that, that's bad news.
 
In fact, the example they show of an ESL smoke detector shows it being wired to the release relay terminals which some detectors have which are meant for releasing electric door locks and such, and not the proper sensor terminals.  No wonder they warn you not to depend on the konnected for life safety!