Mixing old and new 4-wire System Sensor smokes

[Lagerhead]

Does anyone know whether the "old" System Sensor 2112-type smoke detectors can be mixed in a zone with the "new" System Sensor 4WTA-B models?

Specifically, are the old units susceptible to damage from the reverse voltage that is used to activate the sounders on the new units?

 

[Sandpiper]

Does anyone know whether the "old" System Sensor 2112-type smoke detectors can be mixed in a zone with the "new" System Sensor 4WTA-B models?

Specifically, are the old units susceptible to damage from the reverse voltage that is used to activate the sounders on the new units?

The System Sensor 2112 units I'm familiar with respond to the universal 3-pulse temporal fire alarm code, not to voltage reversing. I doubt if voltage reversing would harm the units (but I am not sure), but I know they will quit working if the voltage is reversed.

So, no, they cannot be mixed. I would not recommend using any component in a manner for which is was not designed, especially in a fire safety application.

 

[jlehnert]

You sure the 2112s don't do polarity reversal? I'm pretty sure I'm running 2112s and using polarity reversal to trigger the sounders. Will try to check later this afternoon if I get a chance.

One of the selling points of 4-wire vs 2-wire is the (supposed) ability to mix brands within the zone, so I would venture that you can mix them.


Best answer to the question though would be to drop a line to System Sensor. Straight from the horse's mouth, etc.

 

[gatchel]

Here is the page with links to the installation manual for the 2112:

http://www.systemsensor.com/html/search_all.php?s=2112

Here is a snippet from the Specs page:

Specifications
Diameter: 5.5 inches (140 mm)
Height (including mounting bracket): 2.05 inches (52 mm)
Weight: 7.5 oz. (210 g)
Operating Temperature Range: 32° to 100° F (0° to 38°C)
Operating Humidity Range: 10% to 93% Relative Humidity, Noncondensing
Latching Alarm: Reset by momentary power interruption
Audible Signal: 85 dBA minimum when in alarm or with supply polarity reversed *******************
Heat Sensor: 135° F Fixed Temperature Electronic Thermistor

In short, it looks like the 4WTA-B is a direct replacement for the 2112, since this is the case mixing should not be a problem.

You may want to double check with system sensor to confirm. The voltage reversing doesn't look like it would be a problem.

 

[Sandpiper]

Here is the page with links to the installation manual for the 2112:

http://www.systemsensor.com/html/search_all.php?s=2112

Here is a snippet from the Specs page:

Specifications
Diameter: 5.5 inches (140 mm)
Height (including mounting bracket): 2.05 inches (52 mm)
Weight: 7.5 oz. (210 g)
Operating Temperature Range: 32° to 100° F (0° to 38°C)
Operating Humidity Range: 10% to 93% Relative Humidity, Noncondensing
Latching Alarm: Reset by momentary power interruption
Audible Signal: 85 dBA minimum when in alarm or with supply polarity reversed *******************
Heat Sensor: 135° F Fixed Temperature Electronic Thermistor

In short, it looks like the 4WTA-B is a direct replacement for the 2112, since this is the case mixing should not be a problem.

You may want to double check with system sensor to confirm. The voltage reversing doesn't look like it would be a problem.

Wow. I didn't know there were so many versions of the 2112. It is the 2112ATL that responds to the 3pulse temporal pattern. It looks like the 2112AT and the 2112ATR will respond to voltage reversing. I stand corrected.

Thanks for the help.

 

[Lagerhead]

Thanks gentlemen for your perspectives.

I have 2112TBs with heat but without sounders currently. The 4WTs are meant to be an upgrade by adding sounders, but I am only replacing half of the zone at the moment. This is why I am interested in the mixing question.

I already asked System Sensor via their website, with no response. What I may do is take one of the removed 2112 units and give it the reverse voltage. At worst, I will be sacrificing a spare that is unlikely to be used anyway.

 

[Lagerhead]

Best answer to the question though would be to drop a line to System Sensor. Straight from the horse's mouth, etc.

Well -- naturally, after getting this far -- I heard from System Sensor tech support today:

"They should work fine."

I will proceed, and report if not!!

 

[Lagerhead]

Installed and verified. No issues.