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WTB: Smoke Detectors #2112/24ATR

Lightning has damaged the "initiating" relay of four 2112/24ATR's. Each of the four units exhibit the normal pulsing red LED. Each also sounds its internal horn when the test "button" is depressed. However, each of the four do not place a short across the signalling circuit, thus the panel and all the other detectors do not know that any of the four has tripped. When I "short" the terminals behind the detector the panel and other smoke detectors leap into action and do their temporal thing, plus sounding additional electronic sirens, in a temporal pattern, though not in unison with all the smoke detectors.

We monitor/service this house with twenty-one SD's. The "aux" relay of the 2112/24ATR is used to light up two panels, each with five red LED's indicating which area of the house the smoke is in. Installed in 2001.

The conclusion is that the "initiating" relay that places the "short" across the pair is not being energized, or the points are frozen open.

I replaced each of the four units temporarilly with 2112/24AT's (which do not contain the "aux" relay). All the other units were successfully tested today (fire department present and signed off on Certificate of Compliance - house being sold).

Anyone have any of these System Sensor units in their original boxes that I can buy?

The recommended replacement is 4WTAR-B, but I'm not sure that the reversing relay (RR-2) in the present system will act on the 4WTAR-B in the same fashion as the reversing relay (RRS-MOD) specified for use with a group of 4WTAR-B's.

The RR-2 and the RSS-MOD act differently on the power circuit. The RR-2 simply reverses the polarity, and then opens/closes its relay to produce the temporal pattern, in unison, in all the detectors. The RSS-MOD operates in a different manner (don't know how) on the

4WTAR-B's to produce the temporal pattern, all detectors in unison.

One unfortunate conclusion that I have reached is that the pulsing red LED is an indicator that, as a minimum, there is power at the unit, and that the "initiating" relay is NOT supervised within the detector. Here I have four non-functioning relays, and no outward indication that they are damaged, and incapable of triggering an alarm elsewhere on the premises or at the central station.

Another good reason for periodic testing of smoke detectors, especially after lightning storms!

Thanks. Charlie

Reply to
chasbo
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if it were me I'd go back on the company.. have them spec. a replacement or explain why they built a product with no newer replaceable product available.

But thats just me..

Reply to
RockyTSquirrel

The manufacturer is System Sensor and there is indeed a replacement model. The 4WTAR-B will suit the gentleman's application.

Reply to
Robert L Bass

I wouldn't mix the 2112/24 and series-i smokes when you have line reversal. They do require different line reversal mods. IIRC the RR2 just makes series-i smokes emit a steady tone.

Although I have never tried it using discreet loops and both reversal mods.

Reply to
JoeRaisin

Hmm. I'm not 100% certain but it appears the RRS-MOD will work with older and newer series 2-wire smokes. Here's the short answer from System Sensor on the RRS-MOD:

"The RRS-MOD?s design is flexible to accommodate virtually any application. The RRS-MOD is compatible with both 2- and 4-wire i3 series detectors operating over 12V and 24V systems. The module can be used with either bell/alarm, alarm relay, or NAC outputs, and its field-selectable switch accommodates both coded and continuous alarm signals."

The following is on the RR2:

"The RR2 Polarity Reversal Relay Module is intended for use with 2-wire and

4-wire detectors with built-in sounder, such as the following System Sensor models: 2100AT, 2112/24AT, 2112/24ATR and 2112/24AITR. Per NFPA requirements, the RR2 is designed to allow all detectors on a loop to sound when one goes into alarm. The RR2 can differentiate between steady and pulsed panel outputs."

Checking the cur sheets, both units have nearly identical schematics. Both employ a switch to select continuous or pulsed operation. The newer RRS-MOD unit's output is temporal, whereas the RR2 is "pulsed." This appears to be the only significant difference.

I agree with you that it might not be a good idea to mix the two series on a single IDC. A call to System Sensor's tech support line should get a definitive answer to that one though. Following are their phone numbers.

800-736-7672 USA and 905-812-0767 Canada.

There is one problem with this whole deal that I overlooked at first. There doesn't seem to be a "2WTAR-B" in the current line-up. If the OP needs those relays AND the sounders on 2-wire System Sensor smokes he may be SOL after all. :^(

Reply to
Robert L Bass

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