Putting regular smokes on a polarity reversal module

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DJDiehl2K
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Putting regular smokes on a polarity reversal module

Post by DJDiehl2K » Thu Dec 14, 2017 10:34 am

I only have one IDC and I want to use regular smokes in the hall, and sounder-smokes in rooms. I have a System Sensor 2151 (first gen) and 2151 (second gen). I plan on adding System Sensor 2wta-b's and a RRS-MOD. I could make a circuit like 2151s -> rrs-mod -> 2wta-b's -> eolr
But I'm short on wire. Is there a way to use 2151s on an rrs-mod without damaging the 2151s? I'm assuming that when the module sounds the detectors, it reverses polarity and the current limit is raised. Would this damage 2151's? Would reversing the polarity of an activated 2151 reset it? If I can't use 2151s on an rrs-mod, I'll just have to buy more wire. I thought of using diodes but I think if I put diode protection on the 2151's, it would defeat the rrs-mod because polarity wouldn't reverse, unless maybe I defeat supervision.
Currently a probie at Digital Media & Security
GE Concord 4 Owner | Burglar & Fire Alarm Hobbyist
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harrison
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Re: Putting regular smokes on a polarity reversal module

Post by harrison » Thu Dec 14, 2017 9:12 pm

You should be fine combining them. It shouldn't damage the 2151 to reverse polarity on them, and I believe they are designed to behave normally in such a situation, as in not resetting when polarity is reversed. I've accidentally fed negative 24 volts to a 2W-B and it behaved normally, I would expect the same from the 2151 since it's more or less the same product in a different shape.

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Re: Putting regular smokes on a polarity reversal module

Post by DJDiehl2K » Thu Dec 14, 2017 11:32 pm

harrison wrote:You should be fine combining them. It shouldn't damage the 2151 to reverse polarity on them, and I believe they are designed to behave normally in such a situation, as in not resetting when polarity is reversed. I've accidentally fed negative 24 volts to a 2W-B and it behaved normally, I would expect the same from the 2151 since it's more or less the same product in a different shape.
But it doesn't just reverse polarity, I think it also increases the current on the IDC because the sounders need more current. I'm worried that it could fry a 2151.
Edit: it looks like it switches directly to aux power on the IDC, essentially connecting the smokes directly to non-current limited aux power in reverse. I don't think directly connecting it would be a good idea. I think I'll just have to buy more wire.
Currently a probie at Digital Media & Security
GE Concord 4 Owner | Burglar & Fire Alarm Hobbyist
View System Tests on YouTube

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