Smoke alarm in alarm system.

[HCI]

A smoke alarm that is tied into an alarm system is it an open or closed circuit before being tripped?

 

[Casualguy]

Smokes

Open, typically with an end of line resistor.

 

[HCI]

Ok here is the situation. I am trying to program a vista 20ps. I only have one smoke detector in right now but I am adding another Monday. The detectors also are heat sensitive also. I have it wired like the photo I attached with only 1 at the moment.

here is the problem when I test the detector it works like it is suppose to but after I stop the alarm and reset the detector it still shows a fault on that zone. I have to manually disconnect the wires and reconnect before it will be clear. Is the wiring correct? I am entering the code off sequence twice.

It is only a 2 wire smoke but does have the 2 positive connections.

 

[aboz]

Man seeing this thread birngs back memories, when I was an alarm dispatcher. I had a fire alarm in NYC and I had to dispatch thr FD first then call the premisis. When I called the prem, the woman says, "shoot, I just got out of the shower and the steam set the alarm off, and I am naked." At that moment thr FD showed up.

 

[truckracer]

Normally open usually.

Some smoke detectors are 4 wire meaning two conductors are power and two are normally open supervised contacts. Normally open (No detection) then closes when smoke is detected.

Some new alarm panels like many of the GE Caddx panels require a 2.2K resistor at the end of the line. "EOL resistor" as many veterans in the business refer to it.

Some more expensive and modern detectors are addressable on a data bus.

You have pair of wires that loop through everything and each detector gets it power and sends it's mac address to the panel several times per second. In the setup menu you program the location of that address and that way you know where the smoke is located when the panel gets that address showing alarm mode.