How do I silence my fire alarm without a panel?

I have a fire alarm board and I have no panel. I was able to make light switches for a drill feature, and also one for a silence feature, however, the silence feature just turns the alarm off, and I want it to keep the strobe flashing when silenced. Thanks.

you would need a 4 wire alarm or some sort of syncing module that supports audible silence (which to my knowledge dont exist)

My system sensor classic ceiling mount has 4 wires, with jumper plates. Would that work?

Yeah, System Sensor SpectrAlert Classics are four wire.

How would I do that then so that my horn and strobe go off when pull station is pulled and silence makes only the strobe go off?

I’m assuming you’re using a switch to silence the horn? If so you have to wire the horn and strobe separately, with the horn circuit having the silencing switch on it.

When I pull my pull station, would the strobe and the horn go off still?

Depending if the Switch is on or not. If you want the Silence to go back to ON (Switch Position, so current flows) after the Pull is reset, you will need latching relays.

I want it to go back to off when the pull is reset. How can I do this? Where do the positive and negative and other wires going to next alarm go if I remove jumper plates and use horn and strobe seperate? Thanks

How can I wire them separately?

That will require 3 Relays, Relay 1 is the one that is on and stays on when the silence Switch is turned on. Relay 2 is energized by the output of relay 1 and cuts Power from the HORN NAC. Relay 3 is connected to the reset switch (Or Pull Station being reset) , which energizes (Or De-Energizes, depending on how its wired) when the reset switch is on and cuts the power loop to Relay 1 to deentergize It and Relay 2, which resets the scilence switch.

When the reset switch is ON, (Power to the Board), Current flows into RELAY 1 and the Pull station. When the Pull Station is activated (or if DRILL is turned on), current flows to NAC 2 (Strobe) and to the COM pin on RELAY 2. If RELAY 2 is energized, current does not go anywhere. If RELAY 2 is not, Current will flow from the COM Pin to the NC pin, which is hooked to NAC 1, sounding the Horns. When the SILENCE Switch is Turned ON, Current flows from RESET Switch to the Coil of RELAY 1, which energizes it. Current then flows out of RELAY 1’s NO Pin and though RELAY 3 and then to RELAY 1’s Coil again, this creates a loop, and now RELAY 1 is latched, meaning that the SILENCE Switch wont do anything anymore. Its Done its job.

Also connected to RELAY 1’s NO pin is the Coil for RELAY 2, which Energizes, and disconnects the HORN NAC altogether, with the STROBE NAC still getting Power.

When the Alarm is over, you will need to turn the RESET Switch to OFF, which De-Energizes RELAY 3, which then breaks the loop that RELAY 1 has, which then it De-Energizes, which then RELAY 2 de-energeizes, reconnecting NAC 1. When the Pull Is reset, the RESET Switch MUST be turned off and then on again for it to work.

Is there any way to do so without relays?

My NAC is a horn strobe, so how can I do so with that? On the diagram, it has two different NACs.

The two different NACs are your horn and strobe circuit. But if you’re wanting to have a simpler approach, refer to this diagram:


Red: 24V power
Grey: IDC Circuit
Orange: Strobe Circuit
Green: Horn Circuit (Which has the silence switch (SPST) to shut off the horns)
Black: Common Negative

If you’re planning on using 4 wire smokes, then you would have to use @MrFireAlarm diagram. Because once the smoke detector is activated, you have to cut the power to the detector to reset it.


And what should I do with my system sensor advance 3 wire alarm? Thanks a lot for your help!!

Only use one of the two + terminals, the other one is for panel supervision, but in this case its redundant.

Would I be able to use the strobe only then or can I not control those independently?
Thanks a lot for your help!

What model number is your advance? That will determine that…

System Sensor P2WL-LF

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For that you’re gonna need a System Sensor MDL sync module for two wire system sensor horn strobes like the P2R.

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