Smokes not tripping each other


Active Member
So I'm in the process of installing my 4-wire smokes with my Elk. I've got two smokes on one zone at this point. All the smokes are homerun so I just hooked them both up to the terminal on the same zone. They work great independently in terms of when I hit the test button the Elk goes off and that detector's sounder goes off. But the other one's sounder does not. Aren't they supposed to all go off?

If so, what do I have wrong / misconfigured. I have the NO and Common connectors from both detectors going to the Zone/Neg contacts on the M1 zone, with a resistor bridging them on the panel. And no I don't plan on the resistor being their permanently ... just testing right now.

EDIT: The zone is configured as type 10 if that helps.
I believe you will need the line reversing relay module to power all of the sounders on the zone.
Test the smokes to see if they go into alarm on power reversal by swapping the smokes + and - power leads. If they start sounding, then you need a polarity reversal relay module. Which is basically a double pole, double throw relay wired to reverse the current flow. The reversal modules you buy are UL listed for the application.

You will want to write a Rule so that if the Fire alarm activates then trigger one of the outputs which will trigger the polarity reversal module. Write another Rule so that when the system is disarmed, the output triggering the polarity reversal relay will clear.