Elk and Smoke Detectors


Senior Member
I am getting ready to start moving my fire alarm stuff from my FA panels to the M1 and I want to be sure I understand all that I have been reading here on how to set things up on the Elk. I currently have about 20 2-wire smoke detectors on 8 zones and will be moving to around 30 4-wire smoke detectors. I will only be putting 1 or 2 detectors on each zone so I will pretty much need an end-of-line relay for each detector. Here are some of the things I want to understand from the folks who are already using the Fire Alarm features of the M1:

1- I see that ESL and NAPCO make 4-wire detectors with built-in end-of-line relays. Anybody using these? Is this a good way to go?

2- How do you calculate the power needed for smoke detectors? I was thinking of adding standby current for all 30 + current draw of 30 EOL relays + alarm current for maybe 3 detectors tripped at the same time. Is this reasonable?

3- I am planning to use 10 Amseco motorized Bells for my fire audible circuit. These draw 60mA each for a total of 600mA. Should be no problem for the OUT2 bell circuit, right?

4- I was thinking of getting smoke detectors with built-in sounders to supplement the bells but I am leaning away from that idea because I don't see how bell-silence can work with sounders built into the detectors. Is there a way to silence built-in sounders from a keypad without resetting the tripped detector?

5- If I need more power for my smoke detectors and decide to use a separate power supply such as an Elk P412, then I assume the proper wiring strategy is to put a relay on SAUX and run the P412 power output though the contacts of the relay so a smoke reset will interrupt it. Is this how everybody else is doing it?
I'm installing 11 4 wire smokes in my new residence, each on their own zone.

Perhaps I'm planning this incorrectly (quite possible), but I was planning on a supervisor resistor on each individual zone for the smokes triggered contacts and making a daisy chained run with the power to each alarm and a relay after the last detector, and giving it it's own zone.

In other words, I am planning on running a single power line through each detector, give it an EOL relay with that signal going through a resistor. If the power fails to any of the smokes, it would show on it's own input.

I think they sell the smokes sans the sounder so you can silence them via your panel, so getting ones with sounders will defeat that feature.

Your plan for power supervision will work as long as power actually daisy chains from detector to detector (no T or splitter type connections in the power loop). I thought about doing it that way but the wiring path didn't make sense unless I used a separate wire for power or used 6 conductor fire wire so I would have a return pair for power on each zone to feed to the next zone in the chain.
Spanky said:
I suggest you use System Sensor Smoke Detectors. They are tested by UL for the M1.
System Sensor detectors would be great but they aren't sold through Worthington any more. The retail channels are a little higher per detector than I want to pay.
System Sensor has some of the best detectors on the market. If the price difference is not that much higher than your budget and you can swing it I would seriously consider them.

If you have an existing system of 4 wire detectors and you can phase them in as money permits etc it might make it easier. You cannot mix 2 wire detectors on the same zone and the M1 can only use them on ZN16.


Just woke up and realized you have all 2 wire detectors presently. If they are a type that is compatible with the ELK you could move them over for now and phase in the 4 wires. I beleive that the ELK is limited to 20 on ZN16.