ELK M1G 4 wire smokes EOLR

[jsp]

I have started installing my different sensors. I think I have figured out the wiring and EOLR position for the CO and NG detectors (you will correct me if i'm wrong!!) and now I am not sure I got it for the smokes.

I have ELK M1G control, American Sensors ASD200 4 wire smokes and CO8RD CO detectors.

This is how I think the CO should be connected:

EOLR on NC and NO
Zone Input on NO
Zone NEG on COM
Is that correct? I am doing the same thing for the smokes? In the ELK manual it seems like the EOLR is installed on the alarm contacts but it doesn't seem to be a form c relay on the diagram.

JS

 

[jsp]

I think my assumptions were right, connected everything and powered up with no trouble.

 

[Lagerhead]

In the ELK manual it seems like the EOLR is installed on the alarm contacts but it doesn't seem to be a form c relay on the diagram.

The point of the EOLR (end-of-line relay) is to monitor the power supplied across the length of the smoke detector string, and indicate trouble in the event the power run should be broken (open or shorted at any point) for some reason.. It should be installed at the end of the line, which is to say, at the farthest point in your smoke detector run. You do have your smoke detectors wired all together in parallel in a continuous run, connected to one zone at the panel?

 

[jsp]

The point of the EOLR (end-of-line relay) is to monitor the power supplied across the length of the smoke detector string, and indicate trouble in the event the power run should be broken (open or shorted at any point) for some reason.. It should be installed at the end of the line, which is to say, at the farthest point in your smoke detector run. You do have your smoke detectors wired all together in parallel in a continuous run, connected to one zone at the panel?

I wired them both to their own zones for the moment

 

[apostolakisl]

I'm confusied if we are talking about and end of line resistor, or endo of line relay.

Smoke detectors (the four wire type) have two wires for power and two wires for alarming. The detectors should be daisy chained together and the last detector on the daisy chain should have the resistor between the two alarming wires, closing the circuit (partially) and thus reporting 7ish volts at the panel. If the wire is damaged such that one (or both) of the strands are cut, the panel will report 13ish volts and will indicate trouble. If the wire is damaged such that it shorts, it will report 0 volts at the panel and false alarm. If there is a real fire, the detector will short the wires (prior to the resistor, remeber it is beyond the last detector) and the panel will report 0 volts and alarm.

The two power wires are monitored for damage by using a relay and the two alarm wires. After the last detector in your set of daisy chained detectors, a relay is powered by the same 12 volts that the detectors are powered by. Connected to the NO contacts of that relay are the two alarm wires. If power is making it all the way to the last detector, the relay will also have power, and it will close the NO contacts completing the circuit on the two alarm wires. The resistor is also right there, so when the relay closes the circuit, the panel sees 7ish volts. If power fails to make it to the relay, the contacts will open, and the panel will see 13ish volts and report trouble.

I believe that gas and CO detectors that run on 4 wires do it the same way.

You can buy detectors that have the relay built into them which makes life a little easier. I bought one of these to put at the last location and rest are non-relayed.

You can also put relays at every detector if you like, but the resistor still only goes at the end. Personally, I think that is a little overkill since I am using the screw down terminals of the detectors as the connectors in the daisy chain, there is pretty much no way for electricity to get passed down the line without it also powering that detector.

 

[jsp]

Sorry for the confusion, Resistor.

 

[Zellarman]

The point of the EOLR (end-of-line relay) is to monitor the power supplied across the length of the smoke detector string, and indicate trouble in the event the power run should be broken (open or shorted at any point) for some reason.. It should be installed at the end of the line, which is to say, at the farthest point in your smoke detector run. You do have your smoke detectors wired all together in parallel in a continuous run, connected to one zone at the panel?

Just browsing here, before I possibly pick up an Elk. Wondering though, how there's any significance in the last device hooked up in a parallel circuit, wouldn't they all be seen identically from an electrical standpoint? Maybe they need to be wired in a different way? Isn't having each device w/ a home run connected to the same two terminals technically a parallel circuit?

 

[Del91574]

Parallel is somewhat misleading, they are wired as a NO circuit, in a continuous fashion and not in parallel, otherwise there is no supervision. The point is to wire it so if a wire is disconnected/broken or a device removed the panel will see it. If they all were wired in parallel, removal of a single device/wire would not affect the circuit, not good in a fire alarm.

The EOL and power supervisory relay affects if the panel sees the EOLR on the alarm contact side, and removal of power will cause the relay to remove the EOLR off the alarm contact side of the circuit, same as disconnecting a wire on the same side.

 

[cornutt]

Just browsing here, before I possibly pick up an Elk. Wondering though, how there's any significance in the last device hooked up in a parallel circuit, wouldn't they all be seen identically from an electrical standpoint? Maybe they need to be wired in a different way? Isn't having each device w/ a home run connected to the same two terminals technically a parallel circuit?

From an electrical standpoint, here's how to picture it:

Imagine you have a zone with nothing but an EOL resistor. This zone is always secure; the panel sees the resistance of the EOL resistor all the time. Now add the power supervision relay, which is electrically in series with the EOL resistor. The relay is closed as long as power is applied, so the panel still sees the EOL resistor. If power is removed from the supervision relay, the relay opens and now the panel sees an electrically open zone (infinite resistance). The panel treats this as a trouble condition.

Now, add sensors to the zone. Each sensor is wired across the two legs of the zone. Since the sensors are normally open, this makes no difference to the zone as long as there is no fire; the sensors may as well not be there. However, if a sensor detects, it closes its internal relay, which shorts out the zone. The panel now sees zero resistance on the zone. This is the alarm condition.

Physically, you want to wire the sensors in a point-to-point configuration, as opposed to a home-run or star configuration. And you want the ends of the wires for each leg to be directly on the terminal screws of the sensor, and not twisted together or anything like that. The idea is that if someone tries to remove the sensor, when they unscrew a terminal screw, the wires will fall out and the continuity down the line will be lost. You want the continuity to depend on both of the wires touching the terminal screw. That's why you don't want to twist the wires together, or pigtail the wires.

Consider what happens if a terminal screw is unscrewed at a sensor, or if the cable is damaged. If a zone conductor is broken, the zone goes open and the panel indicates trouble. If a power conductor is broken, the supervision relay at the end of the run loses power and it opens its relay, which opens the zone and the panel indicates trouble. The panel will only indicate alarm if the zone is shorted, which presumably can only happen if a sensor goes into alarm and closes its relay.

 

[Del91574]

From an electrical standpoint, here's how to picture it:



Physically, you want to wire the sensors in a point-to-point configuration, as opposed to a home-run or star configuration. And you want the ends of the wires for each leg to be directly on the terminal screws of the sensor, and not twisted together or anything like that. The idea is that if someone tries to remove the sensor, when they unscrew a terminal screw, the wires will fall out and the continuity down the line will be lost. You want the continuity to depend on both of the wires touching the terminal screw. That's why you don't want to twist the wires together, or pigtail the wires.

Consider what happens if a terminal screw is unscrewed at a sensor, or if the cable is damaged. If a zone conductor is broken, the zone goes open and the panel indicates trouble. If a power conductor is broken, the supervision relay at the end of the run loses power and it opens its relay, which opens the zone and the panel indicates trouble. The panel will only indicate alarm if the zone is shorted, which presumably can only happen if a sensor goes into alarm and closes its relay.

This is also why most FPL, FPLR, FPLP (fire alarm) rated cable is solid conductor, because a stranded conductor can be nicked/broken to the point of just barely working, but not up to full capacity. Really a critical item when an alarm or NAC circuit draws it's full power on alarm and could possibly overload that borderline conductor and actually melt it like a fuse.