You don't want the intelligent smoke detectors. They are mostly meant for commercial applications.
Eric B said:
Eric B, on 10 Mar 2020 - 15:12, said:
Thanks for the suggestions. I'm trying to understand the advantage of the COSMODxW however with the M1G. Do I understand correctly that without the COSMODxW I cannot use the combo CO/Smoke units with the M1G since there is no distinct output for Smoke vs CO from the unit itself?
The COSMO detectors send a notification to the COSMOD interface as to whether it is a smoke or CO event through some type of coding. I'm not sure exactly how they do that. I originally thought that the COSMO could also be connected directly to an alarm panel without the COSMOD (though you'd lose out on the type of event) but I re-read the data sheet and it says that the COSMOD is required.
Eric B said:
Eric B, on 10 Mar 2020 - 15:12, said:
From what I read, the COSMODxW are limited to a total of 12 devices. Which means that if I want more than 12 devices, I need to use 4 different zones on the M1G (2 for the first COSMODxW and 2 for the second one). But that would imply having smokes on multiple zones which you discourage. Can you elaborate why that is not recommended? Is it too complicated to configure? How will that impact the Marcurco, which I expect needs to be installed on a zone by itself?
If you decide to go with the COSMOD/COSMO route, and you need more than 12 detectors, then you need to decide whether you want to go with the 2-wire or 4-wire smokes. I believe it's only the 2-wire smokes that are limited to 12.
[Edit]: I checked with the techs at System Sensor, and they say the limit of 12 also applies to the COSMOD4W. Sigh.
There are two or three places where things get complicated with the smokes. One is that you'd like all the detectors to sound when any one of them triggers an alarm. Each COSMOD does tandem ring for the detectors connected to it, so if one detector triggers, the COSMOD will reverse polarity to all the detectors in the chain, which will cause them all to sound. But if you have two or more COSMODs, then the other COSMODs don't know that they should be sounding, too. To make that happen, you need to connect up the CO and Smoke trigger inputs to voltage outputs on the M1. And then write some rules so that when any smoke/CO input triggers, the M1's trigger output turns on. Plus another set of rules to turn the output off when you do a smoke reset.
Another thing you need to consider is the amount of power the smoke detectors and COSMODs require. Each COSMO-2W has a max power requirement of 50mA. And the COSMOD2W requires another 181 mA.
You'd like to power all the smokes and COSMOD2Ws from the M1's SAUX power outputs, since that is a resettable power output. Being resettable means that when a Smoke Reset command is issued from the keypad, the SAUX power drops for a few seconds, causing the smoke detectors to initiate a reset when the power is restored.
The M1 is limited to a combined total of 1A across all its power outputs, including the Data bus, SAUX and VAUX. So you need to look at your overall current draw for all the other devices you have that are powered by the M1 and see if you can handle all the smokes. Elk has a nice
current draw spread sheet to help you do this.
Say you have 16 smokes, and two COSMOD2Ws. That's 1.16 A to power them, and you're over the max the M1 can provide without even considering any other loads. So you'll need an aux power supply. If you put the smokes on the aux supply, then you'll need a relay to switch the aux power supply output to the smokes to make it resettable via a Smoke Reset operation. The relay would be powered from SAUX. When SAUX drops, the relay drops out, cutting off the aux supply output; basically, it just mirrors what SAUX is doing.
One last complication with having smoke detectors on multiple zones is handling the reset itself. Initially, one detector triggers an alarm condition on one of say 2 fire zones. When you eventually cancel the alarm, the Smoke Reset will drop power to all the smoke detector zones (or COSMOD2Ws). But only one zone was in alarm condition. When power drops on the other zone, that will create a new alarm condition on that zone due to the power monitoring (EOL) relay. And now you have to do a second reset for that condition. But that will trigger a new alarm condition on the other zone. Ultimately, you may have to power off the entire panel and just restart it.
I'm not sure how the COSMODxW behaves when you issue a smoke trigger to it. I don't think it will turn around and create a trigger on the zone input, since that would be a false indication to the panel. But if it did, it would make the reset process much easier since both zones would then be in alarm condition, and a single reset would clear them both together.
A way around the reset problems would be to have individual reset relays controlling power to the zones, and then using rules and M1 outputs to reset the zones independent of each other. It's just all added complexity.
Eric B said:
Eric B, on 10 Mar 2020 - 15:12, said:
If I am going with the COSMODxW, is there a disadvantage of using just COSMO (combo device) everywhere instead of using other detectors, such as the 2251 series? Or is it just a cost issue? Additionally, given the COSMODxW, is there a disadvantage of the 4W units (aside from the EOL relay)? Or phrased differently, are the 2W units that much simpler to install? I would think that if it is just the EOL relay, that it would not be a big deal; don't some of the SystemSensor units already come with an EOLR built in?
The 2251 is part of their intelligent detector series, and is meant primarily for commercial installations.
There's nothing wrong with using COSMO detectors everywhere (except where you should have heat detectors and not smokes).
The 2-wire smokes aren't much different from the 4-wire models. It's just mostly how they are powered. The extra wires create more connection points where something can go wrong due to a poor connection. That's why the EOL relay is there to keep tabs on things.
One advantage of the 4-wire COSMOD4W is that you can also connect heat detectors to the daisy chain, and they don't count against the limit of 12.
[Edit: the following deleted after SS says the limit of 12 applies to the COSMOD4W as well]
If you really need more than 12 smoke detectors and want to avoid having them on more than one zone (I'd recommend that), then going with the 4-wire units us probably the better way to go. Your current draw calculation will tell you whether you'll still need an aux supply and a power control relay to mirror SAUX power.