Home Run 4-Wire Smokes & Elk M1 Gold

When we bought our house it had a non-functioning panel (DMP, I think).  I didn't realize at the time, but the 10 2-W smoke detectors were wired as home-run...using some kind of expansion box at the panel.
 
I initially got an Ademco Vista 21IP panel - as it looked to be a cost-effective option with good availability.
 
Now seems I have a problem - the 10 smokes can't be traditionally daisy chained due to the existing wiring, and can't be 'chained' at the panel as the resistance adds up and I don't want to start messing with custom resistors.
 
The smokes do have 4-conductor wiring available...so I can set them up as separate 4W zones.  That's fine - each gets its own supervision relay, etc - but the Ademco documentation says you can't put them on expansion modules....so there are not enough zones on the panel itself (as Z1 is reserved for a 2W smoke).
 
I say all that to say this: if I go with an Elk M1 Gold instead am I going to run into any issues in running 10 separate 4W smokes?!
 
Appreciate any thoughts - or to point out any incorrect assumptions!

Noelep50 said:

When we bought our house it had a non-functioning panel (DMP, I think).  I didn't realize at the time, but the 10 2-W smoke detectors were wired as home-run...using some kind of expansion box at the panel.
 
I initially got an Ademco Vista 21IP panel - as it looked to be a cost-effective option with good availability.
 
Now seems I have a problem - the 10 smokes can't be traditionally daisy chained due to the existing wiring, and can't be 'chained' at the panel as the resistance adds up and I don't want to start messing with custom resistors.
 
The smokes do have 4-conductor wiring available...so I can set them up as separate 4W zones.  That's fine - each gets its own supervision relay, etc - but the Ademco documentation says you can't put them on expansion modules....so there are not enough zones on the panel itself (as Z1 is reserved for a 2W smoke).
 
I say all that to say this: if I go with an Elk M1 Gold instead am I going to run into any issues in running 10 separate 4W smokes?!
 
Appreciate any thoughts - or to point out any incorrect assumptions!

Click to expand...

 
If you have 4-wire cable running to each smoke and you a 2-wire smoke on each cable, you should be able to daisy chain them back at the panel.
 
I'm not sure why you say that making a daisy chain at the panel would create too much resistance. It's hard to imagine that you have so much wire resistance that it exceeds the maximum zone resistance.  When you build a daisy chain, there should be only one EOL resistor, wired to the last smoke in the chain.

Thanks RAL - I did try chaining them at the panel, and after 3 or 4 of them I started getting constant trouble status (but each of them on their own are fine).  I understand that there is just one EOL resistor per chain.
 
I admit I am just *assuming* it is a resistance build up...I haven't tried measuring it yet.  Equally I haven't tried chaining 4W smokes at the panel either (as I don't have any of the 4W units yet)
 
Much of this is me trying to justify going to the Elk panel as it seems vastly superior - I want to make sure I am not just swapping one problem for another!

Noelep50 said:

Thanks RAL - I did try chaining them at the panel, and after 3 or 4 of them I started getting constant trouble status (but each of them on their own are fine).  I understand that there is just one EOL resistor per chain.
 
I admit I am just *assuming* it is a resistance build up...I haven't tried measuring it yet.  Equally I haven't tried chaining 4W smokes at the panel either (as I don't have any of the 4W units yet)
 
Much of this is me trying to justify going to the Elk panel as it seems vastly superior - I want to make sure I am not just swapping one problem for another!

Click to expand...

 
 
You can't create a daisy chain for 4-wire smokes at the panel if all you have is a single 4-wire cable to each smoke detector.  You'd need two 4-wire cables to each location to be able to do that.
 
Although you can put 4-wire smokes on the Elk, each in their own zone, it creates problems when you need to reset the smokes after an alarm. There was some discussion about that in this thread.
 
I'm not sure why you're seeing trouble conditions when you daisy chain more than 3 or 4 smokes.  What brand/model of 2-wire smoke detector are you using with your panel?   Is it a model that is listed as being compatible with the panel?

My bad - yes, of course they will require 8 to do chained...sorry!
 
That thread is helpful, thank you.
 
I will pull down one of the smokes and find out what it is - I have no problem replacing them (all of them...as I've no idea how old they are)...but want to be confident whether I am aiming at 4W or 2W before doing so!
 
Seems like this is altogether more work than it should be :-( I was hoping that easy support of one smoke per zone would be a 'thing'!
 
thanks again...

Noelep50 said:

Seems like this is altogether more work than it should be :-( I was hoping that easy support of one smoke per zone would be a 'thing'!

Click to expand...

 
 
Smoke detectors are probably the most complicated part of an alarm system to get wired right. 
 
With the home run cables that you have, I think 2-wire smokes are your best option.  But with 2-wire smokes, you need to make sure that you use a model that is compatible with your panel.   You can find a list of models in the Vista 21ip manual (pg 8-2 of the manual I have).

V21ip will support up to 16 2 wire smoke detectors (actual compatibility docs state more, but that's another discussion) on zone 1.
 
Most likely, the DMP was only supporting multiple zones direct into the panel (like an XMP100 or 150). The issue is probably the EOLR or wiring methods, remote chance they're addressible. More details would need to be known.
 
I wouldn't suggest adding multiple 4 wire fire zones on a panel for many reasons unless you're absolutely tied to do so. Easier to run a normal 2 wire zone before going that route. Detectors are cheap.

It's been a while - but I thought I would just provide an update for anyone else who happens across this thread.
 
It turns out the reason I couldn't daisy chain the 2W smokes at the panel was because each one had an EOL resistor...but they were hidden in the void above the smoke, so I hadn't seen them.  Having just one per chain did allow me to begin chaining them at the panel.
 
I did get an Elk M1 Gold anyway - and could not be happier with the panel.
 
Right now I have the smokes dasiy chained off Z8 - but will start switching them out to 4W smokes over time on their own zones.  As it turns out, doing this is a whole lot easier given the home-run wiring as I can just switch them over at the panel.
 
thanks for everyone's help.

Something doesn't sound right, and I work on DMP and all the others.
 
4 conductors fed back to the panel, there's no reason why you can't connect the fire alarm correctly.
 
Multiple 4 wire fire is a bad idea.

Problem with 4w smokes each home runned on their own zone is that you need to supervise for power at each smoke. In other words an eol relay at each one. Otherwise if you had a broken power wire to one of them, you would not know it. They do make 4 wire smokes with built in eol relays if you go that route. But you'll also need more amps to power all those relays.

It's not a supervision issue, that's simple to resolve and power is honestly trivial (around 20-30 mA plus the detector, so a conservative is about 85 mA for each detector in alarm. A full install of 10 smokes would be under 1A in full alarm condition).
 
It's what happens to the system when a reset is performed. Even worse if there's a tandem ring involved.

The Elk power output designated for smokes is fused at 1.1 amps via saux.  Depending on brand and whether they have sounder, you can have well in excess of 50mA per detector (when alarming).  Now you add another 30-50mA for the relay for each one.  You could easily hit 1.1 amp without a huge number of detectors when alarming in tandem.  
 
So you need a separate power supply if indeed you have more than maybe 8 or 10 detectors.
 
Resetting the smokes is trivial.  If you can't use saux to directly power them as a result of too many amps, then you set saux to power a relay coil that closes the circuit from your separate power supply.  Resetting the smokes is done the normal way.  You hit on the menu item that says "reset smokes" on your elk keypad.

And I disagree entirely.
 
10 smokes, in full alarm is 850 mA (varies by manufacturer but 85 mA isn't unreasonable to assume) not exactly a huge number given the M1 is already current starved, I have yet to install a M1 that did not require an aux power supply (besides some very basic EZ8's). Hardware reset via an aux relay is also trivial. Load shedding the detectors to an aux supply is also a trivial exercise.
 
The issue with running multiple detectors with power supervisory relays and resetting the system is when you go through the reset process, every other detector that is NOT in alarm will now be a fire trouble condition and generate the appropriate system response (fire trouble) no matter what. That's a design issue, not an operational issue. Unless the end user spends all sorts of time adding rules and complexities to perform a simple fire alarm reset, as well as entering into very grey areas of legalities.
 
Compound that if you have a tandem ring configured. Each time the non-alarm smoke detectors are reverse powered, the associated circuit will also go into fire trouble and report as such, each temp 3 pulse. Trouble/restore. Compound that with CS monitoring, you're going to be sending a truck load of signals to the CS (3 500 ms trips with a 1.5 sec pause, so that's 60 trouble conditions per minute * X zones).
 
This is part of what happens when running the SS I4 detectors and module on the panel as it is. A fire reset generates a CO trouble (module loses power and relay opens). The same holds true on an M1. It doesn't shunt the other zones during a fire reset, but is a known issue going that route vs. additional cabling and detectors. The only positive is the tandem ring does not affect the other IDC zone.

Well, I don't have an aux power supply on any part of my system that is security related and I have a large system.  I have relays and xep on separate power supply which only runs HA stuff, not security and thus requires no special power failure provisions (seeing as the stuff the HA controls wouldn't work in a power failure anyway).  I can't recall my amp draw off the top of my head, but it is well within normal operating range.
 
850 mA is just for the smokes.  now add another 500 mA for all those relays.  It might be worth looking into diodes on all the relays so reversing polarity shuts down the relays, I'd have to think about that as there may be some unintended consequence.
 
If 10 zones going into trouble mode crashes your CS com, then you better rethink your CS setup.
 
Yup, you're smoke zones will all say trouble when you kill power to them during a reset.  And then when you restore power 2 seconds later they go back to normal and you clear the trouble condition.  Not sure why that is the end of the world. after all, you are standing there at your keypad or whatever clearing things, what's one more thing.  If memory serves me, simply arming/disarming clears trouble codes (provided the trouble is no longer there).  So how many false alarms do you expect to have anyway?  I have had 2 as a result of using a welder in my workshop, a situation I have rectified.  Other than that, none in 8 years.

Glad you engineered and designed your system appropriately for your application. Happy you are pleased with your design criteria and system operation.
 
A System Sensor 4WTAB, whose current draw is only secondary to one with an integral relay, draws a maximum of 35 mA in alarm, and a supervisory relay is another 20 mA in alarm...so 85 mA as a budgetary value is very conservative. In the method of using a secondary relay for reset off the switched power, so that'll be another 20 mA....so lets talk a big house up to code, 550 mA plus a reversing relay, another 25 mA. That puts me at below 600 mA total draw. I'm sure the diode method you propose is UL, FM and also appropriate to be compliant. The trouble condition is going to always occur unless you figure out a way to separate your supervisory relays and backfeed them only upon a reverse voltage condition. Are you proposing putting in a relay card instead?
 
How do you propose the reset and connections Lou, please enlighten on your methodology and experiences. Keep in mind a fire reset is not an instantaneous event. The alarm on the M1 will wait approximately a minute before executing, then interrupt power for 5 seconds.
 
The design flaw isn't going to crash a CS communications route. The CS doesn't care how many signals you send to them. Their response is going to be the same, but if you're looking at POTS, you're going to tie your line up for a considerable amount of time, and assuming you do the right thing of sending restoral reports, even more so. Cell or similar, they don't give a hoot how much you send. Then again, some CS do bill by the volume of signals received from an account, and if you're a BYOD and SIM, pretty easy to burn though your time, isn't it. Of course, a busy POTS line doesn't matter unless the CS is attempting to call the premises though, right?
 
So in your example however, what are you going to dictate your CS do upon receiving multiple trouble conditions repeatedly after a fire alarm signal or false alarm? Industry SOP and ECV dictates dispatch authorities and ask questions later, unless that isn't what you believe is the SOP or what your particular CS is providing you as their response. $20 mil property (without articles inside) that I rewired after a loss was specifically due to the CS not dispatching upon receipt of repeated fire trouble conditions from the property. Let me know if you'd like further information and the news articles.