# Isolation Modules on FAS



## farmantenna

Your understanding of some things is bit off. 
1. by our code in U.S you can not use a 4 conductor cable as you described (class A) because it's useless if severed because you just cut the supply and return of the supervised loop. You run a 2 conductor cable to all the devices then a separate 2 conductor cable from the last device back to FACP separated by at least 4' horizontally and 1' vertically from the supply wire to minimize both being damaged.

An isolation module used in an addressable fire alarm system is placed in the circuit between zones or number of devices and wired just like all the other devices, 2 wires in 2 wires out. No separate run etc. The isolation module will sense when there is short on the addressable loop (SLC) and disconnect the shorted pair of wires preventing a complete loss of the SLC.

If you want to know more , go to Silent Knight or Fire Lite web sites and look under products ,addressable. then modules and then isolation modules


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## ktown

You can't loop back in the same cable (or pipe) with class A wiring. There's actually clearances you have to maintain between the "main loop" and the set going back to the panel - mostly 12" apart except you can go down to 6" for vertical risers between floors. So don't run 2 pipes beside each other on a rack and use the 2nd pipe as the return - the more separation you have, the more resilient the system is from failure.

Depending on construction type, occupancy type, and how picky your FA tech is you typically can't even branch out to devices and return in the same cable, unless you meet a series of requirements (only one room, or single device in zone).

I almost always pipe in a loop to make it easier, but it does use a bit more pipe. If you are using securex then 18/5 is more readily available and you will just have a spare set.


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## eddy current

Navy, if you want, pm me tomorrow and I can send you the ULC’s that show where you need isolators and minimum separations required for a class A loop (DCL-C)


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## Navyguy

OK, so my understanding is correct; my supervisory circuit back to the FACP needs to be a separate cable and/or conduit. So @ktown you mentioned 18/5, so if I am only using two wires, what am I doing with the other three?

Also, where should I be using shielded cable? My reference says that I need it between the annunciator panel only; is there any value in using shielded on the entire system?

Cheers
John


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## Navyguy

eddy current said:


> Navy, if you want, pm me tomorrow and I can send you the ULC’s that show where you need isolators and minimum separations required for a class A loop (DCL-C)


Thanks. I am on the road tomorrow to Toronto, but will get something to you later.

Cheers
John


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## eddy current

Shielded is usually only used on fire phones and speakers. Helps with interference


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## Navyguy

eddy current said:


> Shielded is usually only used on fire phones and speakers. Helps with interference


So when you say "speakers" are you meaning the ones with a "voice" on them or devices like the piezos?

Cheers
John


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## B-Nabs

Navyguy said:


> So when you say "speakers" are you meaning the ones with a "voice" on them or devices like the piezos?
> 
> 
> 
> Cheers
> 
> John


Only audio speakers and fire phones like eddy said. This prevents electrical noise from being amplified and broadcast audibly. Horns/buzzers won't suffer from that problem.

I have heard of shielded cable causing problems where it isn't needed. I heard of a situation where shielded cable was installed on an addressable loop, and the shielding was building up a capacitive charge, and whenever it discharged it put the system in alarm! Between fearing a situation like that, combined with the higher cost and much higher PITA factor vs unshielded FAS, I only install shielded if I absolutely have to. 

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## eddy current

These are from the Canadian ULC’s. First one is showing you where you would need to install isolators on a class A loop. Basically before and after crossing each fire zone. 

The next pics are the rules showing you the minimum separation between the primary wiring (wires running to the devices) and the alternate wiring (wiring after the last device going back to the panel)


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## Navyguy

Thanks for this; it is as I was trying to describe but was not getting the answers I wanted.

So all I need is a "pair" leaving the FACP and "pair" coming back in a separate location from each other... that is all I was asking the guy and not seeing in his answer to me.

Cheers
John


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## ktown

Navyguy said:


> OK, so my understanding is correct; my supervisory circuit back to the FACP needs to be a separate cable and/or conduit. So @ktown you mentioned 18/5, so if I am only using two wires, what am I doing with the other three?
> 
> Also, where should I be using shielded cable? My reference says that I need it between the annunciator panel only; is there any value in using shielded on the entire system?
> 
> Cheers
> John


I only mentioned 18/5 because around here it's the only securex (FAS cable with a bx sheath) that's readily available. If you're using pipe you can either pull single conductor (most devices are max 14ga) or 18/3 FAS cable. The bonding conductor in fire alarm cable is always insulated, so the 3rd and/or 5th conductor is green and used as a bond/"ground" (just like cabtire). If you do end up using 18/5, the other 2 conductors (brown and blue) are not used. 

Lots of good info here regarding spacing and branching - looks like I'm a little off on loop separation distances. 

You only need shielded for the data portion from the FACP to to the annunciator (and speakers if used). We run 1" emt for this nearly always and pull a shielded cat6 for the data and an 18/3 FAS for 24vac power for most annunciators. Annunciator must be located at the primary entrance to the building as designated on the life safety plan - I've had the electrical engineer get this wrong before. 

Also watch where you put the isolators - they need to be on the same side of the firewall that the devices for that zone are in. Except smokes at the top of stairwells or elevator shafts - those isolators go outside the stairwell or shaft. In general for each zone you will have an isolator at the beginning and end of the zone that is within the same fire-walled area. If you have more than those 2 isolators in a physical zone area there's likely something wrong (again except for stairs/elevators where you usually have 2 or even 3 isolators right beside each other). If you are going through a firewall without an isolator on both sides of the wall (or floor) there's likely something wrong.


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## Navyguy

Another few questions regarding these things...

If I have tamper devices and flow switches that are on different zones but physically in the same location, do I still need to put two isolations switches on each zone?

Secondly, since these things cannot be co-located (say on the outside of the door to the sprinkler room), does it matter where they are? Seems to me that they should be in proximity for maintenance / testing / identification, but if I need separation they might be in a totally different part of the building.

Lastly, is there any issue in putting theses things at the FACP? As an example, if I cut a bunch of holes in a splitter cover and mounted them above or beside the FACP, would that be acceptable?

Cheers
John


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## ktown

Navyguy said:


> Another few questions regarding these things...
> 
> If I have tamper devices and flow switches that are on different zones but physically in the same location, do I still need to put two isolations switches on each zone?
> 
> Secondly, since these things cannot be co-located (say on the outside of the door to the sprinkler room), does it matter where they are? Seems to me that they should be in proximity for maintenance / testing / identification, but if I need separation they might be in a totally different part of the building.
> 
> Lastly, is there any issue in putting theses things at the FACP? As an example, if I cut a bunch of holes in a splitter cover and mounted them above or beside the FACP, would that be acceptable?
> 
> Cheers
> John


In general you will need to follow the Fire Alarm Riser diagram on the plans, which will tell you where they are required.

Generally yes you need all those isolators for flow switches. I believe the rationale is that if there is a problem with the flow switch and both isolators weren't present then the faulty flow switch would take down the zones on each side in the loop. And flow switches must be the only device on a zone. 

It might depend on the system but I've wired flow and tamper for the same "sprinkler zone" on the same "fire alarm zone", but they used a different type of isolator that basically made a conventional loop out of the isolator. Then the flow switch is wired to short causing an alarm but the tamper was wired in series to cause a trouble. This would only apply for a tamper switch that is integral to the flow switch.

I know there are a few rules in the ULC for isolator placement if you are trying to do something unconventional, but generally you will have an isolator right before and after a physical fire separation. There are exceptions of course such as shafts (elevator, stair), and things such as sprinkler valves or relay modules. Not sure what you are trying to achieve with the gutter? The Isolators are part of the data loop and are located all around the building typically... 

The easiest way to visualize isolators is that they "cut out" a portion of the data loop - an entire zone - during a fault (such as a fire destroying cable, renovation accidentally cutting cable, faulty device, etc.). Because addressable systems are always wired Class A, all other zones will continue to function as 2 class B loops during the fault (the faulted isolators essentially turn into EOL resistors). Isolators maintain the continuity of the data loop during a fault that would otherwise make the entire data loop inoperable. This might not seem like a big issue for a modest-sized FA system, but addressable systems are highly scalable into the hundreds or even thousands of devices. A single fault taking down the entire loop could be catastrophic in this scenario. With all this in mind, it starts to make sense that isolators should be logically placed at the physical "beginning" and "end" of a zone nearest the fire separation and located throughout the loop. If they were all grouped together then the protection they provide would be limited.


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## Navyguy

There is nothing specified on the drawings, so I am just trying to sort it out.

I guess I have more of a maintenance mind then a physical damage mind; that is why placing them together seems more logical to me. Why would I want to run all over a building sorting out a defective unit when I can put them all in one spot!

I know the diagrams posted above so them on separate floors, but in the case of the sprinkler room if I need 9 zones of supervision and it just seems crazy to have 9 of these things on a wall beside the entrance to the sprinkler room and another 9 somewhere else.

Cheers
John


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## ktown

Navyguy said:


> There is nothing specified on the drawings, so I am just trying to sort it out.
> 
> I guess I have more of a maintenance mind then a physical damage mind; that is why placing them together seems more logical to me. Why would I want to run all over a building sorting out a defective unit when I can put them all in one spot!
> 
> I know the diagrams posted above so them on separate floors, but in the case of the sprinkler room if I need 9 zones of supervision and it just seems crazy to have 9 of these things on a wall beside the entrance to the sprinkler room and another 9 somewhere else.
> 
> Cheers
> John


I've never done a building where separate sprinkler zones originated in a single location, always a valve per floor or whatever.

From my experience you would have 18 Isolators in the sprinkler room, 2 for each zone. You could likely put them all in gutters if thats easier for you. Assuming addressable flow switches as opposed to conventional switches on an Isolator the wiring would look like this:

FACP --- ISO --- FLOW SW --- ISO --- ISO --- FLOW SW --- ISO --- ISO --- FLOW SW (etc) --- ISO --- OTHER ZONES --- ISO --- FACP

I would likely just get a bunch of 4x4 boxes and close nipples. Flex out of every 2nd isolator to the flow switch.



Are there any other devices other than flow valves? 

I would get some more info from the engineer - commercial fire alarm isn't designed by an electrician, there's always an engineer.


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## Navyguy

This drawing is done by an engineer and I have had three suppliers look at it and say it is a mess...

So each floor has it own set of Flow Switches and Valve Tampers (each of them is a separate zone according to the Zone Schedule)...

On the main floor there is Flow Switch and Valve Tamper for the main floor, the riser for the other floors, the stand pipe, Valve tampers on each side of the backflow preventer and main shut off.

On my schedule the Flow Switches and Valve Tampers are on different zones on the floors, but in the sprinkler room just the Valve Tampers are indicated; so if the flows are not separate zones and can be connected with the Valve Tampers, then I can go down to four zones as per the schedule.

It just not make sense to me that they would have Flow Switches on separate zones in other parts of the building and not the sprinkler room.

So here is a screen shot of what I am talking about... picture is worth a 1000 words as the saying goes.

Cheers
John


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## eddy current

Forget the “zone schedule”, that is for addressing. You only need isolators if your loop is crossing an actual fire zone as far as building code is concerned. 

Each sprinkler device is a separate zone or circuit in the fire panel and it is done through addressing. If they are in the same “fire zone” as far as building code is concerned, then you do not need to isolate each of them. They are in the same room, if there is a fire in that room isolators between devices will not help. Isolators are meant to isolate one fire zone from another, not each device. As you leave one zone (like going from one floor to another) and as you enter another.

Sprinkler devices are always conventional, there is no addressable sprinkler devices so you will need a module for each one, but not isolators.


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## eddy current

I bet it is a Siemens panel. For some reason they use the word “zone” in their addressing and it messes people up.


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## Navyguy

Thanks @eddy current. So in my example, since Zone 7, 8, 19, 20 and 21 + the two valves either side of the backflow preventer are all in the same "fire zone", I just need two isolators for the entire thing?

Then I would deal with the "zone identification" through addressing if they are addressable devices. If they are conventional, then no modules either and would end up wiring all of them individually back to the panel as I would have in the past.

Thanks again.

Cheers
John


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## Navyguy

eddy current said:


> I bet it is a Siemens panel. For some reason they use the word “zone” in their addressing and it messes people up.


They have spec'd Mircom….

Even the Mircom guy is shaking his head...

Cheers
John


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## B-Nabs

eddy current said:


> I bet it is a Siemens panel. For some reason they use the word “zone” in their addressing and it messes people up.


I'm quoting a job right now that uses the "zone" terminology as well. Some engineers' minds are just stuck in conventional. 

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## eddy current

Navyguy said:


> Thanks @eddy current. So in my example, since Zone 7, 8, 19, 20 and 21 + the two valves either side of the backflow preventer are all in the same "fire zone", I just need two isolators for the entire thing?
> 
> 
> no you will need four. One on each side of the wall as you enter the room and one on each side of the wall as you leave
> Then I would deal with the "zone identification" through addressing if they are addressable devices. If they are conventional, then no modules either and would end up wiring all of them individually back to the panel as I would have in the past.
> 
> no it is one loop. Each sprinkler device will require a module and your DCLC (data loop) will go from module to module. Each module has a conventional circuit on it with an eol resister. You will wire each sprinkler device as a conventional circuit from the modules then the modules get addressed.
> Thanks again.
> 
> Cheers
> John


....


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## eddy current

Basically think of the module as it’s own conventional panel. It runs conventional devices and supervises the wiring in the same way, two wires, eol resister etc. If the device is activated or if there is a problem with the wiring, it sends information on the data loop back to the main panel.

They are also used in cold areas because addressable devices have temperature restrictions. Like if you have pull stations in a parking garage that is not heated. You install a module in the warm area then run a circuit from it out to the conventional garage devices ending with a resister.

Of course you can also run a class “A” loop without a EOL from the module and back but it is rarely done that way.


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## B-Nabs

Navyguy said:


> Thanks @eddy current. So in my example, since Zone 7, 8, 19, 20 and 21 + the two valves either side of the backflow preventer are all in the same "fire zone", I just need two isolators for the entire thing?
> 
> Then I would deal with the "zone identification" through addressing if they are addressable devices. If they are conventional, then no modules either and would end up wiring all of them individually back to the panel as I would have in the past.
> 
> Thanks again.
> 
> Cheers
> John


With conventional devices (flow, tamper, some others), then they get an addressable module that monitors the conventional device and communicates its status with the panel via the addressable loop. This module has terminals for addressable loop on one side, then terminals that you wire to a NO contact on the conventional device (flow or tamper), and install an end of line resistor across this contact.

In a flow switch, the EOL gets physically installed across the terminals in the switch housing. On a tamper switch there are usually four flying leads coming out the side through a threaded nipple, where you can install a 1110 box with a EOL plate. Two of the leads get wired to the cable coming from the module, and the other two terminated on the EOL plate.

When the module sees the correct resistance value across the conventional terminals it reports back to the panel that the device is normal. If it reads open circuit, it throws a trouble. If it reads short circuit, it either goes into supervisory (tamper switch) or alarm (flow). Which of these happens is determined by programming. 

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## B-Nabs

eddy current said:


> ....





eddy current said:


> Basically think of the module as it’s own conventional panel. It runs conventional devices and supervises the wiring in the same way, two wires, eol resister etc. If the device is activated or if there is a problem with the wiring, it sends information on the data loop back to the main panel.
> 
> They are also used in cold areas because addressable devices have temperature restrictions. Like if you have pull stations in a parking garage that is not heated. You install a module in the warm area then run a circuit from it out to the conventional garage devices ending with a resister.
> 
> Of course you can also run a class “A” loop without a EOL from the module and back but it is rarely done that way.


I see we were posting at the same time  

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## Navyguy

I have done lots of fire alarm stuff over the years... for some reason I am struggling with these things conceptually... old dog - new tricks?

I think once I get my hands on one of these things it will all come together...

I appreciate the assistance guys.


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## fmwowol

An isolation module used in an addressable fire alarm system is placed in the circuit between zones or number of devices and wired just like all the other devices, 2 wires in 2 wires out. No separate run etc. The isolation module will sense when there is short on the addressable loop (SLC) and disconnect the shorted pair of wires preventing a complete loss of the SLC.


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## emtnut

fmwowol said:


> An isolation module used in an addressable fire alarm system is placed in the circuit between zones or number of devices and wired just like all the other devices, 2 wires in 2 wires out. No separate run etc. The isolation module will sense when there is short on the addressable loop (SLC) and disconnect the shorted pair of wires preventing a complete loss of the SLC.


An isolation module used in an addressable fire alarm system is placed in the circuit between zones or number of devices and wired just like all the other devices, 2 wires in 2 wires out. No separate run etc. The isolation module will sense when there is short on the addressable loop (SLC) and disconnect the shorted pair of wires preventing a complete loss of the SLC.


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