Fire alarm system

[mohammad ishfaq khattak]

In fire alarm system what is the purpose of Isolator fault module.please explain in detail.

If possible please give a references of books which explain complete fire alarm system.

Thanks.

khattak

 

[iwire]

http://www.firelite.com/datasheets/df-52389.pdf

 

[nhfire77]

FACP-----0--0------0----LIM----FAULT-----n------n----n



------= SLC

0=detectors, other devices that still work after the fault occurs

LIM=Loop isolator module every device on the load side is isolated and will not work, the line side is unaffected, also the FACP will tell you that the module has isolated the fault at that module

n=devices not working, isolated

FAULT=open or short on SLC

also see style 7 wiring


FACP----LIM--o---LIM----o---LIM---

Every device has a LIM on its line and load side. Very expensive, and very safe


Need a reference for fire alarms start with NFPA 72.

 

[MichaelGP3]

Not all manufacturer's systems will support this last method....

Not all manufacturer's systems will support this last method....

FACP----LIM--o---LIM----o---LIM---

Every device has a LIM on its line and load side. Very expensive, and very safe

There might be jobs out there specified like this, but I've never seen or heard of one. In the current economy, I don't see any coming over the horizon anytime soon.

 

[nhfire77]

There might be jobs out there specified like this, but I've never seen or heard of one. In the current economy, I don't see any coming over the horizon anytime soon.

That's because its typically a european thing. Or in the case of a laboratory that handles nuclear materials or something where "failure is not an option"


Not all manufacturers will supports this? Style 7 is the least common of all the wiring methods. Every panel that a SLC and has Loop Isolation Modules can do this, some just limit the number of LIM's per loop, in which case you would need a panel that supports a lot of SLC's.

Of, course the manual would have to specify that its listed for this and show an example of it.

For simplicity sake, you could just use an isolator base for plug in style detectors. Each base is a device and it would individually isolate the detector in it in the event of a fault.

 

[Stallzer]

Actually we see it on a semi-regular basis here in MN. In hostile environments we see more and more A&E specs calling for Line isolators. It is a very good practice to use and normally won't run up the Job cost if done in a limited basis. We normally only put 1 Isolator per SLC Circuit / Cable, this prevents 1 shorted circuit from dropping the entire SLC bus.

 

[STHOMAS]

I have a couple of Federal Curthouse projects right now that require Style 7 SLC. Spec also requires that all SLC's serving more than one floor to use them, with no more than three floors on a single SLC.

The GSA FPE who wrote the spec knows his stuff...

 

[gadfly56]

There might be jobs out there specified like this, but I've never seen or heard of one. In the current economy, I don't see any coming over the horizon anytime soon.

Port Authority of NewYork/New Jersey for the Staten Island Bridges standpipe upgrade, awarded May 5, spec'd LIM's between every device on the SLC, in Style 7. Siemens XLS was the panel called for, and the max number of LIM's on a DLC is 15. So the max devices is 14, 15, or 16 depending on whether or not a LIM has to be the first and/or last module on the SLC. A DLC is otherwise capable of handling 252 devices. It boosted the DLC counts by 6 for each of six panels at a trade net of ~$2,000 per DLC. Not counting all the additional wiring in plastic coated conduit costing $2.00/foot. A hideous waste of money, since all the devices were located within 50-100 feet of the panels. For this application, upping the count to 5-10 devices between LIM's would have saved significant bucks.

 

[nhfire77]

Port Authority of NewYork/New Jersey for the Staten Island Bridges standpipe upgrade, awarded May 5, spec'd LIM's between every device on the SLC, in Style 7. Siemens XLS was the panel called for, and the max number of LIM's on a DLC is 15. So the max devices is 14, 15, or 16 depending on whether or not a LIM has to be the first and/or last module on the SLC. A DLC is otherwise capable of handling 252 devices. It boosted the DLC counts by 6 for each of six panels at a trade net of ~$2,000 per DLC. Not counting all the additional wiring in plastic coated conduit costing $2.00/foot. A hideous waste of money, since all the devices were located within 50-100 feet of the panels. For this application, upping the count to 5-10 devices between LIM's would have saved significant bucks.

That is a waste. Silent Knight allows 127 LIM per SLC, and 127 addressable devices as well.

 

[DM2-Inc]

...Silent Knight allows 127 LIM per SLC...

I find this interesting considering most isolator modules are basically Galvanic isolators. The reason manufactures have limits on them is the delay in communicating with an addressable device, and the affect this has on powering the device.

What model number is this?

 

[nhfire77]

I find this interesting considering most isolator modules are basically Galvanic isolators. The reason manufactures have limits on them is the delay in communicating with an addressable device, and the affect this has on powering the device.

What model number is this?

here you go:


http://www.silentknight.com/htmfiles/fire/SD500LIM.htm