Integrity monitoring and trouble alarms

[Vagrant]

Does a speaker used as notification appliance for a fire alarm system and forming part of an emergency voice notification system need to have cabling between speaker and local amplifier (less than 10m) and the speaker monitored. Does it need to report trouble alarms, even if the speaker is one of a redundant pair for each area- or would the trouble alarm only be required if both speakers or feeds from the amplifier failed? Single failure would have no impact on the operation of any other system components.
Thanks Vagrant

 

[stookeyfpe]

How will the speaker work if its not cabled (wired) to the fire alarm control unit? I'm missing something in the message.

 

[DRWeig]

Stookey, I read it as, "Do the speaker cable and speaker need to be supervised, even though there are redundant speakers."

I don't think even redundant wiring can be unsupervised -- you need to get a trouble alarm on any short or open circuit, eh?

Vagrant: this is just my opinion, I have limited experience in this field. Wait for Stookey or one of the other regulars, please.

Good on ya,

Goober Dave

 

[EEJaime]

I know that all devices and wiring which are part of the emergency voice notification system must be supervised. Not only that they must be "Listed" for that service. At least I know that is true here in California and definitely in the City of Los Angeles where I had my most recent experience.

In a large volume space, (an airport terminal), we have a complete and very reliable, high performance public address system designed. The Code Consultant worked closely with the Sound Consultant on obtaining proper coverage in all the voluminous spaces. The AHJ rejected the design stating that the speakers where not CSFM listed as emergency voice evacuation system equipment. They had to go back and design a system with vast quantities of "listed" devices which IMO will provide inferior coverage, but that satisfied the AHJ. Added about $200K to the project, but that's not the AHJ's problem.

 

[stookeyfpe]

EEJaime:

Oh, I now see the problem. I hate to break it to you but this issue is going to get worse with the 2010 edition of NFPA 72. For mass notification systems, buildings such as your will be required to comply with signal intelligibility requirements.

In such a case, I guess I would question what the difference is between a CSFM listing (since the CSFM uses the same UL standards as everyone else) and a conventional speaker. I don't think there is a difference, but I can't make a definitive statement without looking at the standards.

 

[Vagrant]

You are right in the reading of the question DRWeig-- I wasn't suggesting it didn't need cable! It is the supervision I was questioning-- and it seems that no matter what the cabling and speakers need to be supervised-- which is in line with advice that was given today. Thanks for the responses.

 

[rbulsara]

Yes, speaker circuits needs to be monitored. For what needs to be reported, it depends on its class, such as A, B, Z etc, per NFPA 72.

Redundancy is not a substitute for monitoring.

Rafiq Bulsara

http://www.srengineersct.com