FA cables

[ryan_618]

What are you guys seeing to satisfy the 2Hr. survivalbility requirement for FA cables in high rise? I have heard that many cities allow a sprinkler system with heads in the ceiling to satisfy this requirement, and some that don't allow this for the requirement. What are you guys seeing?

 

[peter d]

Re: FA cables

I am a native of Rhode Island and this is how the powers that be in my home state decided to solve this issue.

The entire FA system must be installed in metallic raceway and/or MC cable. This applies to all systems (local or fire-station monitored) in anything from one room buildings to high rises. No exceptions.

[ May 16, 2004, 09:25 PM: Message edited by: peter d ]

 

[ron]

Re: FA cables

Ryan,
I don't do many high rises, but I achieve survivability for notification circuits by using a 2 hour rating method. I design for critical buildings, where unfortunately equipment is valued more than anything. So survivability is important even in a large (unlimited area) one story building.
Either CI cable (raceway or no raceway), CIC cable (only in raceway) or 2 hour enclosure around cable.
Installing standard cable in conduit does not achieve survivable circuits as defined by NFPA 72.
NFPA 72 and 70 mention survivability, but I didn't realize that there was a code requirement for it. Is it the building code?

 

[ryan_618]

Re: FA cables

Hi Ron. I beleive it is a requirement of the NFPA 72 for buildings with floors 75 feet above fire department access (high rise). To tell you the truth, you probably know as much about it as I do. I was just curious if people were seeing an NFPA 13 system being used as an alternative acceptable to the AHJ.

 

[ron]

Re: FA cables

NFPA 72 6.9.4. (Survivability) applies only to systems used for partial evacuation or relocation of occupants. I'm not sure if there is a national code that indicates that a high rise must initiate partial evacuation or relocation of occupants. I always thought it was a local modification or a design choice, but I don't work with that much so maybe it is a code someplace.
NFPA 72 6.9.4.3. is very clear on methods to achieve the survivability until it gets to 6.9.4.3.(3) where it allows for "performance alternatives approved by the AHJ" :roll: .

 

[ron]

Re: FA cables

Ryan,
I have been putting more thought into this item. Although the survivability paragraph of the fire alarm and electric code are used on each of my designs, I am having a hard time finding a code requirement for it.
Many building codes require voice evacuation for certain buildings, like a high rise. They do not specifically require "systems used for partial evacuation or relocation of occupants". The code does not indicate the use of the voice evac, just that it is for evacuation, not necessarily "partial evacuation or relocation of occupants". So it may be that NFPA 72 6.9.4. (Survivability) is a good idea, but not required.

 

[ryan_618]

Re: FA cables

Ron, thats interesting. I really don't know a whole lot about the NFPA 72. This "survivabilty" this really intrigued me though. I think I'll have to look deeper into the IBC and 72 to learn more. In many buildings there are "areas of refuge", "areas of safe dispersal" or "egress courts", and I think it may apply to these. I'll let you know what I find out.

Thanks for the help.