2 HR FA AREAS

[mstrlucky74]

Why the heck would they call for ALL wiring to be 2 hour rated even in sprinkler protected areas?

 

[Strathead]

Why the heck would they call for ALL wiring to be 2 hour rated even in sprinkler protected areas?

Purely opinion , but I think the intent of this note is to require 15 feet of separation between conductors and calling that separation (2 hours) probably comes from some guide book. Normally 5 feet is an acceptable separation or horizontal runs.

 

[JFletcher]

would locating standard cable behind a 2 plus hour rated wall be acceptable? Aside from Mi cable, I am not aware of any wire or method that would still function in a fire

 

[gadfly56]

would locating standard cable behind a 2 plus hour rated wall be acceptable? Aside from Mi cable, I am not aware of any wire or method that would still function in a fire

VITALink^® CIC would do it, but it doesn't meet some of the other requirements for NYC.

 

[mstrlucky74]

What dies the 15' separation have to do with a 2 hour rating?

 

[gadfly56]

What dies the 15' separation have to do with a 2 hour rating?

For certain occupancies, where the fire response is NOT immediate and total evacuation (airport, high rise), the notification devices must remain operable for 2 hours, along with anything else that facilitates their operation (Pathway Survivability Level 2). Normally you'd use VITALink or a similar product. In NYC, none of those products meet some of the other requirements of Local Law 39, so the city has crafted this alternative: Install the circuits as Class A AND separate not by 4 feet but by 15 feet, and we'll consider it the equal of Pathway Survivability Level 2. The exception is NOT supposed to use 15 foot separation and a 2-hour rated cable.

 

[mstrlucky74]

For certain occupancies, where the fire response is NOT immediate and total evacuation (airport, high rise), the notification devices must remain operable for 2 hours, along with anything else that facilitates their operation (Pathway Survivability Level 2). Normally you'd use VITALink or a similar product. In NYC, none of those products meet some of the other requirements of Local Law 39, so the city has crafted this alternative: Install the circuits as Class A AND separate not by 4 feet but by 15 feet, and we'll consider it the equal of Pathway Survivability Level 2. The exception is NOT supposed to use 15 foot separation and a 2-hour rated cable.

So it's one or the other?

 

[Strathead]

So it's one or the other?

No, it is the one, 15 feet of separation.

 

[gadfly56]

No, it is the one, 15 feet of separation.

Plus Class A.

If you could find cable complying with LL 39 and being 2-hr fire resistive you could use it without Class A as NYC does not require everything to be Class A. The Port Authority, NJ Transit, LIRR, MTA, etc usually have internal standards that do require Class A, but the NYC code does not.