This question was recently answered in minutes committee meeting.
NYC electrical code 700.9(D) requires 1 hour rating for feeder circuits but NFPA 72 requires 2 hour rating based on chapters 23 and 24 so the more stringent applies. 2014 NEC now clarifies this and says 2 hours.
Here's from the minutes:
700.9(D) Fire Protection: Emergency systems shall meet the additional requirements in 700.9(D)(1) and (D)(2) in assembly occupancies for not less than 1000 persons or in buildings above 23 m (75 ft) in height with any of the following occupancy classes: assembly, educational, residential, detention and correctional, business, and mercantile.
(1) Feeder-Circuit Wiring. Feeder-circuit wiring shall meet one of the following conditions:
(1) Be installed in spaces or areas that are fully protected by an approved automatic fire suppression system
(2) Be a listed electrical circuit protective system with a minimum 1-hour fire rating FPN: UL guide information for electrical circuit protection systems (FHIT) contains information on proper installation requirements to maintain the fire rating.
(3) Be protected by a listed thermal barrier system for electrical system components
(4) Be protected by a listed fire-rated assembly that has a minimum fire rating of 1-hour and contains only emergency wiring circuits.
(5) Be embedded in not less than 50 mm (2 in.) of concrete
(6) Be a cable listed to maintain circuit integrity for not less than 1 hour when installed in accordance with the listing requirements
ANSWER 1:
Section 700.9 does not require a 2 hour rating but it requires full sprinkler protection, 1 hour rating, concrete encasement, or a few other options. NFPA 72 requires the 2 hour based on Chapters 23 and 24, and where the two conflict the more stringent must be applied (i.e. the 2 hour). Section 10.5.10.3.1.3 of NFPA 72/2010 also indicates that whatever protection is provided to the low voltage needs to be applied to the power. All of it adds up to needing 2 hour data and 2 hour power.