All assembly spaces shall be provided with emergency lighting facilities sufficient to provide at least five foot candles of illumination at the floor level. Such lighting shall be on circuits that are separate from the general lighting and power circuits, either taken off ahead of the main switch or connected to a separate emergency lighting power source, and be arranged to operate automatically in the event of failure of the normal lighting system. The provisions of this section shall apply retroactively to all existing places of assembly that are or would be classified in occupancy groups F-3 and F-4 or are changed to such classification under this code, in accordance with the following schedule and specifications:
1. Cabarets, dance halls, night clubs, and taverns having an occupant load exceeding one hundred fifty persons shall complete the installation required by this section on or before April twelfth, nineteen hundred seventy-nine.
2. Cabarets, dance halls, night clubs, and taverns having an occupant load of one hundred fifty persons or less shall complete such installation on or before July twelfth, nineteen hundred seventy-nine.
3. Spaces occupied exclusively as restaurants shall complete such installation on or before October twelfth, nineteen hundred seventy-nine.
4. All other spaces in occupancy groups F-3 and F-4 shall complete such installation on or before January twelfth, nineteen hundred eighty.
5. The wiring shall conform with the electrical code of the city of New York, and have the same protection as specified for wiring in reference standard RS17-3, RS17-3A or 17-3B.
6. Storage battery equipment may be used as the sole source of energy provided it conforms with the provisions of section four of reference standard RS 17-3 or consists of two battery packs listed by an acceptable testing laboratory or conforms with nationally accepted standards for such source of emergency energy.