Except as may be otherwise specifically set forth in this Part, the following provisions of this section shall apply to all places of public assembly.

No other source of artificial illumination of places of assembly shall be permitted except electricity.

All electrical wiring and equipment shall be installed and maintained in accordance with nationally and locally accepted standards.

During public occupancy, all exitways and other occupied portions of such places shall be distinctly illuminated by natural or artificial means. Illumination providing a light intensity of 0.5 foot-candle or more at floor or ground levels shall be deemed in compliance herewith.

In every place of public assembly having a capacity of over 300 persons and customarily using artificial lighting during public occupancy, there shall be installed and maintained in addition to the principal lighting system, an independent substitute lighting system powered by a source of electricity other than that of the principal system and capable of providing through the circuits and fixtures of the principal system or otherwise a distinct illumination for a period of 30 minutes of all exitways and aisles. Such substitute system shall be arranged so as to operate automatically upon failure of electric current in the principal system. A light intensity of 0.5 foot-candle at floor or ground levels shall be deemed distinct illumination within the meaning and intent of this subdivision.