R 408.10682 Emergency illumination.

Rule 682. In a building with natural lighting subject to occupancy by more than 300 persons, and in a building for which no natural lighting is provided and subject to occupancy by more than 100 persons, approved emergency lighting facilities shall be provided for a means of egress so arranged that required exit illumination will be maintained for a period of at least 1/2 hour in the event of failure of normal lighting of the building. Emergency lighting facilities shall be automatic, and there shall be no appreciable period of interruption during the change-over from the normal lighting of the building.