Abstract: A bi-level illumination system for power conservation correlated to the needs of a building stairwell, which even during work hours is only nominal functioning as it does as a back-up to elevator-provided access to work areas, and requiring high level illumination during off-hours which also occurs infrequently, by its focused stairwell end use permitting use of occupancy and time clock sensing means control of the high and low levels of illumination without the undue complexity of bi-level illumination systems used in work areas with constantly changing illumination needs.

Abstract: High level and low level illuminating use of lamps in an office stairwell of the nature requiring a lamp break-in period of conditioning, wherein normally the former level is used during work hours and the latter level during off-hours, in which high level illumination is extended in its use even during off-hours in order to provide a continuous 300-hour break-in period to condition the lamps for their subsequent normal use, only one installation of the lamps thereby being required.