At least one light fixture (1) with one or more high performance gas discharge lamps (2), optionally an integral reflector and associated fittings (3) and fasteners for mounting it in the stall is connected directly to at least one electronic switch unit (4), or alternatively several of these fixtures can be connected to this unit via a distributor unit. The switch unit comprises an optionally integrated variable electronic ballast, transformer, associated electronics and a multi-level ignition device for initiating the discharge process in the lamps at a desired low or high starting energy level, e.g. at 30 % or more of the nominal performance of the lamp. The lighting strength can be increased in a continuous manner to a chosen intensity level between e.g. 30-100 % of the nominal performance of the lamp, and then dimmed again in order to provide the desired lighting regime. The switch unit has a high energy efficiency of more than ca. 96 % and is connected t o and controlled by a light regime regulator (6)
