Abstract

A hall lighting system includes a plurality of downlighting lamps all dedicated to hall illumination during normal power conditions. Each lamp is connected across a low voltage power source defined by the secondary winding of a stepdown transformer having its primary winding connected across a primary power source. When the primary power source is "on" an emergency lighting system has a triple pole double throw relay located in a normal lighting position in which two of the poles of the relay connect a charger to an emergency battery power source of a voltage less than the voltage across the secondary winding and a third pole of the relay connects the lamps across the secondary winding. When the primary power source is off, the first and second poles connect the emergency battery power source to selected ones of the lamps and the third pole disconnects the secondary winding from lamps such that the only load other than system wiring across the emergency battery power source is that of the selected ones of the lamps to provide a minimal lighting of the hall in excess of a set minimum footcandle standard for a period of time in excess of a set minimum lighting period.