Staircase time switch with switch-off early warning switchable. Standby loss 0.7 watt only. Zero passage switching to protect contacts and lamps. This prolongs in particular the lifetime of energy saving lamps. By using a bistable relay coil power loss and heating is avoided even in the onmode. The switched consumer may not be connected to the mains before the short automatic ­synchronisation after installation has terminated. 230V control voltage, supply voltage and switching voltage. Glow lamp current up to 50mA, dependent on the ignition voltage of the glow lamps. Precise variable time range from 1 to 12 minutes, settable by minute scale. Own permanent light switch with the big rotary switch. 3-wire circuit with attic lighting, not resettable. Only for retrofitting of existing systems. After a power failure the lighting is switched on again in case the set time has not elapsed yet. If switch-off early warning function is switched on the light starts flickering approx. 30 seconds before time-out and is repeated three times at decreasing time intervals.