A battery-powered emergency unit that automatically drives a stranded elevator to the nearest landing and opens doors during a mains power failure.
Full Definition
The automatic rescue device (ARD) activates within seconds of a mains power interruption. Its battery bank powers the VVVF drive in low-speed rescue mode, moving the car to the nearest landing at reduced speed (typically 0.1–0.3 m/s). On arrival, the door operator opens to allow passengers to exit before the ARD enters standby. Battery capacity must sustain at least one rescue operation plus several door cycles. EN 81-20 requires that an ARD does not override safety circuit contacts. Periodic battery health testing and replacement (typically every 3–5 years) is required. ARDs significantly reduce entrapment call-out costs.
