An Uninterruptible Power Supply system connected to an elevator installation to provide battery-backed emergency power for automatic rescue device operation, emergency lighting, communication, and controlled car lowering during mains failure.
Full Definition
An Uninterruptible Power Supply (UPS) for elevator applications provides a bridge between mains power failure and either generator start-up or final battery lowering to the nearest floor. Key functions: (1) Automatic Rescue Device (ARD) battery power — enables the controller to drive the car to the nearest floor and open doors to release trapped passengers; (2) Emergency car lighting — EN 81-20 requires a minimum 1-hour emergency light source in the car; (3) Emergency communication — powers the alarm button circuit and two-way communication device; (4) Controller keep-alive — maintains elevator memory and position data during brownouts. UPS sizing is calculated from: ARD drive cycle power (kW), emergency light VA, communication circuit load, and required battery autonomy (typically 1–3 hours). Technologies include sealed lead-acid (VRLA), NiCd, and lithium-ion batteries. The UPS must comply with EN 62040 series and be sized in accordance with the ARD and controller manufacturer specifications. Regular battery replacement (typically every 3–5 years) is a maintenance requirement.
