Unintended Car Movement (UCM) is defined in ASME A17.1‑2019 Section 1.3 as any movement of an elevator car away from a landing that is not intended, resulting from failure of the driving-machine motor, brake, coupling, control system, or other component on which intended car movement depends.

See the Patented Rail-Gripping Solution That Exceeds A17.3-2020 Code Requirements and Redefines Elevator Safety For decades, the elevator...

HydraSafe isn't a band-aid fix - it's a complete elevator brake modernization. Replaces risky friction brakes with rail-locking safety.