Sensor that verifies adequate overhead clearance above the car top before upward movement.
Full Definition
The car top clearance sensor monitors the distance between the top of the elevator car and the overhead structure or counterweight, ensuring that the minimum refuge space required by EN 81-20 (headroom of at least 1.0–1.8 m) is maintained when personnel are on the car top. In some implementations, a physical stop device is used instead of a sensor. The sensor typically uses a magnetic or ultrasonic measurement principle and interfaces with the inspection control to prevent movement that would reduce the refuge space below minimum.
