Safety circuit preventing car movement when doors are not fully closed and locked.
Full Definition
Door open while running (DOWR) protection is a fundamental safety function of every elevator. The door lock contacts and door closed contacts form part of the safety circuit, ensuring the car cannot move unless all landing and car doors are fully closed and mechanically locked. EN 81-20 requires door contacts to be monitored by the safety chain. Modern systems use electronic door monitoring with redundant contact monitoring and self-monitoring capability (SIL 3 capable in some implementations). Any fault in door contact monitoring immediately stops the car.
