Elevators are generally driven by electric motors and are used in automatic lifting facilities for vertically transporting people and objects in multi-story buildings. The elevator mainly comprises a traction system, a guiding system, an electrical control system, and a safety protection system. The traction system provides the elevator with lifting power, the guiding and electrical control system maintains the normal operating state of the elevator, and the safety protection system ensures the safety of the carrying personnel in the event of an unexpected failure or danger to the elevator. The limit switch plays an important role in the elevator safety protection system.

Since the elevator is raised and lowered up and down within a certain height range, when the elevator reaches the bottom and the top of the hoistway, the elevator needs to be stopped to avoid damage to the elevator. The limit switch here must be connected in series to the safety circuit of the motor. When the elevator car is close to the extreme position of the up and down operation, the circuit between the motor and the controller can be cut off by triggering the limit switch, and the elevator will not be able to run.