The LiftMaster WS-SENSOR Mechanical Limit Switch is a genuine replacement part used to establish and maintain open/close travel limits on compatible LiftMaster commercial operators. Actuated by the operator’s limit cam or flag, this mechanical sensor signals the control board to stop movement precisely at the programmed endpoints, helping prevent over‑travel and protecting the operator, door, or gate. It’s a reliable solution for restoring correct limit detection when the original switch has become worn, damaged, or intermittent, and is commonly referenced in LiftMaster parts diagrams as WS-SENSOR for select commercial slide gate operators and industrial door operators.
Installation typically involves powering down the operator, mounting the switch in the designated limit location, and wiring it to the controller’s limit terminals as specified in the operator’s service manual, followed by adjusting the limit cams and test cycling for proper stop points. Because it is a mechanical limit device, no radio pairing or firmware programming is required beyond mechanical adjustment. For safety and UL 325 compliance, installation and testing should be performed by a qualified technician, and compatibility should be verified against the specific operator manual or parts list that calls out WS-SENSOR. This makes the WS-SENSOR an ideal LiftMaster replacement limit switch for commercial applications where dependable, repeatable limit control is essential.