The LiftMaster 50-HERK2 Microwave Motion Detector Vehicle Sensor is a radar-based activation sensor designed to detect moving vehicles and trigger LiftMaster commercial door and gate operators. Commonly used on overhead sectional doors, rolling steel doors, and industrial gates, it provides hands-free vehicle activation for warehouses, distribution centers, parking facilities, and other commercial applications. Using K‑band microwave technology, the 50-HERK2 identifies motion within an adjustable field and sends a dry-contact signal to the operator to open, helping streamline traffic flow for forklifts, trucks, and service vehicles without the need for ground loops.
This sensor operates on accessory power typically available from commercial operators (12–24 VAC/VDC) and delivers an isolated relay output for straightforward wiring to most LiftMaster control boards and many third‑party controllers that accept a momentary contact. The detection pattern and sensitivity are tunable during installation by aiming the sensor and adjusting onboard settings, allowing the field to be focused toward approach traffic and away from cross‑traffic that can cause nuisance activations. As a motion-only radar device, it is intended for activation rather than entrapment protection; use with compliant safety devices such as monitored photo eyes per UL 325 and local codes. The K‑band operating frequency (around 24.15 GHz in the U.S.) provides reliable vehicle motion detection at typical mounting heights above commercial door headers. The 50‑HERK2 is suitable for indoor or protected outdoor industrial environments and serves as a dependable replacement or upgrade accessory for LiftMaster commercial door operators and compatible access systems.
