The LiftMaster CPS-RPEN4 Monitored Retro-Reflective Photo Eye is a commercial door safety sensor designed to provide non-contact entrapment protection for overhead sectional and rolling steel doors. Using a retro-reflective infrared beam, the sensor detects an obstruction across the door opening and signals the operator to stop or reverse. Because the emitter and receiver are combined in a single unit and aimed at a reflective target on the opposite side, wiring is required on only one side of the opening—an advantage for upgrades and replacements in busy commercial and industrial facilities. As a monitored device, it communicates its status to the operator, supporting UL 325 monitored entrapment protection requirements on compatible LiftMaster commercial door operators.
Engineered for demanding environments, the CPS-RPEN4 features a weather-resistant NEMA 4 enclosure suited for indoor or outdoor applications such as warehouses, loading docks, distribution centers, and automotive bays. It is powered by the operator’s low-voltage control circuit and connects to the monitored photo eye input on LiftMaster models that support monitored safety sensors (verify compatibility in the operator manual). Installation involves mounting the photo eye on one side of the doorway, positioning the reflector directly across the opening at the proper height, aligning the beam using the unit’s indicators, and completing wiring to the designated monitored terminals; operator settings may need to be configured to recognize the monitored device. For safe operation and code compliance, install and test the CPS-RPEN4 according to UL 325 and LiftMaster instructions. This monitored, retro-reflective photo eye is an ideal replacement part or upgrade for enhancing safety on LiftMaster commercial door systems.
