The LiftMaster CPS-UN4 Industrial Photo Eyes are monitored, non-contact safety sensors engineered for commercial and industrial door systems. Supplied as a transmitter-and-receiver pair, they create an infrared beam across the door opening; when the beam is interrupted, compatible LiftMaster commercial operators stop and reverse movement to help prevent entrapment. The CPS-UN4 is built in a NEMA 4 rated enclosure, offering watertight and dust-tight protection for harsh indoor or outdoor locations, including washdown and high-moisture environments. When used with compatible LiftMaster operators, the device supports UL 325 compliant entrapment protection for sectional and rolling steel doors in warehouses, factories, loading docks, and similar commercial applications.
Designed as a dependable replacement part or upgrade for monitored photo eye safety on LiftMaster commercial door operators, the CPS-UN4 is typically connected to the operator’s monitored input and powered by the operator’s low-voltage accessory supply. Installation involves mounting the sensors on opposing sides of the doorway near the floor per UL guidelines, aligning the beam (using the unit’s indicator feedback, if provided), and verifying proper stop/reverse operation through the operator’s safety device test procedure. The NEMA 4 housing helps resist rain, splashing, hose-directed water, and windblown dust, making it suited for wet or corrosive-prone environments where standard photo eyes may not endure. For best results and full compliance, follow the specific wiring and setup instructions in the LiftMaster commercial operator manual that supports monitored photo eyes, such as current Logic 5.0 models.
