The LiftMaster 001A4811 CPS Detector/Emitter is an OEM through-beam photoelectric safety sensor set designed for compatible LiftMaster commercial door operators. As part of the Commercial Protector System (CPS), it uses a dedicated transmitter (emitter) and receiver (detector) positioned on opposite sides of the door opening to create an invisible infrared beam. When the beam is interrupted, the connected operator is signaled to stop or reverse, helping protect personnel, vehicles, and equipment in warehouses, loading docks, and other industrial or commercial environments. This replacement photo eye assembly is intended for LiftMaster operators that specifically support CPS-style photo eyes and is not for residential garage door openers.
Typical use involves mounting the detector and emitter facing each other near the doorway—commonly around 6 inches from the floor—securely wiring them to the operator’s safety input terminals, carefully aligning the beam, and verifying proper operation through the operator’s safety test procedure. Alignment is critical for reliable performance; consult the operator’s manual for wiring diagrams, terminal designations, and any monitored/compatibility requirements. This LiftMaster 001A4811 CPS Detector/Emitter set is a dependable replacement part for restoring entrapment protection on commercial and industrial sectional or rolling door systems, supporting compliance with safety practices when installed and tested according to LiftMaster documentation and applicable standards.