Placed next to the door tracks, this infra-red system reverses the door on the way down when the light beam becomes obstructed.
There are 2 types of sensors:
transmitter-receiverinfra-red beam, such as the CPS from LiftMaster.
transmitter-reflectormodulated beam, reflected by a mirror, such as the model 42 GRU‑9000 from Allen Bradley or CPSRL‑N4 from LiftMaster.
For both models, the best efficiency is achieved within 30 feet. These systems are sensitive and the beams must be well aligned. Unless protective posts have been installed on the interior side of the door, we suggest installing an “L” shaped track guard to prevent any disturbance of the beams in high traffic areas.