Photocell

A photocell is a paired safety sensor, one transmitter and one receiver, mounted on each side of a UK power-operated garage door that stops the door closing if the infrared beam between them is broken.

Photocells are a required part of the safety system under BS EN 12453 for power-operated doors. A dirty lens or misaligned pair is one of the most common reasons a UK electric garage door will not close. Realigning or replacing a photocell typically costs £80–£180.