The NEPEAN Power Photoelectric smoke detector is capable of detecting smoke by utilising infrared diodes housed in a specialised optical sensing chamber. It is designed to provide open-area protection, and to be used with a conventional fire alarm panel. The detector has an automatic reset function.

Two LEDs on each detector provide local 360 degree visible alarm indication and flash every six seconds to indicate power is on and detector is functioning. LEDs latch on in an alarm state and will sound when sensitivity is outside limits i.e. smoke is detected.

The principle of detection results from granules in the smoke which reflect infrared light. When there is no smoke present, the diode receives a very weak infrared light. Upon the smoke entering the chamber, the diodes change in status allowing the detector to emit an alarm signal once the smoke reaches a certain density.