There are two types of photocell operation; ON/OFF PHOTOCELL CONTROL and DAYLIGHT HARVESTING CONTROL (see descriptions below). A photocell sensor can be used by itself (e.g., standalone operation) or together with low voltage occupancy sensors.
ON/OFF PHOTOCELL CONTROL Photocell output (blue wire) will turn lights off if ambient light level surpasses threshold and back on if level drops
DAYLIGHT HARVESTING CONTROL Unit will gradually dim lighting in order to maximize energy savings while maintaining desired overall lighting level