Combine with Other Types of Lighting Controls
Expect to combine photo control of interior lighting with other methods of control. Photo controls alone would keep the lights turned on during all hours of darkness. Provide additional controls to turn the lights on and off in response to the presence of people. Photo control alone is useful only for lighting that is required throughout hours of darkness, such as security lighting.
A common pitfall is using manual switches in combination with photo controls. In such cases, the manual switch may inadvertently be left in the on position even though the photo control has turned off the lights. At sunset, the photo control will turn the lights on even though the facility is vacant.
Solving this problem requires a combination of controls. Use a time clock to keep the lights turned off during hours of darkness when the space is normally unoccupied. In addition, install another type of automatic control, such as a motion sensor, to override the time clock if people are present during these hours.