Our Light Controllers are designed for a wide variety of applications, such as a closet door, where the load status (ON/OFF) is determined by the opening and closing of switches. These relays are powered by line voltage and can switch loads varying from 120 Vac or 277 Vac. With model CLC212-D15, money and energy can be saved when a door is inadvertently left open. In this event, the light will switch off after a 15-minute delay. If you wish for the light to remain on indefinitely after the door is open, simply open, close, and reopen the door within three seconds.