The GLS-PLS-120/277 is a 3-Phase Power Loss Sensor designed for use with Crestron Green Light™ systems to activate Override mode during a power failure. In response to a signal from the GLS-PLS-120/277, the lighting system program can be temporarily overridden while designated emergency lighting circuits are changed to their override preset levels and unnecessary lighting and other devices are shut down to minimize the demand on emergency power equipment.

The GLS-PLS-120/277 senses each leg of a 120 or 277 Volt 3-phase feed, providing LED indication of the status of each phase on its front panel. When power is lost on any phase, the corresponding status LED turns off and a contact closure is activated on each of two control outputs. Two isolated control outputs are provided to allow for interfacing with third-party equipment in addition to the Crestron lighting system. Each contact closure output is rated for 1A at 24VDC.

Testing the GLS-PLS-120/277 is facilitated using three Test Switches located behind a small cover plate on the front of the unit. Setting any switch to the TEST position simulates a loss of power on the corresponding phase leg, providing a test of the unit's internal circuitry and any connected equipment.

The steel enclosure is designed for mounting to a vertical surface. Conduit knockouts are provided on the bottom, top, and both sides. All electrical connections are made via screw terminals accessed by removing the front panel.