The Model 2638 3-Phase Monitor combines a 3-phase monitor with a line voltage and phase sequence indicator. Like other Time Mark Monitors, the Model 2638 senses phase loss, phase reversal and low voltage. When power and phasing are correct, the internal relay energizes. LED indicators will show that all phases are present, and the direction of phase rotation. When a fault occurs, the monitor trips its relay and indicates which phase is lost, or, if a reversal is present. This allows you to automatically protect your equipment by correcting the appropriate fault condition. The Model 2638 will automatically reset when correct power is restored. It is available in 208/240 VAC, 480 VAC, or 380 VAC/50 Hz.. Specifications: Automatic Reset: Yes; Contacts: SPDT; Manual Reset: No; Mount: Surface Mount; Phase Sensing: Phase Reversal,Phase Loss; Trip Delay: No; Trip Restart: No; Voltage Sensing: Under Voltage Protection; Voltage Range: 380VAC,50 Hz