The Model 2581 3-Phase Monitor is designed to continuously monitor 3-phase power lines for phase loss, low voltage and phase reversal. The Model 2581 Monitor will detect phase loss on a loaded motor even when regenerated voltage is present. This device consists of a solid-state voltage and phase-angle sensing circuit, driving an electromechanical relay. When correct voltage and phase rotation are applied, the internal relay will energize. A fault condition will de-energize the relay. When the fault is corrected, the monitor will automatically reset . The Model 2581 3-Phase Monitor does not require a neutral connection and can be used with Wye or Delta configured systems. Low voltage trip point is factory set at 10% below nominal. An LED indicator is provided for system troubleshooting.