The Model 258 Continuously Monitors 3-Phase Power Lines For Abnormal Conditions. When Properly Adjusted, The Model 258 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 Autom