The Model 2501 3-Phase Monitor is designed to continuously monitor 3-phase power lines for abnormal conditions. This device features solid-state voltage and phase-angle sensing circuits, which drive a SPDT electromechanical output relay.

When the correct voltage and phase sequence is applied to a specified Model 2501, the output relay will energize. An under voltage, phase reversal, phase unbalance, or phase loss condition will cause the output relay to de-energize. A neutral connection is not required, allowing the Model 2500 or 2501 to be used with either Wye or Delta system configurations.

Each option on the Model 2500 or 2501 monitor is adjustable throughout its operating range. The adjustment pots and LED indicators for VOLTAGE ADJUST, UNBALANCE ADJUST and TIME DELAY are mounted on the front of the unit for easy access.

Seven versions of the Model 2500 or 2501 cover voltage ranges from 120 to 600 VAC, and are UL Listed and CSA Certified.