Phase Loss/Phase Reversal/Under Voltage Only

C259

The Model 259 3-Phase Monitor is designed to protect individual 3-phase equipment and motors, or in conjunction with shunt trip breakers. When correct voltage and phase rotation is applied, an internal DPDT relay energizes.

A fault condition (phase loss, phase reversal, or low voltage) drops out the relay and lights the LED failure indicator. The Model 259 will detect a phase loss condition even when regenerative voltage is present.

The Model 259 may be used with Wye or Delta systems and requires no neutral connection. Standard operating ranges are available from 120 to 575 VAC, 60Hz and 380 VAC, 50Hz
B259

The Model 259 3-Phase Monitor is designed to protect individual 3-phase equipment and motors, or in conjunction with shunt trip breakers. When correct voltage and phase rotation is applied, an internal DPDT relay energizes.

A fault condition (phase loss, phase reversal, or low voltage) drops out the relay and lights the LED failure indicator. The Model 259 will detect a phase loss condition even when regenerative voltage is present.

The Model 259 may be used with Wye or Delta systems and requires no neutral connection. Standard operating ranges are available from 120 to 575 VAC, 60Hz and 380 VAC, 50Hz
A259

The Model 259 3-Phase Monitor is designed to protect individual 3-phase equipment and motors, or in conjunction with shunt trip breakers. When correct voltage and phase rotation is applied, an internal DPDT relay energizes.

A fault condition (phase loss, phase reversal, or low voltage) drops out the relay and lights the LED failure indicator. The Model 259 will detect a phase loss condition even when regenerative voltage is present.

The Model 259 may be used with Wye or Delta systems and requires no neutral connection. Standard operating ranges are available from 120 to 575 VAC, 60Hz and 380 VAC, 50Hz
A257BM-400HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
A257B-400HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
EX257BM-415V/50HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
EX257BM

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
EX257B-415V/50HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
EX257B

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
B257BM-400HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
B257BM

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
B257B-400HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
B257B

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
A257BM

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
A257B

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.
257BM-400HZ

The Model 257 continuously monitors 3-phase power lines for abnormal conditions. When properly adjusted, the Model 257 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 (a manual reset version is also available).

The Model 257 does not require a neutral connection and can be used with Wye or Delta systems. Voltage ranges are sufficiently wide to allow for proper adjustment to existing conditions. Both TRIP and NORM condition indicators are provided to aid in adjustment and system trouble-shooting.