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