Time Mark Corporation 3-Phase Voltage Unbalance Monitor Model D200

The Model 200 3-Phase Voltage Unbalance Monitor is designed to continuously monitor a three-phase line for unbalanced voltage conditions. This device will only energize the relay if an unbalance exists. Zero volts on all three phases is considered a balanced condition. This allows the Model 200 to be used with shunt breakers, so that the breaker can shut off the main power without tripping the monitor. The solid-state sensing circuit drives an internal electromechanical relay. Indicator lights on the monitor show when the voltage balance is within an acceptable range; when an unbalance exists; and when the relay is actually tripped. When an acceptable voltage balance is reapplied, the Model 200 will automatically reset the relay.