The unit’s voltage limits and fault durations can be configured from the programming menu. In addition, one phase can be assigned priority and contactor blocking mode can be enabled and disabled. Relay outputs can also be enabled/disabled from the programming menu. The R-S-T LEDs located on the front panel indicate which phase is being fed to the output. Alarm LEDs indicate fault status. Blocked contactors can be reset and alarms can be dismissed using the relevant buttons on the unit. The unit is supplied by the phase input and does not require a DC supply