The MFU monitoring relays work in window mode, which means they check whether the monitored voltage is between a lower and an upper threshold. The overvoltage and undervoltage thresholds are set using two potentiometers. If the monitored voltage exceeds or falls below the set upper threshold or the set lower threshold for longer than the reaction time set on the front, the output relay opens. The measuring voltage is the same as the supply voltage. Approvals: UL and CSA.
