1. Phase Failure: When voltage value of any phase is lower than 154VAC, output relay status will be OFF, the output relay status will be ON if voltage value is higher than 154VAC.
2. Phase Reversed: In case of incorrect phase sequence connection, output relay status will be OFF. with the return to the normal state of the phase sequence, the output relay status will be ON.
3. Phase Imbalance: when the voltage difference between any two phase is higher than 30VAC, output relay status will be OFF. with the return to the normal state (less then 30VAC), the output relay status will be ON.