Prevents against symmetrical and asymmetrical voltage drop
Functioning
In case of voltage asymmetry above set value between phases causes the switching-OFF the motor. The switching-OFF the motor also occurs in case of phase-to-phase voltage drop below 320V. The motor switching-OFF occurs with 4 sec delay, which prevents any accidental motor disconnecting at temporary voltage drop. The re-connection will occur automatically at voltage increase of 5V above activation voltage (i.e. of value of voltage hysteresis). At occurrence of these disturbances, it is not possible to put a motor to motion. Change of phase sequence, before the monitor, which causes change of motor rotation direction (in relation to that primarily set) along with impossibility of switching-ON the motor.
