!!! product phase-out !!! the preferred successor is 3UG5616-1CR20 phase failure and sequence monitoring 3x 160-690 V, screw terminal digital monitoring relay for 3-phase voltage with N conductor connectable phase sequence phase failure 3 x 90 to 400 V 50 to 60 Hz AC undervoltage and overvoltage 90-400 V hysteresis 1-20 V 0-20 s each for Umin and Umax 1 changeover contact for Umin 1 changeover contact for Umax screw terminal