Relay for monitoring AC voltage in a 3-phase network 3 (N) - 400/230 V. Supply voltage = supervised voltage. Overload capacity ≥1.2Un. Output - 1 changeover contact. Rated voltage 3(N) ̴400/230 V AC 50/60 Hz. Relay performing the following functions: LOST D - phase loss supervision, ASYM D - asymmetry supervision, SEQ D - phase sequence supervision. Unbalance ranges - fixed set 55 V. Off delay - fixed set 4 s.