Voltage, Phase Unbalance, and Sequence Relay RNPP-311.1 is designed to disconnect the load 400 V, 50 Hz in case of inadmissible voltage oscillations in the network with a time duration of at least 0.02 s.

• Inadmissible voltage oscillations in the network with time duration of at least 0.02 s;
• Amplitude symmetry breaking of the mains voltage (phase unbalance);
• Loss, error in sequence, and sticking of the phases.