Monitoring voltage relay HRN-57

• SERVES TO MONITOR VOLTAGE IN A SWITCHBOARD, PROTECTION OF DEVICES IN 3-PHASE MAIN
• RELAY DOESN’T MONITOR PHASE SEQUENCE.
• SUPPLY IS DONE FROM MONITORED VOLTAGE.
• FIXED T1(500MS) AND ADJUSTABLE T2 (0.1 – 10 S) DELAY TO ELIMINATE SHORT VOLTAGE DROPS AND PEAK.
• IN CASE SUPPLY VOLTAGE FALLS BELOW 60 %UN (U OFF LOWER LEVEL) RELAY IMMEDIATELY SWITCH OFF WITH NO DELAY.
• IT IS POSSIBLE TO SET UPPER AND LOWER LEVEL INDEPENDENTLY.
• MONITORING VOLTAGE RELAY IN TWO VARIANTS:

HRN-57: SUPPLY FROM ALL PHASES, MEANS THAT RELAY IS FUNCTIONAL ALSO IN CASE OF FAILURE IN ONE PHASE
HRN-57N: SUPPLY L1-N, MEANS THAT RELAY MONITORS ALSO FAILURE OF NEUTRAL WIRE, REPLACEMENT FOR HRN-52

• FAULTY STATE IS INDICATED BY RED LED AND BY BREAKING OUTPUT RELAY CONTACT.