Table 40:HZPDIF (87) Output signalsName Type DescriptionTRIP BOOLEAN Trip signalALARM BOOLEAN Alarm signalMEASVOLT REAL Measured RMS voltage on CT secondary side6.3.5 SettingsTable 41:HZPDIF (87) Group settings (basic)Name Values (Range) Unit Step Default DescriptionOperation DisabledEnabled- - Disabled Disable/Enable OperationAlarmPickup 2 - 500 V 1 10 Alarm voltage level on CT secondarytAlarm 0.000 - 60.000 s 0.001 5.000 Time delay to activate alarmTripPickup 5 - 900 V 1 100 Pickup voltage level in volts on CT secondarysideR series 10 - 20000 ohm 1 1800 Value of series resistor in Ohms6.3.6 Monitored dataTable 42:HZPDIF (87) Monitored dataName Type Values (Range) Unit DescriptionMEASVOLT REAL - kV Measured RMS voltage on CTsecondary side6.3.7 Operation principleThe 1Ph High impedance differential protection (HZPDIF, 87) function is based on onecurrent input with external stabilizing resistor and voltage dependent resistor. Thestabilizing resistor value is calculated from the function operating value V TripPickupcalculated to achieve through fault stability. The used stabilizing resistor value is set bythe setting R series.See the application manual for operating voltage and sensitivity calculation.6.3.7.1 Logic diagramThe logic diagram shows the operation principles for the 1Ph High impedance differentialprotection function HZPDIF (87), see figure 48. It is a simple one step function with anSection 6 1MRK 502 048-UUS ADifferential protection130Technical manual
