1. Keep the measured current as close as possible to its rated value or lower.Keep it constant during the test, but ensure that it is higher than the setminimum operating current.2. Ensure that the maximum continuous current to the IED does not exceed fourtimes its rated value, if the measurement of the operating characteristics runsunder constant voltage conditions.3. Make the necessary connections and settings of the test equipment for test ofpoint 1 according to figure 37.4. Decrease the measured three-phase impedance slowly and observe theoperation value for the signal ZOUT.5. Compare the operation value with the set value.6. Do the necessary change of the setting of the test equipment and repeat step 4and step 5 for point 2, 3 and 4 according to figure 37.11.4.9.2 Testing the power swing detection function ZMRPSB M13888-27 v6PreconditionsThe following output signals shall be configured to binary outputs: ZOUT,measured impedance within outer impedance boundary, ZIN, measured impedancewithin inner impedance boundary and START, power swing detection.1. Slowly decrease the measured impedance in all three phases until the STARTsignal gets activated.2. Increase the measured voltages to their rated values.3. Decrease instantaneously voltages in all three phases to the values, which areapproximately 20% lower than the voltage that gives the set value R1LIn atthe predefined test current.4. The START signal must not appear.5. Increase the measured voltages to their rated values.11.4.9.3 Testing thetR1 timer M13888-47 v8Preconditions• The input I0CHECK, residual current (3I0) detection used to inhibit the startoutput must be configured to the output signal STPE on the FDPSPDIS orFRPSPDIS function.• The input BLKI02, block inhibit of the start output for subsequent residualcurrent detection is connected to FALSE.1. Program the test equipment for a single-phase to earth fault and energizeFDPSPDIS or FRPSDIS and check that the input BLOCK on the powerswing detection function ZMRPSB is activated.2. Make a test sequence so that a single-phase to earth fault occurs after that thetrajectory of the impedance has passed the outer and inner boundary of1MRK 505 378-UEN A Section 11Testing functionality by secondary injectionLine differential protection RED670 2.2 IEC 143Commissioning manual
