released, the handle can be completely withdrawn from the test switch, restoring thetrip circuits to the protection IED.If a test switch is not used, perform measurement according to the provided circuitdiagrams.Never disconnect the secondary connection of a current transformercircuit without first short-circuiting the transformer's secondarywinding. Operating a current transformer with the secondary windingopen will cause a massive potential build up that may damage thetransformer and cause personal injury.9.4 Connecting the test equipment to the IEDConnect the test equipment according to the IED specific connection diagram and theneeded input and output signals for the function under test. An example of aconnection is shown in figure 10.Connect the current and voltage terminals. Pay attention to the current polarity. Makesure that the connection of input and output current terminals and the connection of theresidual current conductor is correct. Check that the input and output logical signalsin the logic diagram for the function under test are connected to the correspondingbinary inputs and outputs of the IED under test.The MU test equipment must be connected to the CD port on the OEMmodule when process bus IEC61850-9-2LE communication is used.To ensure correct results, make sure that the IED as well as the testequipment are properly earthed before testing.1MRK 511 360-UEN A Section 9Testing IED operationBay control REC670 2.1 IEC 71Commissioning manual
