this position, all voltages and currents are restored and any re-energizing transientsare given a chance to decay before the trip circuits are restored. When the latchesare released, the handle can be completely withdrawn from the test switch,restoring the trip circuits to the protection IED.If a test switch is not used, perform measurement according to the provided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 secondarywinding open will cause a massive potential build up that maydamage the transformer and cause personal injury.9.4 Connecting the test equipment to the IED M11744-2 v8Connect the test equipment according to the IED specific connection diagram andthe needed input and output signals for the function under test. An example of aconnection is shown in figure 9.Connect the current and voltage terminals. Pay attention to the current polarity.Make sure that the connection of input and output current terminals and theconnection of the residual current conductor is correct. Check that the input andoutput logical signals in the logic diagram for the function under test are connectedto the corresponding binary inputs and outputs of the IED under test.To ensure correct results, make sure that the IED as well as the testequipment are properly earthed before testing.1MRK 505 372-UEN A Section 9Testing IED operationBusbar protection REB670 2.2 IEC 71Commissioning manual
