LED Default usage1 Non-Directional Overcurrent Operate2 Non-Directional Earth fault Operate3 Sensitive Earth fault Operate4 Negative Seq. Overcurrent/Phase Discontinuity Operate5 Thermal Overload Alarm6 Breaker Failure Operate7 Disturbance Recorder Triggered8 Circuit Breaker Condition Monitoring Alarm9 Trip Circuit Supervision Alarm10 ARC Protection Operate11 Auto Reclose in Progress3.6.3 Functional diagramsThe functional diagrams describe the default input, output, alarm LED and function-to-function connections. The default connections can be viewed with SMT andchanged according to the application requirements, if necessary.The analog channels, measurements from CTs and VTs, have fixed connectionstowards the different function blocks inside the IED’s standard configuration.Exceptions from this rule are the 12 analog channels available for the disturbancerecorder function. These channels are freely selectable and a part of the disturbancerecorder’s parameter settings, thus not included in the SMT functionality.The analog channels are assigned to different functions as shown in the functionaldiagrams. The common signal marked with 3I represents the three phase currents.The signal marked with I0 represents the measured residual current, via a summationconnection of the phase current transformers.3.6.3.1 Functional diagrams for protectionThe following functional diagrams describe the IED’s protection functionality indetail and according to the factory set default connections in SMT.Section 3 1MRS756378 DREF615 variants70 REF615Application Manual
