GE Multilin 745 Instruction Manual

S2 System Setup745Transformer Management RelaySetpointshttp://www.GEindustrial.com/multilin5ñ34 GE Multilininformation that is often only available from the transformer manufacturerís testreport, including the three-phase resistance of each winding and the load loss atrated load. The harmonic derating factor will only be valid if this information hasbeen entered correctly.The 745 also calculates the total harmonic distortion of the phase current inputsignals. The band of frequencies over which this calculation is made can be changedto be more selective than the default 2nd to 21st harmonics.ï HARMONIC DERATING FUNCTION: Enter ìEnabledî to enable the harmonicderating factor calculations.ï THD MINIMUM/MAXIMUM HARMONIC NUMBER Enter the minimum/maximum harmonic number of the frequency band over which total harmonicdistortion is calculated.FlexCurvesô PATH: SETPOINTS !" S2 SYSTEM SETUP !" FLEXCURVES ! FLEXCURVE A(C)Three programmed custom FlexCurvesô can be stored in the 745 as FlexCurveô A,FlexCurveô B, and FlexCurveô C. This allows the user to save special curves forspecific applications and then select them as required for time overcurrent elementcurves. The custom FlexCurveô has setpoints for entering the times-to-trip atvarious levels of pickup. The levels are as follows: 1.03, 1.05, 1.1 to 6.0 × PU insteps of 0.1, and 6.5 to 20.0 × PU in steps of 0.5.ï FLEXCURVE A DELAY AT n × PU: Enter the trip time for n = 1.03. 1.05,...,20.0 × PU for FlexCurveô A(C). The messages that follow sequentiallycorrespond to the trip times for the various pickup levels as indicated above.Voltage Input PATH: SETPOINTS !" S2 SYSTEM SETUP !" VOLTAGE INPUTThe 745 provides a voltage input for the purposes of energization detection (for theEnergization Inhibit feature of the percent differential element), overexcitationprotection (the Volts-per-Hertz 1 and 2 functions), and frequency protection (theUnderfrequency, Frequency Decay, and Overfrequency functions). Note that thefrequency elements will use the Winding 1 Phase A current input if voltage is notavailable.ï VOLTAGE INPUT PARAMETER: Enter the winding and phase of the voltageconnected to the voltage input.ï NOMINAL VT SECONDARY VOLTAGE: Enter the nominal secondary voltage(in volts) of the voltage transformer.ï VT RATIO: Enter the ratio of the voltage transformer.! FLEXCURVE A [!] FLEXCURVE A DELAY AT1.03 x PU: 0 msRange: 0 to 65000 ms in steps of 1MESSAGE FLEXCURVE A DELAY AT1.05 x pu: 0 msRange: 0 to 65000 ms in steps of 1↓MESSAGE FLEXCURVE A DELAY AT20.0 x pu: 0 msRange: 0 to 65000 ms in steps of 1! VOLTAGE INPUT [!] VOLTAGE SENSING:DisabledRange: Enabled, DisabledMESSAGE VOLTAGE INPUTPARAMETER: W1 VanRange: W1, W2, W3;Van, Vbn, Vcn, Vab, Vbc, VcaMESSAGE NOMINAL VT SECONDARYVOLTAGE: 120.0 VRange: 60.0 to 120.0 in steps of 0.1MESSAGE VT RATIO:1000:1Range: 1 to 5000:1 in steps of 1