Sepam - HV/MV Protection and control units (ENG) - Trinet

Voltage restrained overcurrent protectionANSI code50V-51Vfunction n° F19X for voltage-restrained overcurrent protection 1 ≤ X ≤ 2F20Y for voltage-restrained overcurrent protection 1 ≤ Y ≤ 2Equipmentc single-phase and three-phase current and voltagegeneratorsc phase shifter with angle indicatorc ammetersc voltmeterc chronometerc calculatorc adapter for ECA modulec documentationProcedurec protection parameter setting: V Rest O/C (refer to the section entitledphase overcurrent)v select the curve (definite or IDMT)v set Is to the desired valuev set T to the desired value (10Is IDMT)v disable the unbalance protections;O/C X; U U/V X; U U/V; U/C; E/F X (when the sum of 3 CTs is used)tWiringc B5 or B6 diagramc protective relay:F191/1, F191/2F202/1, F202/2TestT00,2IsI* zonedependenton "u"IsTesting of definite time set pointsIc read the section entitled measurement and testingmethodThis protection is three-phase and may be tested oneach phase individually with single-phase.The set point is adjusted in accordance with thelowest phase-to-phase voltage measured.c checking of the set points for this protection,at rated voltage Uns, is the same as for the phaseovercurrent protection testc for voltage lower than Uns, an adjustment factor isused which, when multiplied by the Is set point,gives the new protection activation set point I*.Set point to be tested I* = K.Isor with K = 1/3 x (4u / Uns - 0.2)c status parameter setting: enter all data itemsv Fn network frequencyv Unp network phase-to-phase voltagev Uns phase-to-phase voltage of the VT secondarycircuitsv number of VTs connected(1 VT for single-phase testing)v select In the CT primary valuev check and set the microswitches on the 3U/Vo,ECM and ECA modules(1)remember to reactivate the protections at the end of testing.X = number of the protective relay.c parameter settingv set Is to the desired valuev set T to 0.05 sc testv inject "u" = Uns (into U21 for single-phase injection)v lower one of the voltages and calculate the ratio u/Unsv gradually increase the current or currents until the protective relay picks upv read the value I* on the ammeterTesting of definite time delayc parameter settingv inject "u" = Uns (into U21 for single-phase injection)v set i higher than Isv set T to the desired valuec testv set the chronometer to zerov start up the chronometer and injection at the same timev the Sepam 2000 relay stops the chronometerv read the value T measured by the chronometerChart giving the Is set point adjustment factor as a function of the change ofvoltage.u/Uns K u/Uns K u/Uns K u/Uns K< 0.2 0.2 0.36 0.413 0.54 0.653 0.72 0.8930.2 0.2 0.38 0.44 0.56 0.68 0.74 0.920.22 0.227 0.4 0.467 0.58 0.707 0.76 0.9470.24 0.253 0.42 0.493 0.6 0.733 0.78 0.9730.26 0.28 0.44 0.52 0.62 0.76 0.8 10.28 0.306 0.46 0.547 0.64 0.787 > 0.8 10.3 0.333 0.48 0.573 0.66 0.8130.32 0.36 0.5 0.6 0.68 0.840.34 0.387 0.52 0.627 0.7 0.867Sepam 2000 - Testing1/7