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

Positive sequence undervoltage and phase rotation directioncheck protectionANSI code 27D - 47function n° F38X 1 ≤ X ≤ 2Equipmentc three-phase voltage generatorc voltmetersc chronometerc documentationWiringc diagram B4c protective relays:F381/1, F381/2 for set point 1F382/1, F382/2 for set point 2 (2)F381/3, F382/3 (2) for phase rotation direction checkTestc read the section entitled measurement and testingmethodc status parameter settingv select Fn network frequency (50 or 60 Hz)v set Unp network phase-to-phase voltagev set Uns VT secondary circuit phase-to-phasevoltagev set the number of wired VTs to 3UProcedurec set P Seq U/V X protection parametersv inject the 3 rated phase voltages Vnsv set Vsd to the desired value (in kV)v disable the other protection set points, the U U/V x, U U/V and N Vol Disp(when sum of VTs is used)Checking of set pontc parameter settingv set T to 0.05 s testv gradually reduce the three voltages at the same time until the relay linked withthe protection picks upv read the Vd value on the pocket terminalv increase the voltages to Vnsv press reset (1) on Sepam 2000 to erase the message and reset the output relayChecking of time delayc parameter settingv set T to the desired valuec testv wire the chronometer so that it starts when voltage injection stops and is stoppedby the output relay linked with the positive sequence undervoltage protectionF38X/2v set the chronometer to zerov cut off the voltage or voltages and start the chronometer at the same timev Sepam's 2000 output relay stops the chronometerv read the t value displayed on the chronometerChecking of phase rotation (1)The protection considers that the network connected to Sepam 2000 is turning inreverse when the positive sequence voltage is less than 10% Un and thephase-to-phase voltages are greater than 80% Un.c inject the rated voltages in inverse order: the rotation message is displayed andpower readout is disabled.c noteBalanced networkVd = Vn = Un/√3Unbalanced networkLoss of 1 phasev Vd = 0.66 Vn = 0.385 UnTwo phases faultv Vd = 0.5 Vn = 0.288 UnThree phases faultv Vd = 0 VTwo phase to earth faultv Vd = 1/3 Vn = 0.192 Un(1)this function may only be activated if your program logic hasbeen customized.(2)only one protective relay is used in standard applications(3)remember to reactivate the protections at the end of testing.X = number of the protective relay.1/34Sepam 2000 - Testing