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

Phase-to-phase undervoltage protectionANSI code 27function n° F32X for U13 phase-to-phase undervoltage protection 1 ≤ X ≤ 2F33X for U13’ phase-to-phase undervoltage protectionF34X for U21 phase-to-phase undervoltage protectionF35X for U21’ phase-to-phase undervoltage protectionF36X for U32 phase-to-phase undervoltage protectionF37X for U32’ phase-to-phase undervoltage protectionEquipmentc single-phase or three-phase voltage generatorc voltmetersc chronometerc documentationWiringc diagram B3 or B4c protective relays:F321/1, F321/2 F322/1,F322/2 for U13F331/1, F331/2 F332/1,F332/2 for U13’F341/1, F341/2 F342/1,F342/2 for U21F351/1, F351/2 F352/1,F352/2 for U21’F361/1, F361/2 F362/1,F362/2 for U32F371/1, F371/2 F372/1,F372/2 for U32’Testc read the section entitled measurement and testingmethod.Since the different phase-to-phase undervoltageprotections are single-phase, the tests may beperformed by using a single-phase injection unit anddisabling the other set points(by setting them to 999 kV).c status parameter settingv select Fn network frequency (50 or 60 Hz)v set Unp network phase-to-phase voltagev select the number of connected VTs given that:- U13 U/V does not exist if the number of VTs is 2- U32 U/V and U13 U/V do not exist if the number ofVTs is 1- U13 U/V does not exist in compactSepam 2000 S25 modelsv select Uns VT secondary circuit phase-to-phasevoltageProcedurec protection parameter setting: U21 U/V Xv disable the other protection set points (Us = 999 kV)v set Us to the desired value (in kV)v set T to the desired valueChecking of set pointc parameter settingv set T to 0.05 sc testv inject voltage Uns into U21v gradually reduce U21 voltage until the relay linked with the protection picks upv read the value on the voltmeterv increase the voltage to Unsv 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 undervoltage protectionv set the chronometer to zerov cut off the voltage and start up the chronometer at the same timev Sepam's 2000 output relay stops the chronometerv read the t value displayed by the chronometer(1)this function may only be activated if your program logic hasbeen customized.(2)remember to reactivate the protections at the end of testing.X = number of the protective relay.1/32Sepam 2000 - Testing