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

Remanent undervoltage protectionANSI code 27Rfunction n° F25 for U’ remanent undervoltage protection 1 ≤ X ≤ 2F35 for U remanent undervoltage protectionEquipmentc single-phase voltage generatorc voltmetersc chronometerc documentationWiringc B3 or B4 diagramc protective relays:F251/1, F251/2F252/1, F252/2 (2)F351/1, F351/2F352/1, F352/2 (2)Testc 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-phasevoltageProcedurec protection parameter setting: REM U/Vv disable the U21 U/V X protection set points (3) (Us = 999 kV)v set Us of protection's REM U/V to the desired value (in kV).Checking of set pointc parameter setingv set T to 0.05 sc testv inject Uns voltage into U21v gradually reduce voltage U21 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 protection F35X/2v set the chronometer to zerov cut off the voltage and start the chronometer at the same timev Sepam's 2000 output relay stops the chronometerv read the t value displayed on the chronometer(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.Sepam 2000 - Testing 1/33