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

TestingRestricted earth fault protection testingc Parameterization of the protection for Test coupling(using the pocket terminal, KP6 = 1)The test indicator lights up.Please noteThis operation should be carried out first since itinhibits tripping of the protection.c Checking of the setting:The Iso set point is checked by simulating a faultbetween the neutral point CT and a phase CT, whenthe circuit breaker is open. In this case, only theneutral point CT detects the fault. There is zerorestraint current.635241654321ECM D2SEPAM 2000ECM D3635241654321CSH 30ATo perform the test, wire according to the diagramopposite.Inject a current in the CSH 30 sensor associated withthe neutral point current measurement CT to checkthe value of the setting.5 A neutral point current CT : 1 turn1 A neutral point current CT : 5 turnsc Check the stability:The stability is checked by considering a phase-toearthfault outside the zone to be protected.This test is only possible if Ino = In for the winding towhich the restricted earth fault protection isconnected.To perform the test, wire according to the diagramopposite.Inject a current into the CSH 30 sensor associatedwith the neutral point current CT and into one of thephase current inputs to simulate a fault outside thezone. Check the stability for a current of 2 In.635241654321ECM D2SEPAM 2000ECM D3635241654321CSH 30A5 A neutral point current CT : 1 turn1 A neutral point current CT : 5 turnsD21 - D22 - D31 - Installation - Use - Commissioning4/9