Eaton AMPGARD Installation, Operation And Maintenance Instructions

Contents

6Instruction Booklet IB48050Effective September 2012Instructions for installationoperation and maintenance of theAMPGARD 15 kV 300A vacuum startereaton Corporation www.eaton.comVacuum contactor300A, 15 kV AMPGARD medium voltage controllers are suppliedwith 300A vacuum contactors The contactor has an interruptingrating of 5000A and is open-rated to carry 300A continuouslyThe contactor enclosed rating is also 300AFigure 9. 300A, 15 kV SL Vacuum ContactorContactors are typically three-pole devices except in the case of thestart contactors on autotransformer starters, which are normallytwo-pole devicesRefer to Instruction Book IB48051 for further details on the operationand maintenance of the vacuum contactorsControllers supplied as transformer feeders or for other specializedapplications are sometimes supplied with contactors that includea mechanical latch device Refer to Eaton for further details on theoperation and maintenance of the latch mechanismSafety interlocksAMPGARD controllers are manufactured with several built-ininterlock provisions and safety features to reduce hazards andprovide proper operating sequencesA mechanical interlock prevents opening the medium voltage doorwith the switch in the closed position Ensure that the mediumvoltage door is fully closed and latched using the two latches on theright side of the door to prevent damage to the interlock bracket onthe back of the doorAn additional interlock prevents closing of the switch unless themedium voltage door is closed (see MV door interlock plungerin Figure 10) On controllers that require two structures (reducedvoltage starters for example), the door to the second structurewill also be interlocked with the switch operating mechanism Thesecond door must be closed before the main door is closed Bothdoors must be closed before the switch operator can be moved tothe closed positionotee:N Attempting to close the switch with the door open can cause damageto the operating mechanismIsolationSwitchDrive RodMV Door Hold-Down InterlockContactorInterlockRodMV DoorInterlockPlungerPilot Holefor CreatingOptionalProvision toLock SwitchClosedPadlockingProvisions(SwitchOpen)Figure 10. Handle Mechanism with Contactor and Door InterlocksMechanical and electrical interlocks are provided to insure that thenon-loadbreak isolation switch cannot be opened or closed unlessthe main contactor is de-energized (see contactor interlock rod inFigure 10) Do not attempt to force the switch operating mechanismwith the main contactor closed The handle mechanism is designedto fail before the isolation switch can be opened with the maincontactor closedm cautionapplying excessive force to the switch hanDle with themechanical interlocks engageD will result in Damage tothe switch.An electrical interlock is provided to disconnect the control powertransformer secondary before the isolating switch stabs aredisconnected from the controller line fingers This interlock ensuresthat the switch is breaking transformer magnetizing current onlyDo not connect additional loads to the controller isolating switchm Dangerif loaDs greater than the interrupting rating of the switchare connecteD to the switch, equipment Damage, personalinjury, or Death may occur.An optional key interlock may be provided to lock the switch in theopen position for special configurations Refer to the specific orderdrawings to determine if key interlocks have been providedOn reversing, two-speed or autotransformer type starters,mechanical interlocks are provided to prevent two or morecontactors from closing at the same time