Eaton 75VCPW-VSR Instruction Book

Contents

11Instruction Book IB02707112EAugust 201550/75VCPW-VSRBreaker To Vacuum Starter Replacement UnitEATON CORPORATION www.eaton.comSECTION 4: DESCRIPTION AND OPERATIONThe VCPW-VSR Vacuum Motor Starter Replacement is a mediumvoltage (4.76 / 7.2kV maximum) vacuum starter used for the controlof three phase motors. The SL Contactor has a current rating of400A.The SL Contactor utilizes Eaton’s vacuum interrupters that exhibitboth a long electrical life and a high interruption capability. Ratingsfor the contactor are shown in Table 4.1. The 400 amp contactorhas three Axial Magnetic (A-M) coils at the fixed end of the vacuuminterrupters. The A-M coils establish a magnetic field within theinterrupter during fault conditions. The field disperses the arc duringfault current interruption, allowing the contactor to interrupt a veryhigh fault current. See Figure 4.2. WARNINGSATISFACTORY PERFORMANCE OF THESE CONTACTORS IS CONTINGENTUPON PROPER APPLICATION, CORRECT INSTALLATION AND ADEQUATEMAINTENANCE. THIS INSTRUCTION BOOK MUST BE CAREFULLY READAND FOLLOWED IN ORDER TO OBTAIN OPTIMUM PERFORMANCE FOR THELONG, USEFUL LIFE OF THE CONTACTOR.4.1 CONTACTOR OPERATIONMechanically Latched StarterThe mechanically latched starter is closed by energizing the startercontrol board with the appropriate control voltage at terminals 1 and2. The control board rectifies the input voltage and applies pulsewidth modulated DC output voltage to the coils. The output voltageis approximately full voltage for the first 200 milliseconds afterenergization, during which time the starter closes and seals. Afterthe starter is electrically closed, a mechanical latch is engaged thatholds the moving armature plate in the closed position. Power isthen removed from the control board. Refer to Figure 4.1, for typicalschematic for latched contactor.To open the starter, the unlatch coil is energized with the appropriatecontrol voltage. The coil engages a release lever on the latchmechanism. The starter is then forced opened by the return spring.Mechanical opening is also provided.Control SchemeA position switch contact is in the contactor closing circuit, whichremains made while the contactor is being racked between the Testand Connected positions. Consequently, it prevents the starter fromclosing automatically, even though the control switch close may havebeen made while the starter is racked to the connected position.When the close contact is made, the MX closes the starter. If theclose contact is maintained after the starter closes, the Y-relayis picked up. The Y/a contact seals in Y until the close contact isopened. The Y/b contact opens the MX circuit, so that even thoughthe starter would subsequently open, it could not be reclosed beforethe close contact was released and remade. This is the antipumpfunction.Auxiliary ContactsAn operating lever attached to the rotating shaft operates a set ofauxiliary contacts located on each side of the starter (Figure 4.2).The standard configuration is 3NO-3NC contact on each side of thestarter. The auxiliary contacts are rated 600V, 10 amps continuous.Minimum ratings are 5 volts, 100 milliamps. Refer to Table 5.1 formake/break ratings.Control VoltagesACDCControl Circuit BurdenClosing (200 Milliseconds)110/120 AC, 125 DC20/240 AcHolding110/120 AC, 120 DC220/240 ACAuxiliary Contact RatingVoltage (Max)Continuous CurrentMaking CapacityBreaking CapacityMin. Voltage/CurrentLatchMechanical LifeTrip VoltageMin. Trip VoltageTrip Burden(24 vDC)(125 vDC)(110 vAC & 120 vAC)Trip TimeMaximum Interrupting Current (3 OPS.)Rated CurrentMaximum Rated VoltageMaking/Breaking CapacityShort Time Current30 Sec.1 Sec.8.7 MS (0.5 Cycle)Mechanical LifeElectrical LifeBILDielectric Strength (60 Hz)Closing Time(Energized To Contact Touch)Opening TimesArcing TimePickup VoltagesDropout Voltage8500 Amps (SL-400)400 A Enclosed7.2kV4000 Amps2400 A6000 A63kA Peak(l2t = 5.89mega-joles)2,500,000 Operations300,000 Operations60 kV (1.2 x 50 Milliseconds)20 kV (1 Minute)80 Milliseconds30 to 330 MillisecondsDip Switch SelectableRefer to Table 5.212 ms (0.75 Cycle) or less80% Rated Coil Voltage60% Rated Coil VoltageSelectable: Refer to Table 5.1110/120, 220/240, 50/60 Hz1 kVA1.8 kVA40 VA50 VA600 V10 A7200 VA125 VA720 VA125 VA5V/100mA250,000 operations24 Volts125 Volts110/120 Volts80% Rated Coil Voltage400 VA400 VA400 VA30 M sec (2 cycles)(AC)(DC)(AC)(DC)(DC)(DC)(AC)Tablt 4.1. SL CNnoacoNr Raoings