Eaton 75VCPW-VSR Instruction Book

Contents

15Instruction Book IB02707112EAugust 201550/75VCPW-VSRBreaker To Vacuum Starter Replacement UnitEATON CORPORATION www.eaton.com4.3 SECONDARY DISCONNECTSThe VSR control circuit is connected to the switchgear controlthrough a multi-contact block (See Section 3 for componentlocation). The movable secondary control contacts mounted on theunit are self-aligning, line-contact, slip-type connectors. The multiplefinger arrangement on the unit makes contact with a stationarymounted element. The contact surfaces on the stationary elementare recessed to prevent accidental short-circuiting of the controlcircuits.These secondary disconnects mate in both the operating and testpositions. No special jumper is required.Mechanical stops prevent over-travel and avoid damage to thedisconnecting devices when the unit is racked into operatingposition. WARNINGINTERLOCKS ARE PROTECTIVE DEVICES FOR PERSONNEL ANDEQUIPMENT. DO NOT BYPASS, MODIFY, OR MAKE INOPERATIVE ANYINTERLOCKS. DOING SO COULD CAUSE DEATH, SERIOUS PERSONNELINJURY, AND/OR PROPERTY DAMAGE.4.4 INTERLOCKSThere are several interlocks built into the VSR-Series vacuumstarter replacements. Each of these interlocks, though different inform, duplicate or exceed in function that of the original breaker.These interlocks exist to safeguard personnel and equipment. Thebasic premise behind the interlocking arrangement on the vacuumreplacement starter is that the starter must not be inserted into orremove from the live circuit while the main contacts are closed.Also considered in the interlocking is that the starter should pose nogreater risk than necessary to the operator in or out of the cell.4.5 RACKING-IN INTERLOCKThe racking-in interlock is designed to prevent moving the starterinto or out of the Connect position, if the starter contacts are closed.VCPW-VSR interlocks are completely compatible with the existingracking system located in the existing VCP-W assembly structure.VCPW-VSR starters utilize a interlock design that is very similar tothe design used on VCP-W breakers.4.6 RACKING MECHANISMThe purpose of the racking device is to move the VSR between theTEST and CONNECTED positions. For the VCPW-VSR, the deviceis a drive screw and drive nut. Although the device is mountedin the switchgear compartment, a brief description here will helpunderstand the operation. For additional information on the insertionand removal of a VSR from its compartment refer to the insertionand removal sections in this manual.The racking device consists of a drive screw, a drive nut, two siderails and a sliding cage. In the TEST position, the nut is all the wayto the front. As the VSR is pushed in, the racking latch snaps on thenut. Turning the crank clockwise while pushing forward advances theVSR toward the CONNECTED position. During this travel, the floortripper TRIP roller is lifted up holding the VSR trip free. When theVSR reaches the CONNECTED position, the crank cannot be turnedany further. A red flag indicates that the VCPW-VSR is fully engaged.If the VSR is closed in the CONNECTED position, engagement ofthe slider will open the contactor and permit use of the rackingcrank. After tripping the VSR, the racking crank can be engaged andthe VSR withdrawn to the TEST position by turning the racking crankcounterclockwise. This position is indicated by no further motion ofthe crank.The VCPW-VSR racking latch can be disengaged only when the VSRis in the TEST position by lifting the latch release. As the VSR iswithdrawn, it comes out with the contacts open.4.7 GROUND CONTACTThe ground contact is an assembly of spring loaded fingers for allVCPW-VSR Vacuum Motor Starter Replacement designs providing adisconnectable means for grounding the starter chassis, after it hasbeen inserted into a switchgear cell (Figure 4.6). The ground contactis located on the underside of the chassis next to the secondarycontact block. An extension of the switchgear ground bus is securedto the cell floor in such a position to engage the ground contactautomatically, when the starter is pushed into the Test position. Itremains engaged in all positions from Test to and including Connect.4.8 OPERATIONS COUNTERAll VCPW-VSR Vacuum Motor Starter Replacement Units areequipped with a mechanical operations counter (Figures 3.3). As thestarter opens, the counter advances the reading by one.Figurt 4.6. GrNund CNnoaco