Eaton 380 VCP-Wind Instructions For The Use, Operation And Maintenance

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Page 16 I.B. 70A2580H02Effective November 20125-2.3 LOADING SPRINGThe contact loading spring is enclosed inside theencapsulated pole. The contact loading springs maintainthe proper contact pressure to keep the contacts closed.No re-adjustment of the breaker is needed after initialassembly.5-2.4 CONTACT WIPE AND STROKEContact wipe is the indication of (1) the force holding thevacuum interrupter contacts closed and (2) the energyavailable to hammer the contacts open with sufficientspeed for interruption.Stroke is the gap between fixed and moving contacts ofa vacuum interrupter with the circuit breaker open.The circuit breaker mechanism provides a fixed amountof motion to the operating rods. The first portion of themotion is used to close the contacts (i.e. stroke) and theremainder is used to further compress the preloadedwipe spring. This additional compression is called wipe.Wipe and Stroke are thus related to each other. A greatdeal of effort has been spent in the design of all Eatonvacuum circuit breakers, in order to eliminate the needfor field adjustments of wipe or stroke.CAUTIONTHERE IS NO PROVISION FOR IN SERVICEADJUSTMENTS OF CONTACT WIPE AND STROKE.ALL SUCH ADJUSTMENTS ARE FACTORY SET ANDSHOULD NOT BE ATTEMPTED IN THE FIELD.5-2 STORED ENERGY MECHANISMWARNINGKEEP HANDS AND FINGERS AWAY FROM THECIRCUIT BREAKER’S INTERNAL PARTS WHILE THECIRCUIT BREAKER CONTACTS ARE CLOSED ORTHE CLOSING SPRINGS ARE CHARGED. THECIRCUIT BREAKER CONTACTS MAY OPEN OR THECLOSING SPRINGS DISCHARGE CAUSING ACRUSHING INJURY. DISCHARGE THE SPRINGS ANDOPEN THE CIRCUIT BREAKERS BEFORE PER-FORMING ANY CIRCUIT BREAKER MAINTENANCE,INSPECTION OR REPAIR.The spring stored energy operating mechanism isarranged vertically in front of all VCP-Wind circuitbreakers (Figure 3-2). It includes all the elements forstoring the energy, closing and tripping of the circuitbreaker, as well as manual and electrical controls.The manual controls are all front accessible. Motionto close and open the interrupter contacts is providedthrough operating rods connecting the mechanismpole shaft to the bell cranks of the interrupterassemblies.5-3.1 OPERATION OF STORED ENERGYMECHANISMThe mechanism stores the closing energy bycharging the closing springs. The mechanism mayrest in any one of the four positions shown in Figure5-2 and as follows:a. Circuit breaker open, closing springs dischargedb. Circuit breaker open, closing springs chargedc. Circuit breaker closed, closing springs dischargedd. Circuit breaker closed, closing springs charged5-3.2 CHARGINGFigure 5-3 is a schematic view of the spring chargingparts of the stored energy mechanism.The major component of the mechanism is a camshaft assembly which consists of a drive shaft towhich are attached two closing spring cranks (one oneach end), the closing cam, drive plates, and a free-wheeling ratchet wheel. The ratchet wheel is actuatedby an oscillating mechanism driven by the motoreccentric. As the ratchet wheel rotates, it pushes thedrive plates which in turn rotate the closing springcranks and the closing cam with it.The closing spring cranks have spring endsconnected to them, which are in turn coupled to theclosing springs. As the cranks rotate, the closingsprings are charged. When the closing springs arecompletely charged, the spring cranks go over deadcenter, and the closing stop roller comes against thespring release latch. The closing springs are now heldin the fully charged position.Closing springs may also be charged manually. Insertthe maintenance tool in the manual charging socket.Move it up and down approximately 36 times until aclicking sound is heard, and the closing springscharging indicator indicates “Charged.” Any furthermotion of the maintenance tool will result in freewheeling of the ratchet wheel.