Eaton 380 VCP-W 16 Instructions For Installation, Operation And Maintenance

Also see for 380 VCP-W 21: Instructions for installation, operation and maintenance

Contents

Page 24 I.B. 3A74792H08Effective 0 9 / 2 0 145-2.3 LOADING SPRING INDICATIONThe contact loading spring indicator is an additionalmethod provided to indicate conditions within the vacuuminterrupter, as well as the overall system condition. Thevisible indication, on each phase, is used to indicatewhether the contact loading springs are maintaining theproper contact pressure to keep the contacts closed.Severe contact erosion or an adjustment need after aninterrupter assembly replacement would result in anunacceptable indication from this indicator (Figures 6-4and 6-5).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. As thestroke increases due to the erosion of contacts, the wipedecreases. A great deal of effort has been spent in thedesign of all Eaton vacuum circuit breakers, in order toeliminate the need for 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 AAND OPEN THE CIRCUIT BREAKERS BEFOREPER- FORMING ANY CIRCUIT BREAKERMAINTENANCE, INSPECTION OR REPAIR.The spring stored energy operating mechanism isarranged vertically in front of all VCP-W and VCP-WRcircuit breakers (Figure 3-5). It includes all theelements for storing the energy, closing and trippingof the circuit breaker, as well as manual and electricalcontrols. The manual controls are all front accessible.Motion to close and open the interrupter contacts isprovided through operating rods connecting themechanism pole shaft to the bell cranks of theinterrupter assemblies.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 Figure5-4 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 5-5 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 38 times until aclicking sound is heard, and the closing springs