Eaton VCP-W Series Instructions For Installation/operation/maintenance/servicing

Also see for 120VCP-W25: Installation, operation and maintenance Instructions for installation, operation and maintenance

Contents

41Instruction Booklet IB131006ENEffective March 2019Instructions for installation,operation, and maintenance of typeVCP-W vacuum circuit breakersEATON www.eaton.com5.3.2 ChargingFigure 21 is a schematic view of the spring charging parts of thestored energy mechanism.The major component of the mechanism is a cam shaft assemblywhich consists of a drive shaft to which are attached two closingspring cranks (one on each end), the closing cam, drive plates, anda free-wheeling ratchet wheel. The ratchet wheel is actuated by anoscillating mechanism driven by the motor eccentric. As the ratchetwheel rotates, it pushes the drive plates which in turn rotate theclosing spring cranks and the closing cam with it.The closing spring cranks have spring ends connected to them,which are in turn coupled to the closing springs. As the cranksrotate, the closing springs are charged. When the closing springsare completely charged, the spring cranks go over dead center, andthe closing stop roller comes against the spring release latch. Theclosing springs are now held in the fully charged position.Closing springs may also be charged manually. Insert the mainte-nance tool in the manual charging socket. Move it up and downapproximately 38 times until a clicking sound is heard, and theclosing springs charging indicator indicates “Charged.” Any furthermotion of the maintenance tool will result in free wheeling of theratchet wheel.5.3.3 Closing operationFigure 20 shows the position of the closing cam and tripping linkage.Note that in Figure 20a in which the circuit breaker is open and theclosing springs are discharged, the trip “D” shaft and trip latch are inthe unlatched position.Once charged, the closing springs can be released to close thecircuit breaker by moving the spring release latch out of the way.This is done electrically or manually by depressing the spring releaselever, which turns the spring release latch out of the way of theclosing stop roller. The force of the closing spring rotates the camshaft through the spring cranks. The closing cam, being attached tothe camshaft, in turn rotates the pole shaft through the main link toclose the circuit breaker.In Figure 20c the linkage is shown with the circuit beaker in theclosed position before the closing springs have been recharged.Interference of the trip “D” shaft with the trip latch prevents thelinkage from collapsing, and the circuit breaker is held closed.Figure 20d shows the circuit breaker in the closed position after theclosing springs have been recharged. Note that the spring chargingrotates the closing cam by one-half turn. Since the cam surfacein contact with the main link roller is cylindrical in this region, thespring charging operation does not affect the mechanism linkage.Since the primary contacts are completely enclosed in the vacuuminterrupter and not adjustable in any way, a “Slow Close” capabilityis not provided with VCP-W circuit breakers.5.3.4 Tripping operationWhen the trip “D” shaft is turned either by the trip button or trip coil,all links return to the original “Open” condition shown in Figure 20a.5.3.5 Trip free operationWhen the manual trip button is held depressed, any attempt to closethe circuit breaker results in the discharge of the closing springswithout any movement of the pole shaft or vacuum interrupter stem.5.4 Control schemesThere are two basic control schemes for VCP-W circuit breakers: onefor DC control and one for AC control voltages (Figure 22), however,there are many other more advanced control schemes that canbe configured by the switchgear provider. There may be differentcontrol voltages or more than one tripping element, but the principalmode of operation is as follows.As soon as the control voltage is applied, the spring charging motorautomatically starts charging the closing springs. When the springsare charged, the motor cut off LS1/bb switch turns the motor off.The circuit breaker may be closed by making the control switch close(CS/C) contact. Automatically upon closing of the circuit breaker, themotor starts charging the closing springs. The circuit breaker may betripped at any time by making the control switch trip (CS/T) contact.Note the position switch (PS1) contact in the spring release circuitin the scheme. The contact remains made while the circuit breakeris being levered between the TEST and CONNECTED positions.Consequently, it prevents the circuit breaker from closing automati-cally, even though the control close contact (CS/C) may have.