Eaton W-VAC Series Instructions For Installation, Operation And Maintenance

Also see for 120W-VAC16: Instructions for installation, operation and maintenance

Contents

Instruction BookPage 32IB131009ENturn. Since the cam surface in contact with the main linkroller is cylindrical in this region, the spring chargingoperation does not affect the mechanism linkage.Since the primary contacts are completely enclosed inthe vacuum interrupter and not adjustable in any way, a"Slow Close" capability is not provided with W-VAC andW-VACW breakers.5-2.4 TRIPPING OPERATIONWhen the trip "D" shaft is turned either by the trip buttonor trip coil, all links return to the original "open" conditionshown in (Figure 5-5a).5-2.5 TRIP FREE OPERATIONWhen the manual trip button is held depressed, anyattempt to close the breaker results in the closingsprings discharging without any movement of the poleshaft or vacuum interrupter stem.5-3 CONTROL SCHEMEThere are two basic control schemes for all the circuit-breakers, one for DC control and one for AC controlvoltages or more than one tripping element, but the prin-cipal mode of operation is as follows:As soon as the secondary disconnects engage, thespring charging motor automatically starts charging theclosing spring, provided control power is available.When the springs are charged, the motor cut off LS1/bbswitch turns the motor off. The breaker may be closedby making the control switch close (CS/c) contact.Automatically upon closing of the breaker, the motorstarts charging the closing springs. The breaker may betripped any time by making the control switch (CS/T)contacts.Note the position switch (PS) contact in the springrelease circuit in the scheme. This contact remainsmade while the breaker is being levered between theTEST and CONNECTED positions. Consequently, itprevents the breaker from closing automatically, eventhough the control switch close contact may have beenmade while the breaker is levered to the CONNECTEDposition.When the CS/C contact is made, the SR closes thebreaker. If the CS/C contact is maintained after thebreaker closes, the Y relay is picked up. The Y/a contactseals in Y until CS/C is opened. The Y/b contact opensthe SR circuit, so that even though the breaker wouldsubsequently open, it could not be reclosed beforeCS/C was released and remade. This is the anti-pumpfunction.5-3.1 TIMINGThe opening and closing times for the circuit breakersvary depending upon the control voltage and the powerrating. However, the typical values are as follows inTable 5.1.Table 5.1 Typical Opening and Closing TimesEvent Time in MillisecondsClosing Time(From Initiation of CloseSignal to Contact Make)75Opening Time(Initiation of Trip Signalto Contact Break)45Reclosing Time(Initiation of Trip Signalto Contact Make) 1905-3.2 SECONDARY DISCONNECTSThe drawout breaker control wiring is arranged to con-nect a 25 point male plug as standard with a corre-sponding female plug mounted in the switchgear com-partment. An additional 25 point plug is optional and canbe supplied when an additional auxiliary switch beyondthe standard is supplied. The fixed circuit breaker uti-lizes a similar fixed secondary connection scheme.The drawout breaker plugs are mounted in small enclo-sure located on the upper left front portion of the basicbreaker element (Figure 3-4). This male plug automati-cally connects or disconnects with a structure mountedfemale plug as the breaker is racked into or out of theconnected position.If the drawout breaker is being used in a flush mountedconfiguration, the breaker must be moved to the discon-nected position for testing. It is recommended that a testcable be used to connect the female and male sec-ondary contacts when in the disconnected position. Thestructure mounted secondary contact blocks are perma-nently mounted and cannot be moved out for direct con-nection with the breaker mounted secondary contacts.The behind the door drawout design utilizes movablecarriage mounted female plugs in the structure. A"TEST" position is available within the structure. Oncethe breaker is racked out to the test position, the struc-ture mounted secondary plug carriage can be manuallyunlatched, and pulled forward until the female plugsmate with the breaker mounted male plugs. To disen-gage the secondary plugs from the "TEST" position,simply push the carriage to the rear.