Eaton 50VCPW-ND250 Installation, Operation And Maintenance Manual

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

Contents

I.B. 32-255-1G Page 31Effective 12/025-5 INTERLOCKS AND INTERFACINGRefer to Paragraph 4-9 of this manual for detailed infor-mation concerning circuit breaker interlocks and theirinterfacing with a switchgear structure compartment. Inaddition, refer to the instruction manual supplied withthe switchgear assembly.5-6 LEVERING MECHANISMThe purpose of the levering device is to move the circuitbreaker between the TEST and CONNECTED posi-tions. For Type VCP-W circuit breakers, the device is adrive screw and drive nut. Although the device ismounted in the switchgear compartment, a briefdescription here will help understand the operation(Figures 4-2 and 4-4). For additional information on theinsertion and removal of a circuit breaker from its com-partment refer to paragraph 4-8.1 in this manual.The levering device consists of a drive screw, a drivenut, two side rails and a sliding cage. In the TEST posi-tion, the nut is all the way to the front. As the circuitbreaker is pushed in, the levering latch snaps on thenut. Turning the crank clockwise while pushing forwardadvances the circuit breaker toward the CONNECTEDposition. During this travel, the floor tripper TRIP rolleris lifted up holding the circuit breaker trip free. When thecircuit breaker reaches the CONNECTED position, thecrank cannot be turned any further. A red flag indicatesthat the circuit breaker is fully engaged.If the circuit breaker is closed in the CONNECTED posi-tion, the slider cannot be pushed forward to permitengagement of the levering crank. After tripping the cir-cuit breaker, the levering crank can be engaged and thecircuit breaker withdrawn to the TEST position by turn-ing the levering crank counterclockwise. This position isindicated by no further motion of the crank.The circuit breaker levering latch can be disengagedonly when the circuit breaker is in the TEST position bylifting the latch release. As the circuit breaker is with-drawn, it comes out with the contacts open and thesprings discharged because of the floor tripping andspring release interlocks.5-7 OPERATIONS COUNTERAll circuit breakers are equipped with a mechanicaloperations counter. As the circuit breaker opens, thelinkage connected to the pole shaft lever advances thecounter reading by one (Figure 3-3).5-8 GROUND CONTACTThe ground contact is an assembly of spring loaded fin-gers providing a disconnectable means for groundingthe circuit breaker chassis, after it has been insertedinto a switchgear structure. The ground contact is locat-ed on the left side of the circuit breaker under themechanism bottom pan. An extension of the switchgearground bus is secured to the cell floor in such a positionto engage the ground contact automatically, when thecircuit breaker is moved into the TEST position. Itremains engaged in all other circuit breaker positionswithin the cell (Figures 4-2 and 4-4).5-9 MOC AND TOC SWITCH OPERATIONSThe MOC (mechanism operated control) switch opera-tor is coupled to the pole shaft (Figure 4-4). In the TESTand CONNECTED positions of the circuit breaker, theoperator aligns directly above the MOC switch bellcrank levers in the compartment. As the circuit breakercloses, the operator moves down and pushes the bellcrank lever to change the MOC switch contact position.Thus, the MOC switch contacts operate in the samemanner as the auxiliary switch contacts in the circuitbreaker. Although the MOC switch operator is providedon all circuit breakers, the compartment mounted MOCswitches are only provided when specified with theswitchgear order.The TOC (truck operated control) switch operator ismounted inside the right foot of the circuit breaker(Figure 4-4). It operates the TOC switch as the circuitbreaker moves to the CONNECTED position in theswitchgear compartment.