TM 96115434NAVFAC P 34(2)Closing Operation. Once the drive springs (Figure 5-15) have been charged, the breaker can be dosed by liftingthe dose lever (Figure 5-12) or by energizing the dosing solenoid (Figure 5-16). Either method disengages the trip dosingroller and allows the drive springs to discharge. The discharging drive springs rotate the drive shaft (Figure 5-17)clockwise. The clockwise rotation of the drive shaft gives the drive spring bearing (Figure 5-18) a downward motion.The drive spring bearing engages the toggle cam, thus rotating the front of the toggle cam up and the rear of the togglecam down the catch. The front of the toggle cam is connected to the main shaft (Figure 5-16) by the drive linkage(Figure 5-18). The upward motion of the front of the toggle cam thus rotates the main shaft counterclockwise andcompresses the return springs (Figure 5-16). The drive connecting links (Figure 5-15) transform the rotary motion of themain shaft into a linear motion which doses the vacuum interrupter contacts. The trip opening cam (Figure 5-18) forcesthe entire toggle assembly to remain latched in this position. When the drive springs discharge, rotating the drive shaft ina counter-clockwise direction, the descending lift arm rotates the drive lever such that the drive lever completes theremaining 360 degrees of rotation to its initial position where it can once again perform a drive spring charging operation.The gear shaft and drive hub rotate with the drive lever. The drive hub rotates out of contact with the drive block sincethe gear (Figure 5-17) rotates freely on the gear shaft, the gear remains stationary. The rotation of the drive hub is suchthat the pawl lift slide follows the cammed surface of the drive hub until the pawl lift slide moves back below the gearteeth, permitting the drive pawi to engage the gear. The charging motor limit switch cam (Figure 5-16) rotates with thegear shaft and doses the charging motor limit switch, energizing the charging motor which once again charges the drivesprings.(3)Opening Operation. With the return springs (Figure 5-16) charged, the operating mechanism is now ready toperform an opening operation. If the open lever (Figure 5-12) is lifted or if the opening solenoid (Figure 5-16) isenergized, the trip opening cam (Figure 5-18) will be rotated clockwise out from under the toggle bearing. The force ofthe charged return springs pushing down on the front of the toggle cam will cause the rear of the toggle subassembly torotate clockwise. When the rear of the toggle cam dears the catch, the return springs will completely discharge, rotatingthe main shaft (Figure 5-16) and the toggle cam clockwise. The clockwise rotation of the main shaft is transformed to alinear motion by the drive connecting links (Figure 5-15). The drive connecting links are connected to the vacuuminterrupters (Figure 5-13), and their motion opens the vacuum interrupter contacts.(4)Spring Discharge Interlocks. The spring discharge interlocks (Figure 5-15) are located directly below the openingand dosing solenoids (Figure 5-16). Three cams, located on the floor of the skeleton cell, engage the spring dischargeinterlocks in such a manner that the primary disconnects (Figure 5-13) cannot be engaged or disengaged with theinterrupter contacts in the closed position and all springs are automatcally discharged whenever the load circuit breaker isinserted into or removed from its cell.WARNINGDischarge to ground the primary disconnects and vacuum Interrupter mid-band rings beforehandling to prevent Injury to personnel as a result of electrocution.WARNINGTo avoid Injury to personnel, always remove the load circuit breaker CB101 from Its cubideand discharge or block the return drive springs.WARNINGTo avoid Injury to personnel, no electrical component will be worked on while energized.Ensure equipment Is "tagged out" In accordance with Chapter 1, Section III, of the Operatorand Organizational Maintenance Manual and equipment Is NOT energized. Residual voltage Ispresent at the generator leads with the regulator turned off, reaching SEVERAL HUNDREDVOLTS on the generator set. Proper Insulation and Isolation of metering equipment must beobserved when testing this generator. USE PROPER TEST EQUIPMENT TO CHECK FORVOLTAGE before proceeding with work.5-41
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business