Eaton 75VCPW-VSR Instruction Book

Contents

21Instruction Book IB02707112EAugust 201550/75VCPW-VSRBreaker To Vacuum Starter Replacement UnitEATON CORPORATION www.eaton.comsimultaneously, (DO NOT MOVE THE INSULATOR ON THE MIDDLEPHASE) while rocking the main shaft open and closed.5. Tighten locknuts securing threaded rod to top of each insulator.Use bottle wrench to insure standoff insulator does not rotate duringthis operation.6. Perform test as described in section 6 on Vacuum Integrity Checkbefore returning contactor to service.6.2 CNil Rtplactmtno1. Remove the coil leads from terminals 5 and 6 on the controlboard. Cut the wire-tie securing the coil leads to the baseplate.2. Remove the coil mounting angle by removing the two anglemounting bolts located on the bottom of the contactor baseplate.(Figure 6.7). Be careful not to allow the angle to move abruptly asthe bolts are removed since there is pressure applied to the angle bythe return spring. Remove coil assembly from contactor.3. Remove the locknut holding the return spring bolt on the back ofthe mounting angle (Figure 6.8). Note: After removing locknut, countthe threads protruding through the mounting angle to insure correctlength during reassembly.4. Unscrew the spring assembly by hand and remove from the angle(Figure 6.9).5. Slip the two coils from the cores.6. Install the two new coils over the cores. (Figure 6.10)7. Thread the return spring assembly into the mounting angle untilthe locknut under the bottom spring retainer just contacts the angle.The number of threads protruding through the mounting angleshould be the same as counted in step 3 above. Do not overtightensince this would compress the return spring and prevent the properforce from being applied to the operating plate on opening. The rearlocknut for the return bolt should then be tightened on the back ofthe angle.8. Secure the angle to the contactor baseplate using the twomounting bolts. Sufficient force must be applied to the angle tocompress the return spring and allow the threaded holes in theangle to align with the appropriate holes in the baseplate.9. Connect the coil leads to the appropriate terminals on thecontrol board. Secure the leads using a wire tie and the hole in thebaseplate to insure that the leads do not become abraised. Beforethe contactor is reinstalled, verify proper operation using test power.When power is applied, the contactor should close cleanly. Whenpower is removed, the moving armature should securely contact thestop assembly.6.3 CNnorNl BNard Chtck and RtplactmtnoTo verify the output of the control board, apply rated control voltageto terminals one and two. WARNINGVERIFY THAT THE APPLIED POWER CANNOT BE FED BACK INTO ANY CPTOR OTHER CIRCUIT, WHICH MAY GENERATE DANGEROUS VOLTAGES.Using a standard hand-held multimeter, check the dc output of theboard at terminals 5 and 6. The voltage should be approximately 9 to16 volts. If there is no output, the board must be replaced. If there isan output voltage, but it is not within this range, remove the boardand verify the dip switch settings.To remove the board, wires connected to terminals 1, 2, 5, and 6must be disconnected. Make certain that the wires are properlymarked before disconnecting to insure the ability to reconnect themto the proper terminal. After the wires are disconnected, loosenthe mounting screws located at the top and the bottom of theterminal block. The board may now be withdrawn from its mountingcompartment.Before a new board is installed, make certain that the dip switchesare properly set. Refer to Table 5.1 and Table 5.2. Installation is theopposite of removal.6.4 STOP ASSEMBLY REPLACEMENTIf the stop assembly becomes worn it should be replaced.To replace, close the contactor with test power. Remove thetwo bolts securing the assembly to the baseplate. Install a newassembly. Hand-tighten bolts. Set gap between the armature plateand stop to 0.534 in. 0.004 in. using adjustment block provided withreplacement stop assembly, torque bolts to 214 lb-in (24.2 N-M).(See Figure 6.11)6.5 AUXILIARY CONTACT MAINTENANCE ANDREPLACEMENTIf standard contact blocks become oxidized due to very low currentlevels passing through the contacts, they may be cleaned byperiodically disconnecting them from the circuit and circulatingapproximately 10 amps through the contacts for a short period oftime. If one or more of the auxiliary contacts fail, it is recommendedthat the complete contact block assembly be replaced. Disconnectwiring to each contact, making sure to properly mark each wireto insure proper reconnection. Remove the two mounting screwssecuring the contact assembly to the bearing retainer. Install thereplacement assembly, securing with the two mounting screws. Thecontacts are properly adjusted when the plunger to operating armgap is .110 inches. (Figures 6.12 and 6.13).Figurt 6.5. RtmNval Nf Vacuum InotrrupotrFigurt 6.6. InsoallaoiNn Nf BNlo and Shuno SuppNros