Eaton 75VCPW-VSR Instruction Book

Contents

20Instruction Book IB02707112EAugust 201550/75VCPW-VSRBreaker To Vacuum Starter Replacement UnitEATON CORPORATION www.eaton.comSECTION 6: REPLACEMENT OFCOMPONENTS6.1 REPLACEMENT OF VACUUM INTERRUPTERSIf the vacuum interrupters fail the vacuum integrity or wear check, orif they have more than 300,000 operations, they must be replaced.The three interrupters must be replaced as a set. WARNINGTHERE ARE BELLOWS IN EACH INTERRUPTER THAT SEAL THE MOVINGCONTACT FROM THE ATMOSPHERE. THESE BELLOWS ARE FRAGILEAND MUST BE PROTECTED FROM ANY TORSIONAL LOADING. ANAPPROPRIATE TOOL MUST SUPPORT THE MACHINED FLATS ON EACHEND OF THE INTERRUPTER WHEN TIGHTENING ANY HARDWARE ONTHE INTERRUPTER. BOTTLE WRENCH, CUTLER-HAMMER PART NUMBER4A36081H01, IS PROVIDED WITH EACH SET OF REPLACEMENT VACUUMINTERRUPTERS AND SHOULD BE USED IN THIS APPLICATION.Remove each vacuum interrupter using the steps listed below:1. Loosen locknut securing threaded rod to top of standoff insulator(Figure 6.1). Note the number of threads between the two 10mmnuts.2. Rotate insulator clockwise to screw insulator off threaded rod.3. Remove clamp securing lower end of the vacuum interrupter tothe housing (Figure 6.2).4. Remove bolt and shunt supports securing end of the lowerterminal to the housing (Figure 6.3).5. Remove the bolt securing the vacuum interrupter to the upperterminal (Figure 6.4).6. Hold insulator down and rotate lower portion of the vacuuminterrupter assembly forward to remove (Figure 6.5).7. Insert new the vacuum interrupter assembly (reverse of step 6).8. Install the bolt securing the vacuum interrupter to the upperterminal, do not tighten.9. Install bolt and shunt supports securing lower terminal to housing(Figure 6.6). When tightening insure laminated shunt is straight andshunt supports are in the correct position.10. Tighten bolt securing vacuum interrupter to upper terminal whileholding bottle wrench on upper vacuum interrupter stem. Torque to200 lb-in (22.6 Nm). Insure the laminated shunt is not twisted.11. Install clamp securing lower end of vacuum interrupter tohousing.12. Rotate insulator counter-clockwise until the number of threadsnoted in step 1 is obtained.6.1.1 ADJUSTING VACUUM INTERRUPTERSAfter 3 new vacuum interrupter’s have been installed, set the properopen gap using the steps listed below. Three battery operated testlights or continuity testers are needed for the proper setting of theopen gap.1. Attach test lights across the upper and lower terminals of eachinterrupter.2. Rotate insulator on middle phase bottle until light flickers. Rotateclockwise if light is not on, counterclockwise if light is on.3. From the point the light flickers, rotate insulator on middle phasebottle counter-clockwise three and twothirds turns to establisha 5.5mm open gap. Use markings on insulator to verify correctrotation. (Two thirds turn is equal to 8 divisions that are molded onthe surface of the insulator.)4. Slowly rotate the main shaft, closing the vacuum interrupter’s,until the middle phase light is on. Adjust the insulators on the twooutside phases so that the lights on all three phases come onFigurt 6.1. LNNstning LNcknuoFigurt 6.2. RtmNving Clamp Stcuring LNwtr TtrminalFigurt 6.3. RtmNving BNlo and Shuno SuppNrosFigurt 6.4. RtmNving BNlo Stcuring Upptr Ttrminal