Eaton Cooper Power NR Series Maintenance Instructions Manual

Contents

6. With the mechanism closed, the moving contactsshould be within 1/16-inch of full engagement, asmeasured between the top edge of the moving contactinsulator and the bottom edge of the contact box sideplate as shown in Figure 10. To obtain this dimension,adjust the effective length of the insulated operatinglink by adjusting the attaching point for the contactarm assembly in the slotted hole of the link. Be sureto retighten the elastic stop nut when adjustment iscompleted.Complete contact box assemblyTo replace the complete contact box assembly proceed asfollows:1. Detach the opening springs and disconnect the togglelink from the bell crank as described in "Moving ContactArm Assembly" section, Steps 1 and 2.2. Remove the hex nuts, lockwashers and flatwashersthat retain terminal leads to bushing rods.3. Remove four hex head machine screws with pre-assembled lockwashers that secure the contactstructure to the head casting. Contact structureremoved from switch is shown in Figure 11.4. To replace contact structure:A. Slip toggle link over bell crank lever and securewith C-ring.B. Attach contact structure to head casting with hourhex head machine screws with lockwashers.C. Attach opening springs to toggle link.D. Install moving and stationary contact assemblies, ifnecessary, as described previously.E. Attach terminal leads to bushing rods with flat-washers, lockwashers and hex nuts.Actuator mechanismThe actuator mechanism requires little attention. When theswitch is removed from service for its periodic maintenanceinspection, check the condition of the selector switchcontacts, and holding switch contacts if so equipped.Also check the condition of the wiring, motor and cams.Components of a standard actuator mechanism are shownin Figure 12. Figure 13 shows the wiring diagram of theswitch actuator with the various accessory connectionsshown in dotted lines.S-32S-11S-12S-21S-31MSA0 1 G 2 3 4+ + + + +Legend0 Auxiliary Circuit1 Holding CircuitG Ground2 Closing Circuit3 Opening Circuit4 Auxiliary CircuitM AC MotorS-1 Selector-switch opening-circuit contacts1S-1 Selector-switch closing-circuit contacts2S-3 Auxiliary switch actuated directly from main shaftSA Surge arresterFigure 13. Wiring diagram with accessory connectionsindicated by broken lines.Operating Shaft Drive LeverElastic Stop NutDrive LeverTerminal Strip ForCustomer ConnectionsDrive MotorSelector SwitchClosing SpringFigure 12. Standard actuator mechanism with auxiliaryswitch option.5 Pin / 3 Conductor Or6 Pin / 6 ConductorReceptacleWhite Motor Lead ToTerminal GRed Selector SwitchLead To Terminal 2Black Selector SwitchLead To Terminal 3Pin9TYPE NR OIL SWITCH MAINTENANCE INSTRUCTIONS MN230001EN February 2016