Eaton LBS Series Installation, Operation And Maintenance Manual

Contents

Page 6Fig. 6 Handle OperationThe quick-make mechanism provides power toovercome blowout forces that occur if the switch isclosed into a fault. These forces are not transmitted tothe operating handle since it is not rigidly connected tothe blades. The switch can therefore be safely closedunder short circuit conditions within its fault-close rating.Load interruption is accomplished by flicker blades andcontact fingers located inside a DE-ION arc chute. Onopening the switch, the main blades open first and allcurrent is shunted through the spring-loaded flickerblades. Further travel of the main blades cause theflicker blades to snap out of their contact fingers. Arcingtakes place within the arc chutes between the contactfingers and flicker blades.4.3 Fuse ReplacementWARNING!When accessing fuses, failure to assure that thefuses are de-energized may result in equipmentdamage, bodily injury, or death.Make sure that all power sources are de-energizedbefore attempting to access the fuses.When specified, the Type LBS switch is supplied withCutler-Hammer Type CLE or HLE current limiting powerfuses. Fuse puller, part number 6391D55G01, issupplied with fuses rated 450 amps or less to aid in theinsertion and removal of the fuses. Instructions forusing the fuse puller are mounted on the inside of theswitch enclosure door. Fuses rated 600E to 1350E areof the bolted type and are mounted in auxiliarycompartments.HandleStorageClipsSECTION 5 - MAINTENANCEAn LBS switch should be thoroughly inspected prior toinitial energizing. Every 100 operations or yearlythereafter a cursory inspection to clean, lubricate, andcheck for signs of wear and tear, damage, etc., isrecommended as described in section 5.1. If anyproblems are discovered they should be corrected byfollowing procedures in sections 5.2 and 5.3. After 30interruptions at the rated current or after the switch hasbeen exposed to fault currents, the switch should bethoroughly inspected at the first opportunity. If theswitch has been moved or otherwise subjected tomechanical strain, inspection procedures described inSection 3 should be performed.The rated mechanical life of the LBS is 500operations.5.1 Inspection ProcedureWARNING!Failure to completely disconnect the switch from allpower sources prior to inspection or maintenancemay result in severe injury or death.An LBS switch must be completely disconnected fromall power sources before performing inspection.5.1.1 Main Blade and Flicker Blade ContactInspectionCheck main blades and flicker blades for arc erosion.Severely damaged blade assemblies should bereplaced as described in Sections 5.3.1 and 5.3.2.If flicker blades become rough from arc erosion, theymay be smoothed with a few light strokes of a fine file.No attempt should be made to file out pit marks. Do notuse any abrasive material for cleaning. If questionable,don’t file the flicker blades.The main blade current carrying contact surfaces mustnot be filed. Opening and closing the switch will keepthem clean. If main blade current carrying contactsurfaces are burned, they must be replaced.5.1.2 Arc Chute Inspection