Eaton VR+ Series Supplemental Instructions

Also see for VR+ Series: Instruction book Instruction book

 WARNINGTHERE IS NO PROVISION FOR IN-SERVICE ADJUSTMENTSOF CONTACT WIPE AND STROKE. ALL SUCH ADJUSTMENTSARE FACTORY SET AND SHOULD NOT BE ATTEMPTED INTHE FIELD.Contact Erosion and WipeSince the contacts are contained inside the interrupter,they remain clean and require no maintenance. However,during high current interruptions, or high numbers ofoperations, it is possible for a minimal amount of erosionon the contact surfaces. It is also possible for furthercompaction of the conductor electrodes that has beenknown to reduce the amount of contact wipe. TheVR-Series+ vacuum interrupter assembly incorporatesboth the original vacuum interrupter erosion indicatorand the contact-spring wipe into one all-encompassingindicator. The adequacy of the remaining contact erosionand wipe can easily be determined by observing thevacuum interrupter side of the operating rod assemblyon a closed circuit breaker. The procedure to determinethe adequacy of the “T” cutout on the vacuuminterrupter assembly is depicted in Figures 6.1 and 6.2.Some configurations may require the use of a smallmirror and flashlight to clearly see the “T” cutout. Aslong as any part of the “T” cutout is visible on eachpole unit, the contact surfaces and spring pressure areadequate for the circuit breaker to interrupt its full ratednameplate short circuit and carry continuous currentwithout over-heating. If the wipe is inadequate (no partof the “T” cutout is visible) then the vacuum interrupterassembly must be replaced. Field adjustment is notpossible.Vacuum Bottle Contact Inspection Contact Wipe and Stroke: Blue Contact Springsotee:N Click the image above to view a satisfactory contact wipe and stroke.Any part of “T” Cutout Visible - “Wipe” Satisfactory“T” Cutout Not Visible - “Wipe” Unsatisfactory WARNINGFAILURE TO REPLACE A VACUUM INTERRUPTER ASSEMBLYWHEN THE “T” CUTOUT IS NOT VISIBLE WILL CAUSE THECIRCUIT BREAKER TO FAIL TO INTERRUPT AND THEREBYCAUSE PROPERTY DAMAGE OR PERSONAL INJURY.Contact Wipe and StrokeContact wipe is the indication of (1) the force holding thevacuum interrupter contacts closed and (2) the energyavailable to hammer the contacts open with sufficientspeed for interruption.Stroke is the gap between fixed and moving contacts ofa vacuum interrupter with the circuit breaker open.The circuit breaker mechanism provides a fixed amountof motion to the operating rods. The first portion of themotion is used to close the contacts (i.e. stroke) and theremainder is used to further compress the preloadedwipe spring. This additional compression is called wipe.Wipe and stroke are thus related to each other. As thestroke increases due to the erosion of contacts, thewipe decreases. A great deal of effort and ingenuity hasbeen spent in the design of VR-Series+ circuit breakers,in order to eliminate any need for field adjustment ofwipe or stroke.otee:N It may be necessary to use a small mirror and flashlight toclearly see the “T” shape indicator. The figure below shows theprocedure for determining the contact wipe of each spring type.7EATON | Visual Instruction Booklet Essentials | November 2018