Eaton 50VCPW-ND250 Installation, Operation And Maintenance Manual

Also see for 120VCP-W25: Instructions for installation/operation/maintenance/servicing Instructions for installation, operation and maintenance

Contents

energy available in terms of over travel in inches toclose the breaker contacts to their full extent. It maybe used periodically to monitor thehealth of the mecha-nism.At times, circuit breakers are called upon to operateMOC switches (mechanism operated control switches)that place extra load upon the closing mechanism of thecircuit breaker. If this load is excessive, it can preventthe circuit breaker from closing fully. In such a case, itis important to determine that the circuit breaker willclose fully. The CloSureTM Test provides this assurance.General Information: The CloSureTM Test can be per-formed on the VCP-W, VCP-WR, VCPW-ND, DHP-VR,W-VACR, and W-VAC lines of vacuum circuit breakersRefer to Table 6.4 a for list of circuit breakers. If theCloSureTM travel obtained is as specified, the mecha-nism performance is satisfactory. If the CloSureTMtravel does not conform as shown in Figure 6-12, con-tact Cutler-Hammer for further information. (See Step13).DO NOT ATTEMPT TO INSTALL OR PERFORMMAINTENANCE OR TESTS ON THE EQUIPMENTWHILE IT IS ENERGIZED. NEVER PUT YOURHANDS NEAR THE MECHANISM WHEN THE CIR-CUIT BREAKER IS IN THE CHARGED OR CLOSEDPOSITION. DEATH OR SEVERE PERSONAL INJURYI.B. 32-255-1GPage 38Effective 12/02secondary disconnect pins with shooting wire. Connectthis wire to the high potential lead of the test machine.Ground the circuit breaker frame. Starting with zero,increase the voltage to 1125 volts rms, 60 Hz. Maintainthe voltage for one minute. Successful withstand indi-cates satisfactory insulation strength of the secondarycontrol circuit. Remove the shooting wire and reconnectmotor leads.6-8 PRIMARY CIRCUIT RESISTANCE CHECKSince the main contacts are inside the vacuum cham-ber, they remain clean and require no maintenance atany time. Unlike many typical circuit breaker designs,VCP-W breakers do not have sliding contacts at themoving stem either. Instead they use a highly reliableand unique flexible clamp design that eliminates theneed for lubrication and inspection for wear.If desired, the DC resistance of the primary circuit maybe measured as follows: close the circuit breaker, passat least 100 amps DC current through the circuit break-er. With a low resistance instrument, measure resis-tance across the studs on the circuit breaker side of thedisconnects for each pole. The resistance should notexceed the values shown in Table 6.3.6-9 MECHANISM CHECKMake a careful visual inspection of the mechanism forany loose parts such as bolts, nuts, pins and rings.Check for excessive wear or damage to the circuitbreaker components. Operate the circuit breaker sever-al times manually and electrically. Check the closingand opening times to verify that they are in accordancewith the limits in Table 5.2.6-9.1 CLOSURE™ TESTIntroduction: The CloSureTM Test is a simple yetextremely effective means to determine and monitor theability of the mechanism to close the breaker contactsfully. It provides a quantitative measure of the extraRated ContinuousCurrent (amperes)120020003000Resistance(microohms)604020Table 6.3 Typical Resistance Measurements! WARNINGFigure 6-5 Status Indicators (“A” shows the contactstatus indication and “B” shows the spring indication.)OpenDischargedAB