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

I.B. 32-255-1G Page 29Effective 12/02been made while the circuit breaker is levered to theCONNECTED position.When the CS/C contact is made, the SR closes the cir-cuit breaker. If the CS/C contact is maintained after thecircuit breaker closes, the Y relay is picked up. The Y/acontact seals in Y until CS/C is opened. The Y/b contactopens the SR circuit, so that even though the circuitbreaker would subsequently open, it could not bereclosed before CS/C was released and remade. This isthe anti-pump function.5-4.1 TIMINGThe opening and closing times for the circuit breakersvary depending upon the control voltage and the powerrating. Typical values for VCP-W outdoor breaker ele-ments are shown in Table 5.2.5-4.2 SECONDARY DISCONNECTSThe circuit breaker control wiring is arranged to connecta standard 25 point male plug with a correspondingswitchgear compartment mounted female plug. The cir-cuit breaker plug is fixed mounted on the left side underthe bottom pan of the mechanism (Figure 4-4). Thefemale plug is mounted in the compartment on a mov-able carriage (Figure 4-2).The secondary disconnects engage automatically as thecircuit breaker is levered into the CONNECTED posi-tion, and disengage as the circuit breaker is withdrawnfrom the CONNECTED position. To engage the sec-ondary contacts while the circuit breaker is in the TESTposition, raise the handle and pull the carriage all theway towards the front (Figure 4-5). This will latch thecontacts. To disengage the contacts, simple push thecarriage to the rear.5-4.3 UNDERVOLTAGE TRIP DEVICEThe undervoltage trip device for VCP-W circuit breakersis an electromechanical device that operates to openthe circuit breaker at 30% or less of the voltage rating ofthe trip coil. The device does not open the circuit break-er at values above 60% of the voltage rating of its tripcoil. It may operate, however, to open the circuit breakerwhen the voltage across the trip coil is greater than30%, but less than 60% of the voltage rating of its tripcoil. The circuit breaker can be closed as long as thevoltage to the trip coil is maintained at 85% or above therated level. The undervoltage trip device is availableonly as an instantaneous type with rated voltages of48VDC, 125VDC, 250VDC, 120VAC and 240VAC.For a basic understanding of the operation of the under-voltage trip device refer to the specific items identified inFigure 5-6 and the following operation description.1. With the circuit breaker closed and sufficient voltageon the Undervoltage Trip Device coil, the movingclapper (1) is held to the stationary yoke (2) by themagnetic force produced by the coil (3) against theextension springs (4) pulling the moving clapperapart from the yoke.2. The moving clapper is connected to the mechanismTrip D Shaft Lever (5) by a slotted link (6).3. When the voltage to the Undervoltage Trip Coil goesdown as described earlier, the extension springsforce overcomes the reduced magnetic force andpulls the moving clapper up. The slotted link in turnupsets the Trip D Shaft and the circuit breaker tripsopen.4. As the circuit breaker opens, the reset lever (8) con-nected to the pole shaft lever (7) operates to resetthe moving clapper. As long as the circuit breakerremains open, the reset lever holds down the movingclapper to the yoke.5. When the circuit breaker closes, the reset levermoves away from the moving clapper. If the Under-voltage Trip Device coil has at least 85% of the ratedvoltage applied, the moving clapper is held to theyoke by the magnetic force, even though the resetlever has moved up.Event Milliseconds (maximum)Closing Time(From Initiation of Close 45-60Signal to Contact Make)Opening Time(Initiation of Trip Signal 30-45to Contact Break)Reclosing Time(Initiation of Trip Signal 140-165to Contact Make)Table 5.2 Circuit Breaker Timing