Eaton DST-2-VR+ Series Instruction Book

Contents

23Instruction Book IB182942EN July 2018 www.eaton.comDST-2-VR+VR-Series+ Replacement Circuit BreakerFigurt 5.4. DST-2-7.5-VR+ in Conntct Position g. (Domestic Version) In the “test” position, the breaker can beoperated manually and electrically, thus allowing maintenancetests or checks. To operate the breaker electrically, the secondarycontrol block must be engaged at this time. The slider is locatedon the lower right hand area of the circuit breaker frame. Ifelectrical testing is desired at this stage, engage the secondarycontrol block slider by releasing the slide latch and pushingthe slider toward the rear several inches. Push firmly on thefront side of the slider until the contact block engages with thecorresponding cell receptacle. Return the manual motor cutoffswitch to the “on” position. The spring charging motor will beginto run and charge the closing spring. The breaker is now inthe “test” position, with control voltage applied, and ready forelectrical or manual testing.g. (Canadian Version) In the test position, the breaker can beoperated manually and electrically, thus allowing maintenancetests or checks. To operate the breaker electrically, the secondaryblock must be engaged. On Canadian versions, the secondaryblock for 250Vdc versions is located on the lower, rear, center ofthe breaker. Other Canadian versions, the secondary disconnectoperates in a manner similar to the domestic US models detailedabove. The secondary block automatically engages in the testposition. Return the manual motor cut-off switch to the “on”position. The spring charging motor will begin to run and chargethe closing springs. The breaker is now in the “test” position, withcontrol voltage applied, and ready for manual or electrical testing.(* For DST-2-7.5-VR+ with centered secondary disconnect block)h. To install the breaker in the connected position the leveringhandle will have to be used. Insure the breaker is open andengage the levering handle with the breaker and floor leveringcutouts. (See Figure 5.5)i. Depress the Interlock Pedal and start levering in the breaker byshifting the levering handle back and forth. Once movement hasstarted, the pedal should be released. The closing springs may bein the charged state but the internal PS switch will open circuitthe close spring release coil (preventing an electrical close).At this point any attempt to mechanically close the breaker willcause a trip-free operation with no recharging of the closingsprings (PS2 has open-circuited the charging motor circuit andthe Interlock Pedal operation has automatically turned the motorcutoff switch to “off”). As advancement into the cell continues,the primary voltage source shutters will open allowing the breakerstabs to engage with the source.j. Continue moving the breaker into the cell using the leveringhandle from the test position until a mechanical stop is reached.This is the fully engaged or connected position. The connectposition can be verified by the inability to move the breakerin or out, the Interlock Pedal is up and has released the tripmechanism, and the cell label “operating” is visible on the floor ofthe cell in front of the breaker’s left front wheel. Manually returnthe motor cutoff switch to the “on” position. The breaker is nowready for service.5.10.3 REMOVAL PROCEDURE (LEVERING-IN VERSION)To remove the breaker from the cell it must be in the open position.Insure the breaker is open and engage the levering handle.The Interlock Pedal must be depressed which will raise the tripmechanism and trip the breaker. Move the breaker out using thelevering handle illustrated in Figure 5.5. The breaker will start comingout of the cell before the main stabs are disconnected and will be ina non-operable mode and will go through a trip-free operation if anyattempt to close it is made in the intermediate position. Also, thesecondary control block will disengage automatically before the mainstabs are disconnected.otte:N (Canadian Version) The secondary block will remain connected until thebreaker is removed from the test position.The shutters will close after the main stabs have cleared, isolatingthe breaker from its source. Continue levering out until the positionindicator on the floor of the cell shows test and the Interlock Pedalrises to lock the breaker in position. At this time you are in the testd. Push the circuit breaker into the cell until all the wheels are onthe guide rails and the spring discharge linkage has not cycled.(For Canadian breakers, the interlock plunger will rest in thefirst cell position.) No mechanical stop will be reached. This isthe “disconnect” position and the breaker can still be operatedbecause there is no interface of the cell floor interlocks withbreaker interlock linkage. No cell labeling is provided to verify thisposition.e. Depress the pedal and push or lever the breaker further into thecell. (Figure 5.3)otte:N Depressing of the Interlock Pedal automatically positions the motorcutoff switch to “off”.f. Once movement has started, the Interlock Pedal should bereleased if depressed. The levering handle may be required tomove the breaker completely into the test position and its use isillustrated in Figure 5.3. An audible click of the interlock plungerengaging the interlock rail will be observed when moving fromthe disconnect position. The Interlock Pedal will travel down atthe beginning of movement and rapidly rise to lock the breaker inthe test position at the end of the normal travel from disconnectto test. The movement of the handle provides an open signalthat remains throughout all intermediate breaker positions andthe floor trip will be combined with a closing signal between thedisconnect and test position to discharge the closing springs.The breaker remains in the trip-free state until the test position isreached. The test position can be verified by the inability to movethe breaker in or out, the Interlock Pedal is in the up position, andthe cell label “test” is visible on the floor of the cell in front of thebreaker’s left front wheel.