Eaton DST-2-VR+ Series Instruction Book

Contents

24 Instruction Book IB182942EN July 2018 www.eaton.comDST-2-VR+VR-Series+ Replacement Circuit Breakerposition and the trip mechanism is released, allowing the breakerto be operated either electrically or mechanically. If you desireto electrically open or close the breaker in the test position, thesecondary control block must be re-engaged and the manual motorcutoff switch turned “on”.To remove the breaker from the test position to the disconnectposition, the breaker must be tripped if closed, the Interlock Pedalmust be depressed, and the secondary contact block should bedisengaged. When moving out of the test position, a floor closesignal will combine with the trip signal from the Interlock Pedal toforce a trip-free condition. This will cause the charging springs todischarge leaving the breaker in the open position and the closingsprings discharged. The breaker is in a non-operable state.Once the breaker is withdrawn past the floor trip activation area, it isin the disconnected position. The levering handle should be removedat this point. The breaker is ready to be removed from the cell ifdesired.otte:N For Canadian breakers, the interlock plunger will engage in thedisconnect position in the interlock rail on the cell floor.5.11 OPERATION, INSERTION, AND REMOVAL FOR 5kVAND 15kV MODELS WITH ROTARY RACKING PROVISIONS5.11.1 Optrational Positions (Domtstic and somt CanadianRotary Racking Vtrsions)The breaker has three basic operational positions:(1) Breaker withdrawn from the circuit breaker compartment (cell)in “disconnect” position.(2) Breaker in the cell in the “disconnect/test” position.(3) Breaker in the “connect” position.otte:N Some Canadian versions of the DST-2 have four operational positions,they have a “withdrawn”, a “disconnect”, a “test”, and a “connect” position.These versions have one mechanical stop “disconnect” and one for testunlike all US versions which have a common Disc/Test position.The “disconnect/test” and “connect” positions can be verified bythe breaker position indicator shown in Figure 5.5.5.11.2 5kV Instrtion Proctdurt (DST-2-5-VR+ 250, Domtsticand Canadian Rotary Racking Vtrsion)a. Verify that the circuit breaker racking system is in the fullywithdrawn position. This is an important step, as breakermaintenance outside the breaker compartment may have requiredthat the rotary racking be positioned so that the circuit breakercould be closed. It must be returned to the fully withdrawncondition prior to insertion in the circuit breaker compartment. WARNINGTHE BREAKER CAN BE OPERATED WHEN WITHDRAWN FROM THECELL, HOWEVER, THE ROTARY RACKING HANDLE MUST BE USED TORACK THE BREAKER TO THE CONNECT POSITION, AS SHOWN ON THEBREAKER POSITION INDICATOR. THE BREAKER MUST BE RACKED TO THEDISCONNECT/TEST POSITION, AS SHOWN ON THE BREAKER POSITIONINDICATOR, BEFORE INSERTING IT INTO THE CELL.b. From the withdrawn position, align the center groove of thebreaker wheels with the guide rails of the cell.c. Check that the closing spring status indicator reads“DISCHARGED” and that the main contact status indicator reads“OPEN”. Manually trip, close, and trip the breaker as needed toobtain this status.otte:N The motor cutoff switch is located on the lower cover where it can beeasily accessed (See Figure Set 3.3). Position the switch to “OFF” beforeinserting the breaker into the cell.d. Push the circuit breaker into the cell until the mechanical stop isreached; this will be indicated by an audible click. At this point,the mechanical stop has fallen in the front slot of the guide rail.In this position, the breaker can be operated. This position canalso be verified by noting that the foot petal moves upward as themechanical stop drops. When the interlock foot petal moves up, italso exposes the racking screw hex head.otte:N For Canadian versions with separate “disconnect” and “test” positions,it will be necessary to step on the racking interlock petal and push the circuitbreaker to the next mechanical stop. At that mechanical stop, the circuitbreaker is in the “test” position. Provisions in the racking system preventthe circuit breaker from being pushed beyond this mechanical stop evenwhen the interlock petal is depressed; any additional movement toward the“connect” position must be achieved with the rotary racking feature. With thecircuit breaker in the “test” position, item (e.) below can be performed.e. In the “Disc/Test” position, the breaker can be operated manuallyand electrically, thus allowing maintenance tests or checks. Tooperate the breaker electrically, the secondary control block mustbe engaged at this time. The slider is located on the lower righthand area of the circuit breaker frame. If electrical testing isdesired at this stage, engage the secondary control block sliderby releasing the slide latch and pushing the slider toward the rearseveral inches. Push firmly on the front side of the slider until thecontact block engages with the corresponding cell receptacle.Return the manual motor cutoff switch to the “on” position. Thespring charging motor will begin to run and charge the closingspring. The breaker is now in the “test” position, with controlvoltage applied, and ready for electrical or manual testing. NOTICEONCE THE SECONDARY DISCONNECT BLOCK IS ENGAGED IN THE “TEST”POSITION, IT WILL REMAIN CONNECTED THROUGHOUT FURTHER INWARDMOVEMENT AS THE BREAKER ADVANCES FROM THE “DISC/TEST” TO THE“CONNECT” POSITION.THE SPRING CHARGING MOTOR WILL ENERGIZE, IF THE MOTOR CUT-OFFSWITCH IS IN THE “ON” POSITION (FIGURE SET 3.3), AND CHARGE THECLOSING SPRINGS AS THE SECONDARY CONNECTION IS MADE AS LONGAS CONTROL POWER IS AVAILABLE.f. From the “Disc/Test” position, the circuit breaker can be advancedto the “connect” position. It is NOT ntctssary to sttp on thtracking inttrlock ptdal whtn tht circuit brtaktr is in thisposition. Place the rotary racking handle onto the rotary rackinghex head. Turn the rotary racking handle clockwise until the“connect” position is reached and the handle can no longer beturned, as indicated on the switchgear floor mounted breakerposition indicator, Figure 5.5. Do not forct tht rotary rackinghandlt btyond this point as brtaktr damagt will occur.Figurt 5.5. Rotary Racking Brtaktr Position Indicator