Summary of Contents for LA 3000

Page 1: ...j i 3 feT ALUS CHALMERS INSTRUCTION BOOK r AIR CIRCUIT BREAKER TYPE LA 3000 LA 000 BWX 6670 1 APRIL 1967 y Courtesy of NationalSwitchgear com ...

Page 2: ...TING MECHANISM A DESCRIPTION AND FUNCTION 1 STORED ENERGY MECHANISM 2 CLOSING MECHANISM MAINTENANCE CLOSING RACKING MECHANISM AND DRAWOUT INTERLOCK CONTROL MAINTENANCE AND ADJUSTMENT LUBRICATION B C D E F SECTION I I I CONTACT STRUCTURE A DESCRIPTION AND FUNCTION B MAINTENANCE ADJUSTMENT AND REPLACEMENT v SECTION IV STATIC OVERCURRENT TRIP DEVICE A INTRODUCTION B DESCRIPTION SELECTION OF SETTINGS ...

Page 3: ... TYPICAL STATIC OVERCURRENT TRIP DEVICES 9 TYPICAL BREAKER RATING PLATE AND CURRENT TRANSFORMERS 9A SHAFT LOCKS AND CALIBRATING MARKS FOR STATIC TRIP DEVICES 9B PORTABLE TEST SET FOR STATIC TRIP DEVICES 9C TYPICAL TRIP CURVE SELECTIVE STATIC TRIP TYPICAL TRIP CURVE DUAL STATIC TRIP 9D 9E 9F CONNECTIONS FOR FUNCTION TEST 10 RELEASE MAGNET 12 SECONDARY DISCONNECT 13 AUXILIARY SWITCH 14 SHUNT TRIP DE...

Page 4: ...c H 125 5 000 H0 626 750 5 2 7 RELEASE SOLENOID 18 V RELAY 19 SHUNT TRIP 20 TRIP LOCKOUT 21 STORED ENERGY MOTOR 22 GROUNDING FINGER 23 UNDERVOLTAGE ATTACHMENT 24 LATCH INTERLOCK COVER TERMINAL BLOCK LIMIT SWITCH BREAKER NAMEPLATE PHASE BARRIER ARC CHUTE PRIMARY DISCONNECTS RELEASE MAGNET 9 MANUAL TRIP BUTTON INTERLOCK BUTTON AUXILIARY SWITCH BELL ALARM ATTACHMENT SECONDARY DISCONNECTS MECHANICAL C...

Page 5: ...TON 3 AUXILIARY SWITCH 4 BELL ALARM ATTACHMENT 5 SECONDARY DISCONNECTS 6 MECHANICAL CLOSING BUTTON 7 POWER CHARGING SWITCH B STATIC O C TRIP DEVICE IT RELEASE SOLENOID ft V RELAY ft SHUNT rm 2Q TR LOCKOUT 21 STORED ENERGY MOTOR 22 GROUNDING FINGER 23 UNOERVOLTAGE ATTACHMENT 24 LATCH INTERLOCK 9 COVER 10 TERMINAL BLOCK II LIMIT SWITCH 12 BREAKER NAMEPLATE 13 PHASE BARRIER 14 ARC CHUTE 15 PRIMARY DI...

Page 6: ...will not in any case assume responsibility for allied equip ment of any kind C RECEIVING AND INSPECTION FOR DAMAGE Immediately upon receipt of this equipment carefully remove all packing traces and examine parts checking them against the packing list and noting any damage Incurred in transit If such Is disclosed a damage claim should be filed at once with the transportation company and Al 1 is Cha...

Page 7: ...ces should receive a thorough check prior to placing the breaker in service to be certain that adjustments are proper and parts are not damaged Cubicle mounted breakers of the drawout type are equipped with a drawout interlock to prevent movement of a closed breaker into or out of the connection position See Section II of the Instruction Book for a description of the interlock Its operation should...

Page 8: ...s 1 l I i t u 7 l TOGGLE LATCH PNION 9 MOTOR T 1 SPRING 46 TRIP LATCH E VI h1 I Tl P 4S 5 ANGLE BIAS Du LevEft i fcr t 44 TR P SHAFT i i i 5 f j i TRIP TS Sr It s BUTTON i J hi j J l PROP j_ C LATCH M V liH i m T l 1 i i Sjj 2S CHS i ai 4 f p ci LLrf M 2T I SCREW STOKED THT n 1r ENERGr INDJCATOft a I STORED PROP LATCH ADJUSTING LEVER ENERGY J I LfNK SPRINGS LATCH FIG 2 TYPICAL OPERATING MECHANISM ...

Page 9: ...ELEAS PLUNGER 10 BLOCK 14 trrr v 1 L PROP LATCH STOP SCREW fT IX CONNECTING 14 Jr j 1 R00 f m 1 5 1 4 LATCH ROLL ARMATURE ECCENTRIC 3 SCREW STOREDiENERGY SPRINGS 16 FIXED CENTER MOVABLE CENTER FIG 3 CLOSED POSITION O 31 L A T C H TRIP SHAFT ZI FIG 4 TRIP FREE POSITION FIG 5 OPEN POSITION TYPE LA OPERATING MECHANISMv Tt 440 184 401 AUGUST 30 1963 li Courtesy of NationalSwitchgear com ...

Page 10: ... the motor by actuation of the power charging switch 1 7 1A 7 causes the motor to rotate pinion shaft 9 to drive gear 10 This gear is provided with a driving pin 12 positioned to engage with a corresponding pin II on eccentric 13 The eccentric is revolved clockwise about fixed center A driving the connecting rod 14 to the right The motion of the connecting rod to the right compresses the pair of s...

Page 11: ... release of trip latch 27 Trip shaft 28 is rotated counterclockwise by action of the various trip devices or the manual trip button This rotation of the trip shaft permits trip latch 27 to rotate counterclockwise about fixed center 0 thus toggle latch 26 f s released and permitted to rotate clockwise about center E Releasable center C Is now free to rotate with the toggle latch permitting the forc...

Page 12: ...40 Align the hole in the maintenance closing link with the holes In arm 42 and insert the pin that is attached to the maintenance closing link 5 As the closing mechanism is now linked to screw 43 clockwise rotation of the operating crank will slowly move the main contacts to the contact touch position 6 Reversal of operating crank rotation to counterclockwise will slowly return the contacts to the...

Page 13: ... stop in the last slot in the trip button With the trip button in this position interlock latch 2 39 is raised permitting movement of the interlock and breaker past the fixed stop on the floor of the cubicle compartment 2 Move slide near the top of the sheet metal cover to the right to uncover the square end of screw 2 19 3 With the switchgear operating crank rotate screw 2 19 to position racking ...

Page 14: ...YOND THE LIMITS OF DISCONNECT OR CONNECT POSITION CAUTION f The electrical control on the breaker Is designed to ensure complete operation and prevent repeated attempts to close pumping The following is the operational sequence of a typical wiring diagram Figure 7 which is shown with the stored energy springs in the discharged posItion 1 With the three contacts motor limit contact 88b normally clo...

Page 15: ...ted position 3 Discharge stored energy springs 4 Remove arc chutes and examine for burned cracked or broken parts 5 Wipe the contacts with a clean cloth saturated with a non toxic cleaning fluid 6 Replace badly burned or pitted contacts 7 Wipe all insulated parts with a clean cloth saturated with a non toxic cleaning fluid Bearing pins and other sliding or rotating surfaces should be cleaned and t...

Page 16: ...8 i open just prior to the spring charge latch position The 3 4 5 Motor Drive Unit The motor drive unit 2 7 is mounted on the operating mechanism Shou1d frame and held in position by three mounting screws 2 4 realignment of the unit be necessary add or remove spacers to provide alignment of the motor shaft with the pinion 2 9 vertically The motor shaft should also be positioned as closely as possi...

Page 17: ...INGS INNER MOVABLE MAIN CONTACT SCREW STATIONARY MAIN CONTACT BLOCK PIN F OUTER MOVABLE MAIN CONTACT tC SH ELD tfi 2SJ PIN B PLATE n U J SCREW HINGE x CONTACT FINGER t 7 HINGE 24 J SCREW CONTACT SPRINGS 56 HINGE CHANNEL CONTACT BLOCK 15 1 SCREW 114 m BASE l 53 o cis FIG 6 LA 3000 BREAKER PANEL ASSEMBLY r SEPTEMBER 3 1963 71 440 136 401 ...

Page 18: ... T S r t SCREW 1 ft ripj H Ml m 1 STATIONARY MAIN CONTACT BLOCK nsi3Z r 1 1 n PIN irf i h f u M T 1 ili rr T OUTER MOVABLE MAIN CONTACT I t 10 I SHIELD ri I fCFOtZu tfl n 25 PIN TOE f f A t l i Vv S V PLATE f 1 n il SCREW HINGE 1 i T ig x a HINGE 24 SCREW I o HINGE CONTACT BLOCK 1 15 CHANNEL r 13 22 SCREW I14 l i BASE m o 7 m FIG LA 4000 BREAKER PANEL ASSEMBLY SEPTEMBER 3 1963 71 440 137 401 V ...

Page 19: ...he initial contact point When the breaker is called upon to interrupt a current the main contacts 22 20 and 2 separate transferring the current to the arcing contacts 1 and 4 without arcing When the arcing contacts part an arc is drawn between the contact surfaces Due to the inherent magnetic and thermal effects of the arc It w i l l rapidly move upwards along the arc runner and into the arc chute...

Page 20: ... removal of the arc chutes as follows 3 4 5 a Disconnect rods from movable main contact by removing pin from arm 09 b Remove the four screws 14 which mount base 13 on channel 12 This will permit disassociation of the complete three phase contact structure from the breaker as a complete integral unit c Remove screw 24 and spring back plate 26 over roll pins 25 Rotate the movable main contact past t...

Page 21: ...u o A cn Y i 3 o 88 A cn T O 8 M Y o o T S A O b N s o V A 9 a X b r 6 1 I H Lh i 4 m 6 7 HI A 0 X X 2 9 0 TRANSFORMERS MAGNETIC TRIP COIL i 4 V V T 2 5 62 63 4 5 6 O O o c o 1 i 8 o7 TERMINAL BLOCK FIG 7 TYPICAL WIRING DIAGRAM 71 240644 40i 9PPT 4 1963 ...

Page 22: ...ERS l SWITCH ACTUATOR T i ADJUSTING SCREW o i i 4 LOCKNUT I 7 LIMIT SWITCH ci i 4 n i i V L U l l I i i L _ V FIG 8 TYPICAL LIMIT SWITCH CLOSED POSITION SEPT 4 1963 71 240 645 401 Courtesy of NationalSwitchgear com ...

Page 23: ...Is rectified to provide D C energy to the release magnet trip coil and also a regulated D C power supply to operate transistor circuits Potentiometers or rheostats connected in parallel with the auxiliary transformers provide an A C signal voltage proportional to the primary current This acts as the intelligence input for the device and the magnitude of this A C voltage determines whether or not t...

Page 24: ...rves any combinations of which may be selected by settings on the front plate of the device Selectivity between coordinated circuit breakers can be maintained throughout the f u l l inter rupting range of the circuit breakers The Model D device monitors the currents in each of the three phases The arrangement of the current time curves is shown in Figure 9D Selective Model DG Same as the Model D e...

Page 25: ...int A Therefore the circuit will carry up to 1200 Amps without tripping the circuit breaker Above 1200 Amps a trip operation wt 11 occur 1 The pick up selection is continuous and may be set between marks if Usual practice Is to sjjet all pick up knobs at the same and different phases can have desired mark but this Is not necessary different pick up settings r depends solely on the primary The rati...

Page 26: ...he same curve Figures 90 and 9E Is used for defining time delay 3 Breaker rating per Figure 9A Phase pick up setting E 2400 Amps Ground pick up setting 40 480 Amps An actual ground current of 1920 Amps is flowing 1920 Amps ground current is four times and w i l l cause a t r i p operation in four and one half seconds on the minimum time band as shown on he current time curve Figure 9E However this...

Page 27: ...lso there are two groups of time bands provided one for long time delay and one for short time delay corresponding to the curves on Figure 9D The knob at the middle of the left side of the Models D DG front plate Is a three position switchfmarked to Indicate LONG TIME BAND SETTING The three positions provide for selection of a MINIMUM INTERMEDIATE or MAXIMUM time ba d as shown on Figure 9 The knob...

Page 28: ...00 Amps and 12 000 Amps w i l l t r i p the breaker a f t e r a time delay defined by the maximum long time curve Figure 90 t r i p the breaker in the time Indicated by the minimum short time curve Currents above 12 000 Amps w i l l t I f the phase pick up settings were changed to B 1500 Amps then the short time band would be used for currents of 15 000 Amps and above h 17 Courtesy of NationalSwit...

Page 29: ... and slipping it off the shaft Then be sure the shaft lock is loosened see FIgure 9B and turn the shaft counter clockwise as far as it wi 11 go Keep the shaft in that position and replace the knob so that it Is directly over the red calibration dot With the shaft lock loosened the knob may now be turned to the selected dial position the shaft locked and the device returned to service Testing The t...

Page 30: ...will describe in detail the steps to be taken to carry out the tests Tests may be conducted on the complete circuit breaker either in the disconnected cubicle position or removed from the cubicle It Is not required to remove or disconnect any permanent wiring on the circuit breaker as long as primary and control circuits are not connected to the breaker It wlU II iii iiQ i ni iMi iimilii ltwi irnB...

Page 31: ...t jthe A setting will give faster trip times Settings other than A require more current to get the desired multiples of pick up e g 3 Amps at j E setting is required for 3X pick up Thehfunction test may be repeated using terminals 2 4 and 3 4 Models A1 and 0 or terminal 3 2 Models AG and DG It is not recommended to test terminals 4 2 on the Models AG and DG since the ground detection transformer c...

Page 32: ...e spring loaded armature does not reset during trip operation as explained above spacers 1008 may be added to obtain positive reset of the armature If adding spacers does not allow armature to be reset the magnetic release latch should be replaced If breaker mechanism is not at fault Do not attempt to disassemble the magnetic release latch as this will destroy the magnetic field set up by the perm...

Page 33: ... DUAL STATIC TRIP DEVICE r i i rm si a r wsm C i m i 4 m V I 3 J i a m t mm I m yi I SS i i m vm m c E a ssad 205420 205419 MODEL DG SELECTIVE STATIC TRIP DEVICE MODEL D 0 1 SELECTIVE STATIC TRIP DEVICE FIG 9 TYPICAL STATIC OVERCURRENT TRIP DEVICES DATE 2 24 67 Courtesy of NationalSwitchgear com ...

Page 34: ...own In Table 1 However the frame s i z e l i m i t s the group IX transformer to C p o s i t i o n One transformer is a v a i l a b l e for the LA 4000 r n TABLE 1 CURRENT TRANSFORMERS 1 I TRANSFORMER GROUP NO AVAILABLE CONTINUOUS CURRENT RATINGS AND KNOB POSITIONS M HB D wwi E LA 3000 B c A 2400 1500 1800 2500 3000 2100 VIII 1200 2000 II LA 4000 4000 2500 3000 IX 2000 3500 4 The other LA breakers...

Page 35: ...m m smmsm WM0 msmmm vV 205 23 205424 SHAFT LOCKS CAUTION LOOSEN SHAFT LOCKS BEFORE ROTATING KNOBS CALIBRATION REFERENCE POINTS 205422 FIG 9B SHAFT LOCKS AND CALIBRATION MARKS FOR STATIC OVERCURRENT TRIP DEVICES Courtesy of NationalSwitchgear com ...

Page 36: ... H f m a fe SS jtisyfiliMBl V I i I 1 t ft l i SI V Mi i pit w SK4 V l i 205251 5 I t 1 PORTABLE TEST SET FOR STATIC OVERCURRENT TRIP DEVICES 1 t f K i t B yf r rJ 205245 TYPICAL TEST ARRANGEMENT 2 24 67 FI6 9C Courtesy of NationalSwitchgear com ...

Page 37: ... GO WITH ANY OF THE THREE LONG 7 i T3I TIME DELAY CURVES 1AKIM M SHORT TIME BAND 1 INTERMEDI ATE SHORT T IME 1 I f 1NIMUM SHORT TIME BAND 1 o 89 07 0 0 04 rifiHmaiwr m n i rn w a y ARE TOTAL CLEARING SHOWN DOTTED BELOW ITS MM iJ HI SISiSSNc8ggSg5itTi6iviH 88 ScSR 5fcHfflEf RESPECTIVE CURVE U bti TtrfctW fl I jfe M feij t ETOTTir tfIh I 5pT injft jjTftr IS S T I m j shiife Jntc U flr if i j i ig t ...

Page 38: ... I i r m is If 5rj Sr IT LIZ JJ i 1 at t E 1 f c 1 i s r 2 rr i asi T r I K If 5 m 4 iii i M i I iff 1 rr i i r T K 1 1 m T ftW J v Tv IP ifc m IV 1 1 tf ii i i J 1 v sin 1 M 1 i i S 81 DUAL STATIC OVERCURRENT TRIP DEVICE MODEL A A 1 A GyA ZVAG f TYPICAL CURVE FIG 9E CURRENT IN MULTIPLES OF PICKUP K 71 240 556 404 JANUARY 13 1964 Courtesy of NationalSwitchgear com ...

Page 39: ...J S VARIABLE VOLTAGE TRANSFORMER O 5 O O 5 O m 0 6 0 0 6 0 i ft 0 7 0 TO TRIP COIL ON CIRCUIT BREAKER X 1 MODEL MODEL D CH TERMINAL BLOCK MODEL AOLAB 1 06 TERMINAL BLOCK TO NOT TEST ON TERMINAL 4 REFER PARAGRAPH 2 FOR DESCRIPTION OF TEST EQUIPMENT m n m FI6 9F CONNECTIONS FOR FUNCTION TESTS MARCH 7 8967 72 140 868 401 ...

Page 40: ...OPEN 1008 1002 1004 i 1007 RESET ARM tooa SPACER 1009 NUT 1010 TRIP ARM 1011 TRIP PIN 1001 TRIP ROD 1002 MAGNET 1003 PLATE 1004 COIL 1005 BREAKER TRIP ARM 1006 SHAFT FIG 10 TYPICAL RELEASE MAGNET MARCH 15 1907 72 240 069 401 v Courtesy of NationalSwitchgear com ...

Page 41: ... STRIP 5 SHIELD 4 i FIG 12 TYPICAL SECONDARY DISCONNECTS AUGUST 26 1963 71 240 642 401 The electrical attachments are wired to the terminals of a secondary disconnect assembly which is mounted on the left side of the breaker Three blocks of ten terminals each can be mounted on the breaker The secondary disconnect assembly Is accessible from the front of the breaker and aligns with a stationary uni...

Page 42: ...ions by direct connection to the breaker mechanism The contacts are factory set for a open when breaker is open and b closed when breaker is open position but each rotor 4 may be adjusted individually in steps of 30 degrees This adjustment Is made by removing cover 2 and lifting the entire rotor assembly out of case 1 after dis connecting arm 5 from the linkage Cotter pin 8 and bearing 6 are remov...

Page 43: ...it immediately after the breaker is tripped Energization of the coil 7 causes armature 2 to pick up and rotate trip shaft 8 thereby tripping the breaker If adjustment of the shunt trip is necessary make the following adjustments with the mechanism and trip shaft in the reset pos it i on I Position screw 4 to provide 1 16 1 64 clearance between washer and angle 5 and 1 4 1 64 clearance between tubi...

Page 44: ...functions to close or open an alarm circuit upon automatic overcurrent tripping of the breaker The relay coil is wired to terminals 7 and 8 of the static trip device This Is a latching type relay and relay contacts 2 are reset to open position shown by actuating reset plunger 6 Spacer washers 4 are used to position the relay to ensure correct engagement of latching arm 5 when resetting the contact...

Page 45: ...terlocking armatures The bell alarm relay I coil is wired to terminals 7 and 8 of the static trip device As this is a latching type relay the alarm relay contacts 2 are reset electrically to the open position shown by actuating reset relay 4 If the device is not stable during breaker operation or if either armature falls to pick up when actuated loosen hex head screws 7 to reposition the terminal ...

Page 46: ...ied Adjusting screw 8 should be set to provide an air gap qf 1 4 between the solenoid pole head and armature with the device de energized as shown In the front view A 1 8 gap should be maintained between trip arm IS and trip rod 10 when the device Is energized with the breaker closed as shown Pick up and dropout should be adjusted so that the device picks up at a voltage of 80 or more of rated val...

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