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Summary of Contents for AK-2-100

Page 1: ...REAKERS AK 2 3 2A 3A 50 50S AK 2 3 2A 3A 75 75S AK 2 3 2A 3A 1QO 100S TYPES AKT 2 3 50 SOS_ AKU 2 3 2A 3A 50 SOS AKF 2C 2D 2E GENERAL f j ELECTRIC GEK 7303B Supersedes GEH l 798A GEI 50211 GEH 1799 GEI 50212A GEH 1823A GEI 67077 GEI 50210A GEI 74600 ...

Page 2: ...T ACTING TRIPPING DEVICE EC lB SERIES OVERCURRENT TRIPPING DEVICE Ec 1 SERIES OVERCURRENT TRIPPING DEVICE EC 2 EC 2A REVERSE CURRENT TRIPPING DEVICE AIC 50 ONLY POWER SENSOR TRIP e SELECTIVE TRIPPING BREAKER ACCESSORIES o PRIMA RY D1SCONN EC1 S SECONDARY DISCONN ECTS DRAWOUT MECHANISMS SHUNT TRIPPING DEVICE ELL AI AR AND LOCl tJT I E TICE OPEN FUSE LOCKOUT DEVICE CE lJS 1 1 8 RENEWAL PARTS 3 3 3 4...

Page 3: ... AK 2 75C The C indicates the interrupting rating has been increased to the rno ooo amp class AKT 2 50 The T indicates incr ased continuous rating of 2000 amps AK 3 50 AK 3 75 AK 3 100 The 3 indicates the breaker ls equippe i with the Power Sensor OVercurrent Trip Device AK 2 50X The x indicates the breaker has very special features or it includes _ two or more of the design extensions previously ...

Page 4: ... the closing springs At the endofthe charg ing oper tion w chtakes approximately5seconds a latch plate engages the prop roller to prevent _the closing springs from discharging With the closing springs fully charged the breaker is ready for a closing operation upon release of the prop roller This may be accom plished either m ually by depressi ng the closing lever on the breaker or electrically by ...

Page 5: ...ing force To il stall the safety pin of the manµal stored energy mechanism refer to the section entitled STORED ENERGY MANUAL MECHANISM on page 17 of these instrucUons With the safety pin restraining the closing spring force the contacts will close s lowly when the breaker is manually operated a1lowing the operation of the mechanism and the contact align ment o be visually observed allowing the in...

Page 6: ... out Faulty control circuit component Improper contact sequence main contacts not sufficienUy parted when arcing contacts part Short circuit current leJel above inter rupting r ating of breaker Loss of contact wipe or pressure REMEDY Adjust contacts Clean contacts Rep ace contacts Clean surfaces of current carrying parta Relocate or proVide adequate enclosure Increase capacity of bus or cable Tigh...

Page 7: ...he reaker from the outside pole units 3 Remove the clevispin 14 Fig 6 13 Fig 7 from the center pole unit 4 Remove the six nuts from the back frame using a socket wrench with an extension These include the two nuts at the top of the frame Low Voltage Power Circuit Breakers GEK 7303 5 Remove the auxiliary switch operating rod 5 Fig 20 6 Check along the trip shaft for a mech anical interference or co...

Page 8: ... quencher as indicated in Fig 5 6 Muffler 7 Compound Support 8 Steel Back Plate 9 Spacer Block 3 Remove bolt fastening cap 4 and barrier plate assembly 4 Barrier plates may now be lifted from as sembly for inspection 5 In reassembling make sure components are positioned so that holes for self tapping hard ware are in line Do not strip threads in compound by overstressing screws POLE UNIT ASSEMBLY ...

Page 9: ...nsulated link 12 to tl e breaker mechanism In addition to ste e1 springs shunting the current from the contact directly to the lower contact block steer springs 17 force liiie con cts ag nst the pins to prevent pitting at the pivot pomt The movable main contact jassembly also contains main and intermediate contacts 5 Intermediate Barrier 6 Outer Barrier 7 Side Plate In order to function properly a...

Page 10: ...per contact wipe andpressure on the center pole dimension A should be increased to increase wipe and decreased to decrease wipe 2 To ch ange dimension A removethe clevis pin 14 and rotate the clevis as necessary 3 To prevent overstressing the clevisthreads 13 dimension A should not exceed 3 16 in and space A should be filled with shims to 0 005 in of being solid 4 With the proper center pole WiJ e...

Page 11: ...f the m tenance h dle ith _ the safetypin rel trammg th_e closingsprings If the gap is under the required minimum it is usually possible to form the arcing contacts and obtain the re_quired dimensions FO form e con tacts place a piece of conchnt approximately two feet long over the contact andform the contact either forward or backward If the proper dimen sions are still not obtained the movable a...

Page 12: ...e unit assembly AK 75 and AK 100 The movable arcing contacts 4 should be replaced when the stationary arcing contacts are replaced 1 Separate the front frame from the back frame as describedunderSEPARATIONOF FRONT AND REAR FRAMES 2 Remove pins 8 and 19 and withdraw the contacts 12 3 Reassemble parts in reverse order Stotio ory lntermediate and Main Contad1 Fig 6 _ 1 Remove stationary arcing ctonac...

Page 13: ...surefollow Low Voltage Power Circuit Breakers GEK 7303 Fig 9 8039669 Front view of back frame assembly AK 3 50 1 Power Sensor Coil Assembly 2 Disconnect Plug 3 Tr msformer Taps in Amper s ing contact replacement See ADJUSTING CONTA_ CT WIPE AND PRESSURE OPERATING MECHANISMS ELECTRICALLY OPERATED AK 50 75 and 100 MANU L AK 50 The ele trically operated mechanism includes a motor and a gear reduction...

Page 14: ...IIC tJE CHANSM N a osED POSITl I CLOONG SPRf lG ClSOtARGED 1 Spring z Cam 3 Link 4 Reset Spring 4A Spring Adjusting Nuts 5 Prop 6 Adjus ting Screw 7 Adjusting Screw Stop Pin 8 Prop Return Spring 9 Roller 10 Trip Latch 11 Trip Shaft lZ Clevis Pin 13 Clevis 14 Latch Buffer Stop Bronze Material 15 Roller 16 Prop 13 2 9 8 7 6 5 The breaker is now ready to close when a closing signal is given Fig 11 54...

Page 15: ...ted Adjustments Fig 11 All adjustments should be made with the opera ting mechanism in the reset position as shown in Low Voltage Power Circuit Breakers GEK 7303 1 Fig 13 8018984 Rear view of front frame AK 50 showing cam shaft locking plate nd cam shaft removed Fig llB The mechanism should be reset by manual operation with_the safety pin in place and with roller 15 clear of cam 2 1 The gap betwee...

Page 16: ...arrested by pi ap and latch arrangement The subsequent closing operation is accomplished by tripping the latch to release the prop which in turn allows the springs to continue the interrupted discharging operation and close the breaker The gear reduction unit for the standardbreaker is not interchangeable with the gear reduction uniLon the quick close unit because the quick close gear reduction un...

Page 17: ...h 120 degrees When approximately 70 degrees of the fourth clockwise stroke have been completed the closing springs which have been charged during the previous strokes ot the closing handle are driven over center and the breaker closes This mechanism consists basically of a closing spring assembly ratchet wheel and output crank assembly handle shaft and pawl assembly and the closing handle Closing ...

Page 18: ...in and Chain 13 Shims 23 Closing Handle Shaft and Pawl Asm 4 Safety Pin Hole 14 Groove Pin 24 Roll Pin 5 Closing Springs 15 Nylok Screw 25 Main Closing Crank 6 Guide Rod 16 Ratchet Wheel Shaft and Asm 26 Pawl Buffer Stop 7 Pawl Springs 17 Ratchet Wheel 27 Butter stop Shims 1 Front Escutcheon 18 Side Plate Shims 28 Buffer Stop Support 9 Front Bearing Plate 19 Side Plate Mounting Bolts 29 Handle Ret...

Page 19: ...o 16 lb 3 Ga_p between contacts when center pole is open 1 1 2 in to 1 3 4 in 4 Overlap between the center pole contacts and the arcing contacts of the outer poles 3 16 in to 7 16 in _ Measurements of the center pole contact wipe 20 and pressure may be made by following the same procedure as outlined for the standard pole unit in POLE UNIT ASSEMBLY Overlap of the center pole contacts and the outer...

Page 20: ... from the factory 2 It may be necessary to add buffer stop shims 27 to the buffer stop 26 to provide a clearance of 1 64 to 1 32 inch between the pawls 21 and the buffer stop when the pawls are touching the ratchet wheel teeth extending a max Tra_ de mark of Republic Steel Corp Low Voltage Power Circuit Breakers GEK 7303 imum distance from the center of rotation of the ratchet wheel 17 This measur...

Page 21: ...ould be remove d If it is to be decreased they should be added Shims may be removed by sliding them to the front of the breaker They are slotted for easy r_ emoval Effect of this ad j1 1stmen on contact wipe and overlap is negligible 3 Tighten hardware Contact Replacement Stationary Contacts Fig 17 1 Remove arc quencher see ARC QUENCHER 2 Remove screw 5 from braid 3 Drift out pin 4 and remove cont...

Page 22: ...ngular link 6 set across the a terminals ofthe auxiliary switch 4 Set arrow on new auxiliary switch shaft 5 Push auxiliary switch shaft 8 into square hole in link breaker open _ 6 Replace mounting hardware and wiring Adjustment Fig 18 The a contacts of the auxiliary switch should close before the arcing contacts of the breaker close This may be checked by slowly closing the The closing of the a co...

Page 23: ... the escutcheon A hole is provided in the escutcheon to allow operationof the switch Remove the escutcheon to gain access to the switch CUT OfF SWITCHES Fig 21 The motor cut off switches are mounted on the side of the front frame When the breaker control circuit is energized the motor circuit is main tained through the closed contacts of switch 1 thus charging the closing springs At the end of the...

Page 24: ...C to be moni tored is connected to Terminals 1 and 2 of the the time delay box The undervoltage device on the breaker is always connected through either its secondary disconnects or terminal board to ter minals 4 and 5 of the time delay box The undervolt e device is set to pickup at approximately Soto of bus voltage and drop out between 30 and 60 The u ndervoltage device coil circuit is con tinuou...

Page 25: ...59 1830 Ohms 2 6275081 G 61 440 Ohms REPLACEMENT 1 Disconnect coil leads 2 Remove four mounting screws 21 and remove device 3 Install new device in reverse order Coil ls 1 Disconnect leads to coil 2 Remove two screws 16 3 Re ove magnet and coil assembly 4 Straighten laminations around shading ring 5 5 Remove shading ring and straighten lower end of coil _ clamp 13 6 Remove coil Install new coil in...

Page 26: ...t instan aneous tripping is adjustable Irqm bO percent to 250 percent of the continuous current rating of the device Whenever this is used it is the only characteristic of the device Instantaneous tripping used in conjunction with any other characteristic is always high set When armature 1 or 22 closes ag ainstthe mag net 11 motion is transmitted through the mech anism linkage rotating tripping li...

Page 27: ...move stud 23 4 Remove two screws fastening magnet 11 to lower stud 5 Device is now free of breaker Reassembly is accomplished by reversing the procedure When reassembling the magnet to the lower stud be sure to replace any spacing washers in the same location in which they were found during disassembly If this is not done misalignment and consequent malfunction may result ADJUSTMENTS Fig 26 Before...

Page 28: ...ween the connecting rod and the insulated coupling which ties onto the trip paddle 14 The approxi mate distance between the pivot centers on the ends of the connecting rod assembly is six inches The correct exact distance is that which will just cause tripping of the breaker when the arm ature is closed to a point 1 32 in short of contact with the magnet A step by step procedure for making this ad...

Page 29: ...calib ratio spring 11 After the magnetic force produced by an overcurrent condition overco es this restraining force the armature movement is further retarded by the flow of silicone oil in a dashpot which produces an inverse time delay characteristic The mechanism is shown on Fig 27 INSTA TAN EOUS TRIPPING Fig 27 a Adjustable instantaneous tripping takesplace after the magnetic force produced by ...

Page 30: ... travel at least 5 32 in 5 Replace new devi9e in rever se order 6 Adjust device as described above NOTE Component parts of any overcurrent tripping devices are not replaceable It will be necessary to install a new device when parts are worn or damaged J 1 4 Fig 29 8024843 801449 8019485 Overcurrent tripping device EC 2 ...

Page 31: ...ipped with this setting at the 2 3 mark and the 1C characteristic at the 1 3 mark The stand ard characteristic curves are plottedatthese same settings Time values are inversely proportional to the effective length of the dashpot arm Therefore the linkage setting that gives the shortest time value is the one at which dimension 11 A Fig 29 is greatest The time adjustment screw 4 may be turned by ins...

Page 32: ... The trip screw 6 on the end of the armature 7 should be set so that it does not contact the trip paddle on the trip shaft until the air gap between armature and pole piece is reduced t 3 32 in or less measured at the rivet in the pole piece Also the armature must have a 91in imum of 1 32 in of travel beyond the point m its motion at which the breaker is tripped Replacement of the EC 2 EC 2A devic...

Page 33: ...justing nut upward one and one half turns 4 Tighten the locking nut and the mfnimum 1 32 in overtravel of the trip rod should be obtained Low Voltage Power Circuit Breakers GEK 7303 REPLACEMENT Fig 31 After removing the wiring for the potential coil the reverse current device can be removed and replaced by following the procedure outlined for replacing the series overcurrent device For wiring see ...

Page 34: ... trouble shooting 3 A PST 1 Power Sensor Test Kit must be available rig 39 Check the Power Sensor Unit for correct function f r each pick up setting and one point on each time d lay characteristic Then check for the correct operation ofeachphaseof the Power Supply Unit This procedure is described in the instruction manual GEK 7301 for the PST 1 Test Kit If the test results for this test do not dev...

Page 35: ... rmance o t1 e Power Sensor Unit and the Power SUpply Unit it may be advisable or required to test the magnetic coils by the use of a Hi current Low voltage type test set In this event on1y one test per phase need be made This test should be made at some convenient multi ple of pick up setting suchas 3Xcurrent setting for comparison with published time current curves In the event the breaker is eq...

Page 36: ...ews 5 Remove Power Supply Unit with control wiring 6 Reassemble in reverse order SENSOR Coils AK 3 50 Only_ Fig 32 1 Disconnect J_ lug between the Power Supply Unit and the sensor coils and rempve tapped screw holding female plug to breaker mechanism frame 2 Separate front frame from back frame as described under SEPARATION OF FRONT REAR FRAMES Fit 38 7612 6 2 Grow1d Sensor Coil Remotely Located 1...

Page 37: ...acitor 4 Female Disconnect Plug 5 Male Disconnect Plug 6 Mounting Brackets 6 2 __ Fig 35 8039649 Power Sensor Unit 1 Mounting Screw 2 Captive Thumb Screw 3 Name Plate Fig 36 8039903 Magnet Trip Device 1 Name Plate 2 Spring 3 Mounting Bracket 4 Adjusting Screw 5 Trip Arm 6 Armature 7 Clamp 8 Coil 9 Magnet 3 ...

Page 38: ... J 0 Q J u II I J 5ouRCE tu I 0 I w 2 w u w J A 0 z cf r r 5 c i t a ROl NO SENSOt I C 011 2I I u 1n 1oillT CMLI 47 11 1 0lMO t a E I rn P1 ID Po cl S1 PL 1t PQ1 4 A isoA C 01L I 1 r i1 I I 1 fa 1 I la I In I aR ic la OUTL NE __ f_ ___J SI TYPICAL iir O JtJO l A JLT ColJNEC TION ReAKE c _e 1 ii Oui JO SENSO OISCO tNEC l ANO IUTERNAl VNO S N OR COi l P l RiOI P I POWER SEl JSoR TRIP II a 17 n n 7 t...

Page 39: ...supported cyl inder now move to center pole d O t side Pole until coils are removed place coils with resistor board on clean flat surface When removing coils from your arm be careful not to break orf ul interconnecting coil wires Also note location of spacers Spaces may vary in thickness their purpose is to space coils out for a firm fit SELECTIVE TRIPPING Selective tripping is obtained when the b...

Page 40: ...A l 1 1 l l 1 l 44 HH V I A I I I I 1 a l 1 l N r l Ii 11 I I LI I I I I I 1J 1 J JJI I J j i 2 i 2 SX T 1 r 2 Sll _ 1ox u IOX r A A X X 1 1 a J I I Ml11 I I JI Ill I I A I I I I llt 1 a r1 n A1C 1S AK IO AIC IS AIC0 7S AIC IOO It I I 1 I I I I I I 11 1 MULTl LES OP TUNSfOIMH TAP I Figure 42A 109HL687 Long time delay short time delay and instantane ous time current curves for solid state trip devi...

Page 41: ...r r r rr rr r r r I 1 r J I 0 30 Soc J 1 l I r I Ii o 24Sec r l r I o tts l t0 r i 0 12 Soc I 1 0 06 Sec 1 I I I 1 I IUIII I IJ JI t I I I I 1 I I I l l I I I a I r I I 1 r I I ttl I 11 1 I I 1 I I C E TIN M L E I U I N U TIPL S OF GROUND TIii SETTING Figure 42B 109HL689 Ground fault short time delay time current curves for solid state trip device JI I J A ...

Page 42: ...ion from being performed wlien the breaker is closed Ins erting the breaker into the housing causes the racking pins on the housing to engage the semi circular slot in the racking c m 4 In this position the breaker is ready to be fully racked in by operating the racking handle 1 The first upward stroke of the racking handle causes the racking pin on the housing to engage the trip interlock link an...

Page 43: ...be carefully noted and the number of turns of the nuts shoula be counted so that in reassembly the original amount of compression can be restor d by replacing the nuts to their fo rmer position on the bolts The primary disconnects should always be kept lubricated with G E Co D50H47 grease SECONDARY DISCONNECTS The secondary disconnects for all breakers serve as connections between breaker control ...

Page 44: ...REWS 6 MAGNET 7 COIL 8 CLAMP 9 ARMATURE 10 ARMATURE ARM 1 II TRIP PADDLE 12 CLAMP Shunt tripping device 3 Bend lower end of clamp 8 straight and remove 4 Remove coil anq install new coil in re verse order BELL ALARM AND LOCKOUT DEVICE FIG 46 The device operating link 2 is engaged with the breaker crossbar side link pin 1 thereby operating the device whenever the breaker is tripped by the overcurre...

Page 45: ...hook around the shunt trip armature lever 8 in a manner that will assure the device latch and catch are disengaged before the breaker opens OPEN FUSE LOCKOUT DE VICE Fig 47 The open fuse lockout device consists of 2 or 3 separately operated devices one per phase each wired in par allel to cor responding breaker fuses This device is furnished on all AKU bre ers breaker fuse combinations and LB 1 pr...

Page 46: ...5 5 t 6 7 8 J 14 guide 2 Continue lowering the device until movement is restricted by the device wiring harness 2 Disconnect leads to coil 6 3 Remove two screws holding the trip device to the device mounting plate 4 Bend lower e nd f brass clamp straight 5 Remove coil Install new coil and replace parts in reverse order I TRIP PADDLE 2 ROD GUIDE 3 ROD 4 LOCK NUT 5 1 RIP DEVICE t COIL 7 LINK ASSEMBL...

Page 47: ...EK 7303 Allen Wrenches 1 16 in for No 6 screw 5 64 in for No 8 screw 3 32 in for No 10 screw 1 8 in for 1 4 in screw 5 16 in for 3 8 in screw with adapter shank for 1 2 in drive ratchet 3 8 in for 1 2 in screw Miscellaneous 8 oz ball peen hammer 1 4 in Spintite wrench long shank 3 8 in Spintite wrench NOTE Obtain tools from local hardware do not order from the General Electric Co RENEWAL PARTS Whe...

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