GE MicroVersaTrip AK-50, Maintenance Manual

Page 1: ...GFH 71 GtHA7 GfH li GF 50J Gtl 501 GFJ 502 Gf 57C r V LOW VOLTAGE POWER CIRCUIT BREAKERS TYPES t AK 50 AK 75 AK 100 AKF 1C AKF 1D AKF 2D f LOW VOLTAGE SWITCHGEAR DEPARTMENT GENERAL0ELECTRIC Courtesy of NationalSwitchgear com ...

Page 2: ...G DEVICES EC 1A AND EC IB SERIES OVERCURRENT TRIPPING DEVICE EC 1 SERIES OVERCURRENT TRIPPING DEVICE EC 2 AK 1 50 ONLY REVERSE CURRENT TRIPPING DEVICE AK 50 ONLY 20 20 20 21 22 23 26 26 28 SELECTIVE TRIPPING 26 BREAKER ACCESSORIES PRIMARY DISCONNECTS AK 50 ONLY SECONDARY DISCONNECTS DRAWOUT MECHANISM SHUNT TRIPPING DEVICE BELL ALARM AND LOCKOUT DEVICE DYNAMIC BRAKE FOR ELECTRICAL BREAKERS 28 28 29...

Page 3: ... 2 re KB W4K r vi HLrJi o r AOOmONAL AUK _L CONTACTS WHEN REO 0 4 JL D 6 L 8 E SB a KS o o 2 o Jo 0 4 o o So 0 0 LI 5 I I o 4 o o S o o 6 o I 2 4 2 I MANUAL MAINTENANCE CLOSING OF ELECTRICAL BREAKERS CONNECTION DIAGRAM v Kt v i r I I T T F4 FI FJ T LIC r43 pi n G1 G4 e RJ AJ Sk4 2M2 T1 An electricalbreaker may be closed manually by means of the maintenance handle furnished with the breaker M 0 I 1...

Page 4: ...laced in the motor circuit to prevent pre charging when the breaker is in the closed position The breaker may be tripped elec trically by any of the electrical trip ping devices described in these in structions The breaker may also be tripped by the automatic overcurrent or reverse current tripping devices if so equipped All these devices tripthe breaker in a similar manner i e the device trip arm...

Page 5: ... exist A complete inspec tion of the breaker including contacts and arc quenchers should always be made after the breaker has interrupted a short circuit 4 Remove the six nuts from the back frame using a socket wrenchwith an extension These include the two nuts at the top of the frame 5 Remove the auxiliary switch op erating rod 5 Fig 17 6 Check along the trip shaft for a mechanicalinterference or...

Page 6: ...e trip unit Replace overcurrent trip device Checkapplication of overcurrent trip device Checkapplication of overcurrent trip device Replace overcurrent trip device Overcurrent pick up too low False Tripping Overcurrent time setting too short Bind in overcurrent trip device Failure to Close and Latch Re align and adjust attachments Binding in attachments preventing resetting of latch Latch out of a...

Page 7: ...support 7 2 Remove the channel shaped re taining bar by removing two screws and two nuts 4 Rock muffler 6 slightly and re move The inner barriers 5 can now 2 Remove the two channel shaped be removed for inspection retaining bars which bear against the front of the arc quencher by removing four screws two on each side 1 Be sure the breaker is open 3 Lift the quenchers clear of the movable arcing co...

Page 8: ... to the breaker mechanism I Remove arc quenchers see above and lay on sides on a flat sur face 2 Remove hardware from one side of arc quencher as indicated in Fig 5 3 Remove boltfasteningcap 4 and barrier plate assembly i 4 Barrier plates may now be lifted from assembly for inspection 5 In reassembling make sure components are positionedsothat holes for self tapping hardware are in line Do not str...

Page 9: ...g contacts on separate poles 1 16 in If it is desired to ad vance or retard the closing of the main contacts of a pole loosen the bolts holding the adjustment plate 10A of that pole and slide plate to the left to advance contact closing or to the right to retard contact closing Make this adjustment on the outer poles us ing thecenter pole as a reference Upon retightening adjustment plate bolts mak...

Page 10: ... contact block 25 Fig 7 and remove insulation 3 Fig 7 2 Remove screws from shunting braids 5 3 Remove pin 3 freeing the sta s dtionary contacts and springs 22 4 Install new springs and station 2 Remove screws 27 and remove bracket which holds pin 24 in place 5 Adjust contact wipe and pres See ADJUSTING CONTACT sure WIPE AND PRESSURE 3 Remove main and intermediate contact stop 20A which holds the l...

Page 11: ...ng mechanism similar tothe standard breaker This mechanism can be quickly recognized by the presence of two cut off switches land 3 Fig 20 Later Type AKF 1C and AKF 2D breakersare equipped with dynamic brake type mechanisms These mechanisms can easily be identi fied by the presence of three cut off switches Refer tothe section of these instructions entitled DYNAMIC BRAKE for a description of the o...

Page 12: ...ich allows the trip latch 10 to release the latch prop 5 This allows the forces of the contact and opening springs to reposi tion the operating mechanism linkage to the position shown in Fig HA In this position the operating cycle may be repeated it 3 As the crank turns the roller pushes the paddle arm upward there by charging the closingsprings through the spring charging arm 15 of the crank shaf...

Page 13: ...g mechanism the roller 9 On Types AK 1 50 1to 10 and AK 1 75 1 to 3 breakers form the latch buffer stop 14 to maintain the adjustment On Types AK 2 75 and AK 2 100 breakers the latch buffer stop is on the mechanism frame and can be adjusted by loosening the re taining screws to reposition the latch buffer stop Wk Z 3 i MECHANISM N CLOSED POSITION CLOSING 5PRNG DISCHARGED 1 Spring 2 Cam 3 Link 4 Re...

Page 14: ... closing springs which have been charged dur ing the previous strokes of the closing handle are driven over center and the breaker closes 4 Remove four bolts at the bottom of the front frame and one bolt at top of gear reduction unit The motor and gear unit may now be removed NOTE If it is desired to re place only the motor unit dis connect the motor leads and re move only the hardware fasten ing ...

Page 15: ...nd Asm 26 Pawl Buffer Stop 27 Buffer Stop Shims 28 Buffer Stop Support 29 Handle Return Spring 30 Mechanism Roller 32 Output Crank 21 Ratchet Pawl6 22 Manual Closing Handle 23 Closing Handle Shaft and Pawl Asm 24 Roll Pin 1 Upper Spring Pin 2 Safety Pin Holder 3 5afety Pin and Chain 4 Safety Pin Hole 5 Closing Springs 6 Guide Rod 7 Pawl Springs 8 Front Escutcheon 9 Front Bearing Plate 10 Bearing P...

Page 16: ...h is recom mended Shims should be obtained from the factory 6 Remove the front escutcheon by removing four screws holding it to the front frame center support 7 Remove the handle return spring 29 by unhooking either end of the spring 2 It may be necessary to add buf fer 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...

Page 17: ...by If measurements reveal either in sliding them to thefront of the breaker correct center pole contact wipe or They are slotted for easy removal incorrect overlap of contacts adjust Effect of this adjustment on contact mentfi should be made by the following wipe and overlap is negligible procedure 1 Remove arc quenchers see ARC QUENCHER 2 Insert safety pin in push rod See Fig 3 under MAINTENANCE ...

Page 18: ...opened and closed 5 Push auxiliary switch shaft 8 into square hole in link breaker open 6 Replace mounting hardware and wiring The auxiliary switch is mounted on the left side of the front frame As the crossbar 4 moves with the con tacts to the open or closed position it operates a triangular link 6 through an operating rod 5 The triangular link rotates the operating shaft 8 of the auxiliary switc...

Page 19: ...ting rod as de scribed for the standard breakers AKF BREAKERS Fig 19 Replacement Fig 19 The auxiliary switch mounting and linkage on the AKF breakers are dif 1 Disconnect all leads to auxiliary switch ELECTRICAL CLOSING DEVICES AND CONTROLS A closing switchand motor mecha nism are provided for closing the breaker electrically springs and through the operating rod 4 thus opening switch 1 contacts a...

Page 20: ...ER VOLTAGE TRIPPING DEVICE Fig 21 Device 1 Disconnect coil leads The instantaneous undervoitage de vice is mounted in the same location and manner as the time delay device Its construction is similar tothe time delay device with the exception of the time delay feature The omission of this feature eliminates the cylinder 10 plunger 12 connecting rod 11 clevis 7 bracket 1 and adjusting nut 8 from th...

Page 21: ...ig 22 1 Long time delay short time de lay and instantaneous tripping 1 The air gaps between magnet 22 and armatures 18 and 19 are set by adjustingscrews 25 When replacing the device refer to the drawing which accompanies each newdevice for spe cific gap dimensions The gap dimen sion is measured from the magnet to the armature at the point where the gap is largest Tighten the locking nuts on adjust...

Page 22: ...Connecting Rod 16 Dashpot Fig 23 Dlrecf octing fnpping device 19 Clamp 20 Stud 21 Calibration Scale 22 Inst Calibration Spring High Set 23 Clamping Nut 24 Calibration Washer 25 Armature 26 Magnet C M and EC JB conjunction with any other character istic is always high set non adjust able on the EC 1A SHORT TIME DELAY TRIPPING Fig 23 The short time delay armature 1 is restrained by a calibration spr...

Page 23: ...t the fac tory the air gaps between magnet 11 and armatures 1 and 14 are set These gaps are measured at their wid est point between the front edge of the armature and magnet The gap for the short time delay armature is 11 64 in and for the long time delay armature is 17 64 in Both have a plus and minus tolerance of 1 64 in 4 Close the armature against the gage and magnet k 5 If the breaker does no...

Page 24: ... silicone oil in adashpot which pro filer retarded byan escapement mech duces an inverse time delay charac nism which produces an inverse time teristic The mechanism is shown on delay characteristic The mechanism Fig 24B is shown on Fig 24A LONG TIME DELAY TRIPPING Fig 24 The armature 10 is restrained by the calibration spring 11 After the produced by an overcurrent condition overcomes the restrai...

Page 25: ...nd mounting screws 4 Before installing a new device check the travel of the trip arm with a rod or wire and push the armature solidly against the magnet see Fig 25 The trip arm should travel at least 5 32 in 5 Replace new device in reverse 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 de v...

Page 26: ...r and should be lined up with the center of the de sired calibration mark 15 to obtain the proper instantaneous trip setting 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 to 3 32 in or less measured at the rivet in the pole piece Also the armature must have a min...

Page 27: ... rod and vary the position of the adjusting nut 2A thus establishing the position of the adjusting nut where the breaker is just tripped 1 T rip Paddle 2 Series Coil 2A Adjusting Nut 2B Locking Nut 3 T rip Rod 4 T rip Crank 5 Setting Sealing Screw Calibration Spring 7 Potential Coil 8 Calibration Nut 9 Pole Pieces 10 Armature 11 Counter Weight 12 Stop Screw 13 Mounting Screw 14 Screw CM t O NO I t...

Page 28: ... current characteristics BREAKER ACCESSORIES PRIMARY DISCONNECTS AK 50 ONLY at the top rear of the breaker A ter minal board serves the same purpose on stationary mounted and general pur pose enclosure mounted breakers These secondary disconnects allow re moval of the breaker without the neces sity of having to detach external con nections The movable part of the secondary disconnects consists of ...

Page 29: ...ing the entire racking operation The fifth and final stroke of the racking handle releases the trip interlock and allows the breaker to be closed since the breaker is now fully racked in 7 Place new contact tip on end of wire and crimp r 8 Pull wire through hollow tube un tilcontact tip fits snugly against end of hollow tube 9 Crimp tab on other side of as sembly to hold wire in place 10 Any hollo...

Page 30: ...eset as described above The lockout adjusting screw is fur nished only with the lockout feature Adjustments 4 With the manual tripbutton fully depressed position the trip rod re lease collar 16 on the trip rod 14 so that the latch 4 and catch 15 are disengaged before the breaker opens 1 Adjust the bellalarm device latch 4 so that a clearance of 1 16 in 1 64 in is maintained with the catch 15 when ...

Page 31: ...nd the cir cuit assumes the position of Fig 34B When a closing operation is desired the remote closing button is closed to energize the K relay andthe circuit as sumes the conducting circuit shown by the solid circuit in Fig 34C The cir cuit from X is through K 1 7 R 1 2 K 8 2 F 1 2 R 3 4 to Y The polarity of the field with respect to the armature is such that the motor will run in the forward dir...

Page 32: ...o 2 8 in shank Phillips No 3 Long thin slotted screw Standard slotted screw Short shank slotted screw Offset ratchet screwdriver slotted No 3400 Yankee Offset ratchet screwdriver Phillips No 3412 Yankee 8 in adjustable 1 4 in 5 16 in open end 1 2 in 9 16 in open end 5 8 in 3 4 in open end 3 8 in 7 16 in open end 11 32 in 5 16 in open end 5 8 in 6 point open box When ordering renewal parts ad dress...