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1

GE PowerVac

 

®

 5kV VL

for PowerVac

 

®

 Vacuum Circuit Breakers

Type PV VL 4.16-250-0

with ML-19 Mechanism

Instructions

DEH 40012

g

Courtesy of NationalSwitchgear.com

Summary of Contents for PowerVac 5kV VL

Page 1: ...1 GE PowerVac 5kV VL for PowerVac Vacuum Circuit Breakers Type PV VL 4 16 250 0 with ML 19 Mechanism Instructions DEH 40012 g Courtesy of NationalSwitchgear com ...

Page 2: ...r other conditions that could cause personal injury or death are present in this equipment or may be associated with its use Warning notices are also used for situations in which inattention or lack of equip ment knowledge could cause either personal injury or damage to equipment CAUTIONS Caution notices are used for situations in which equipment might be damaged if care is not taken NOTES Notes c...

Page 3: ...nterlock 12 4 5 Primary Contact Penetration 14 4 6 Stationary Auxiliary Switch MOC 16 4 7 Stops 16 4 8 Ground 16 4 9 Secondary Coupler 17 4 10 Position Switch 17 Chapter 5 Operation 5 1 Description 18 5 2 Close Spring Charging 19 5 3 Trip Free Operation 20 5 4 Closing Operation 20 5 5 Opening Operation 21 Chapter 6 Control Circuit 6 1 Typical Wiring Controls 22 Chapter 7 Mechanical Check and Slow ...

Page 4: ...djustments 11 1 General 35 11 2 Wipe Adjustment 35 11 3 Contact Gap Adjustment 36 11 4 Trip Coil Plunger 37 11 5 Close Coil Plunger 38 11 6 Control Switch Adjustment 39 11 7 Adjustment of MOC Switch 39 11 8 Positive Interlock 40 Chapter 12 Repair and Replacement 12 1 General 44 12 2 Replacing Interrupters 44 12 3 Primary Bushing 45 12 4 Mechanism 45 12 5 Control Switches 45 12 6 Trip Coil Replacem...

Page 5: ...Transducer Installation Part 0144D1235G00X 34 29 Wipe Insulator 35 30 Contact Gap Adjustment Opening Buffer 36 31 Contact Gap measurement wipe indicator check and wipe measurement 36 32 Trip coil gap adjustment 37 33 Trip coil button with gage 37 34 Trip coil assembly 37 35 Close coil assembly front view 38 36 Close coil gap adjustment front view 38 37 SM LS CHG switch adjustment left side view 39...

Page 6: ...withstand energizing fault levels so that protective equipment may clear the circuit safely Additional dis cussion on this concept is covered in Chap ter 20 of ANSI NFPA 70B Electrical Equip ment Maintenance 3 Although interlocks to reduce some of the risks are provided the individual s actions while performing service or maintenance are essential to prevent accidents Each person s knowledge his m...

Page 7: ...meplate also describes the control power re quirements for that breaker The application of a breaker must be such that its voltage current and interrupting ratings are never exceeded Since this book is written to include all ratings of the breaker as well as several design varia tions the instructions will be of a general char acter and all illustrations will be typical unless otherwise specified ...

Page 8: ...are in operation to prevent condensation Rollers latches etc of the operating mechanism should be coated with GE part No 0282A2048P009 Mobil 28 red grease to prevent rusting If the breaker is stored for any length of time it should be inspected periodically to see that corrosion has not started Should the breaker be stored under unfavorable atmospheric con ditions it should be serviced before bein...

Page 9: ...gn of switchgear has always been the interchangeabililty of break ers GE Switchgear has been very successful in achieving that goal for many years Analy sis of instruction book adjustments shop tol erances and service advice letters issued in recent years however has demonstrated that tolerances in switchgear equipment installed and presently operating can change result ing in situations where it ...

Page 10: ... metal clad compartment of identi cal rating The rating interference bolt has been assembled to match the current rating of the compartment This assembly is done by fasten ing a bolt on the lower left side of the breaker truck to align with the proper cubicle interfer ence plate This bolt should not be removed Figure 5 Figure 5 Rating Interference Bolt Courtesy of NationalSwitchgear com ...

Page 11: ...s a trip free and discharged condition when rack ing the breaker in the connected or disconnect position When the breaker is raised or lowered the positive interlock roller and lever are forced forward by the postitive interlock cam on the right side of the switchgear cell The interlock roller and lever are held in this forward position during raising and lowering operations prevent ing the breake...

Page 12: ...brackets until the lifting brackets are in the fully lowered position The breaker should then enter the housing freely After first assuring that the breaker is in the open position push the breaker into the unit until it rests against the rear of the front lifting saddle of the elevating mechanism The clearance between the interference block on the breaker and the interference block on the interlo...

Page 13: ...on 7 When the breaker is fully elevated the clear ance between the breaker lifting rail and the upper stop bolts should not be more than 125 and not less than 094 8 The positive interlock roller should be cen tered in the upper VEE and the interlock roller should have 1 16 clearance to the stationary plate directly under it 9 In order to lower the breaker from the con nected position the breaker s...

Page 14: ...ine contact tube and socket design the tube being backed up by heavy garter springs 1 Each segment of the stationary discon necting device should make a heavy im pression in the contact lubricant on the breaker studs as shown in Figure 9 Con tact wipe should start not less than 125 from the top of the contact ball although each contact need not start at the same location 2 The penetration of the b...

Page 15: ...ion Final Position 1 2 to 5 8 Electrical Wipe Initial Electrical Contact 3 4 to 7 8 Travel 3000A Contact Wipe area should be a minimum of 60 contact width 1200A 2000A Contact Wipe should be a line 1 16 to 1 8 wide grease wipe 8 3 16 M 26 9 3 4 M 36 12 3 4 M 36HH Courtesy of NationalSwitchgear com ...

Page 16: ...tant interfaces required for reliable opera tion of the equipment such as 1 Primary disconnect penetration 2 Secondary coupler penetration 3 The positive interlock mechanism A major goal in the design of switchgear has always been the interchangeability of breakers GE Switchgear has been very successful in achieving that goal for many years Analysis of instruction book adjustments shop tolerances ...

Page 17: ...acting block surfaces should touch and the fe male block edge move upward between1 32 to 1 8 See Figure 11 Figure 11 Secondary disconnect coupler 1 2 3 1 Secondary disconnect block shims 2 16 Secondary disconnect pins 3 Ground pin for use with a test cabinet PowerVac 5kV Vertical Lift Chapter 4 Installation 4 10 Position Switch TOC The position switch is an optional device mounted in the rear left...

Page 18: ...ings and overcome bearing and other frictional forces PowerVac 5kV Vertical Lift Chapter 5 Operation The energy then stored in the wipe and open ing springs will open the contacts during an opening operation Closing and opening operations are controlled electrically by the control switch on the metal clad door or remote relaying Mechanical control for maintenance or emergen cies is provided by man...

Page 19: ...m 1 WARNING DO NOT ATTEMPT TO MANU ALLY CHARGE A CHARGED BREAKER TO DO SO COULD DAMAGE THE CHARGING CLUTCH AND MAKE THE MANUAL CHARG ING FEATURE INOPERABLE The manual charging system Figure 14 works directly on the cam shaft where a one way clutch Figure 14 Item 2 driven by a manual handle provides rotation of the ratchet wheel Manual pumping of the handle advances the ratchet wheel and the holdin...

Page 20: ...Driving pawl 7 52 LCS switch 4 Holding pawl 8 Trip latch Spring charging is accomplished electrically by a rotating eccentric on the output shaft of a gear motor Figure 15 Item 6 which in turn drives pivoted charging arms Figure 15 Item 1 The charging arms oscillate about the centerline of a ratchet wheel Figure 15 Item 2 A driving pawl Figure 15 item 3 mounted within the charging arms oscillates ...

Page 21: ...charging is possible when the breaker is in the closed position because the linkage is held in place by the prop 5 5 Opening Operation By either energizing the trip solenoid Figure 13 Item 3 or depressing the manual trip button Figure 1 Item 7 the trip latch Figure 16 Item 6 is rotated permitting the linkage to collapse The vacuum interrupter contacts will then open under the force of the wipe spr...

Page 22: ...o normally closed 52Y relay contacts and the Latch Checking Switch LCS If the trip latch is reset an auxiliary switch contact 52b is also in series with the close coil and closes when the breaker is open and opens when the breaker is closed During a close operation the cam rotation closes the SM LS contact allowing the 52Y relay to be energized The 52Y relay opens its contacts in the close coil ci...

Page 23: ...n Figure 20 Figure 20 Typical breaker wiring diagram Replacement for breakers with MS mechanisms Replacement breakers for old units with stored energy mechanisms AM breakers with ML type mechanisms are typically wired per the draw ing in Figure 21 The wiring on your breakers may be different Consult your nameplate for the correct drawing number and call your local GE office when ad ditional copies...

Page 24: ...24 Figure 21 Typical breaker wiring diagram Replacement for breakers with ML mechanisms PowerVac 5kV Vertical Lift Chapter 6 Control Circuit Courtesy of NationalSwitchgear com ...

Page 25: ...g spring is charged by a ratcheting mechanism that advances one ratchet tooth at a time Approximately eight complete strokes are required When the spring is fully charged the spring load is held by the closing latch The spring indicator Figure 1 Item 5 changes from DISCHGD to CHARGED and a positive snap is heard as the spring travels over center CAUTION AFTER THE SPRING IS COM PLETELY CHARGED AS I...

Page 26: ...ipe indicator has four red lines that make up a total distance of 0 125 The wipe indicator was preset at the factory so that when the breaker is charged and closed all four red lines should be visible above the wipe plate 8 1 Primary Contact Erosion The vacuum interrupter is a sealed unit and the contacts are not visible The contacts are de signed for 0 125 total wear When 0 125 of wear has occure...

Page 27: ...the breaker Using the same procedure as above re mark the tape This new mark will be near the bottom of the tape Trip the breaker remove the tapes and re apply them to a flat surface Measure the distance between the two lines A caliper will give an accurate reading of the con tact gap Dimension B The gaps must be between 0 480 PowerVac 5kV Vertical Lift Chapter 8 Dimensional Checks 1 Operatingrodi...

Page 28: ...icable breaker voltage rating If the test should experience a failure STOP turn off the test set and discharge the breaker circuit 1 Check the test setup and leads for con nection errors 2 Wipe down the breaker to remove any moisture dust and contamination 3 Retest the breaker at the proper test volt age Secondary Circuit Prior to hi potting the breaker secondary circuit disconnect the motor leads...

Page 29: ... mine its internal dielectric condition and vacuum integrity CAUTION DISCONNECT THE SURGE SUPPRES SORS BEFORE HI POTTING THE CIRCUIT BREAKER AND VACUUM INTERRUPTERS The vacuum integrity test is performed using an AC hi potential tester A vacuum integrity test of the interrupter is required to insure that no loss of vacuum has occurred With the breaker open individually check each interrupter by co...

Page 30: ...alibration instructions on particular devices typically are provided by supplied instruction books Instruction books supplied by manufacturers address components that would normally re quire service or maintenance during the useful life of the equipment However they can not in clude every possible part that could require at tention particularly over a very long service period or under adverse envi...

Page 31: ...ptions The erosion rate of the primary contacts in the vacuum interrupters is very low for no load and normal load switching operations However fault current interruptions at or near the breaker rating may result in appreciable contact erosion With frequent fault interruptions it is neces sary to perform maintenance based on the num ber of interruptions After each 20 full fault inter ruptions the ...

Page 32: ...Wipe clean and coat lightly with 0282A2048P009 grease all silvered primary contact surfaces such as the movable con tact rod of the interrupter and the primary disconnect fingers 2 Clean and coat lightly with 0282A2048P009 grease the pins of the secondary coupler PowerVac 5kV Vertical Lift Chapter 10 Maintenance 10 9 Recommended Maintenance The following operations should be performed at each main...

Page 33: ... operation may be checked by trip ping a charged breaker open while maintaining a close signal Instantaneous reclose time 85 150 milliseconds Time from application of trip signal until breaker contacts reclose Figure 27 Opening Speed Adjustment 1 Lock Nuts 2 Opening Spring 3 Outer Bell Crank 4 Primary Cross Shaft PowerVac 5kV Vertical Lift Chapter 10 Maintenance Figure 26 Sample Operating Speed Gr...

Page 34: ... Figure 28 Travel Transducer Installation Part 0144D1238G001 1 Clamp 3 Transducer 2 Connecting Link 4 Mounting Bracker PowerVac 5kV Vertical Lift Chapter 10 Maintenance Courtesy of NationalSwitchgear com ...

Page 35: ... wipe close the breaker and proceed as follows 1 Loosen but do not remove the two cap screws Figure 29 Item 7 holding the in terrupter clamp 2 Check that the interrupter clamp is loose A light prying at the clamp half junction may be required to loosen the wedging ac tion of the clamp 3 Hold the hexagon projection Figure 29 Item 4 at the bottom of the operating rod insulator 1 inch wrench and loos...

Page 36: ...separation or gap between the primary contacts within the vacuum interrupter Before attempting to mea sure or set the gap adjustment verify that the wipe settings are within acceptable limits Any change of the wipe settings will affect the gap settings 1 With the breaker in the open position and the closing spring discharged the buffer arm should be stopped against the buffer Pressing the stem int...

Page 37: ...hat the close roller Figure 32 is reset and in contact with the close cam Depress the trip plunger until it contacts the trip release lever arm Set the gap between the under side of the trip plunger mushroom head Figure 32 Item 1 and Figure 34 and the top of the trip coil housing Figure 32 Item 2 to 0 375 Allow the trip plunger to fully reset and loosen the lover collar Figure 32 Item 4 and push i...

Page 38: ...ke in the coil To check the closing coil plunger gap the breaker should be open and the closing spring charged and gagged Adjusting plate Figure 35 Item 10 is spring loaded against the pivot for the arm this set the close coil actuating arm Figure 34 Item 1 The collar and washer Figure 35 Item 4 Item 5 are assembled to the close plunger Figure 36 Item 3 to the dimension indicated 375 This is the i...

Page 39: ...ve interlock trips the breaker This is a vi sual check See Figure 38 1 Positive Interlock actuator 4 Close latch 2 Positive Interlock switch 5 CL MS switch 3 Switch adjustment nuts 6 Switch plunger Figure 38 CL MS and positive Interlock switch adjustment right side view 11 7 Adjustment of MOC Switch The Stationary Auxiliary Switch is an optional switch mounted in the switchgear cubicle When the br...

Page 40: ...switch interface the following ad justments should be verified PowerVac 5kV Vertical Lift Chapter 11 Mechanical Adjustments Nominal breaker plunger travel is 1 1 16 Nomi nal auxiliary switch rod travel is 1 1 16 It is imperative that a gap is present between the top of the plunger and the bottom of the rod when the breaker is in the fully connected posi tion and the breaker is open To assure the m...

Page 41: ...een top of plunger interlock and Resulting travel of the aux Travel bottom of aux switch rod switch rod To be measured Min Max Min Max 1 1 16 001 1 16 1 1 1 16 Adjustment of Plunger Interlock Breaker raised to connect position Gap adjustment as a function of breaker plunger travel to assure proper switch operation Courtesy of NationalSwitchgear com ...

Page 42: ...Linkage Positions Breaker Open Spring Charged Figure 41A Toggle Linkage Positions View from Right Side Breaker Closed Spring Charged Figure 42A Toggle Linkage Positions View from Right Side Breaker Closed Spring DisCharged Figure 42 Toggle Linkage Positions View from Right Side Courtesy of NationalSwitchgear com ...

Page 43: ... Motor Cutoff See Figure 47 Switch PowerVac 5kV Vertical Lift Chapter 11 Mechanical Adjustments TABLE 2 ADJUSTMENTS CLOSING OPENING ITEM BREAKER SPRING SPRING MEASUREMENT Contact Closed Charged Charged Adjust operating rod to obtain Wipe required dimensions Contact Open Charged Discharged Use buffer shims to advance Gap or retard gap adjustment Contact Erosion Trip Closed Discharged Charged Turn a...

Page 44: ...SUPPORT ASSEM BLY SPECIAL TOOLS AVAILABLE ONLY AT THE FACTORY ARE REQUIRED TO PREVENT DAMAGING THE VACUUM INTERRUPTER BELLOWS 1 Toremove the ML 19 element from the main truck or frame a Remove rear cover disconnect surge suppressors remove rear interphase barrier support and interphase b Disconnect element to primary bus at the element end c Detach the Secondary Connecter Bracket Be sure to mark i...

Page 45: ...d install gag tool 2 Depress the close and then the trip but tons 3 Pump the manual close handle 3 4 times 4 With the 5 16 Allen wrench remove the pivot bolt Figure 49 on the closing spring Figure 49 Item 3 5 Remove the closing spring 6 Disconnect the trip linkage tension spring Figure 44 Item 4 3 Remove interrupter assembly fasteners 8 four on the upper standoff and four on the lower Remove the o...

Page 46: ...st be positioned below the posi tive interlock cam Figure 44 item 9 slightly touching 12 The set screw in the collar Figure 44 item 3 should then be tightened to the plunger extension The adjustment screw Figure 44 item 8 must not be readjusted Apply locite to the threads on the pivot bolt Charge the breaker and electrically close and trip the breaker to make certain the reassembly of the mechanis...

Page 47: ...tion un der CLOSE COIL PLUNGER 12 8 Auxiliary Switch Replacement With the breaker open and the closing spring discharged remove outer X washer from aux iliary switch pin on the main drive shaft Re move mounting hardware securing the auxil iary switch to the side sheet slide switch and bracket from breaker Observe and make note of the direction of the index mark on the end of the shaft and the posi...

Page 48: ...ch 2 Cam Shaft 8 Close Latch 3 Manual Charge and One way Clutch 9 Close Cam 4 Buffer Overtravel Stop 10 Prop 5 Ratchet Wheel 11 Main Shaft 6 Driving Pawl 12 Auxilary Switch 13 Pivot Bolt Figure 45 Front View of ML 19 Breaker Mechanism Lower 4 3 9 2 5 6 8 11 10 12 7 13 1 Courtesy of NationalSwitchgear com ...

Page 49: ...apscrews securing the motor to the mechanism plates Disengage the motor output shaft from the charge linkage arms and withdraw motor To install the new motor reverse the above pro cedure 12 10 Y Relay Replacement Before removing the Y relay make sure all leads are marked with terminal locations fig ure 41 Next disconnect all leads and remove the two fasteners securing the Y relay s shock absorbing...

Page 50: ... 2 Manual Charge Mechanism 3 Gag Tool 4 Closing Spring Figure 49 Closing Spring Gag PowerVac 5kV Vertical Lift Chapter 12 Repair and Replacement Figure 48 Motor Cutoff Switch switch Courtesy of NationalSwitchgear com ...

Page 51: ...ecify the complete nameplate in formation Include the manufacturing date of both the breaker and the mechanism See Figure 50 2 Specify the quantity catalog number if listed reference number if listed and description of each part ordered and the parts bulletin number 3 Standard hardware such as screws bolts nuts washers etc are not listed in this bulletin Such items should be purchased locally 4 Fo...

Page 52: ...cuit Amps 29 Close Coil 0282A73406002 Volts 125 DC Trip Coil 1 0282A70156006 Volts 125 DC Trip Coil 2 Volts Tripping Amps Charging Motor 0177C50506001 Volts Connector Diagram 020988250P002 Wt 470 LBS Mech Type ML 18 Date Mfg 4 99 Vac Inter Type 50F Req 625 1222W Caution Before Installing Or Operating Read Instr DEH 40012 GE Industrial Systems W Burlington IA 52655 USA SO 977673 Impulse Range Facto...

Page 53: ...perating temperatures The bus bars are in serted into the sleeves leaving only the bolted joints exposed The bus terminates before and after the breaker unit Current transformers may be located along the bus on either side of the breaker for control applications 5 Breaker Testing Provisions Optional provisions for testing the breaker unit after removing it from the cubicle can be fur nished The te...

Page 54: ...aker Positioning Before proceeding to place the breaker in the operating position the steps as outlined in Chapter 4 must be taken WARNING DO NOT INSTALL OR REMOVE THE BREAKER OR MAKE ADJUSTMENTS UNLESS THE BREAKER IS OPEN 4 1 Rub a small amount of 0282A2048P009 lubricant on the silvered portion of the breaker studs ground shoe and 16 sec ondary coupler pins to form a thin coat ing for contact pur...

Page 55: ...ig ure 9 c Should the inspection of the contacts show that the breaker is not being raised to the proper position readjust the up per stop bolts and limit switches to raise or lower the breaker to the proper loca tion Lock the stop bolts in the new posi tion Figure 6 d If proper contacting cannot be attained by the above methods additional adjust ments may be necessary CAUTION DO NOT MAKE THESE AD...

Page 56: ...ng WARNING IF THE BREAKER IS IN THE CLOSED POSITION WHILE ATTEMPTING TO LOWER THE BREAKER ENGAGING THE CLUTCH HANDLE WILL CAUSE THE BREAKER TO OPEN AND THE CLOSING SPRING TO DISCHARGE All switches shown with breaker in lowered or removed position REMOVABLE ELEVATING MOTOR ASSEMBLY Courtesy of NationalSwitchgear com ...

Page 57: ...or switch 6 Check motor 7 Adjust upper LE and lower LF limit switches for proper breaker position 8 Check and adjust leaf springs to provide proper tilt to operate limit switches 9 Check plug and receptacle for proper connections 10 Check clutch and mechanism Table 4 Elevating Motor Troubleshooting DO NOT USE RAISE LOWER SWITCH TO STOP START MOTOR Figure 52 Electrical schematic diagram for typical...

Page 58: ...e when equipment is energized whether it be a tool or a part of the body may under certain conditions in effect short circuit this gap and may cause a breakdown in the pri mary circuit to ground and cause serious dam age or injury or both 6 Stationary Auxiliary Switch MOC On units equipped with stationary auxiliary switches the clearance between the end of the switch mechanism operating rod and th...

Page 59: ...59 Figure 53 Positive interlock M 26 units PowerVac 5kV Vertical Lift Chapter 14 Stationary Cubicle Subassembly Courtesy of NationalSwitchgear com ...

Page 60: ... include the temperature and hu midity PowerVac 5kV Vertical Lift Chapter 14 Stationary Cubicle Subassembly Hi potential tests are not required but if it seems advisable based on the insulation resistance tests or after repairs the test voltage should not exceed 14kV AC 60 Hz These voltages are 75 of the factory test voltages and are in accordance with ANSI standards Potential transformers and con...

Page 61: ...red for the remainder of the switchgear line up cubicles order the same kit number WARNING FAILURE TO FOLLOW THE IN STRUCTIONS BELOW COULD CAUSE A CLOSED BREAKER TO BE RAISED TO WARDS THE CONNECTED POSITION CAUSING INJURY OR DEATH TO THE OP ERATOR AND EXTENSIVE EQUIPMENT DAMAGE To make the modification proceed as follows 1 Remove and save the existing switch operator bracket 2 Install the new swit...

Page 62: ...system and trip free function the following checks should be made a With the breaker closed and in the el evated position the positive interlock roller on the breaker must remain locked and not allow the motor handle to be moved far enough to engage the clutch and close the clutch switch contacts that energize the motor circuit There should be 1 16 clearance between the clutch and motor coupler wh...

Page 63: ...63 PowerVac 5kV Vertical Lift Appendix A Appendix 1A Positive Interlock system Courtesy of NationalSwitchgear com ...

Page 64: ...terlock Plate and install H H thread cutting screw McMaster Cat 90088A539 1 4 F W 1 4 L W Positive Interlock Cam Plate New Switch Operator Bracket shown blocking lower notch 2 Replace with 1 4 20x5 8 LG H H M bolt 1 4 L W 1 4 F W for ref Existing Switch Operator Bracket 7 8 REF 11 16 REF 2 5 8 Plate Interlock Courtesy of NationalSwitchgear com ...

Page 65: ...65 PowerVac 5kV Vertical Lift Appendix A Appendix Figure 3A Motor Operation Switch Actuator 1 8 REF 3 5 8 2 1 4 1 9 16 11 16 1 2 2 5 8 A A Courtesy of NationalSwitchgear com ...

Page 66: ...e__________________________ TROUBLE When Discovered o I n s t a l l a t i o n o I nS e r v i c e o Maintenance o Te s t Other__________________________________ Recloser Mode at Time of Trouble o De energized o Closed o Open o Tr i p p i n g o C l o s i n g o Reclosing o F a u l t I n t e r r u p t i o n o Load Switching o Line Switching Recloser Response at Time of Trouble o Not Called to Operate ...

Page 67: ...failure 4 Oscillograms attach with explanation interpretation 5 Attach a description of the exact position of all mechanical components from the control solenoid through a l li n t e rr upter contacts as applicable photograph each in detail before mechanisms are moved supply copies of photos with report 6 Describe arc damage and location of arc p roducts relative to valve seals photograph each in ...

Page 68: ...r all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation operation or maintenance Should further information be desired or should particularproblems arise which are not covered sufficiently for the purchaser s purposes the matter should be referr ed to the General Electric Company GE Industrial Systems Courtesy of NationalSwit...

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