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Cover 2074-98
Table of Contents
15.5kV, 25.8kV and 27.6kV Power Circuit Breaker
Introduction and Safety ....................................................... 2
Introduction ............................................................................. 2
Qualified Person ...................................................................... 2
Signal Words ........................................................................... 2
Hazardous Procedures ............................................................ 2
Field Service Operation ........................................................... 2
General Description .............................................................. 3
Introduction ............................................................................. 3
Scope ...................................................................................... 3
General Description ................................................................ 3
Receiving, Handling & Storage ............................................ 4
Receiving ................................................................................ 4
Inspection ............................................................................... 4
Shipping Damage Claims ........................................................ 4
Lifting and Moving .................................................................. 5
Lifting Power Circuit Breaker with Crane ................................ 5
Storage .................................................................................... 5
Installation ............................................................................. 6
Location .................................................................................. 6
Preparation for Installation ...................................................... 6
“X” Bracing Installation Instructions
(for High Seismic Applications Only) ............................... 6
Foundation-General Requirements ......................................... 7
Electrical Connections .......................................................... 8
Primary Lead Connections ...................................................... 8
Ground Connections ............................................................... 8
Secondary Control Wiring ....................................................... 8
Instrument Transformers ..................................................... 9
Current Transformers .............................................................. 9
Installation Checks and Initial Functional Tests ............... 10
Introduction ........................................................................... 10
Inspections, Checks, And Tests Without Control Power ...... 10
Spring Discharge Check ........................................................ 10
Physical Inspections .............................................................. 11
Manual Spring Charging Check ............................................. 11
As-Found and Vacuum Check Tests ...................................... 11
Automatic Spring Charging Check ........................................ 11
Final Mechanical Inspection and
Testing Without Control Power ..................................... 11
Inspection ............................................................................. 11
Testing ................................................................................... 12
Interrupter/Operator Description ...................................... 13
Introduction ........................................................................... 13
Vacuum Interrupters ............................................................. 13
Stored Energy Operating Mechanism ................................... 13
Modes Of Operation - Discussion ......................................... 14
Spring Charging Mode .......................................................... 14
Closing Mode ........................................................................ 15
Trip Free Mode ...................................................................... 15
Opening Mode ...................................................................... 15
Rapid Auto-Reclosing Mode ................................................. 15
Closing And Tripping Springs ................................................ 15
Trip Free Operation ............................................................... 16
Damper ................................................................................. 16
Manual Spring Charging ........................................................ 16
Spring Charging Motor .......................................................... 17
Close Solenoid, Trip Solenoid and Anti-Pump Relay ............. 17
Auxiliary Switch ..................................................................... 17
Limit Switches ...................................................................... 17
Standard Schematic Diagrams .............................................. 17
Capacitor Trip Device (Optional) ............................................ 18
Maintenance ........................................................................ 21
Inspection and Maintenance Intervals .................................. 21
Recommended Hand Tools ................................................... 21
Recommended Maintenance and Lubrication ...................... 21
De-energize the Circuit Breaker ............................................ 22
Checks Of Primary Power Path ............................................ 22
Cleanliness Check ................................................................. 22
Checks of the Stored Energy Operator Mechanism ............. 23
Maintenance and Lubrication ................................................ 23
Fastener Check ..................................................................... 23
Manual Spring Charging And Contact Erosion Checks ......... 23
Vacuum Interrupter Stroke Check ......................................... 24
Damper Assembly Check ..................................................... 25
Electrical Control Checks ...................................................... 25
Check Of The Wiring And Terminals ..................................... 25
Automatic Spring Charging Check —
Control Power Required ................................................ 25
Electrical Close And Trip Check —
Control Power Required ................................................ 26
Checks Of Spring Charging Motor ........................................ 26
High Potential Tests .............................................................. 26
Vacuum Integrity Check ........................................................ 26
High Potential Test Voltages ................................................. 26
Vacuum Integrity Test Procedure .......................................... 27
As-Found Insulation and Contact Resistance Tests .............. 27
Insulation and Contact Resistance Test Equipment .............. 27
Insulation and Contact Resistance Test Procedure ............... 27
Inspection And Cleaning Of Breaker Insulation .................... 28
Functional Tests .................................................................... 28
Relays and Instruments ........................................................ 28
Equipment Surfaces .............................................................. 28
Operator Adjustments ........................................................ 29
Spring Charging Adjustment ................................................. 29
Spring Release Latch “Bite” Adjustment ............................. 30
Overhaul .............................................................................. 31
Introduction ........................................................................... 31
Circuit Breaker Overhaul ....................................................... 31
Replacement At Overhaul ..................................................... 31
Replacement Of Closing Springs .......................................... 31
Replacement Of Opening Spring .......................................... 32
Replacement Of Closing and Tripping Solenoids
(Devices 52SRC and 52T) ............................................. 32
Replacement of Anti-Pump Relay (Device 52Y) .................... 32
Replacement of the Auxiliary Switch .................................... 32
Replacement of Motor Cutoff Switch (Device LS1)
and Spring Charged Switch (LS2) ................................. 33
Replacement of Trip Latch Reset Check Switch
(Device LS3) .................................................................. 33
Replacement of Damper Assembly ...................................... 34
Replacement of Spring Charging Motor (Device 88) ............ 34
Replacement of Vacuum Interrupters ................................... 34
Index of Figures and Tables .................................................. 34
Recommended Hand Tools ................................................... 34
Preparation ............................................................................ 35
Vacuum Interrupter Removal ................................................ 35
Vacuum Interrupter Replacement ......................................... 35
Periodic Maintenance and Lubrication Tasks ................... 39
Troubleshooting .................................................................. 40
Ordering Replacement Parts ................................................. 42
Appendix .............................................................................. 43
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