Breaker preventive maintenance check off list

1. 

Check that breaker is open and discharged. 


2.

Record breaker serial number and number of operations. 


3.

Inspect for damage to breaker (exterior). 


4.

Perform a visual inspection of the breaker and remove dust and contaminants from the interrupter housing, insulation, and mechanism. Do not use compressed air. 


5.

Inspect the interrupters and operating mechanism carefully for loose nuts, bolts and damaged parts. All cam latch and rollersurfaces should be inspected for damage or excessive wear. 


6.

Check that the trip coil plunger and close coil plunger move freely. 


7. 

Inspect condition of primary and secondary disconnects. 


8.

Inspect for evidence of overheating or tracking. 


9. 

Lubrication 

  • On all sleeve, needle, and roller bearings apply 2 or 3 drops of  oil. 

  • On each silver plated primary disconnect finger assembly, wipe clean and apply a light coat of lubricant (red grease). 

  •  On the vacuum interrupter connector rod (movable, each pole) apply a light coat of lubricant (red grease). 

10.

Operate the breaker slowly to be sure there is no binding or friction and that the movable contact of the interrupter can move to the fully opened and fully closed position.


11.

Check interrupter and mechanism adjustments. 


12.

Check contact erosion indicator. 


13. 

Inspect transfer finger wear. 


14. 

Check all wiring for tightness of connections and possible damage to insulation. 


15. 

Check primary circuit integrity by means of a 2500 volt megohmmeter (breaker in the closed position phase to phase and phase to ground) 


16. 

Check control circuit integrity by means of a 500/1000 volt megohmmeter. (Note: Disconnect motor leads to prevent winding insulation damage.) 


17. 

Perform a high potential test (vacuum integrity test) on each vacuum interrupter as described in instruction book. 


WARNING: X-Radiation may constitute a health hazard. Refer to instruction book for proper procedures. 


18. 

Operate the breaker using the test cabinet and observe the following: 

  •  Breaker charges properly. 
  •  Breaker closes and opens correctly. 
  •  Breaker trips freely. 
  •  Indicators show correct position. 

19. 

Place breaker in the equipment in the test position and operate it electrically. 


20. 

Check the operation of all electrical relays (including protective relay devices), solenoid switches, motors, control switches, and indicating devices. 


21. 

Check negative interlock. 


22. 

Check positive interlock. 


23. 

Check spring discharge interlock.