A. All new breakers must have a complete inspection at the end of 1 year.
B. Only breakers having field experience to support the program should be
scheduled for extended inspection periods.
C. Breakers used on special applications, such as capacitor and reactor switching,
should be considered separately.
D. If recurring troubles are found on a certain type of breaker, the inspection
schedules should be adjusted until the trouble is eliminated.
E. Breakers interrupting a large number of faults should be given special attention
to determine whether or not early internal inspection is required.
F. When oscillographs indicate abnormal breaker operation, an immediate
inspection of the breaker should be made.
Contact Pressure Springs
* Check springs for loss of temper, breaks, or other deterioration.
* Check flexible shunts at contact hinges for overheating and fraying. Tighten
Magnetic, Air, or Oil Blowout Devices
* Check arc-rupturing blowout coils, magnetic circuit, arc chutes, deion grids, oil
blast, or other interrupters for proper operation.
* Check contact crosshead for misalignment, breaks, bends, or looseness on lift rod.
Lift Rods and Guides
* Check contact lift rods for breaks, weakening, or warping, and pulling out at ends.
Check adequacy of guides.
Operating Rods, Shafts, and Bell Cranks
* Check for loose locknuts, setscrews, keys, bearings, bent rods, or twisted shafts, etc.
Clean moving parts of rust, dirt, and accumulated grease and oil. Wash out
bearings, pivots, and gears with chlorothene or other suitable cleaner; and operate
breaker several times to work out dirt and old lubricant. Lubricate with new grease
or oil. In cold climates, it is important to use lubricant that will not stiffen too much
with cold. Wipe off excess oil. Enclosed dust-tight bearings should require less