59
Sub-assembly Item Inspect for
Primary power path
Vacuum interrupter
1. Cleanliness.
2. Contact erosion.
Note: Perform with manual-spring checks.
3. Vacuum integrity.
Note: Perform with high-potential tests.
Primary disconnects
1. Burnt or damaged fingers.
2. Lubrication of contact surfaces.
Vacuum interrupter contact resistance
1. Record contact resistance with contacts closed
and check at each maintenance interval to
monitor condition.
Vacuum interrupter operator mechanism
Cleanliness 1. Dirt or foreign material.
Fasteners 1. Tightness of nuts and other locking devices.
Manual-spring check
1. Smooth operation of manual charging, manual
closing and manual tripping.
Lubrication
1. Evidence of excessive wear.
2. Lubricaion of wear points.
Electrical controls
Wiring 1. Mechanical damage or abrasion.
Terminals and connectors 1. Tightness and absence of mechanical damage.
Close and trip solenoids, anti-pump relay,
auxiliary switches and secondary disconnect
1. Automatic charging.
2. Close and trip with control power.
High-potential test
Primary circuit-to-ground and between
primary disconnects
1. 60-second withstand 14 kV or 27 kV or 28.5 kV,
60 Hz (20 kV or 38 kV or
40 kV dc).
Control circuit-to-ground 1. 60-second withstand 1.5 kV, 60 Hz.
Insulation Barrier and all insulating components
1. Cleanliness.
2. Cracking, crazing, tracking or other sign of
deterioration.
Table 7: Periodic maintenance and lubrication tasks
Maintenance and
troubleshooting
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