44
Overhaul
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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
1. Record contact resistance with
Resistance
contacts closed and re-check
each year to monitor condition.
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 and manual closing
and tripping.
Lubrication
1. Evidence of excessive wear.
2. Lubrication 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
1. Automatic charging
Relay, Auxiliary Switches,
Secondary Disconnect
2. Close and trip with control power
Spring Charging Motor (88)
1. Replace brushes after 10,000
operations
High Potential Test
Primary Circuit to Ground and
1. 60 second withstand, 14 or 27kV,
between Primary Disconnects
60 Hz (20 or 38kV DC) (depend-
ing upon voltage rating of breaker)
Control Circuit to Ground
1. 60 second withstand, 1500V, 60 Hz
Insulation
Barriers and all Insulating
1. Cleanliness
Components
2. Cracking
Periodic Maintenance and Lubrication Tasks