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Maintenance
2. The second step in the removal procedure is to de-en-
ergize control power to the circuit breaker. Open the
control power disconnect device.
3. Rack the circuit breaker to the "DISCONNECT" posi-
tion.
4. Perform the spring discharge check. This is done by
first pressing the red Trip pushbutton. Second, press
the black Close pushbutton. Third, press the red Trip
pushbutton again, and observe the spring condition
indicator. It should read Discharged (Refer to Circuit
Breaker Operator Manual SGIM-9918).
5. Remove the circuit breaker from the switchgear.
Circuit Breaker Operator Tasks
Perform tests as described in manual SGIM-9918.
Checks of the Primary Power Path
Refer to Circuit Breaker Operator Manual SGIM-9918.
Cleanliness Check
Refer to Circuit Breaker Operator Manual SGIM-9918.
In addition to the circuit breaker operator, Figure 5 shows a
side view of the circuit breaker with the insulating barriers
removed in order to show the upper and lower primary
disconnects.
These components must be clean and free of dirt and any
foreign objects. Use a dry lint free cloth. For stubborn dirt,
use a clean cloth saturated with denatured alcohol (ex-
cept for the vacuum interrupters). For stubborn dirt on a
vacuum interrupter use a damp cloth and then thoroughly
dry using a dry lint free cloth.
The phase barriers are plates of glass polyester insulat-
ing material which are attached to the circuit breaker to
provide suitable electrical insulation between the vacuum
interrupter primary circuits and the switchgear.
Always re-install the phase barriers carefully to their origi-
nal location prior to inserting the circuit breaker into the
switchgear.
Primary Disconnects
Figure 5 is a side view of the circuit breaker showing the
upper and lower primary disconnects.
Inspect the primary disconnect arms for physical integrity
and absence of mechanical damage. Any evidence of
burning or pitting would indicate weakness of the contact
finger springs.
Using a clean cloth saturated with denatured alcohol, clean
old lubricant from primary disconnects, and apply contact
lubricant (part #15-172-791-233) in a thin layer.
Figure 5. Primary Power Path
Fastener Check
Inspect all fasteners for tightness. Replace any fasteners
that appear to have been frequently removed, show dam-
age or are missing.
Electrical Control Checks:
Wiring and Terminals Check
Refer to Circuit Breaker Operator Manual SGIM-9918.
Secondary Disconnect Check
In addition to checking the terminals of the secondary
disconnect, ensure that secondary disconnect assembly
moves freely and is aligned for proper engagement.
Automatic Spring Charging Check
Refer to Circuit Breaker Operator Manual SGIM-9918.
Electrical Close and Trip Check
Refer to Circuit Breaker Operator Manual SGIM-9918.
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