1. The first step is to de-energize the circuit breaker. Press-
ing the Open pushbutton opens the circuit breaker prior
to removal from the switchgear (Refer to Circuit Breaker
Operator / Manual SG-9918 (3AH) or SG-3398 (3AF).)
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/Test position.
4. Perform the spring discharge check. This is done by
first pressing the red Open pushbutton. Second, press
the black Close pushbutton. Third, press the red Open
pushbutton again, and observe the spring condition in-
dicator. It should read Discharge (Refer to Circuit Breaker
Operator / Manual SGIM-9918 (3AH) or SG-3398 (3AF).)
5. Remove the circuit breaker from the switchgear. Refer
to the preceding installation section of this manual for
special instructions and precautions regarding removal
of a circuit breaker which is not at floor level.
Maintenance
Checks of the Primary Power Path
The primary power path consists of the three vacuum
interrupters and the six primary studs. These components
are checked for cleanliness and condition (Figure 6). The
vacuum interrupters are discussed in the Circuit breaker
Operator Manual SGIM-9918 (3AH) or SG-3398 (3AF).
Cleanliness Check
Figure 6 is a side view of the GER Circuit Breaker with the
insulating barriers removed (furnished on certain models
only) to show the vacuum interrupter and the primary
studs.
11
Note: Maximum Contact Resistance is read from pri-
mary bus stab to primary bus stab. A value of 30
micro-ohms should be added to the maximum con-
tact resistance specified in Circuit Breaker Operator
Manual SGIM-9918 (3AH). The 3AF Circuit Breaker
Operator micro-ohm values match those listed in the
Manual SGIM-9918.
Figure 5. Continuous Current Interlock (Circuit Breaker in Connect Position)