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Maintenance
Removal from switchgear
Prior to performing any inspection or maintenance checks or tests, the circuit breaker must be removed from the switchgear. The "Installation checks and initial functional tests" section (refer to page 8) describes the removal procedure in detail. The principal steps are repeated here for information and guidance, but without the details of the preceding section.
1.The first step is to
2.The second step in the removal procedure is to
3.Rack the circuit breaker to the DISCONNECT position.
4.Perform the spring discharge check. This is done by first depressing the red trip pushbutton. Second, depress the black close pushbutton. Third, depress the red trip pushbutton again, and observe the spring condition indicator. It should read DISCHARGED.
5.Remove the circuit breaker from the switchgear. Refer to page 10 of "Installation checks and initial functional tests" section of this instruction manual for special instructions and precautions regarding removal of a circuit breaker not at floor level.
6.The circuit breaker can be located either on the floor or on a pallet. Each circuit breaker has four wheels and handles to allow one person to maneuver the unit on a level surface without assistance.
Checks of the primary power path
The primary power path consists of three vacuum interrupters and three upper- and three
Some test engineers prefer to perform the
Also, the
These instructions follow the recommendation these tests (contact-
Cleanliness check
Figure 37: Type 38-3AH3 vacuum circuit breaker showing vacuum interrupters and primary disconnects (outer phase barrier removed) is a side view of the type 38- 3AH3 vacuum circuit breaker with the outer-insulating barriers removed to show the vacuum interrupter and the upper- and lower-primary disconnects.
All of these components must be cleaned and free of dirt or any foreign objects. Use a dry
For stubborn dirt on a vacuum interrupter, use a cloth and warm water and a small amount of mild
Figure 36: Trip-control pushbutton (lower button)
Figure 37: Type 38-3AH3 vacuum circuit breaker showing vacuum interrupters and primary disconnects (outer-phase barrier removed)
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