SECTION 7-Breaker Maintenance (Cont.}
7. 1 4
BUFFER ASSEMBLY
When the breaker is closed, the energy in the closing
spring i s transferred to the main shaft through the
mechanism. The main shaft then drives the contacts
closed. The end plate assembly on each end of the main
shaft is driven against the buffer assembly shown in Fig.
40.
This prevents the mechanism from overdriving the
contacts.
When the breaker is opened, the end plate assembly is
driven against the "opposite end of the buffer assembly.
The buffer is a stop absorbing the opening energy of the
mechanism. See Fig.
41 .
FIG.
40 -
BUFFER/END PLATE R E LATIONSHIP-BREAKER CLOSED
END PLATE
FIG.
41
- BUFFER/END PLATE RELATIONSHIP-BREAKER OPEN
31
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