SECTION 7-Breaker Maintenance (Cont.)
7.1 4 BUFFER ASSEMBLY
When the breaker is closed , the energy in the c losing
spring i s transferred to the m a i n shaft thro u g h 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.
E N D PLATE
When the break�r 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 RELATIONSHIP-BR EAKER CLOSED
E N D PLATE
FIG. 41
-
BUFFER/END P LATE R E LATIONSHIP-BREAKER OPEN
31
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