Type
50-DH-50 Air Circuit Breaker
of the closing stroke the mechanism push rod
roller pin strikes that switch lever causing it to
rotate and permit the switch to make contact
in this case contact is maintained when the circuit
breaker is in the latched position. On a trip-free
operation the push rod roller pin moves forward to
engage the vertical leg of the switch lever thus caus
ing a rotation of that lever to permit closure of the
cut-off switch contacts.
Latch Checkin� Switch
The latch checking switch, Figure 14, mounts
on the frame by two screws as shown in the refer
ence figure. The switch operates directly from
Fig. 14-Latch C
14
the tripping lever and makes contact when the
tripping lever is in the normal position and breaks
contact when the tripping lever is raised.
Operation Counter
The operation counter mounts on the upper
auxiliary switch bracket. After mounting in place
and connecting to the auxiliary switch extension of
the breaker lever, the operation counter arm should
be loosened and set so that only one number is
recorded for each operation of the mechanism. This
setting should be checked for both manual and
electrical operation of the mechanism.
CAUTION
Do not attempt to close by
hand, against an energized
circuit, any breakers covered
by this instruction book. To
insure
sufficient
closing
force and speed, these break
ers should be closed electri
cally from an adequate power
source. See
N
.
E
.
M
.
A
.
Stand
ard SG
6-213.
I
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