SECTION 7-Breaker Maintenance (Cont.)
7.12.1
COMPONENT REPLACEMENT
To gain access to the electrical control components,
the breaker's front escutcheon must be removed. Type B
and
D
breakers require that both the deep molded escut
cheon and the shallow steel escutcheon be removed.
Before removing the front escutcheon on Type
A
or B
breakers, a supporting block should be placed under the
front frame to keep if from tlipping forward.
Referring to Fig.
36A,
the X-relay or K-relay and F and
G
switches are mounted on the same bracket. This mounting
bracket is fastened to the right-hand mechanism side frame
by two hex-head
1/4-20
screws. Removing these screws
allows the bracket to be pulled forward from between the
mechanism side plates. The W-relay must also be un
fastened from the left side frame to allow enough freedom
for all the devices and the wiring harness to be taken from
between the side frames. With the bracket removed, in
dividual devices can be replaced easily.
The closing solenoid is mounted by means of mounting
bracket to the bottom of the breaker frame. The most con
venient way to take off the solenoid is to remove the moun
ting bracket and then disconnect the solenoid from the
bracket. The pin connecting the armature to the closing
link must also be removed.
The charging motor is secured through three spacers to
the mechanism frame. The front mounting bolt is accessi
ble using a socket and universal joint through the opening
in the side of the breaker's frame. The upper rear mounting
bolt is accessible using a socket and universal joint over
the top of the frame. The lower rear mounting bolt is ac
cessible using a socket and universal joint through the
opening in the frame's side by the buffer assembly. Slow
close the breaker to move the flywheel assembly out of the
way.
The ratchet on the camshaft is removed by driving out
the rol l pin which fastens it to the camshaft. Before this
can
be
done,
the charging motor must be removed and the
closing spring
arranged for "slow-dosing" as described
earlier. Tum the camshaft, using the maintenance handle,
until the roll
pin is well
started, tum the camshaft to gain
enough
space for
the roll pin to clear the
breaker
frame.
Before removing
the ratchet note the position of the
ratc
h
e
t
'
s roller or
mar1( the ratchet's hub and the camshaft.
When replacmg
the
ratchet, be sure It Is oriented with
respect to the camshaft
as
it
was
originally and not di
s
pl
a
c
ed
180
degrees
Align
the mark made on the hub with the
mark on the
camshaft
or position the roller as It was. If the
ratchet
is
displaced
1�
degrees,
the holes in the ratchet's
hub
wil l
not completely
line up with the holes in the cam
shaft.
The driv1ng
pawl
IS
assemb
l
ed
to the charging motor's
drive pin
as
shown
1n
Fig.
368.
To
replace
the driving pawl:
1 .
Remove
the
c
har
gin
g motor.
2.
Remove
the
retaJning ring
from
the drive pin. Slip off
the components.
3.
Wipe off
any
grease
or
dirt
from
the drive pin.
DO NOT
LUBRICA TE.
4.
Install the
components
as
shown.
28
1
3
5
6
4
1.
RETAINER RING
4.
SPRING WASHER
2.
WASHER
.010•
5. WASHER .032•
3.
PAWL ASM
6.
MOTOR DRIVE PIN
FIG. 36B - DRIVING PAWL ASSEMBLY DETAILS
The holding pawl pivots on a pin which is assembled to
the mechanism frame. Refer to Fig.
36C.
To replace the
holding pawl:
1 .
Remove the front escutcheon for accessibility.
2.
Using the maintenance handle, rotate the ratchet
enough to disengage the holding pawl.
3.
Remove the retaining ring and washer from the pivot
pin.
4.
While holding the spring pressure from the holding
pawl, remove the existing pawl and slip on the new pawl.
5.
Install the washer and retaining ring.
6.
Verify that the holding pawl engages a minimum of
4
ratchet laminations.
7.
Verify that the holding pawl pivot pin is perpendicular
to the mechanism frame. The hardware which assembles
the pivot pin to the frame must be torqued to
250
in-lbs
minimum. If this hardware must be retightened, add
LOG
TITE 290
to the shaft threads.
8.
Install the front escutcheon. Tighten the escutcheon
hardware to
80
±
10
in-lbs.
3
4
6
7
5
1.
MECHANISM FRAME
5. PAWL ASM
2.
PIVOT PIN
6.
WASHER
.Q10•
3.
SPRING
7.
RETAINING RING
4.
WASHER .032"
FIG. 36C - HOLDING PAWL ASSEMBLY DETAILS
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