SECTION 7-Breaker Maintenance (Cont.)
7.1 2.1
COMPONENT REPLACEMENT
To gain access to the electrical control components,
the breaker's front escutcheon must be removed. Type B
and D breakers requ i re 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 u nder the
front frame to keep if from tipping 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 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 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 roll 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-closing" as described
earlier. Turn the camshaft, using the maintenance handle,
until the roll pin is well situated , turn the camshaft to gain
enough space for the roll pin to clear the breaker frame.
Before removing the ratchet note the position of the
ratchet roller or mark the ratchet hub and the camshaft.
When replacing the ratchet, be sure it is oriented with
respect to the camshaft as it was originally and not displac
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 180 degrees, the holes in the ratchet
hub will not completely line up with the holes i n the cam
shaft.
The d riving pawl is assembled to the charg i n g motor
drive pin as shown in Fig. 36B. To replace the driving pawl:
1 .
Remove the charging motor.
2. Remove the retaining ring from the drive pin. Sli p off
the components.
3. Wipe off any grease or d i rt from the drive pin.
DO NOT
LUBRICA TE.
4. Install the components as shown.
28
5
2
4
1 . RETAINER RING
4. SPRI NG WASH ER
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 holdi ng 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 m ust be torqued to 250 in-lbs
minimum. If this hardware must be retightened, add LOC
TITE
290
to the shaft threads.
8. Install the front escutcheon. Tighten the escutcheon
hardware to 80
±
10 in-lbs.
3
4
1 . MECHANISM FRAME
5.
PAWL ASM
2. PIVOT PIN
6. WASHER .01 0 "
3. SPRI NG
7.
RETAINING RING
4. WASHER .032 "
6
7
5
FIG. 36C - HOLDING PAWL ASSEMBLY DETAILS
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