45. Removal and Replacement of Switches
d. Removal and Replacement of Motor
and Impeller.
a. Power Duct Switches.
(1) Remove the two screws from the
(1) Operate the associated circuit
bottom edge of the plate that holds
breaker switch to OFF (fig. 10).
the exhaust blower to the front wall.
(2) Remove the screws from the
(2) Lift the exhaust blower away from
brackets at each end of the switch.
the wall.
Remove the two brackets and "the
(3) Remove the four bolts that secure
switchplate.
the blade guard and motor brackets
(3) Remove the s witch mounting
to the blower ring.
screws and the switch.
(4) Tag and disconnect the motor leads
(4) Tag and remove the wires from the
from the capacitor and power cord.
switch and connect them to there-
(5) Remove the power cord clamp.
placement switch (fig. 37).
(6) Remove the four screws that se-
(5) Replace the switch by the proce-
cure the motor mounting bracket
dures given in (1) through (4) above.
to the motor.
b. Door Microswitch.
(7) Loosen the two Allen-head set
(1) Disconnect ac power from the AN/
screws that secure the impeller to
MSC-31 .
the motor shaft and remove the
(2) Carefully pry off the power duct
impeller.
cover between the POWER INDI-
(8) Slide the impeller (setscrews to-
CATOR NEON LAMP and LIGHT 1
ward the motor) onto the shaft of
switch (fig. 14) .
the new motor and tighten the set-
(3) Tag and remove the wires from the
screws.
NO and C terminals of the switch
(9) Secure the motor bracket to the new
(fig. 37).
motor.
(4) Unscrew the ringnut from the door
(10) Connect the motor leads to the
side of the switch, and remove the
capacitor and power cord (fig. 31).
switch.
(11) Replace the power cord clamp.
(5) Replace the switch by reversing the
(12) Position the motor bracket and
procedures given in (1) through (4)
blade guard on the blower ring.
above.
(13) Replace and tighten the bolts that
secure the motor bracket and blade
guard to the blower.
Light Fixture Components
(14) Replace the exhaust blower by
reversing the procedures given in
Note. The fluorescent light fixtures are fabricated
(1) and (2) above.
as part of the power duct. The radiofrequency fil-
(15) Replace the exhaust blower cover
ters are sealed units; they are not repairable and
(para 36).
are replaced as a complete unit.
a. Operate the associated LIGHT switch
to OFF; remove the light shield and the
fluorescent lamp (para 34 a).
b. Carefully pry off the associated power
duct cover.
c. Tag and disconnect the wires from the
defective component (fig. 32) and remove
the defective component from the power
duct.
d. Secure the replacement component in
the power duct.
e. Connect the wires to the replacement
component.
