c. Installation. Install
air conditioning filter in
3-22. Fresh Air Inlet
the mist eliminator and
reverse order of rerno-
Screen, CB Intake
3-25. fresh Air Damper Door Control
Duct Cover, Fan Guard, and
Condenser Coil Grille and Screen
a. General. The condenser coil grille and
screen, and fan guard protect the condenser coil
and fan, A fresh air inlet screen permits the
entry of outside air which is controlled by the
fresh air damper door with the control spring
and chain. Removal of the screen provides access
to the refrigerant service valves. The CB intake
duct cover provides for attachment of a chemical,
biological filter unit.
b. Removal. Refer to figure 3-6 and remove the
fresh air inlet screen, intake cover, fan guard.
and condenser coil grille and screen.
c. Installation. Install the fresh air inlet
screen, intake cover, fan guard, and condenser
coil grille and screen in reverse order of removal.
a. General. The fresh air darnper door control
chain controls a damper door to permit drawing
in fresh makeup air when operating in either the
cooling or heating mode. Pull chain to open
damper and release to close.
b. inspect. Inspect for broken chain and repair
(1) Refer to figure 3-4 and remove intake
grille if required.
(2) Refer to figure
3-26. Control Panel
3-9 and repair or replace
3-23. Evaporator Fan and Inlet Ring
a. General. The centrifugal impeller-type eva-
porator fan is mounted on one end of a double ex-
tended shaft motor. The other shaft end mounts
the condeser fan. The inlet ring serves to direct
the flow of air and reduce fan noise.
(1) Refer to figure 3-4 and remove the in-
(2) Refer to figure 3-5 and remove the air
(3) Refer to figure 3-7 and remove the inlet
ring and evaporator fan.
c. Installation. Install the evaporator fan, inlet
a. General. The control panel located on top of
the junction box, houses the rotary selector
switch, thermostat, and a two-speed condenser
fan switch. In certain applications the control
panel may be remotely located. Refer to para-
graphs 2-2 and 2-3.
b . R e m o v a l .
(1) Refer to figure 3-4 and remove the
lower front access cover.
(2) Refer to figure 3-10 and remove the con-
c. Installation. Installation is the reverse of re-
3-27. Rotary Selector Switch
ring, air conditioning filter, and intake grille in
reverse order of removal.
3-24. Condenser Fan
a. General. The axial flow-type condenser fan is
mounted on one end of a double extended shaft
motor. The other shaft end mounts the evapora-
(1) Refer to figure 3-6 and remove the fan
g u a r d .
(2) Refer to figure 3-8 and remove the con-
c. Installation. Install the condenser fan and
fan guard in reverse order of removal.
a. General. The rotary selector switch is a man-
ually operated, five-position switch used to select
The operating mode. The operating modes are:
COOL. VENTILATE, OFF, LO-HEAT and HI-
(1) Refer to figure 3-10 and remove the con-
(2) Refer to figure 3-11 and remove the ro-
tary selector switch.
(1) With power off and switch in the Hi-
Heat position, check for continuity between ter-
minals 12 and 1A, 22 and 2B, 21 and 2C,32 and
3A, 31 and 3C, 42 and 4A, and 41 and 4C. If con-
titiuity is indicated between any other terminals,
or if continuity is not indicated between the above
mentioned terminals, switch is defective and must
(2) With power off and switch in LO-HEAT
position, check for continuity between terminals