Section XI. MAINTENANCE OF FAN MOTOR

mechanical. interference and that the fan wheel

b. Removal. Removal of the evaporator fan

turns in a concentric pattern around the shaft.

must be accomplished by the following:

(1) Remove the intake air grille (para 4-13).

4-31.

Condenser

Fan

(2) Remove the air filter (para 4-21).

a . General. The air conditioner is equipped with

( 3 ) Remove the inlet ring by removing the six

an axial, type condenser fan. The condenser fan is

screws and washers.

mounted on one end of the double shafted

(4) Loosen the two set screws in the fan hub

evaporator/condenser fan motor. The direction of

using a 1/8 inch Allen type wrench.

r o t a t i o n is clockwise when viewed from the back of

(5) Remove the fan wheel from the motor

the air conditioner.

s h a f t . If the wheel will not move by hand, utilize a

b. Removal. Removal of the condenser fan must

w h e e l puller with a center piece of not greater than

be accomplished by the following steps.

1/2 inch diameter. In the event a wheel puller is not

(1) Remove the condenser fan guard (para 4-

available, two 5/16-18 screws may be inserted in

14).

the two threaded holes located in the fan hub.

(2) Loosen the two set screws in the fan hub

T h e s e screws should be tightened evenly against the

using a 1/8 inch Allen type wrench.

motor flange to remove the fan wheel.

(3) Remove the fan wheel from the motor

c. Service. Service of the fan wheel consists of

s h a f t . If the wheel will not move by hand, utilize a

cleaning accumulated contamination. The wheel

w h e e l puller with a center piece of not greater than

should be inspected for cracked welds, bent blades

1/2 inch diameter. In the event a wheel puller is not

o r cones and concentricity of the cone to the back

a v a i l a b l e , two 1/4-20 screws may be inserted in the

plate. Defective wheels should be replaced before

two threaded holes located near the center of the

the air conditioner is returned to service.

wheel. These screws should be tightened evenly

d. Installation. Installation of the evaporator

a g a i n s t the motor end bell to remove the wheel.

f a n shall be in the reverse order of removal. Place

c. Service. Service of the fan wheel consists of

t h e fan wheel on the motor shaft with the keyways

cleaning accumulated contamination.

a l i g n e d . Install the key into the keyway and drive in

d. Installation. Installation of the condenser

so it is flush with the hub of the fan wheels.

f a n shall be in the reverse order of removal. Place

P r e s s u r e should only be applied only to the hub of

t h e fan wheel on the motor shaft with the keyways

the wheel during installation to prevent distortion

a l i g n e d . Install the key into the keyway and drive in

of the cone and blades. The wheel should be in-

so that it is flush with the hub of the fan wheel. The

stalled so that there is a minimum amount of

w h e e l should be installed so that the end of the hub

c l e a r a n c e between the cone of the wheel and the fan

i s flush with the end of the motor shaft. Torque the

i n l e t ring. The end of the fan hub should be flush

t w o set screws to 82 inch pounds. After installation

with the end of the motor shaft at this condition.

of the wheel, spin to insure that there is even

T o r q u e the two set screws to 82 inch pounds when

c l e a r a n c e between the outside of the wheel and the

fully tightened. A bent or broken fan inlet ring

fan shroud. After installation of the fan guard,

should be replaced. After installation of the fan

check to insure that there is no mechanical in-

w h e e l and inlet ring spin to insure that there is no

terference between the guard and the wheel.

Section XI. MAINTENANCE OF FAN MOTOR

4-32. General

connector from the terminal box located on the

l o w e r portion of the motor housing near the motor

The

evaporator/condenser

fan

motor

double

mounting flange. Test the fan motor for resistance

shafted, dual speed permanent split capacitor

w i t h a multimeter set on the low ohm scale. Touch

motor which drives both the condenser and

the loads of the multimeter to the pins of the

evaporator fans. The motor is flange mounted to

electrical receptacle connector. The multimeter

the bulkhead between the evaporator and con-

should indicate a low resistance value across each

denser compartments. The overload protector is

pair of pins. The resistance from Terminal C to

l o c a t e d inside the motor housing. It's purpose is to

Terminals B and E should be greater than the

protect the motor from the effects of excessive

resistance from Terminal C to Terminals A and D.

temperature or current draw.

A n open circuit reading from Terminal C to all the

4-33. Fan Motor Testing

remaining four pins indicates that the internal

Obtain access to the fan motor by removing the

thermal protector is open. If this is the case, suf-

condenser fan (para 4-31). Remove the electrical

ficient time should be allowed for the thermal

4-9