Section IV. REMOVAL AND INSTALLATION OF MAJOR COMPONENTS

contacts. Check relay coil K1 and solenoid valves

(g) Fan motor thermal protector: con-

L1 and L2.

tinuity.

d. Heating. Heat from the heaters and air flow

(h) Check for 30 volts AC output from

are the two basic requirements for heating

transformer T.

(i) C h e c k f o r 2 4 v o l t s D C o u t p u t f r o m

operation. Check air flow as outlined in paragraph

rectifier CR.

5-11b above.

( 1 ) Place the selector switch in the LO-HEAT

(j) C h e c k c a p a c i t o r C 1 .

p o s i t i o n and the temperature control in the extreme

(5) If all control components appear to be

clockwise position. Wait for five minutes then

functioning properly and the fan motor fails to

check air flow for heat.

o p e r a t e or operates improperly check the fan motor

(2) Measure continuity across selector switch

w i n d i n g s for continuity, shorts and proper voltage.

contacts S/W1, 2 to A and S/W2, 2 to B. Check

c. Cooling. P r o p e r r e f r i g e r a n t c h a r g e , com-

thermal protector S3.

presser operation and air flow are the three basic

requirements for cooling operation. Check air flow

(3)

Measure

for

continuity

across

circuit

breaker contacts B1 and B2.

as outlined in paragraph b above.

(4)

Place

selector

switch

HI-HEAT

(1) Place the selector switch in the COOL

p o s i t i o n and check second set of heaters operation.

position, and rotate thermostat to extreme decrease

(5) Measure for continuity across selector

p o s i t i o n . Wait for five minutes then check air flow

switch contacts S/W3, 2 to A, S/W2, 2 to B and

for coolness and listen for compressor operation.

S/W1, 2 to A.

(2) If compressor operates but cooling is

(6) Measure continuity and resistance to

insufficient, check refrigerant through sight glass.

ground across each heater to isolate a particular

(3) If compressor fails to operate, check

heater that is malfunctioning.

voltage on load side of circuit breaker then check

( 7 ) Check for continuity across thermostat S1,

same voltage on load side of K1 contact.

contacts R to BL.

(4) Check temperature control thermostat.

( 8 ) Check voltage across relay coil K2 and for

Reset pressure switches S6 and S5. Measure

continuity across its contacts A1 to A2.

continuity across pressure switch contacts.

(5) Check relay coil K6 and its time delay

Section IV. REMOVAL AND INSTALLATION OF MAJOR COMPONENTS

5-12. G e n e r a l

(3) Remove junction box assembly (para 4

36).

This section provides instructions for the removal

( 4 ) Remove flare nuts from each end of the

and installation of major components for the air

dehydrator.

conditioner. Removal instructions for other

(5) Remove screw and clamp holding the

components are contained in Chapter 4 of this

dehydrator and remove the dehydrator from its

m a n u a l . The procedures included in this section are

mounting bracket.

p r e s e n t e d in logical order for complete disassembly

b. Installation. Installation of the dehydrator

of the air conditioner.

s h a l l be in reverse order of removal. Always install

a new dehydrator when the system has been opened

Before removing any components from

to the atmosphere. Insure that the dehydrator is

the air conditioner, care must be taken

i n s t a l l e d with the outlet toward the sight glass. The

to disconnect the input power to the

dehydrator is marked with an arrow showing the

unit. This will insure the safety of-

direction of flow. Evacuate and recharge the

personnel and prevent damage to the air

refrigerant system (para 5 - 8 d and para 5 - 8 e ) .

conditioner.

5-14. Fan Speed Pressure Switch S8

a. Removal.

(1) Discharge the refrigerant system (para 5-

Refrigerant system must be discharged

8 b ).

before opening refrigerant circuit (para

(2) Remove the two screws securing the lower

5-8b).

front panel and remove) the panel.

5-13. Dehydrator

(3) Remove junction box assembly (para 4-

a. Removal.

36).

(1) Discharge the refrigerant system (para 5-

(4)

Remove

fifteen

screws

and

remove

top

8b).

panel.

( 2 ) R e m o v e two screws and remove the front

(5) Discharge the refrigerant and unscrew the

access panel.

pressure switch from the refrigerant system.

5-7