Electrical Heater Thermostat

the control box. The selector switch is a manually

operated, five-position switch. Automatic control

of both the heating and cooling cycles is provided

by the temperature control. The control panel may

be used in a remote position by utilizing a block off

plate and a remote control cable (fig. 2-1).

b. Removal. Refer to figure 5-7, and remove the

control box front panel and control panel,

c. Disassembly. Refer to figure 5-8, and disas-

semble the control panel.

d. Reassembly. Replace defective parts and

reassemble the control panel in reverse order of

removal as illustrated on figure 5-8.

e. Installation. Install the control panel and con-

trol box front panel in reverse order of removal as

illustrated on figure 5-7.

5-10. Tubing and Fittings

The refrigerant tubes used on the air conditioner

consist of copper tubing and the necessary fittings.

The joints of the refrigerant tubes are soldered.

Inspect the tubing for cracks and breaks. Replace

any defective tubing with tubes of the same

length, size, shape, and material When removing

Figure 5-3. Power receptacle connector removal

and installing the solenoid valves, direct the flame

and installation.

away from the valve body to protect it from heat

damage. Keep the flame at the outside of the dis-

tributor when disassembling or reassembling the

b. Removal. Remove outdoor thermostat as illus-

expansion valve. Test the installation of tubes and

trated on figure 5-5.

fittings for leaks. Replace rubber insulation as

c. Testing. Test the thermostat for continuity

necessary.

with a multimeter set on OHMS. Refer to the

Note. If the refrigerant system has been open to the

wiring diagram for the points to establish conti-

atmosphere, replace the dehydrator. Pressure test and

nuity.

evacuate the system before charging. When removing

tubing, pass dry nitrogen through lines when soldering for

d. Installation. Replace defective thermostat

prevention of copper oxides.

and install in reverse order of removal as illus-

trated in figure 5-5.

5-11. Phase Sequence Relay

a. General. The phase sequence relay is used

5-8. Electrical Heater Thermostat

when the air conditioner has a Whirlpool com-

pressor. It is not required when the unit has a

a. Testing. Tag and disconnect the leads and

Bendix-Westinghouse Compressor. The phase se-

test the electrical heater thermostat for continuity

quence relay prevents operation of the unit unless

with a multimeter set on OHMS. Refer to the

the phase sequence is correct and the fan and com-

wiring diagram for the points to establish conti-

pressor motor rotate in the proper direction. It is

nuity.

located in the upper left corner of the control box.

b. Removal. Refer to figure 5-6, and remove the

b. Removal. Refer to figure 5-9, and remove

electrical heater thermostat.

phase sequence relay.

c. Installation. Replace a defective thermostat

c. Installation. Replace a defective phase se-

and make sure all electrical connections are clean

quence relay. Install the phase sequence relay in

and secure. Refer to figure 5-6, and install the

reverse order of removal as illustrated on figure

electrical heater thermostat in reverse order of re-

5-9.

moval as illustrated.

d. Test. Test phase sequence relay by referring

to wiring diagram and checking for continuity or

5-9. Control Box and Control Panel

open circuit across the normal] y closed or nor-

a. General. The control panel houses the selector

mally open contacts. Also test the relay solenoid

switch and temperature control and is mounted on

for continuity.

AGO 20053A