Figure 5-5. Pressure-temperature curve.

Figure 5-5. Pressure-temperature curve.

Caution: Never adjust the expansion valve

5-14. Thermostatic Expansion Valves

unless it is absolutely necessary. Refer to figure

a. General. A 2.1 ton thermostatic expansion

5-4 and adjust the thermostatic expansion

valve controls the flow of liquid refrigerant into

valves.

the evaporator coil during the cooling cycle. The

one-half ton thermostatic expansion valve func-

Note. Both expansion valves adjust in the same

manner.

tions when the unit is in the bypass cycle. Each

expansion valve is provided with a superheat set-

d. Installation.

ting to insure the operating efficiency of the refri-

(1) Install the thermostatic expansion

gerant system.

valves by reversing the order of removal.

b. Removal.

(2) Replace the dehydrator (para 5-18).

(1) Remove top cover (para 3-15).

(3) Evacuate and recharge the refrigerant

(2) Discharge the system (para 6-1).

(3) Refer to figure 5-3 and remove the ther-

5-15. High Pressure Cutout Switch

mostatic expansion valves.

a. General. The high pressure cutout switch

c. Adjustment.

5-8