COMPRESSOR CRANKCASE HEATER. - TM-5-4120-339-140120

TM 5-4120-339-14

(9) Refer to paragraph 4-4d and repair any leaks found.

(10) With the air conditioner operating in the cooling mode, check the pressures. Pressures should be as

given in table 4-3.

(11) Close all valves and remove gages.

Table 4-3. Air conditioner operating pressures

AMBIENT

RETURN AIR

SUCTION

DISCHARGE

TEMPERATURE

PRESSURE

120F

90F DB/75F WB

85-95 PSIG

387-395 PSIG

49C

32C DB/24C WB

5.98-6.68 ks/cm2

27.21-27.71 ks/cm2

95F

80F DB/67F WB

70-80 PSIG

253-263 PSIG

35C

26.66C DB/19.44C WB

4.92- 5.62 ks/cm2

17.8-18.5 ks/cm2

DB = dry bulb WB = wet bulb

4-23.

COMPRESSOR CRANKCASE HEATER.

a. Inspection. Refer to figure 4-20 and inspect the compressor crankcase heater for damage which would impair

serviceability.

b. Test. Refer to figure 4-20 and check for continuity between pins F and G of compressor electrical receptacle.

c. Replace. Replace compressor crankcase heater if damage would impair serviceability or if failure occurs

during testing.

4-24.

TUBING AND PIPING.

a. Inspection. Inspect tubes and pipes for breaks and for damage which would impair serviceability.

b. Test. Refer to paragraph 4-4c and check tubes and pipes for refrigerant leakage.

Repair. Refer to paragraph 4-4d and repair all leaks found.

d. Replace. Replace unrepairable tubing and piping as follows:

(1) Refer to figure 4-2 and release refrigerant from the system.

(2) Refer to figure 4-18 and replace defective tubing and/or piping.

(3) Refer to paragraph 4-8 and purge the refrigerant system.

(4) Refer to paragraph 4-4c and check replaced tubing or piping and the dehydrator for leaks. Refer to

paragraph 4-4d and repair any leaks found.

(5) Refer to figure 4-4 and evacuate the refrigerant system.

4-46