Daewoo Nubira. Manual - part 185

7B – 8

I

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM

DAEWOO V–121 BL4

A/C SCHEMATIC

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM  7B – 9

DAEWOO V–121 BL4

DIAGNOSIS

GENERAL DIAGNOSIS

TESTING THE REFRIGERANT
SYSTEM

If you suspect a problem in the refrigerant system, check
for the following conditions:

1.  Check the outer surfaces of the radiator and the

condenser cores to be sure that the airflow is not
blocked by dirt, leaves, or other foreign material.
Check between the condenser and the radiator, as
well as all outer surfaces.

2.  Check for restrictions or kinks in the condenser

core, the hoses, and the tubes.

3.  Check the operation of the blower fan.
4.  Check all the air ducts for leaks or restrictions. Low

airflow rate may indicate a restricted evaporator
core.

5.  Check for slippage of the compressor clutch.
6.  Check the drive belt tension.

INSUFFICIENT COOLING ”QUICK
CHECK” PROCEDURE

Perform the following ”hand–feel” procedure to get a quick

idea of whether the A/C system has the proper charge of
Refrigerant–134a. The air temperature must be above
21

³

C (70

³

F) for most models.

1.  Warm up engine. Run the engine at idle.
2.  Open the hood and all the doors.
3.  Turn the A/C switch ON.
4.  Turn the temperature control knob to full cold.
5.  Turn the blower speed to setting 4.
6.  ”Hand–feel” the temperature of the evaporator out-

let pipe. The pipe should be cold.

7.  Check for other problems. Refer to ”Testing the Re-

frigerant System”  in this section.

8.  Leak check the system. Refer to ”Leak Testing the

Refrigerant System” in this section. If you find a
leak, discharge the system and repair the leak, as
required. After completing the repair, evacuate and
charge the system.

9.  If there is no leak, refer to ”Insufficient Cooling

Diagnosis”  in this section.

7B – 10

I

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM

DAEWOO V–121 BL4

A/C PERFORMANCE TEST

RELATIVE
HUMIDITY

(%)

AMBIENT AIR

TEMPERATURE

³

C 

³

F

LOW SIDE

PRESSURE

kPa psig

ENGINE

SPEED (RPM)

CENTER DUCT AIR

TEMPERATURE

³

C 

³

F

HIGH SIDE

PRESSURE

kPa psig

20

21 70
27 81
32 90

38 100

200 29
200 29
207 30
214 31

2000

4 39
7 45
9 48

14 57

1034 150
1310 190
1689 245
2103 305

30

21 70
27 81
32 90

38 100

200 29
207 30
214 31
221 32

2000

6 43
8 46

11 52
16 61

1034 150
1413 205
1827 265
2241 325

40

21 70
27 81
32 90

38 100

200 29
207 30
221 32
269 39

2000

7 45
9 48

13 55
18 64

1138 165

1482 215
1931 280
2379 345

50

21 70
27 81
32 90

38 100

207 30
221 32
234 34
276 40

2000

8 46

12 54
15 59
21 70

1241 180
1620 235
2034 295
2413 350

60

21 70
27 81
32 90

38 100

207 30
228 33
248 36
296 43

2000

9 48

13 56
17 63
23 73

1241 180
1655 240
2068 300
2482 360

70

21 70
27 81
32 90

38 100

207 30
234 34
262 38
303 44

2000

10 50
14 57
18 64
24 75

1276 185
1689 245
2103 305
2517 365

80

21 70
27 81
32 90

207 30
234 34
269 39

2000

10 50
15 59
19 66

1310 190
1724 250
2137 310

90

21 70
27 81
32 90

207 30
248 36
290 42

2000

10 50
17 63
22 72

1379 200
1827 265
2275 330

MANUAL CONTROL HEATING, VENTILATION, AND AIR CONDITIONING SYSTEM  7B – 11

DAEWOO V–121 BL4

PRESSURE–TEMPERATURE RELATIONSHIP OF R–134A

TEMPERATURE

³

C (

³

F)*

PRESSURE

kPa (psig)*

TEMPERATURE

³

C (

³

F)*

PRESSURE

kPa (psig)*

–8.89 (16)

105.70 (15.33)

37.78 (100)

856.84 (124.27)

–7.78 (18)

114.87 (16.66)

38.89 (102)

886.56 (128.58)

–6.67 (20)

124.32 (18.03)

40.00 (104)

916.35 (132.98)

–5.56 (22)

134.11 (19.45)

41.11 (106)

947.92 (137.48)

–4.44 (24)

144.24 (20.92)

42.22 (108)

979.64 (142.08)

–3.33 (26)

154.65 (22.43)

43.33 (110)

1012.11 (146.79)

–2.22 (28)

165.48 (24.00)

44.44 (112)

1045.21 (151.59)

–1.11 (30)

176.65 (25.62)

45.56 (114)

1079.14 (156.51)

0.00 (32)

188.16 (27.29)

46.67 (116)

1113.75 (161.53)

1.11 (34)

200.02 (29.01)

47.78 (118)

1149.12 (166.66)

2.22 (36)

212.30 (30.79)

48.89 (120)

1185.18 (171.89)

3.33 (38)

224.98 (32.63)

50.00 (122)

1222.07 (177.24)

4.44 (40)

238.08 (34.53)

51.11 (124)

1259.72 (182.70)

7.22 (45)

272.49 (39.52)

52.22 (126)

1298.12 (188.27)

10.00 (50)

309.58 (44.90)

53.33 (128)

1337.35 (193.96)

12.77 (55)

349.51 (50.69)

54.44 (130)

1377.35 (199.76)

15.56 (60)

392.33 (56.90)

57.22 (135)

1480.91 (214.78)

18.33 (65)

438.18 (63.55)

60.00 (140)

1589.57 (230.54)

21.11 (70)

487.27 (70.67)

62.78 (145)

1703.62 (247.08)

23.89 (75)

539.67 (78.27)

65.56 (150)

1823.04 (264.40)

26.67 (80)

609.38 (88.38)

68.33 (155)

1948.04 (282.53)

29.44 (85)

655.09 (95.01)

71.11 (160)

2078.77 (301.49)

32.22 (90)

718.39 (104.19)

73.89 (165)

2215.29 (321.29)

35.00 (95)

785.61 (113.94)

76.67 (170)

2357.81 (341.96)

* All values rounded to two decimal places.

EVAPORATOR RANGE: From –6.67 to 7.22

³

C (20 to 45

³

F), the temperatures represent the gas temperatures inside the

coil and not on the coil surfaces. Add 1.67 to 5.56

³

C (3–10

³

F) to the temperature for coil and air–off temperatures.

CONDENSER RANGE: From 110 to 160

³

F, temperatures are not ambient. Add 19.4 to 22.2

³

C (35 to 40

³

F) for proper

heat transfer, then refer to the pressure chart.

Example:

32

³

C (90

³

F) ambient temperature

+ 22

³

C + (40

³

F)

54

³

C (130

³

F)

Condenser temperature = 1379 kPa (200 psig)

Based on 48.3 km/h (30 mph) air flow.