c. Suction-tube temperature (F) at low-side service ®tting.

d. Suction (low-side) pressure (psig).

5.Using ``Superheat Charging Table,'' compare outdoor-air temperature (F db) with evaporator inlet-air temperature (F wb) to determine desired system operating superheat temperature. See Tables 5A-5I and 6A-6F.

6.Using ``Required Suction-Tube Temperature (F)'' table, compare desired superheat temperature with suc- tion (low-side) operating pressure (psig) to determine proper suction-tube temperature. See Table 7.

7.Compare actual suction-tube temperature with proper suction-tube temperature. Using a tolerance of ±3° F, add refrigerant if actual temperature is more than 3° F higher than proper suction-tube temperature, or remove refrig- erant if actual temperature is more than 3° F lower than required suction-tube temperature.

NOTE: If the problem causing the inaccurate readings is a refrigerant leak, refer to Check for Refrigerant Leaks sec- tion on page 27.

Table 5A Ð Superheat Charging Table, 50SS018

TEMP (F)

 

 

 

 

 

 

EVAP AIR Ð CFM

 

 

 

 

 

 

 

 

 

 

 

 

600

 

 

 

 

 

 

AIR ENT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Evap Air Ð Ewb (F)

 

 

 

 

 

 

COND

 

 

 

 

 

 

 

 

 

 

 

 

 

54

56

58

60

62

 

64

 

66

 

68

70

72

74

76

65

 

SPH

17.3

18.5

19.6

20.8

24.2

 

27.7

 

28.5

 

29.3

29.3

29.3

29.3

29.3

70

 

SPH

13.8

14.9

16.1

17.3

20.7

 

24.1

 

25.7

 

27.3

27.3

27.3

27.3

27.3

75

 

SPH

10.2

11.4

12.5

13.7

17.1

 

20.6

 

22.9

 

25.2

25.2

25.2

25.2

25.2

80

 

SPH

8.2

8.8

9.5

10.2

13.6

 

17.0

 

20.1

 

23.1

23.9

24.1

25.4

26.1

85

 

SPH

6.1

6.2

6.5

6.6

10.0

 

13.5

 

17.3

 

21.1

22.6

24.1

25.6

27.1

90

 

SPH

*

*

*

5.0

8.1

 

11.4

 

15.2

 

19.0

20.5

22.0

23.5

25.0

95

 

SPH

*

*

*

*

6.2

 

9.4

 

13.2

 

17.0

18.5

20.0

21.5

23.0

100

 

SPH

*

*

*

*

*

 

7.3

 

11.1

 

14.9

17.2

19.5

21.7

24.0

105

 

SPH

*

*

*

*

*

 

5.3

 

9.1

 

12.9

15.9

18.9

21.9

24.9

110

 

SPH

*

*

*

*

*

 

*

 

6.7

 

10.8

13.8

16.8

19.8

22.8

115

 

SPH

*

*

*

*

*

 

*

 

*

 

8.8

11.8

14.8

17.8

20.8

LEGEND

*Do not attempt to charge system under these conditions Ð refrigerant slugging may occur.

Ewb Ð Entering Wet Bulb

 

SPH Ð Superheat at Compressor (F)

 

Table 5B Ð Superheat Charging Table, 50SS024

TEMP (F)

 

 

 

 

 

 

EVAP AIR Ð CFM

 

 

 

 

 

 

 

 

 

 

 

 

800

 

 

 

 

 

 

AIR ENT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Evap Air Ð Ewb (F)

 

 

 

 

 

 

COND

 

 

 

 

 

 

 

 

 

 

 

 

 

54

56

58

60

62

 

64

 

66

 

68

70

72

74

76

65

 

SPH

18.2

19.0

19.9

20.7

22.5

 

24.2

 

25.1

 

25.9

26.6

27.2

27.9

28.6

70

 

SPH

17.1

17.6

18.1

18.6

20.4

 

22.1

 

23.0

 

23.9

24.9

26.0

27.1

28.1

75

 

SPH

16.0

16.2

16.4

16.6

18.3

 

20.1

 

21.0

 

21.8

23.3

24.8

26.2

27.7

80

 

SPH

14.8

14.7

14.6

14.5

16.3

 

18.0

 

19.7

 

21.3

22.4

23.5

24.6

25.8

85

 

SPH

13.7

13.3

12.9

12.5

14.3

 

16.0

 

18.4

 

20.7

21.5

22.3

23.1

23.8

90

 

SPH

11.1

10.9

10.7

10.4

12.2

 

13.9

 

16.3

 

18.7

19.9

21.0

22.2

23.4

95

 

SPH

8.5

8.4

8.4

8.4

10.1

 

11.9

 

14.3

 

16.6

18.2

19.8

21.4

23.0

100

 

SPH

7.3

7.5

7.7

7.9

8.9

 

9.9

 

12.2

 

14.6

16.6

18.6

20.6

22.6

105

 

SPH

6.2

6.6

6.9

7.3

7.6

 

7.8

 

10.2

 

12.5

14.9

17.3

19.7

22.1

110

 

SPH

*

*

*

5.3

5.5

 

5.8

 

8.1

 

10.5

13.3

16.1

18.9

21.7

115

 

SPH

*

*

*

*

*

 

*

 

6.1

 

8.4

11.6

14.9

18.1

21.3

LEGEND

*Do not attempt to charge system under these conditions Ð refrigerant slugging may occur.

Ewb Ð Entering Wet Bulb

 

SPH Ð Superheat at Compressor (F)

 

28

Page 28
Image 28
Carrier 50SX024-060 Ð Superheat Charging Table, 50SS018, Ð Superheat Charging Table, 50SS024, Temp F Evap AIR Ð CFM