SUBCOOLING METHOD (COOLING, TXV) — To check
and adjust charge during cooling season, use Table 5 and the
following procedure:
1. Operate unit a minimum of 15 minutes before checking
charge.
2. Measure liquid line temperature near liquid line service
valve, and measure liquid pressure at liquid line service
valve. Use a digital thermometer for all temperature
measurements. DO NOT use mercury or dial-type
thermometers.
3. Refer to Table 5. Find temperature point at which the re-
quired subcooling temperature intersects the measured liq-
uid line pressure.
4. If the measured liquid line temperature does not agree
with the required liquid line temperature, ADD refriger-
ant to lower the temperature, or REMOVE refrigerant to
raise the temperature (allow a tolerance of ± 3 F).
Table 3 — Superheat Charging Table
(Superheat Entering Suction Service Valve)
OUTDOOR
TEMP (F)
INDOOR COIL ENTERING AIR (F) WB
50 52 54 56 58 60 62 64 66 68 70 72 74 76
55
9 12 14 17 20 23 26 29 32 35 37 40 42 45
60
7 10 12 15 18 21 24 27 30 33 35 38 40 43
65
*
6 10 13 16 19 21 24 27 30 33 36 38 41
70
*
*
7 10 13 16 19 21 24 27 30 33 36 39
75
*
*
*
6
9 12 15 18 21 24 28 31 34 37
80
*
*
*
*
5
8 12 15 18 21 25 28 31 35
85
*
*
*
*
*
*
8 11 15 19 22 26 30 33
90
*
*
*
*
*
*
5
9 13 16 20 24 27 31
95
*
*
*
*
*
*
*
6 10 14 18 22 25 29
100
*
*
*
*
*
*
*
*
8 12 15 20 23 27
105
*
*
*
*
*
*
*
*
5
9 13 17 22 26
110
*
*
*
*
*
*
*
*
*
6 11 15 20 25
115
*
*
*
*
*
*
*
*
*
*
8 14 18 23
LEGEND
WB — Wet Bulb
*Do not attempt to charge system under these conditions or refrig-
erant slugging may occur.
Table 4 — Required Suction-Tube Temperature (F)
(Entering Suction Service Valve)
SUPERHEAT
TEMP (F)
SUCTION PRESSURE AT SERVICE PORT (psig)
61.5 64.2 67.1 70.0 73.0 76.0 79.2 82.4 85.7
0
35
36
39
41
43
45
47
49
51
2
37
39
41
43
45
47
49
51
53
4
39
41
43
45
47
49
51
53
55
6
41
43
45
47
49
51
53
55
57
8
43
45
47
49
51
53
55
57
59
10
45
47
49
51
53
55
57
59
61
12
47
49
51
53
55
57
59
61
63
14
49
51
53
55
57
59
61
63
65
16
51
53
55
57
59
61
63
65
67
18
53
55
57
59
61
63
65
67
69
20
55
57
59
61
63
65
67
69
71
22
57
59
61
63
65
67
69
71
73
24
59
61
63
65
67
69
71
73
75
26
61
63
65
67
69
71
73
75
77
28
63
65
67
69
71
73
75
77
79
30
65
67
69
71
73
75
77
79
81
32
67
69
71
73
75
77
79
81
83
34
69
71
73
75
77
79
81
83
85
36
71
73
75
77
79
81
83
85
87
38
73
75
77
79
81
83
85
87
89
40
75
77
79
81
83
85
87
89
91
9