Amana GSH13018 Service Instructions Manual page 46

SERVICING
CHECKING SUPERHEAT
Refrigerant gas is considered superheated when its tem-
perature is higher than the saturation temperature correspond-
ing to its pressure. The degree of superheat equals the
degrees of temperature increase above the saturation tem-
perature at existing pressure. See Temperature - Pressure
Chart Table 7.
1. Attach an accurate thermometer or preferably a thermo-
couple type temperature tester to the suction line at a
point at least 6" from the compressor.
2. Install a low side pressure gauge on the suction line ser-
vice valve at the outdoor unit.
3. Record the gauge pressure and the temperature of the
line.
4. Convert the suction pressure gauge reading to tempera-
ture by finding the gauge reading in Temperature - Pres-
sure Chart and reading to the left, find the temperature in
the °F. Column.
5. The difference between the thermometer reading and pres-
sure to temperature conversion is the amount of super-
heat.
EXAMPLE:
a. Suction Pressure = 84
b. Corresponding Temp. °F. = 50
c. Thermometer on Suction Line = 63°F.
To obtain the degrees temperature of superheat subtract 50.0
from 63.0°F.
The difference is 13° Superheat. The 13° Superheat would
fall in the ± range of allowable superheat.
SUPERHEAT ADJUSTMENT
The expansion valves used on Amana® brand coils are
factory set and are not field adjustable. If the superheat
setting becomes disturbed, replace the valve.
On systems using capillary tubes or flow control restrictors,
superheat is adjusted in accordance with the "DESIRED
SUPERHEAT vs. OUTDOOR TEMP" chart as explained in
section S-103 CHARGING
46
Temp. Gauge Pressure
°F. (PSIG) Freon-22
-40 0.61
-38 1.42
-36 2.27
-34 3.15
-32 4.07
-30 5.02
-28 6.01
-26 7.03
-24 8.09
-22 9.18
-20 10.31
-18 11.48
-16 12.61
-14 13.94
-12 15.24
-10 16.59
-8 17.99
-6 19.44
-4 20.94
-2 22.49
0 24.09
2 25.73
4 27.44
6 29.21
8 31.04
10 32.93
12 34.88
14 36.89
16 38.96
18 41.09
20 43.28
22 45.53
24 47.85
26 50.24
28 52.70
30 55.23
32 57.83
34 60.51
36 63.27
38 66.11
40 69.02
42 71.99
44 75.04
46 78.18
48 81.40
50 84.70
52 88.10
54 91.5
56 95.1
58 98.8
Table 7
Temp. Gauge Pressure
°F. (PSIG) Freon-22
60 102.5
62 106.3
64 110.2
65 114.2
68 118.3
70 122.5
72 126.8
74 131.2
76 135.7
78 140.5
80 145.0
82 149.5
84 154.7
86 159.8
88 164.9
90 170.1
92 175.4
94 180.9
96 186.5
96 192.1
100 197.9
102 203.8
104 209.9
106 216.0
108 222.3
110 228.7
112 235.2
114 241.9
116 248.7
118 255.6
120 262.6
122 269.7
124 276.9
126 284.1
128 291.4
130 298.8
132 306.3
134 314.0
136 321.9
136 329.9
140 338.0
142 346.3
144 355.0
146 364.3
158 374.1
150 384.3
152 392.3
154 401.3
156 411.3
158 421.8
160 433.3