Goodman Mfg RT6100004R13 - Manual (Page 55)

SERVICING
55
Temp.
°F.
Gauge Pressure
(PSIG) Freon-22
Temp.
°F.
Gauge Pressure
(PSIG) Freon-22
-40
-38
-36
-34 0.61
1.42
2.27
3.15 60
62
64
65 102.5
106.3
110.2
114.2
-32
-30
-28
-26 4.07
5.02
6.01
7.03 68
70
72
74 118.3
122.5
126.8
131.2
-24
-22
-20
-18 8.09
9.18
10.31
11.48
76
78
80
82 135.7
140.5
145.0
149.5
-16
-14
-12
-10 12.61
13.94
15.24
16.59 84
86
88
90 154.7
159.8
164.9
170.1
-8
-6
-4
-2 17.99
19.44
20.94
22.49 92
94
96
96 175.4
180.9
186.5
192.1
0
2
4
6 24.09
25.73
27.44
29.21 100
102
104
106 197.9
203.8
209.9
216.0
8
10
12
14
31.04
32.93
34.88
36.89 108
110
112
114 222.3
228.7
235.2
241.9
16
18
20
22 38.96
41.09
43.28
45.53 116
118
120
122 248.7
255.6
262.6
269.7
24
26
28
30 47.85
50.24
52.70
55.23 124
126
128
130 276.9
284.1
291.4
298.8
32
34
36
38 57.83
60.51
63.27
66.11 132
134
136
136 306.3
314.0
321.9
329.9
40
42
44
46 69.02
71.99
75.04
78.18 140
142
144
146 338.0
346.3
355.0
364.3
48
50
52
54 81.40
84.70
88.10
91.5
158
150
152
154 374.1
384.3
392.3
401.3
56
58 95.1
98.8
156
158
160 411.3
421.8
433.3
S-109 CHECKING SUBCOOLING
Refrigerant liquid is considered subcooled when its tempera-
ture is lower than the saturation temperature corresponding
to its pressure. The degree of subcooling equals the degrees
of temperature decrease below the saturation temperature at
the existing pressure.
1. Attach an accurate thermometer or preferably a thermo-
couple type temperature tester to the liquid line as it
leaves the condensing unit.
2. Install a high side pressure gauge on the high side (liquid)
service valve at the front of the unit.
3. Record the gauge pressure and the temperature of the
line.
4. Convert the liquid line 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
pressure to temperature conversion is the amount of
subcooling.
EXAMPLE:
a. Liquid Line Pressure = 260
b. Corresponding Temp. °F. = 120°
c. Thermometer on Liquid line = 109°F.
To obtain the amount of subcooling subtract 109°F from 120°F.
The difference is 11° subcooling. The normal subcooling
range is 9° - 13° subcooling for heat pumps units, 14 to 18 for
straight cool units.
S-110 CHECKING EXPANSION VALVE
OPERATION
1. Remove the remote bulb of the expansion valve from the
suction line.
2. Start the system and cool the bulb in a container of ice
water, closing the valve. As you cool the bulb, the suction
pressure should fall and the suction temperature will rise.
3. Next warm the bulb in your hand. As you warm the bulb,
the suction pressure should rise and the suction tempera-
ture will fall.
4. If a temperature or pressure change is noticed, the
expansion valve is operating. If no change is noticed, the
valve is restricted, the power element is faulty, or the
equalizer tube is plugged.
5. Capture the charge, replace the valve and drier, evacuate
and recharge.