ComfortStar 18 Installation Manual page 20

5. Use the final superheat value, refrigerant
temperature and pressure from STEP 4, to
determine the proper suction gauge pressure using
Table 14-1.
Example: Assume a 12º F final superheat value and
suction temp of 58º F.
1. Locate 12º F final Superheat in Table 14-1.
2. Locate the Suction Temperarature (58º F) in
the left column.
3. The Suction Gage Pressure should be ap-
proximately 133 PSIG. (This is the shown as
the intersection of the Final Superheat column
and the Suction Temperature row.
Design Superheat Value = ________ºF
Superheat Correction = ________ ºF
Final Superheat Value = ________ ºF
R410A Refrigerant Superheat Chart
Final Superheat (°F)
Suction
6 8 10 12
Temp
(°F)
Suction Gauge Pressure (PSI)
40 105 101 97 93
42 109 105 101 97
44 114 109 105 101
46 118 114 109 105
114 109
48 123 118
50 128 123 118 114
52 133 128 123 118
54 138 133 128 123
56 143 138 133 128
138 133
58 148 143
60 153 148 143 138
62 159 153 148 143
64 164 159 153 148
66 170 164 159 153
164 159
68 176 170
70 182 176 170 164
72 188 182 176 170
Table 14-1
6. Adjust refrigerant level to attain proper final superheat.
NOTE
Add refrigerant if the measured superheat is
higher than the final superheat value.
Connect gages to refrigerant bottle and unit as
illustrated (Fig. 14-5).
Purge all hoses.
Open bottle.
Stop adding refrigerant when gas line pressure
matches the Refrigerant Charging Chart.
NOTE
Recover refrigerant if the measured
superheat is lower than the final superheat
value.
14 16 18
89 86 82
93 89 86
97 93 89
97
101 93
105 101 97
109 105 101
114 109 105
118 114 109
118
123 114
128 123 118
133 128 123
138 133 128
143 138 133
143 138
148
153 148 143
159 153 148
164 159 153
17
Figure 14-5
7. Stabilize the system.
Wait 20 minutes for the system condition to stabilize
between adjustments.
NOTE
When the liquid line pressure match the chart,
the system is properly charged.
Remove gages.
Replace service port caps to prevent leaks. Tighten
finger tight plus an additional 1/6 turn.
20 MIN.
Figure 14-6
8. Record system Information for reference Table 14-2.
Record system pressures and temperatures after
charging is complete.
Description
Outdoor model number
Measured Outdoor Ambient
Measured Indoor Ambient
Liquid Gage Pressure
Suction Gage Pressure
Suction Line Temperature
Table 14-2
Value
°F
°F
PSIG
PSIG
°F