Page 16
5 − Compare the subcooling value with those in table 6. If
subcooling is greater than shown, recover some refrig-
erant. If subcooling is less than shown, add some refrig-
erant. Be aware of the R−410A refrigerant cylinder. It will
be light maroon−colored. Refrigerant should be added
through the vapor line valve in the liquid state.
TABLE 5
R−410A Temperature (°F) − Pressure (Psig)
°F
Psig
°F
Psig
°F
Psig
°F
Psig
32
100.8
64
181.6
96
299.4
126
451.8
34
105.0
66
187.7
98
308.2
128
463.5
36
109.2
68
194.1
100
317.2
130
475.6
38
113.6
70
200.6
102
326.4
132
487.8
40
118.0
72
207.2
104
335.7
134
500.2
42
122.6
74
214.0
106
345.3
136
512.9
44
127.3
76
220.9
108
355.0
138
525.8
46
132.2
78
228.0
110
365.0
140
539.0
48
137.1
80
235.3
112
375.1
142
552.3
50
142.2
82
242.7
114
385.4
144
565.9
52
147.4
84
250.3
116
396.0
146
579.8
54
152.8
86
258.0
118
406.7
148
593.8
56
158.2
88
266.0
120
417.7
150
608.1
58
163.9
90
274.1
122
428.8
152
622.7
60
169.6
92
282.3
124
440.2
154
637.5
62
195.5
94
290.8
126
451.8
156
652.4
TABLE 6
SSB*H4 Subcooling Values for Charging
Second Stage (High-Capacity)
Saturation Temperature
Liquid Line Temperature
=
Subcooling Value
Model
SPB036H4S41
SPB048H4S41
SPB060H4S41
°F (°C)*
6 (3.3)
6 (3.3)
9 (5.0)
*F: +/−1.0°; C: +/−0.5°
Charge Using the Approach Method, TXV Systems
Outdoor Temperature > 65ºF (18ºC)
Use the same digital thermometer to check the outdoor
ambient temperature and the liquid line temperature.
The following procedure is intended as a general guide and is
for use on expansion valve systems only. For best results, in-
door temperature should be 70°F (21°C) to 80°F (26°C).
Monitor system pressures while charging.
1 − Record outdoor ambient temperature using a digital
thermometer.
2 − Attach high pressure gauge set and operate unit for sev-
eral minutes to allow system pressures to stabilize.
3 − Compare stabilized pressures with those provided in
table 8, Normal Operating Pressures." Pressures high-
er than those listed indicate that the system is over-
charged. Pressures lower than those listed indicate that
the system is undercharged. A temperature/pressure
chart for R−410A refrigerant is provided in table 5 for
your convenience. Verify adjusted charge using the ap-
proach method.
4 − The difference between the ambient and liquid tempera-
tures should match values given in table 7. If the values
don’t agree with the those in table 7, add refrigerant to
lower the approach temperature, or recover refrigerant
from the system to increase the approach temperature.
Be aware of the R−410A refrigerant cylinder. It will be
light maroon−colored. Refrigerant should be added
through the vapor valve in the liquid state.
TABLE 7
SSB*H4 Approach Values for Charging (Second
Stage)
Liquid Line Temperature
Outdoor Temperature
=
Approach Temperature
Model
SSB036H4S41
SSB048H4S41
SSB060H4S41
°F (°C)*
10 (5.6)
8 (4.4)
3 (1.7)
*F: +/−1.0°; C: +/−0.5°
IMPORTANT
Table 8 is not a procedure for charging the system but
may be used to perform maintenance checks. Minor
variations in these pressures may be due to differ-
ences in installations. Significant deviations could
mean that the system is not properly charged or that
a problem exists with some component in the system.
TABLE 8
Normal Operating Pressures In psig
(/− 10 and vapor+/− 5 PSIG)*
Temp. of
air enter-
SSB036H4S41
SSB048H4S41
SSB060H4S41
air enter-
ing out-
door coil
5
F (
5
C)
Liquid
Suc-
tion
Liquid
Suc-
tion
Liquid
Suc-
tion
First Stage (Low Capacity)
65 (18.3)
227
137
224
142
215
136
75 (23.9)
261
142
258
144
250
139
85 (29.4)
302
145
299
146
291
142
95 (35.0)
347
147
345
148
337
144
105 (40.6)
396
150
395
150
388
146
115 (46.1)
452
154
450
153
444
148
Second Stage (High Capacity)
65 (18.3)
244
132
235
135
220
130
75 (23.9)
278
139
269
137
256
133
85 (29.4)
321
142
313
139
299
136
95 (35.0)
368
144
361
141
347
138
105 (40.6)
419
147
412
143
402
141
115 (46.1)
476
150
471
146
462
143
*These are typical pressures only. Indoor indoor match up, in-
door air quality, and indoor load will cause the pressures to vary.
