Advertisement
Installer's Guide
Installer's Guide
SUBCOOLING CHARGING IN COOLING ABOVE 55°F OD AMBIENT
The manufacturer has always recommended installing
approved matched indoor and outdoor systems.
All 13 SEER split systems are AHRI rated with only TXV
indoor systems.
The benefits of installing approved indoor and outdoor split
systems are maximum efficiency, optimum performance and
the best overall system reliability.
The following charging methods are therefore prescribed for
systems with indoor TXVs.
1. Subcooling (in the cooling mode) is the only recommended
method of charging above 55°F ambient temperatures.
2. For best results - the indoor temperature should be kept
between 70°F to 80°F. Add system heat if needed.
3. At start-up, or whenever charge is removed or added, the
system must be operated for a minimum 20 minutes to
stabilize before accurate measurements can be made.
4. Measure Liquid Line Temperature and Refrigerant
Pressure at service valves.
5. Determine total refrigerant line length, and height (lift)
if indoor section is above the condenser.
6. Determine the Design Subcool Charging Temperature
from the unit nameplate.
7. Locate this value in the appropriate column of the
Subcooling Charging Table. Locate your liquid line
temperature in the left column of the table, and the
intersecting liquid line pressure under your nameplate
subcool value column. Add refrigerant to raise the pres-
sure to match the table, or remove refrigerant to lower
the pressure. Again, wait 20 minutes for the system
conditions to stabilize before adjusting charge again.
8. When system is correctly charged, you can refer to
System Pressure Curves (in Service Facts) to verify
typical performance.
SUBCOOL CHARGING TABLE CORRECTIONS FOR LINE LENGTH AND RISE
60
50
40
30
25
20
15
10
0
Subtract 5 psig from S.C. Table Pressure
10
6
Use Design Subcool Value from Table
20
25
TOTAL REFRIGERANT LINE LENGTH (FEET)
R-22 SUBCOOLING CHARGING TABLE
DESIGN SUBCOOLING VALUES (°F)
LIQUID
TEMP.
8
(°F)
LIQUID LINE PRESSURE (psi)
45
89
50
98
55
107
60
117
65
128
70
139
75
151
80
163
85
176
90
190
95
205
100
220
105
236
110
253
115
271
120
289
125
309
Add 5 psig to Subcool Charging Table Pressure
30
40
10
12
14
93
96
100
102
105
109
111
115
119
121
126
130
132
137
141
144
148
153
156
161
166
168
174
179
182
187
193
196
202
208
211
217
223
226
233
239
243
249
256
260
267
274
278
285
293
297
305
313
317
325
333
60
80
18-BC56D1-5
Advertisement
