Operating And Temperature Pressures - Lennox XC21 Installation Instructions Manual

Operating and Temperature Pressures

Minor variations in these pressures may be expected due to differences in installations. Significant differences could mean
that the system is not properly charged or that a problem exists with some component in the system.
Table 4. Normal Operating Pressures (Liquid +10 and Suction +5 psig)*
IMPORTANT
XC21 −024
5F (5C)**
Liquid
209
65 (18.3)
242
75 (23.9)
85 (29.4) 281
95 (35.0) 324
372
105 (40.6)
115 (46.1) 426
213
65 (18.3)
75 (23.9) 245
85 (29.4) 285
329
95 (35.0)
376
105 (40.6)
115 (46.1) 432
* Typical pressures only, expressed in psig (liquid +/− 10 and vapor+/− 5 psig); indoor match up, indoor air quality, and indoor load will cause the
pressures to vary. These operating pressures are also listed on the unit charging sticker (401104S) located on the unit access panel.
** Temperature of air entering outdoor coil.
°F
−40
−35
−30
−25
−20
−15
−10
−5
0
5
10
15
20
25
30
35
40
45
50
55
Use this table to perform maintenance checks; it is not a procedure for charging the
system. Minor variations in these pressures may be due to differences in installations.
Significant deviations could mean that the system is not properly charged or that a
problem exists with some component in the system.
−036
Vapor Liquid
First Stage (Low Capacity)
144 211
145 244
146 285
148 330
151 380
152 436
Second Stage (High Capacity)
138 214
142 247
142 288
144 330
147 384
151 445
Table 5. HFC−410A Temperature (°F) − Pressure (Psig)
°C Psig
−40.0 11.6
−37.2 14.9
−34.4 18.5
−31.7 22.5
−28.9 26.9
−26.1 31.7
−23.3 36.8
−20.6 42.5
−17.8 48.6
−15.0 55.2
−12.2 62.3
−9.4 70.0
−6.7 78.3
−3.9 87.3
−1.1 96.8
1.7 107
4.4 118
7.2 130
10.0 142
12.8 155
−048
Vapor Liquid
142 215
144 250
146 288
149 338
151 387
154 459
137 217
140 251
141 289
143 336
145 385
148 437
°F
60
65
70
75
80
85
90
95
100
105
110
115
120
125
130
135
140
145
150
Page 29
−060
Vapor Liquid
140 229
142 264
144 306
146 353
149 405
152 468
124 238
133 276
138 317
141 368
144 420
146 478
°C
15.6
18.3
21.1
23.9
26.7
29.4
32.2
35.0
37.8
40.6
43.3
46.1
48.9
51.7
54.4
57.2
60.0
62.8
65.6
Vapor
134
137
140
144
146
146
130
133
135
139
141
143
Psig
170
185
201
217
235
254
274
295
317
340
365
391
418
446
476
507
539
573
608
XC21 SERIES