Page 17
XP15 SERIES
1 Check the airflow as illustrated in figure 26 to be sure the indoor airflow is as
required. (Make any air flow adjustments before continuing with the following
procedure.)
2 Measure outdoor ambient temperature; determine whether to use
cooling
mode
or
heating mode
to check charge.
3 Connect gauge set.
4 Check Liquid and Vapor line pressures. Compare pressures with Normal
Operating Pressures table 5, (
The reference table is a general guide. Expect
minor pressure variations. Significant differences may mean improper charge or
other system problem.
)
5 Set thermostat for heat/cool demand, depending on mode being used:
Using cooling mode
When the outdoor ambient temperature is 60°F (15°C) and
above. Target subcooling values in table below are based on 70 to 80°F (21−27°C)
indoor return air temperature; if necessary, operate heating to reach that
temperature range; then set thermostat to cooling mode setpoint to 68ºF (20ºC).
When pressures have stabilized, continue with step 6.
Using heating mode
When the outdoor ambient temperature is below 60°F (15°C).
Target subcooling values in table below are based on 65−75°F (18−24°C) indoor
return air temperature; if necessary, operate cooling to reach that temperature range;
then set thermostat to heating mode setpoint to 77ºF (25ºC). When pressures have
stabilized, continue with step 6.
6 Read the liquid line temperature; record in the LIQº space.
7 Read the liquid line pressure; then find its corresponding temperature in the
temperature/ pressure chart listed in table 12 and record it in the SATº space.
8 Subtract LIQº temp. from SATº temp. to determine subcooling; record it in SCº space.
9 Compare SCº results with table below, being sure to note any additional charge for
line set and/or match−up.
10 If subcooling value is greater than shown in tables 6 through 11 for the applicable unit,
remove refrigerant; if less than shown, add refrigerant.
11 If refrigerant is added or removed, repeat steps 6 through 10 to verify charge.
USE COOLING
MODE
USE HEATING
MODE
60ºF (15º)
SATº
LIQº
–
SCº
=
SUBCOOLING
Figure 28. Using Subcooling Method
Table 5. Normal Operating Pressure − 10 and Vapor +5 PSIG*
IMPORTANT
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.
5
F (
5
C)**
XP15−024
XP15−030
XP15−036
XP15−042
XP15−048
XP15−060
Liquid
Vapor
Liquid
Vapor
Liquid
Vapor
Liquid
Vapor
Liquid
Vapor
Liquid
Vapor
HEATING OPERATION
20 (−7.0)
315
65
308
62
284
59
293
58
312
62
349
61
30 (−1.0)
340
81
317
76
296
71
312
71
332
76
375
74
40 (4.4)
364
97
339
89
313
87
321
82
353
92
384
88
50 (10)
394
115
359
107
326
106
337
103
374
110
406
107
COOLING OPERATION
65 (18.3)
237
141
250
141
260
139
265
141
242
139
255
136
75 (23.9)
274
143
292
143
298
141
309
144
279
140
297
138
85 (29.4)
319
145
336
145
344
143
360
147
322
142
343
140
95 (35.0)
364
147
385
147
393
145
408
149
370
144
392
142
105 (40.6)
415
149
438
148
446
148
462
151
423
147
447
145
115 (49.0)
469
152
497
151
506
150
522
154
479
149
510
148
*These are most−popular−match−up pressures. Indoor match up, indoor air quality, and indoor load cause pressures to vary.
**Temperature of the air entering the outdoor coil.
