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406905-UIM-C-1009
SUBCOOLING CHARGING METHOD - TXV INDOOR
For cooling operation, the subcooling values are shown in parentheses
on the charging charts provided with the unit.
1.
Set the system running in cooling mode by setting the thermostat
at least 6°F below the room temperature and operate system for at
least 10 – 15 minutes.
2.
Refer to the technical guide for the recommended indoor airflow
and verify it is correct (it should be about 400 SCFM per ton).
3.
Measure and record the indoor wet bulb (WB) and the outdoor
ambient dry bulb (DB) temperature.
4.
Using the charging chart located on the unit, find the intersection
of the indoor wet bulb and the outdoor dry bulb. This is the recom-
mended liquid pressure (and subcooling value).
5.
Measure and record the pressure at the liquid valve pressure port
and compare to the value obtained in step 4.
6.
Add charge if the measured liquid pressure is lower than the rec-
ommended value. Remove / recover charge if the measured liquid
pressure is above the recommended value.
TABLE 2: R-410A Saturation Properties
PRESSURE
TEMP. °F
PSIG
45
130
46
132
47
135
48
137
49
140
50
142
51
145
52
147
53
150
54
153
55
156
56
158
57
161
58
164
59
167
SECTION VII: ELECTRICAL
CONNECTIONS
GENERAL INFORMATION & GROUNDING
Check the electrical supply to be sure that it meets the values specified
on the unit nameplate and wiring label.
Power wiring, control (low voltage) wiring, disconnect switches and over
current protection must be supplied by the installer. Wire size should be
sized per NEC requirements.
All field wiring must USE COPPER CONDUCTORS ONLY and be
in accordance with Local, National, Fire, Safety & Electrical Codes.
This unit must be grounded with a separate ground wire in accor-
dance with the above codes.
6
PRESSURE
TEMP. °F
TEMP. °F
PSIG
60
170
61
173
62
176
63
179
64
182
65
185
66
188
67
191
68
194
69
197
70
201
71
204
72
207
73
211
74
214
Example: The liquid pressure listed at the intersection of the indoor
WB and the outdoor DB 320 psig. Pressure at the liquid valve is 305
psig. It would be necessary to add refrigerant to increase the liquid
pressure to 320 psig.
Condenser subcooling is obtained by calculating the difference of the
saturated refrigerant temperature of the pressure measured at the liquid
base valve and the liquid tube temperature as measured at the liquid
base valve.
Subcooling Temp. (TC) = Saturated Temp. (TS) – Liquid Temp. (T)
IT IS UNLAWFUL TO KNOWINGLY VENT, RELEASE OR DIS-
CHARGE REFRIGERANT INTO THE OPEN AIR DURING
REPAIR, SERVICE, MAINTENANCE OR THE FINAL DISPOSAL
OF THIS UNIT.
WHEN THE SYSTEM IS FUNCTIONING PROPERLY AND THE
OWNER HAS BEEN FULLY INSTRUCTED, SECURE THE
OWNER'S APPROVAL.
PRESSURE
TEMP. °F
PSIG
75
217
90
76
221
91
77
224
92
78
228
93
79
232
94
80
235
95
81
239
96
82
243
97
83
247
98
84
250
99
85
254
100
86
258
101
87
262
102
88
266
103
89
270
104
The complete connection diagram and schematic wiring label is located
on the inside surface of the unit service access panel.
FIELD CONNECTIONS POWER WIRING
1.
Install the proper size weatherproof disconnect switch outdoors
and within sight of the unit.
2.
Remove the screw from the field wiring access cover on the ser-
vice valve end of the unit. Slide the cover down and remove from
unit.
3.
Run power wiring from the disconnect switch to the unit.
4.
Route wires from disconnect through power wiring opening pro-
vided and into the top of the field wiring box as shown in Figure 6.
5.
Install the proper size time-delay fuses or circuit breaker, and
make the power supply connections.
PRESSURE
PRESSURE
TEMP. °F
PSIG
274
105
278
106
282
107
287
108
291
109
295
110
299
111
304
112
308
113
313
114
317
115
322
116
326.
117
331
118
336
119
Johnson Controls Unitary Products
PSIG
341
345
350
355
360
365
370
375
380
385
391
396
401
407
412
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