Subcooling Charging In Cooling Above 55°F Od Ambient - Trane 4TTR3 Installer's Manual

Installer's Guide
SUBcOOLinG chARGinG in cOOLinG ABOVE 55°F Od AMBiEnt
The Trane company has always recommended installing
Trane approved matched indoor and outdoor systems.
All Trane split systems are ARI 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 twenty (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 pressure to
SUBCOOL CHARGING TABLE CORRECTIONS FOR LINE LENGTH AND RISE
60
50
40
30
25
20
15
10
0
Subtract 10 psig from S.C. Table Pressure
10
6
LIQUID
TEMP
˚
( F)
55
60
65
70
75
80
85
90
95
100
105
110
115
120
125
Installer's Guide for charging method.
Use Design Subcool Value from Table
20 25
TOTAL REFRIGERANT LINE LENGTH (FEET)
match the table, or remove refrigerant to lower the
pressure. Again, wait twenty (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.
R-410A REFRIGERANT CHARGING CHART
DESIGN SUBCOOLING (
8 9 10
LIQUID GAGE PRESSURE (PSI)
179 182 185
195 198 201
211 215 218
229 232 236
247 251 255
267 271 275
287 291 296
309 313 318
331 336 341
355 360 365
381 386 391
407 413 418
435 441 446
464 470 476
495 501 507
Refer to Service Facts or
Add 10 psig to Subcool Charging Table Pressure
30 40
˚
F)
11 12 13
188 191 195
204 208 211
222 225 229
240 243 247
259 263 267
279 283 287
300 304 309
322 327 331
346 351 355
370 376 381
396 402 407
424 429 435
452 458 464
482 488 495
514 520 527
From Dwg. D154557P01 Rev. 2
60 80
18-AC71D1-5
14
198
215
232
251
271
291
313
336
360
386
413
441
470
501
533