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.
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.
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
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 match the table, or
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LIQUID |
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| DESIGN SUBCOOLING (˚F) |
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TEMP |
| 8 | 9 |
| 10 | 11 |
| 12 |
| 13 | 14 |
(˚F) |
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| LIQUID GAGE PRESSURE (PSI) |
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55 |
| 179 | 182 |
| 185 | 188 |
| 191 |
| 195 | 198 |
60 |
| 195 | 198 |
| 201 | 204 |
| 208 |
| 211 | 215 |
65 |
| 211 | 215 |
| 218 | 222 |
| 225 |
| 229 | 232 |
70 |
| 229 | 232 |
| 236 | 240 |
| 243 |
| 247 | 251 |
75 |
| 247 | 251 |
| 255 | 259 |
| 263 |
| 267 | 271 |
80 |
| 267 | 271 |
| 275 | 279 |
| 283 |
| 287 | 291 |
85 |
| 287 | 291 |
| 296 | 300 |
| 304 |
| 309 | 313 |
90 |
| 309 | 313 |
| 318 | 322 |
| 327 |
| 331 | 336 |
95 |
| 331 | 336 |
| 341 | 346 |
| 351 |
| 355 | 360 |
100 |
| 355 | 360 |
| 365 | 370 |
| 376 |
| 381 | 386 |
105 |
| 381 | 386 |
| 391 | 396 |
| 402 |
| 407 | 413 |
110 |
| 407 | 413 |
| 418 | 424 |
| 429 |
| 435 | 441 |
115 |
| 435 | 441 |
| 446 | 452 |
| 458 |
| 464 | 470 |
120 |
| 464 | 470 |
| 476 | 482 |
| 488 |
| 495 | 501 |
125 |
| 495 | 501 |
| 507 | 514 |
| 520 |
| 527 | 533 |
| Refer to Service Facts or |
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Installer's Guide for charging method. |
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| From Dwg. D154557P01 Rev. 2 | ||||
SUBCOOL CHARGING TABLE CORRECTIONS FOR LINE LENGTH AND RISE
REFRIGERANT LINE LIFT (FEET)
60
50
40
30
25 | Add 10 psig to Subcool Charging Table Pressure |
20 |
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15Use Design Subcool Value from Table
10
0Subtract 10 psig from S.C. Table Pressure
10 | 20 | 25 | 30 | 40 | 60 | 80 |
TOTAL REFRIGERANT LINE LENGTH (FEET)
SUBCOOLING CHARGING BELOW 55°F OD AMBIENT – IN HEATING ONLY
1.The Subcool Charging Method in cooling is not recom- mended below 55°F outdoor ambient.
2.The only recommended method of charging at outdoor ambients below 55°F, is to weigh in the charge in the heating mode.
3.Use Nameplate charge plus standard charge adders for line length.
4.Check liquid line temperature and pressure (at the OD valves) to obtain a minimum of 10°F subcooling.
5.Add charge if a minimum of 10°F subcooling is not obtained with the nameplate charge plus line length correction.
6.It is important to return in the spring or summer to accurately charge the system in the cooling mode at outdoor ambients above 55°F.
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