CHARGING INFORMATION
FOR COMPLETE CHARGING DETAILS, REFER TO THE OUTDOOR UNIT INSTALLATION INSTRUCTIONS.
AIRFLOW CHECK - Both airflow and refrigerant charge must be monitored
for a proper system set‐up. It may be necessary to alternately check and
adjust the airflow and the refrigerant charge.
NOTE - Be sure that filters and indoor and outdoor coils are clean before testing.
To determine temperature drop across indoor coil (Delta-T), measure the entering air dry
bulb (DB) and wet bulb (WB) temperatures at the indoor coil. Find Delta-T in table 1.. Mea
sure coil's leaving air DB and subtract that value from entering air DB. The measured differ
ence should be within +
3ºF (+1.8ºC) of table value; if too low, decrease the indoor fan speed
(refer to indoor unit for information). If the Delta-T is too high, increase the indoor fan speed.
Repeat charging procedure and Delta-T (air flow adjustment) procedure until both are cor
rect.
Example: assume entering air DB - 72, WB - 64, leaving DB - 53. Therefore, Delta-T should
be 15 (per table); delta across coil is 72 - 53 or 19 (which is 4ºF higher than table value); action
necessary: increase fan speed.
Table 1. Evaporator Coil Delta-T
Dry bulb 80 24 24 24 23 23 22 22 22 20 19 18 17 16 15
temperature 78 23 23 23 22 22 21 21 20 19 18 17 16 15 14
of air 76 22 22 22 21 21 20 19 19 18 17 16 15 14 13
entering 74 21 21 21 20 19 19 18 17 16 16 15 14 13 12
indoor 72 20 20 19 18 17 17 16 15 15 14 13 12 11 10
coil (ºF) 70 19 19 18 18 17 17 16 15 15 14 13 12 11 10
ºF 57 58 59 60 61 62 63 64 65 66 67 68 69 70
[ Wet bulb temperature of air entering indoor coil ]
Table 2. Superheat (SH) Value RFC System - +5ºF
40 15 18 20 23 26 29 32 34 38 41 43 46 48 51
45 13 16 18 21 24 27 30 33 36 39 41 44 46 49
50 11 14 16 19 22 25 28 31 34 37 39 42 44 47
Dry bulb 55 9 12141720232730333638404244
temperature 66 7 10121518212427303335384043
of ambient 65 ‐ 6 10 13 16 19 21 24 27 30 33 36 38 41
air entering 70 ‐ ‐ 7 1013161921242730333639
outdoor 75 ‐ ‐ ‐ 6 9 121518212428313437
unit (ºF) 80 ‐ ‐ ‐ ‐ 5 8 12 15 18 21 25 28 31 35
85 ‐‐‐‐‐‐811151922263033
90 ‐‐‐‐‐‐59131620242731
95 ‐‐‐‐‐‐‐6101418222529
100 ‐‐‐‐‐‐‐‐81216212428
105 ‐‐‐‐‐‐‐‐5913172226
110 ‐‐‐‐‐‐‐‐‐611152025
115 ‐‐‐‐‐‐‐‐‐‐8141824
ºF 50 52 54 56 58 60 62 64 66 68 70 72 74 76
[ Wet bulb temperature of air entering indoor coil ]
Model -18 -24 -30 -36 -42 -48 -60
Table 3. Normal Operating Pressures
1
°F(°C)
2
TXV System - Liquid Line (+10 psig) / Vapor Line (+5 psig)
65 (18) 244 / 135 249 / 137 241 / 134 253 / 134 250 / 135 240 / 130 242 / 130
70 (21) 262 / 136 268 / 138 259 / 135 274 / 135 268 / 137 257 / 131 266 / 131
75 (24) 281 / 137 288 / 138 279 / 136 293 / 136 288 / 138 278 / 132 286 / 132
80 (27) 302 / 138 309 / 140 300 / 137 315 / 137 310 / 139 299 / 133 309 / 133
85 (29) 323 / 139 331 / 140 322 / 138 338 / 139 332 / 140 323 / 134 332 / 134
90 (32) 346 / 141 355 / 142 345 / 140 361 / 139 356 / 140 344 / 135 357 / 135
95 (35) 369 / 142 379 / 143 369 / 141 385 / 141 381 / 141 369 / 136 381 / 136
100 (38) 394 / 143 402 / 144 393 / 142 410 / 142 406 / 143 394 / 137 407 / 137
105 (41) 417 / 145 430 / 145 418 / 143 436 / 143 432 / 143 418 / 139 433 / 138
110 (43) 445 / 146 457 / 146 445 / 144 463 / 145 459 / 145 446 / 140 459 / 140
115 (45) 476 / 148 485 / 147 474 / 145 491 / 146 490 / 145 477 / 141 488 / 141
RFC System - Liquid Line (+10 psig) / Vapor Line (+5 psig)
65 (18) 244 / 135 244 / 125 243 / 116 252 / 129 250 / 135 248 / 127 255 / 126
70 (21) 262 / 136 263 / 128 262 / 120 271 / 131 268 / 137 266 / 130 274 / 128
75 (24) 281 / 137 282 / 131 283 / 124 290 / 133 288 / 138 284 / 132 294 / 131
80 (27) 302 / 138 303 / 134 305 / 128 312 / 136 310 / 139 305 / 134 317 / 134
85 (29) 323 / 139 326 / 137 328 / 132 334 / 139 332 / 140 325 / 137 339 / 136
90 (32) 346 / 141 347 / 138 351 / 135 356 / 141 356 / 140 347 / 139 362 / 138
95 (35) 369 / 142 372 / 141 376 / 139 380 / 143 381 / 141 371 / 141 386 / 140
100 (38) 394 / 143 396 / 143 401 / 142 405 / 145 406 / 143 394 / 143 413 / 142
105 (41) 417 / 145 421 / 145 427 / 145 429 / 147 432 / 143 418 / 144 435 / 144
110 (43) 445 / 146 449 / 147 454 / 147 456 / 148 459 / 145 445 / 146 462 / 146
115 (46) 476 / 148 479 / 149 482 / 149 483 / 151 490 / 145 472 / 147 490 / 148
Table 4. Approach (APP) Values
3
- TXV System - ºF (ºC) +1ºF (0.5ºC)
All 8 (4.5) 8 (4.5) 9 (5.0) 10 (5.6) 10 (5.6) 6 (3.3) 9 (5.0)
Table 5. Subcooling (SC) Values
4
- TXV System - ºF (ºC) +1ºF (0.5ºC)
All 8 (4.1) 8 (4.1) 7 (3.8) 4 (2.2) 8 (4.4) 10 (5.6) 8 (4.4)
1 Typical pressures; indoor evaporator match up, indoor air quantity, and evaporator load will cause
the pressures to vary.
2 Temperature of air entering outside coil.
3 Approach = Liquid Line Temp. minus Outdoor Ambient Temperature
4 Subcooling = Saturation Temp. minus Liquid Line Temp Temperature
*2P0507* *P401238S*
05/07 401238S
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