Lennox LGH480 User Manual

Page 34
LGH/LCH420, 480, 540, 600
D-Refrigerant Charge and Check
WARNING-Do not exceed nameplate charge under any condition.
This unit is factory charged and should require no further
adjustment. If the system requires additional refrigerant,
reclaim the charge,
evacuate the system, and add required
nameplate charge.
NOTE - System charging is not recommended below 60°F
(15°C). In temperatures below 60°F (15°C) , the charge
must be weighed into the system.
If weighing facilities are not available, or to check the
charge, use the following procedure:
IMPORTANT - Charge unit in cooling mode. Make sure hot
gas reheat is not energized.
1- Attach gauge manifolds and operate unit in cooling
mode at full CFM with economizer disabled until system
stabilizes (approximately five minutes). Make sure all
outdoor air dampers are closed.
2- Check each system separately with all stages operating.
3- Use a thermometer to accurately measure the outdoor
ambient temperature.
4- Apply the outdoor temperature to tables 7 through 12 to
determine normal operating pressures. Pressures are
listed for sea level applications at 80°F dry bulb and
67°F wet bulb return air.
5- Compare the normal operating pressures to the
pressures obtained from the gauges. 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. Correct
any system problems before proceeding.
6- If discharge pressure is high, remove refrigerant from
the system. If discharge pressure is low, add refrigerant
to the system.
 Add or remove charge in increments.
 Allow the system to stabilize each time
refrigerant is added or removed.
7- Use the following approach method along with the
normal operating pressures to confirm readings.
TABLE 7
LGH/LCH420S - R410A - VFD
Outdoor
Coil En
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
Dis.
+
10
psig
Suc.
+
5
psig
Dis.
+
10
psig
Suc.
+
5
psig
Dis.
+
10
psig
Suc.
+
5
psig
Dis.
+
10
psig
Suc.
+
5
psig
65F* 280 112 310 115 310 137 312 141
75F 330 115 360 118 350 140 350 143
85F 380 117 410 121 400 142 380 141
95F 420 121 470 125 450 144 435 143
105F 495 124 530 128 510 146 490 147
115F 535 128 590 131 570 148 550 150
TABLE 8
LGH/LCH420H - R410 - VFD
Outdoor
Coil En
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
DIs
+
10
psig
Suc
+
5
psig
Dis
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
65F* 250 121 280 124 260 140 270 140
75F 300 124 320 126 305 142 306 142
85F 330 126 370 127 340 143 350 144
95F 390 130 420 131 400 146 390 147
105F 420 131 470 132 450 147 460 148
115F 470 134 540 134 510 149 520 150
TABLE 9
LGH/LCH480S - R410A - VFD
Outdoor
Coil En
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
DIs
+
10
psig
Suc
+
5
psig
Dis
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
65F* 282 114 317 116 315 138 316 139
75F 336 116 361 118 353 139 351 143
85F 389 119 414 121 403 142 396 145
95F 429 122 470 124 451 144 441 144
105F 502 126 529 128 511 147 498 147
115F 547 130 595 131 576 149 558 150
TABLE 10
LGH/LCH480H - R410A - VFD
Outdoor
Coil En
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
DIs
+
10
psig
Suc
+
5
psig
Dis
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
65F* 250 121 283 124 267 140 273 140
75F 301 124 324 126 305 142 306 142
85F 331 136 371 127 349 143 355 144
95F 390 130 420 131 398 146 389 147
105F 428 131 477 132 456 147 459 148
115F 479 134 537 134 516 149 522 150
TABLE 11
LGH/LCH540S - R410A - VFD
Outdoor
Coil En
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
DIs
+
10
psig
Suc
+
5
psig
Dis
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
65F* 285 119 324 124 320 138 310 139
75F 329 121 368 125 355 139 350 140
85F 391 125 418 128 400 142 400 142
95F 454 127 476 129 460 144 450 144
105F 497 130 525 133 515 145 500 147
115F 554 133 580 136 570 147 555 149
TABLE 12
LGH/LCH600S - R410A - VFD
Outdoor
Coil En
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3 Circuit 4
DIs
+
10
psig
Suc
+
5
psig
Dis
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
DIs
+
10
psig
Suc
+
5
psig
65F* 251 109 300 111 297 135 295 135
75F 304 111 342 113 338 136 335 137
85F 343 114 388 115 382 139 384 140
95F 398 117 433 117 433 141 424 142
105F 445 119 489 119 485 142 477 144
115F 490 122 545 121 537 145 521 146

Lennox LGH480 Specifications

General

Brand	Lennox
Model	LGH480
Category	Air Conditioner
Language	English