Lennox LGH094U Unit Information page 51

B-Refrigerant Charge and Check - Fin/Tube Coil - TXV
LGH/LCH092H, 102H, 120H, 150S, 150H
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, re­
claim 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 standard cooling mode.
1- Attach gauge manifolds and operate unit in cooling
mode with economizer disabled until system stabilizes
(approximately five minutes). Make sure outdoor air
dampers are closed.
2- Check each system separately with all stages operat­
ing.
3- Use a thermometer to accurately measure the outdoor
ambient temperature.
4- Apply the outdoor temperature to tables 9 through 18
to determine normal operating pressures. Pressures
are listed for sea level applications at 80
5
and 67 F wet bulb return air.
5- Compare the normal operating pressures to the pres­
sures 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.
S Add or remove charge in increments.
S Allow the system to stabilize each time refrigerant
is added or removed.
7- Use the following approach method along with the nor­
mal operating pressures to confirm readings.
TABLE 9
LGH/LCH092H Fin/Tube Coil - TXV
CIRCUIT 1
Outdoor
Dis­
Coil
charge Suction
Entering
+10 psig
Air Temp
o
65 F 235
o
75 F 272
o
85 F 312
o
95 F 357
o
105 F 407
o
115 F 460
5
F dry bulb
CIRCUIT 2
Dis­
charge Suction
+5 psig +5 psig
+10 psig
137 262 137
139 298 141
142 338 144
146 380 146
149 428 149
154 477 153
LGH/LCH092H Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
o
65 F 242
o
75 F 279
o
85 F 319
o
95 F 364
o
105 F 414
o
115 F 467
LGH/LCH102H Fin/Tube Coil - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
o
65 F 241
o
75 F 277
o
85 F 318
o
95 F 362
o
105 F 411
o
115 F 464
LGH/LCH102H Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
o
65 F 249
o
75 F 285
o
85 F 327
o
95 F 370
o
105 F 420
o
115 F 473
LGH/LCH120H Fin/Tube Coil - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 259
755 F 297
855 F 338
955 F 382
1055 F 431
1155 F 486
LGH/LCH120H Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 266
755 F 303
855 F 344
955 F 391
1055 F 443
1155 F 499
Page 51
TABLE 10
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig +10 psig
134 262
137 297
140 338
143 379
146 427
151 476
TABLE 11
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig +10 psig
139 273
141 307
143 348
145 389
148 437
150 486
TABLE 12
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig +10 psig
137 272
139 306
141 347
143 389
146 436
148 485
TABLE 13
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig +10 psig
137 283
140 321
143 360
146 406
149 453
151 505
TABLE 14
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig +10 psig
134 281
137 310
140 358
143 403
146 450
149 497
Suction
+5 psig
139
143
146
148
151
155
Suction
+5 psig
141
144
147
149
151
152
Suction
+5 psig
142
145
148
150
152
154
Suction
+5 psig
139
142
144
146
148
151
Suction
+5 psig
139
141
143
145
146
148