Lennox LCH036 Installation Instructions Manual page 78

E-Refrigerant Charge and Check - Fin/Tube Coil & TXV
LGH/LCH092H, 102H, 120H, 150S
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 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
operating.
3- Use a thermometer to accurately measure the
outdoor ambient temperature.
4- Apply the outdoor temperature to tables 10 through
16 to determine normal operating pressures.
Pressures are listed for sea level applications at
5
80 F dry bulb and 67
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.
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
normal operating pressures to confirm readings.
5
F wet bulb return air.
LGH/LCH092H Fin/Tube - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 240
755 F 277
855 F 317
955 F 362
1055 F 410
1155 F 460
LGH/LCH092H Fin/Tube Hot Gas Reheat - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 247
755 F 284
855 F 324
955 F 367
1055 F 417
1155 F 468
LGH/LCH102H Fin/Tube - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 245
755 F 281
855 F 322
955 F 367
1055 F 415
1155 F 465
LGH/LCH102H Fin/Tube Hot Gas Reheat - TXV
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 250
755 F 289
855 F 328
955 F 374
1055 F 425
1155 F 478
Page 28
TABLE 10
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig
+10 psig
142 257
143 292
145 333
148 378
151 422
154 472
TABLE 11
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig +10 psig
140 257
142 294
144 334
145 375
147 423
150 469
TABLE 12
CIRCUIT 1 CIRCUIT 2
Dis­
Suction
charge
+5 psig
+10 psig
142 262
144 298
146 341
149 384
152 430
154 475
TABLE 13
CIRCUIT 1 CIRCUIT 2
Dis­
Suction charge
+5 psig
+10 psig
140 262
143 301
145 339
147 382
149 429
151 473
Suction
+5 psig
141
142
145
147
149
152
Suction
+5 psig
141
144
147
149
152
154
Suction
+5 psig
142
144
146
148
150
153
Suction
+5 psig
141
144
147
150
153
155