Lennox LGH240H

Page 77
B-Fin/Tube Coil
WARNING-Do not exceed nameplate charge under
any condition.
This unit is factory charged and should require no fur-
ther adjustment. If the system requires additional refrig-
erant,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 normal cooling mode.
1 - Attach gauge manifolds and operate unit in cooling
mode with economizer disabled until system
    
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 24 through
35 to determine normal operating pressures.
Pressures are listed for sea level applications at

5 - Compare the normal operating pressures to
the pressures obtained from the gauges. Minor
variations in these pressures may be expected due
󰀨󰀨
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

TABLE 24
LG/LC Series 156H Std.
Outdoor
Coil En-
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
 255 136 263 136 273 140
   301  311 144
 333 141 342 141 353 146

378 144 387 143  148

431 148 438 145  150

484 150  146 502 152
TABLE 25
LG/LC Series 156H Reheat
Outdoor
Coil En-
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
 265 134 273 135 273 140
 302 138 311 138 311 144
 343 140 352 140 353 146
 388 143  142  148
 441 147 448 144  150
   500 145 502 152
TABLE 26
LG/LC Series 180H Std.
Outdoor
Coil En-
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
 248 137 257 135  137
 285   137  137
 328 143 336  338 140
 374 146 383 141 385 144
 425 148 433 144 435 147
  151 488 147 488 151
TABLE 27
LG/LC Series 180H Reheat
Outdoor
Coil En-
tering Air
Temp
Circuit 1 Circuit 2 Circuit 3
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
Dis.
+10
psig
Suc.
+5
psig
 258 136 267 133  137
  138 304 135  137
 338 142 346 137 338 140
 384 145   385 144
 435 147 443 142 435 147
 488 150  145 488 151
TABLE 28
LG/LC Series 180U
Outdoor
Coil En-
tering Air
Temp
Circuit 1 Circuit 2
Dis. +10
psig
Suc. +5
psig
Dis. +10
psig
Suc. +5
psig
 258 136 267 133
  138 304 135
 338 142 346 137
 384 145  
 435 147 443 142
 488 150  145