Lennox LCH156H, Installation Instructions Manual

Page: 36 / 59

Page 36
LGH/LCH156, 180, 210, 240, 300S
E-Refrigerant Charge and Check - Fin/Tube Coil
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 normal cooling mode.
1- Attach gauge manifolds and operate unit in cooling
mode 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 9 through 20
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 9
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
65 F 255 136 263 136 273 140
75 F 292 139 301 139 311 144
85 F 333 141 342 141 353 146
95 F 378 144 387 143 398 148
105 F 431 148 438 145 449 150
115 F 484 150 490 146 502 152
TABLE 10
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
65
_
F 265 134 273 135 273 140
75
_
F 302 138 311 138 311 144
85
_
F 343 140 352 140 353 146
95
_
F 388 143 397 142 398 148
105
_
F 441 147 448 144 449 150
115
_
F 494 149 500 145 502 152
TABLE 11
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
65 F* 248 137 257 135 259 137
75 F 285 139 294 137 296 137
85 F 328 143 336 139 338 140
95 F 374 146 383 141 385 144
105 F 425 148 433 144 435 147
115 F 479 151 488 147 488 151
TABLE 12
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
65 F* 258 136 267 133 259 137
75 F 295 138 304 135 296 137
85 F 338 142 346 137 338 140
95 F 384 145 393 139 385 144
105 F 435 147 443 142 435 147
115 F 488 150 498 145 488 151
TABLE 13
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
65 F 246 135 256 136
75 F 282 138 293 139
85 F 324 140 336 142
95 F 368 142 387 145
105 F 407 145 421 147
115 F 461 148 475 151