Refrigerant Charge And Check - Fin/Tube Coil - Lennox LGH180H Installation Instructions Manual

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.
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.
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.
TABLE 9
LG/LC Series 156H Std.
Circuit 1
Outdoor
Dis. Suc.
Coil En­
+10 +5
tering
psig psig
Air Temp
65_F 255 136
75_F 292 139
85_F 333 141
95_F 378 144
105_F 431 148
115_F 484 150
LGH/LCH156, 180, 210, 240, 300S
Pressures
Circuit 2 Circuit 3
Dis. Suc. Dis. Suc.
+10 +5 +10 +5
psig psig psig psig
263 136 273 140
301 139 311 144
342 141 353 146
387 143 398 148
438 145 449 150
490 146 502 152
LG/LC Series 156H Reheat
Circuit 1
Outdoor
Dis.
Coil En­
+10
tering
psig
Air Temp
65_F 265
75_F 302
85_F 343
95_F 388
105_F 441
115_F 494
Circuit 1
Outdoor
Dis.
Coil En­
+10
tering
psig
Air Temp
65_F* 248
75_F 285
85_F 328
95_F 374
105_F 425
115_F 479
LG/LC Series 180H Reheat
Circuit 1
Outdoor
Dis.
Coil En­
+10
tering
psig
Air Temp
65_F* 258
75_F 295
85_F 338
95_F 384
105_F 435
115_F 488
Outdoor
Coil En­
Dis. +10
tering
psig
Air Temp
65_F 246
75_F 282
85_F 324
95_F 368
105_F 407
115_F 461
Page 36
TABLE 10
Circuit 2
Suc. Dis. Suc.
+5 +10 +5
psig psig psig
134 273 135
138 311 138
140 352 140
143 397 142
147 448 144
149 500 145
TABLE 11
LG/LC Series 180H Std.
Circuit 2
Suc. Dis. Suc.
+5 +10 +5
psig psig psig
137 257 135
139 294 137
143 336 139
146 383 141
148 433 144
151 488 147
TABLE 12
Circuit 2
Suc. Dis. Suc.
+5 +10 +5
psig psig psig
136 267 133
138 304 135
142 346 137
145 393 139
147 443 142
150 498 145
TABLE 13
LG/LC Series 180U
Circuit 1 Circuit 2
Suc. +5 Dis. +10
psig psig
135 256
138 293
140 336
142 387
145 421
148 475
Circuit 3
Dis. Suc.
+10 +5
psig psig
273 140
311 144
353 146
398 148
449 150
502 152
Circuit 3
Dis. Suc.
+10 +5
psig psig
259 137
296 137
338 140
385 144
435 147
488 151
Circuit 3
Dis. Suc.
+10 +5
psig psig
259 137
296 137
338 140
385 144
435 147
488 151
Suc. +5
psig
136
139
142
145
147
151