Lennox LGA Series Unit Information page 33

II-PLACEMENT AND INSTALLATION
Make sure the unit is installed in accordance with the
installation instructions and all applicable codes. See
accessories section for conditions requiring use of the
optional roof mounting frame (LARMF 03/07).
III-CHARGING
WARNING-Do not exceed nameplate charge under any
condition.
This unit is factory charged and should require no further
adjustment. If the system requires charge, 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:
1- Attach gauge manifolds and operate unit in cooling
mode until system stabilizes (approximately five min-
utes). Make sure outdoor air dampers are closed.
2- Use a thermometer to accurately measure the outdoor
ambient temperature.
3- Apply the outdoor temperature to tables 10 through 15
to determine normal operating pressures.
4- 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.
5- If discharge pressure is high, remove refrigerant from
the system. If discharge pressure is low, add refriger-
ant to the system.
D Add or remove charge in increments.
D Allow the system to stabilize each time refriger-
ant is added or removed.
6- Use the following sub-cooling method along with the
normal operating pressures to confirm readings.
Outdoor Coil
Entering Air Temp
65_F
75_F
85_F
95_F
105_F
115_F
Outdoor Coil
Entering
Air Temp
65_F
75_F
85_F
95_F
105_F
115_F
Outdoor Coil
Entering
Air Temp
65_F
75_F
85_F
95_F
105_F
115_F
Outdoor Coil
Entering
Air Temp
65_F
75_F
85_F
95_F
105_F
115_F
Outdoor Coil
Entering
Air Temp
65_F
75_F
85_F
95_F
105_F
115_F
Page 33
TABLE 10
LGA/LCA036H
DIscharge Suction +5
+10psig
155
178
210
234
265
300
TABLE 11
LGA/LCA036S
DIscharge Suction +5
+10psig
167
197
226
256
286
315
TABLE 12
LGA/LCA042H
DIscharge Suction +5
+10psig
161
185
213
243
274
310
TABLE 13
LGA/LCA042S
DIscharge Suction +5
+10psig
176
206
237
267
297
328
TABLE 14
LGA/LCA048H
DIscharge Suction +5
+10psig
171
194
219
248
280
315
psig
79
81
82
84
85
87
psig
78
80
82
84
86
87
psig
78
81
83
84
86
87
psig
75
77
78
80
82
84
psig
76
77
78
79
81
82