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.
TABLE 10
LGA/LCA036H
Outdoor Coil
Entering Air Temp
DIscharge
+10psig
Suction +5
psig
65_F 155 79
75_F 178 81
85_F 210 82
95_F 234 84
105_F 265 85
115_F 300 87
TABLE 11
LGA/LCA036S
Outdoor Coil
Entering
Air Temp
DIscharge
+10psig
Suction +5
psig
65_F 167 78
75_F 197 80
85_F 226 82
95_F 256 84
105_F 286 86
115_F 315 87
TABLE 12
LGA/LCA042H
Outdoor Coil
Entering
Air Temp
DIscharge
+10psig
Suction +5
psig
65_F 161 78
75_F 185 81
85_F 213 83
95_F 243 84
105_F 274 86
115_F 310 87
TABLE 13
LGA/LCA042S
Outdoor Coil
Entering
Air Temp
DIscharge
+10psig
Suction +5
psig
65_F 176 75
75_F 206 77
85_F 237 78
95_F 267 80
105_F 297 82
115_F 328 84
TABLE 14
LGA/LCA048H
Outdoor Coil
Entering
Air Temp
DIscharge
+10psig
Suction +5
psig
65_F 171 76
75_F 194 77
85_F 219 78
95_F 248 79
105_F 280 81
115_F 315 82
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