Lennox KGC Series Unit Information page 35

B-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 standard cooling mode.
1 - Attach gauge manifolds and operate unit in cool-
ing mode with economizer disabled until system
stabilizes (approximately five minutes). Make sure
outdoor air dampers are closed.
2 - Check each system separately with all stages
operating.
3 - Use a thermometer to accurately measure the out-
door ambient temperature.
4 - Apply the outdoor temperature to TABLE 14 to
TABLE 17 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 varia-
tions 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 refriger-
ant is added or removed.
7 - Use the following approach method along with the
normal operating pressures to confirm readings.
KGC/KCC092S Fin/Tube - W & W/O Reheat
Outdoor
Coil
Discharge
Entering
+ 10 psig
Air Temp
65°F 270
75°F 310
85°F 352
95°F 401
105°F 453
115°F 511
KGC/KCC102S Fin/Tube - W & W/O Reheat
Outdoor
Coil
Discharge
Entering
+ 10 psig
Air Temp
65°F 269
75°F 308
85°F 350
95°F 396
105°F 447
115°F 502
Page 35
TABLE 14 581129-01
CIRCUIT 1 CIRCUIT 2
Suction + Discharge
5 psig + 10 psig
128 255
131 295
133 338
136 388
140 433
145 488
TABLE 15 581130-01
CIRCUIT 1 CIRCUIT 2
Suction + Discharge
5 psig + 10 psig
128 276
132 314
135 359
139 407
141 458
146 513
Suction +
5 psig
140
146
151
155
160
162
Suction +
5 psig
138
142
146
149
152
156