Lennox LCH092H Unit Information page 54

TABLE 14
LCH150S Fin/Tube Coil - TXV
CIRCUIT 1
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 275
755 F 312
855 F 354
955 F 398
1055 F 449
1155 F 500
TABLE 15
LCH150S Fin/Tube Coil Hot Gas Reheat - TXV
CIRCUIT 1
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
655 F 280
755 F 319
855 F 360
955 F 407
1055 F 455
1155 F 510
TABLE 16
LGH/LCH150H Fin/Tube - TXV
CIRCUIT 1
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
65°F 276
75°F 317
85°F 357
95°F 399
105°F 450
115°F 502
TABLE 17
LGH/LCH150H Fin/Tube Hot Gas Reheat - TXV
CIRCUIT 1
Outdoor
Dis­
Coil
charge
Entering
+10 psig
Air Temp
65° F 296
75° F 334
85° F 378
95° F 422
105° F 470
115° F 520
C-Charge Verification - Approach Method - AHRI Testing
(Fin/Tube Coil Continued)
1 Using the same thermometer, compare liquid tempera­
ture to outdoor ambient temperature.
Approach Temperature = Liquid temperature (at con­
denser outlet) minus ambient temperature.
2 Approach temperature should match values in table 18.
An approach temperature greater than value shown indi­
cates an undercharge. An approach temperature less
than value shown indicates an overcharge.
CIRCUIT 2
Dis­
Suction Suction
charge
+5 psig +10 psig +5 psig
140 298
142 335
143 374
146 419
149 465
151 514
CIRCUIT 2
Dis­
Suction charge Suction
+5 psig +5 psig
+10 psig
136 296
141 335
142 376
144 420
147 466
150 518
CIRCUIT 2
Dis­
Suction Suction
charge
+5 psig +5 psig
+10 psig
131 275
133 314
136 363
139 408
142 457
145 509
CIRCUIT 2
Dis­
Suction Suction
charge
+5 psig +5 psig
+10 psig
135 286
137 318
139 364
142 409
144 458
147 509
3 The approach method is not valid for grossly over or
undercharged systems. Use tables 8 through 17 as a
guide for typical operating pressures.
APPROACH TEMPERATURE - FIN/TUBE COIL - TXV
139
Unit
141
142
092
146
102
148
120 & 150
150
150H
092, 120 & 150
Hot Gas Reheat
102
Hot Gas Reheat
136
141
D-Refrigerant Charge and Check - Fin/Tube Coil & RFC
143
144
WARNING-Do not exceed nameplate charge under any
147
condition.
150
This unit is factory charged and should require no further
adjustment. If the system requires additional refrigerant, re­
claim 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.
125
128
If weighing facilities are not available, or to check the
131
charge, use the following procedure:
136
IMPORTANT - Charge unit in standard cooling mode.
140
1 Make sure outdoor coil is clean. Attach gauge manifolds
142
and operate unit at full CFM in cooling mode with econo­
mizer disabled until system stabilizes (approximately five
minutes). Make sure all outdoor air dampers are closed.
2 Check each system separately with all stages operat­
ing. Compare the normal operating pressures (see table
19) to the pressures obtained from the gauges. Check
135
unit components if there are significant differences.
136
3 Measure the outdoor ambient temperature and the suc­
138
tion pressure. Refer to the appropriate circuit charging
140
curve to determine a target liquid temperature.
142
Note - Pressures are listed for sea level applications.
146
4 Use the same thermometer to accurately measure the
liquid temperature (in the outdoor section).
D If measured liquid temperature is higher than the
target liquid temperature, add refrigerant to the
system.
D If measured liquid temperature is lower than the
target liquid temperature, recover some refrigerant
from the system.
5 Add or remove charge in increments. Allow the system
to stabilize each time refrigerant is added or removed.
6 Continue the process until measured liquid tempera­
ture agrees with the target liquid temperature. Do not
Page 54
TABLE 18
Liquid Temp. Minus Ambient Temp.
1st Stage
6°F + 1 (3.3°C + 0.5) 7°F + 1 (3.9°C + 0.5)
6°F + 1 (3.3°C + 0.5) 9°F + 1 (5.0°C + 0.5)
6°F + 1 (3.3°C + 0.5) 10°F+1 (5.6°C + 0.5)
4°F + 1 (2.2°C + 0.5) 6°F+1 (3.3°C + 0.5)
6°F + 1 (3.3°C + 0.5)
(4.4°C + 0.5)
6°F + 1 (3.3°C + 0.5)
(5.0°C + 0.5)
LCH150S
2nd Stage
8°F + 1
9°F + 1