Lennox LGH120H4M User Manual

Page 52
TABLE 15
LGH/LCH150S Fin/Tube Coil - TXV
Outdoor
Coil
Entering
Air Temp
CIRCUIT 1 CIRCUIT 2
Dis
charge
+
10 psig
Suction
+
5 psig
Dis
charge
+
10 psig
Suction
+
5 psig
655 F 275 140 298 139
755 F 312 142 335 141
855 F 354 143 374 142
955 F 398 146 419 146
1055 F 449 149 465 148
1155 F 500 151 514 150
TABLE 16
LGH/LCH150S Fin/Tube Coil Hot Gas Reheat - TXV
Outdoor
Coil
Entering
Air Temp
CIRCUIT 1 CIRCUIT 2
Dis
charge
+
10 psig
Suction
+
5 psig
Dis
charge
+
10 psig
Suction
+
5 psig
655 F 280 136 296 136
755 F 319 141 335 141
855 F 360 142 376 143
955 F 407 144 420 144
1055 F 455 147 466 147
1155 F 510 150 518 150
TABLE 17
LGH/LCH150H Fin/Tube - TXV
Outdoor
Coil
Entering
Air Temp
CIRCUIT 1 CIRCUIT 2
Dis
charge
+
10 psig
Suction
+
5 psig
Dis
charge
+
10 psig
Suction
+
5 psig
65°F 276 131 275 125
75°F 317 133 314 128
85°F 357 136 363 131
95°F 399 139 408 136
105°F 450 142 457 140
115°F 502 145 509 142
TABLE 18
LGH/LCH150H Fin/Tube Hot Gas Reheat - TXV
Outdoor
Coil
Entering
Air Temp
CIRCUIT 1 CIRCUIT 2
Dis
charge
+
10 psig
Suction
+
5 psig
Dis
charge
+
10 psig
Suction
+
5 psig
65° F 296 135 286 135
75° F 334 137 318 136
85° F 378 139 364 138
95° F 422 142 409 140
105° F 470 144 458 142
115° F 520 147 509 146
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 19.
An approach temperature greater than value shown indi
cates an undercharge. An approach temperature less
than value shown indicates an overcharge.
3- The approach method is not valid for grossly over or
undercharged systems. Use tables 9 through 18 as a
guide for typical operating pressures.
TABLE 19
APPROACH TEMPERATURE - FIN/TUBE COIL - TXV
Unit
Liquid Temp. Minus Ambient Temp.
1st Stage 2nd Stage
092
6°F + 1 (3.3°C + 0.5) 7°F + 1 (3.9°C + 0.5)
102
6°F + 1 (3.3°C + 0.5) 9°F + 1 (5.0°C + 0.5)
120 & 150S
6°F + 1 (3.3°C + 0.5) 10°F+1 (5.6°C + 0.5)
150H
4°F + 1 (2.2°C + 0.5) 6°F+1 (3.3°C + 0.5)
092, 120 & 150
Hot Gas Reheat
6°F + 1 (3.3°C + 0.5)
8°F + 1
(4.4°C +
0.5)
102
Hot Gas Reheat
6°F + 1 (3.3°C + 0.5)
9°F + 1
(5.0°C +
0.5)
F-Refrigerant Charge and Check - Fin/Tube Coil & RFC
LGH/LCH150S
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, 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.
If weighing facilities are not available, or to check the
charge, use the following procedure:
IMPORTANT - Charge unit in standard cooling mode.
1- Make sure outdoor coil is clean. Attach gauge manifolds
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
20) to the pressures obtained from the gauges. Check
unit components if there are significant differences.
3- Measure the outdoor ambient temperature and the suc
tion pressure. Refer to the appropriate circuit charging
curve to determine a target liquid temperature.
Note - Pressures are listed for sea level applications.
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
go below the target liquid temperature when adjusting

Lennox LGH120H4M Specifications

General

Brand	Lennox
Model	LGH120H4M
Category	Air Handlers
Language	English