Lennox LGM036 User Manual

Page 21
LGM/LCM036, 048, 060, 074
TABLE 6 581010-01
LG/LC 048U NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
Discharge
+
10 psig
Suction + 5
psig
655 F 252 142
755 F 289 145
855 F 332 147
955 F 379 149
1055 F 428 151
1155 F 484 153
TABLE 7 581011-01
LG/LC 060U NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
Discharge
+
10 psig
Suction + 5
psig
655 F 261 135
755 F 299 138
855 F 341 140
955 F 388 142
1055 F 441 144
1155 F 499 146
TABLE 8 581012-01
LG/LC 074U NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
Discharge
+
10 psig
Suction + 5
psig
655 F 268 128
755 F 307 134
855 F 351 137
955 F 399 140
1055 F 450 142
1155 F 505 144
TABLE 9
SUBCOOLING TEMPERATURE
Unit
Liquid Saturated Temp. Minus
Liquid Temperature
036U 11°F + 1 (6.0°C + 0.5)
048U 11.5°F + 1 (6.4°C + 0.5)
060U 13.5°F + 1 (7.5°C + 0.5)
074U 15°F + 1 (8.3°C + 0.5)
C-Compressor Controls
See unit wiring diagram to determine which controls are
used on each unit. Optional controls are identified on
wiring diagrams by arrows at junction points.
1- High Pressure Switch (S4)
The compressor circuit is protected by a high
pressure switch which opens at 640 psig +
10 psig
(4413 kPa +
70 kPa) and automatically resets at 475
psig +
20 psig (3275kPa + 138 kPa).
2- Low Pressure Switch (S87)
The compressor circuit is protected by a loss of
charge switch. Switch opens at 40 psig +
5 psig (276
+
34 kPa) and automatically resets at 90 psig + 5
psig (621 kPa +
34 kPa).
3- Prognostics and Diagnostics Sensors (RT42, RT44,
RT46, RT48)
Four thermistors are located on specific points in the
refrigeration circuit. The thermistors provide constant
temperature feedback to the Unit Controller to protect
the compressor. Thermistors take the place of the
freezestat and low ambient pressure switch.
4- Compressor Crankcase Heater (HR1)
Crankcase heater must be energized at all times to
prevent compressor damage due to refrigerant
migration. Energize crankcase heater 24 hours before
unit start-up by setting thermostat so that there is no
cooling demand (to prevent compressor from cycling)
and apply power to unit.

Lennox LGM036 Specifications

General

Brand	Lennox
Model	LGM036
Category	Air Conditioner
Language	English