Page 15
TABLE 12
LGA/LCA036H Humiditrol
t
Units
Outdoor Coil
Entering Air Temp
DIscharge
+10 psig
Suction +5
psig
65
_
F
153
79
75
_
F
182
81
85
_
F
211
82
95
_
F
240
83
105
_
F
269
85
115
_
F
298
86
TABLE 13
LGA/LCA048H Humiditrol
t
Units
Outdoor Coil
Entering Air Temp
DIscharge
+10 psig
Suction +5
psig
65
_
F
157
75
75
_
F
188
77
85
_
F
219
79
95
_
F
249
81
105
_
F
280
83
115
_
F
310
85
TABLE 14
LGA/LCA060H Humiditrol
t
Units
Outdoor Coil
Entering Air Temp
DIscharge
+10 psig
Suction +5
psig
65
_
F
169
72
75
_
F
201
74
85
_
F
233
76
95
_
F
265
79
105
_
F
297
81
115
_
F
329
84
E−Charge Verification − Subcooling Method
If ambient temperature is above 60
_
F (15
_
C), read
liquid line temperature. Read liquid line pressure from
gauge and convert to condensing temperature using
standard R−22 temperature/pressure conversion chart
(or conversion scale on gauge). The difference
between the condensing temperature and the liquid line
temperature is subcooling (subcooling = condensing
temperature minus liquid line temperature). The
subcooling should approximate the value given in table
15. Add refrigerant to increase subcooling and remove
refrigerant to reduce subcooling.
TABLE 15
SUBCOOLING
Unit
Temperature
LGA/LCA036H Humiditrol Units
14
_
F + 1 (7.7
_
C + 1)
LGA/LCA048H Humiditrol Units
16
_
F + 1 ( 9
_
C + 1)
LGA/LCA060H Humiditrol Units
15
_
F + 1 (8.3
_
C + 1)
F−Compressor Controls
1− High Pressure Switch (S4)
The compressor circuit is protected by a reset high
pressure switch which cuts out at 450 psig + 10 psig
(3103 kPa + 70 kPa) and automatically resets at 300
psig + 20 psig (2096 kPa + 138 kPa).
2− Low Pressure Switch (S87)
The compressor circuit is protected by a loss of
charge switch. Switch cuts out at 25 psig (172 kPa)
and automatically resets at 55 psig (379 kPa).
3− Freezestat (S49)
The compressor is protected by a freezestat located
on the indoor coil. The freezestat opens at 29
_
F+3
and closes at 58
_
F+4.
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.
5− Low Ambient Pressure Switch (S11)
Switch maintains adequate discharge pressure by
de−energizing condenser fan when liquid pressure
falls below 140 psig + 10 (965 kPa + 6). S11 is
installed in the liquid line.
6− Discharge Line Thermostat (S40)
S
ingle Phase and High Efficiency Units Only
Switch opens when discharge line temperature
reaches 94
_
F +5 and closes when temperature falls
below 74
_
F +5. Prevents crankcase heater operation
in warm weather.
