Refrigerant Charge And Check - Fin/Tube Coil - Lennox KGB024 Installation Instructions Manual

C-Refrigerant Charge and Check - Fin/Tube Coil
KGA/KCA 036 to 060
WARNING-Do not exceed nameplate charge under
any condition.
This unit is factory charged and should require no further
adjustment. If the system requires charge, 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:
1- Attach gauge manifolds and operate unit in cooling
mode until system stabilizes (approximately five
minutes). Make sure outdoor air dampers are closed.
2- Use a thermometer to accurately measure the
outdoor ambient temperature.
3- Apply the outdoor temperature to tables 7 through 12
to determine normal operating pressures.
4- Compare the normal operating pressures to the
pressures obtained from the gauges. Minor
variations 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.
5- If discharge pressure is high, remove refrigerant from
the system. If discharge pressure is low, add
refrigerant to the system.
S Add or remove charge in increments.
S Allow the system to stabilize each time
refrigerant is added or removed.
6- Use the following approach method along with the
normal operating pressures to confirm readings.
TABLE 7
KGA 036S -3 & LOWER; KCA 036S -2 & LOWER
NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
655 F
755 F
855 F
955 F
1055 F
1155 F
Discharge Suction + 5
+10 psig psig
269 146
311 148
357 150
407 152
466 155
532 157
KGA 036S -4 & HIGHER; KCA 036S -3 & HIGHER
NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
65° F
75° F
85° F
95° F
105° F
115° F
KGA 048S -3 & LOWER; KCA 048S -2 & LOWER
NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
65° F
75° F
85° F
95° F
105° F
115° F
KGA 048 -4 & HIGHER; KCA 048S -3 & HIGHER
NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
65° F
75° F
85° F
95° F
105° F
115° F
KGA 060S -4 & LOWER; KCA 060S -3 & LOWER
NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
65° F
75° F
85° F
95° F
105° F
115° F
Page 43
TABLE 8
Discharge Suction + 5
+10 psig psig
275
312
353
399
450
506
TABLE 9
Discharge Suction + 5
+10 psig psig
280
321
365
414
467
526
TABLE 10
Discharge Suction + 5
+10 psig psig
279
319
360
404
454
506
TABLE 11
Discharge Suction + 5
+10 psig psig
265
302
344
391
442
499
507348-04
137
139
142
146
149
150
142
144
147
149
151
153
132
136
140
144
147
148
136
137
139
142
146
148
12/2015