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IV− SYSTEMS SERVICE CHECKS
Refrigerant Charge and Check
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 name-
plate 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 min-
utes).
2− Check each system separately with all stages operat-
ing.
3− Use a thermometer to accurately measure the outdoor
ambient temperature.
4− Apply the outdoor temperature to tables 5 through 9 to
determine normal operating pressures.
5− Compare the normal operating pressures to the pres-
sures 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.
6− If discharge pressure is high, remove refrigerant from
the system. If discharge pressure is low, reclaim the
charge, evacuate the system then add refrigerant.
D Add or remove charge in increments.
D Allow the system to stabilize each time refriger-
ant is added or removed.
7− Use the following approach method along with the nor-
mal operating pressures to confirm readings.
TABLE 5
KHA024S NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
Dis. + 10 psig Suct. +5 psig
65_F
226 147
75_F
258 148
85_F
304 151
95_F
351 154
105_F
402 157
115_F
460 160
TABLE 6
KHA030S NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air Temp
Dis. + 10 psig Suct. +5 psig
65_F
235 145
75_F
273 148
85_F
316 151
95_F
363 153
105_F
416 156
115_F
476 158
TABLE 7
KHA036S NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air
Temp
Dis. + 10 psig Suct. +5 psig
65_F
247 140
75_F
289 143
85_F
331 145
95_F
381 148
105_F
434 151
115_F
492 154
TABLE 8
KHA048S NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air
Temp
Dis. + 10 psig Suct. +5 psig
65_F
272 139
75_F
313 142
85_F
359 145
95_F
410 148
105_F
465 150
115_F
529 152
TABLE 9
KHA060S NORMAL OPERATING PRESSURES
Outdoor Coil
Entering Air
Temp
Dis. + 10 psig Suct. +5 psig
65_F
265 136
75_F
304 139
85_F
348 141
95_F
397 144
105_F
447 147
115_F
507 149
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