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TABLE 9
2nd stage High Capacity
Model Number
Subcooling Values
Conversion Temp. − Liquid Line Temp.
°
F (
°
C)
HPXA16−024
11.0 + 1 (6 + .5)
HPXA16−036
8.5 + 1 (4.7 + .5)
HPXA16−048
7.5 + 1 (4.1 + .5)
HPXA16−060
7.0 + 1 (3.9 + .5)
Charging Using Normal Operating Pressures
and the Approach Method
Outdoor Temp. > 65
F (18
C)
The following procedure is intended as a general guide and
is for use on expansion valve systems only. For best results,
indoor temperature should be 70°F (21°C) to 80°F (26°C).
Monitor system pressures while charging.
1 − Record outdoor ambient temperature using a digital
thermometer.
2 − Attach high pressure gauge set and operate unit for
several minutes to allow system pressures to stabilize.
3 − Compare stabilized pressures with those provided in
tables 11 and 12, Normal Operating Pressures." 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 sys-
tem. Pressures higher than those listed indicate that
the system is overcharged. Pressures lower than
those listed indicate that the system is undercharged.
Verify adjusted charge using the approach method.
Approach Method
4 − Use the same digital thermometer used to check out-
door ambient temperature to check liquid line tempera-
ture. Verify the unit charge using the approach method.
5 − The difference between the ambient and liquid temper-
atures should match values given in table 10. If the val-
ues don’t agree with the those in table 10, add refriger-
ant to lower the approach temperature or recover re-
frigerant from the system to increase the approach
temperature.
TABLE 10
2nd Stage High Capacity
Model Number
Approach Temperature
Liquid Line Temp. − Outdoor Ambient °F (°C)
HPXA16−024
4.0 + 1 (2.2 + .5)
HPXA16−036
7.0 + 1 (3.9 + .5)
HPXA16−048
8.0 + 1 (4.4 + .5)
HPXA16−060
10.0 + 1 (5.6 + .5)
IMPORTANT
Use table 11 and table 12 as a general guide when
performing maintenance checks. This is not a proce-
dure for charging the unit (Refer to Charging/Check-
ing Charge section). Minor variations in these pres-
sures may be expected due to differences in installa-
tions. Significant differences could mean that the
system is not properly charged or that a problem ex-
ists with some component in the system.
