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a. Liquid Line Pressure = 417 PSI
b. Corresponding Temp. = 120°F
c. Thermometer on Liquid line = 109°F.
a. Suction Pressure = 143 PSI
b. Corresponding Temp. = 50°F
c. Thermometer on Suction Line = 59°F
For TXV systems, to adjust superheat, unscrew the
cover from the expansion valve, locate the adjustment
screw, and turn it clockwise (in) to increase superheat
or counterclockwise (out) to decrease superheat. It is
recommended to make small adjustments at a time, 1/8-1/4
turn increments. Replace adjustment cap. Wait a minimum
of 15 minutes between adjustments to allow time for the
TXV and pressures to stabilize.
All package units with xed orice devices are charged
using the superheat method at the compressor suction line.
To increase super heat, remove charge and to decrease
super heat, add charge. After superheat is adjusted, it is
recommended to check unit subcooling at the condenser
coil liquid line. See Design Superheat and Subcooling table
for targets on each model.
Single Stage Cooling Application: Refer to the Design
Superheat & Subcooling table
Two Stage Cooling Application : Run unit on Low Stage
cooling and refer to Design Superheat & Subcooling table
1. Purge gauge lines. Connect service gauge manifold
to access ttings. Run system at least 10 minutes to
allow pressure to stabilize.
2. Temporarily install thermometer on liquid (small) line
near liquid line access tting with adequate contact
and insulate for best possible reading.
3. Check subcooling and superheat. System should
have a subcooling and superheat within the range
listed on the Design Superheat and Subcooling table.
a. If subcooling and superheat are low, adjust TXV
superheat, then check subcooling.
b. If subcooling is low and superheat is high,
add charge to raise subcooling then check
superheat.
c. If subcooling and superheat are high, adjust
TXV valve superheat, then check subcooling.
d. If subcooling is high and superheat is low, adjust
TXV valve superheat and remove charge to
lower the subcooling.
NOTE: Do NOT adjust the charge based on suction
pressure unless there is a gross undercharge. If an under
charge is suspected recover the charge, re-evacuate
the system and recharge per data plate. No adjustments
should be made if suspecting a charge issue.
4. Disconnect manifold set, installation is complete.
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