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SERVICING
to rise subcooling to 8°F ± 1°F(*1), then check super-
heat.
d. If subcooling is 8°F ± 1°F(*1) and superheat is high,
adjust the TXV valve to 7 to 9°F superheat, then
check subcooling.
e. If subcooling and superheat are high, adjust the TXV
valve to 7 to 9°F superheat, then check subcooling.
f. If subcooling is high and superheat is 7 to 9°F, re-
move charge to lower the subcooling to 8°F ± 1°F(*1),
then check superheat.
g. If subcooling is high and superheat is low, adjust the
TXV valve to 7 to 9°F superheat and remove charge
to low the subcooling to 8°F ± 1°F(*1).
h. If subcooling is 8°F ± 1°F(*1) and superheat is low,
adjust the TXV valve to 7 to 9°F superheat and re-
move charge to lower the subcooling 8°F ± 1°F(*1),
then check the superheat.
NOTE: It is recommended to add charge in 4 oz.
increments each time to achieve the target subcooling.
4. Disconnect manifold set. Installation is complete.
SUBCOOLING ADJUSTMENT ON EEV APPLICATIONS
NOTE: Subcooling information is valid only while the unit is
operating at 100% capacity or 100% compressor speed in
CHARGE MODE.
Compressor speed is displayed under STATUS menu in the
thermostat.
1. Run system at least 20 minutes to allow pressure to
stabilize. During the adjustment of subcooling, ambient
temperature should be greater than 65°F and less than
105°F. If ambient temperature is out of range, don't ad-
just
subcooling.
2. For best results, temporarily install a thermometer on the
liquid line at the liquid line service valve. Ensure the
thermometer makes adequate contact and is insulated
for
best possible readings. Use liquid line temperature to
determine sub-cooling.
3. The system subcooling should fall in the range shown in
following table. If not in that range, adjust subcooling
according to the following procedure.
a. If subcooling is low, add charge to adjust the subcool-
ing to 8°F ± 1°F(*1).
b. If subcooling is high, remove charge to lower the
subcooling to specified range.
NOTE: It is recommended to add charge in 4 oz.
increments each time to achieve the target subcooling.
4. Disconnect manifold set. Installation is complete.
CHECKING THERMOSTATIC EXPANSION VALVE
OPERATION
1. Remove the remote bulb of the thermostatic expansion
valve from the suction line.
2. Start the system and cool the bulb in a container of ice
water, closing the valve. As you cool the bulb, the suc-
tion pressure should fall and the suction temperature will
rise.
3. Next warm the bulb in your hand. As you warm the bulb,
the suction pressure should rise and the suction tem-
perature will fall.
4. If a temperature or pressure change is noticed, the
expansion valve is operating. If no change is noticed,
the valve is restricted, the power element is faulty, or the
equalizer tube is plugged.
5. Capture the charge, replace the valve and drier, evacu-
ate and recharge.
NON-CONDENSABLES
If non-condensables are suspected, shut down the sys-
tem and allow the pressures to equalize. Wait at least 15
minutes. Compare the pressure to the temperature of the
coldest coil since this is where most of the refrigerant will
be. If the pressure indicates a higher temperature than that
of the coil temperature, non-condensables are present.
Non-condensables are removed from the system by first
removing the refrigerant charge, replacing and/or installing
liquid line drier, evacuating and recharging.
COMPRESSOR BURNOUT
When a compressor burns out, high temperature develops
causing the refrigerant, oil and motor insulation to decom-
pose forming acids and sludge.
If a compressor is suspected of being burned-out, attach
a refrigerant hose to the liquid line dill valve and properly
remove and dispose of the refrigerant.
NOTICE
Violation of EPA regulations may result in fines
or other penalties.
Now determine if a burn out has actually occurred. Confirm
by analyzing an oil sample using a Sporlan Acid Test Kit,
AK-3 or its equivalent.
Remove the compressor and obtain an oil sample from the
suction stub. If the oil is not acidic, either a burnout has not
occurred or the burnout is so mild that a complete clean-up
is not necessary.
If acid level is unacceptable, the system must be cleaned
by using the clean-up drier method.
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Table of Contents
Troubleshooting
