SERVICING
18
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, ambi-
ent temperature should be greater than 65°F and less
than 105°F. If ambient temperature is out of range,
don’t adjust 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 subcool-
ing according to the following procedure.
a. If subcooling is low, add charge to adjust the sub-
cooling as specified in the following table.
2 TON
10-12°F
3 TON
13-15°F
4 TON
8-10°F
5 TON
11-13°F
b. If subcooling is high, remove charge to lower the
subcooling to specified range.
NOTE:
Not more than 0.8 lb. (13 oz.) of refrigerant be add-
ed to the system at a time to achieve the target subcooling.
It is recommended adding 4 oz. refrigerant each time, then
wait 20 minutes to stabilize the system.
4. Disconnect manifold set. Installation is complete.
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.
CAUTION
Do not allow the sludge or oil to contact the skin. Severe
burns may result.
NOTE:
The Flushing Method using R-11 refrigerant is no
longer approved by the Manufacturer.
REFRIGERANT PIPING
The piping of a refrigeration system is very important in
relation to system capacity, proper oil return to compressor,
pumping rate of compressor and cooling performance of
the evaporator. A bi-flow filter drier must be brazed on by
the installer onsite. Ensure the bi-flow filter drier pain finish
is intact after brazing. If the paint of the steel filter drier
has been burned or chipped, repaint or treat with a rust
preventative. The recommended location of the filter drier
is before the electronic expansion valve at the indoor unit.
The liquid line must be insulated if more than 50 ft. of liquid
line will pass through an area that may reach temperatures
of 30°F of higher than ambient in cooling mode and/or if
the temperature inside the conditioned space may reach a
temperature lower than ambient in heating mode.
FVC50K oils maintain a consistent viscosity over a large
temperature range which aids in the oil return to the com-
pressor; however, there will be some installations which
require oil return traps. These installations should be avoid-
ed whenever possible, as adding oil traps to the refrigerant
lines also increases the opportunity for debris and moisture
to be introduced into the system.
Avoid long running traps in horizontal suction line.
