Subject to change without notice.
9
KWV-20G*ATA**
REV — 02/26/20
in pressure causes a drop in temperature of
the refrigerant. When the warmer ambient air
is drawn over the cooler evaporator coil, the
warmer or latent heat is exchanged. As the heat
is being exchanged, the exchange of heat energy
causes the liquid refrigerant to boil into a vapor
and greatly reducing the temperature of the air on
the outlet side of the coil. The liquid refrigerant
is converted into the lower temperature, lower
pressure refrigerant causing it to changing into a
vapor state.
Filter Drier
The filter drier, filters loose particles, moisture and
possible brazing residue from the system. If the
unit starts tripping on low pressure cutout and the
refrigerant line is frosted up to the outlet of the
filter drier, check the refrigerant pressure drop
across the filter drier and replace the filter drier if
necessary.
Sight Glass
A liquid sight glass is located before the liquid
line solenoid valve. During the cooling mode of
operation, pure liquid should flow through the
liquid sight glass. The liquid refrigerant will appear
clear enough to see the back of the inside of the
sight glass. Flashing (bubbles) will appear in
the sight glass during the first minute or two of
operation until the expansion valve fully adjusts.
If flashing is constant during the cooling mode, it
may be an indication the unit is short of refrigerant.
There may also be some flashing during hot gas
bypass operation. See the Troubleshooting Chart
for further details.
Thermostatic Expansion Valve
The expansion valve regulates the amount of
liquid refrigerant entering into the evaporator. As
the liquid enters into the expansion valve, the
valve will start to change the state by changing
the pressure of the liquid refrigerant as it passes
through and starts to enter the evaporator coil.
When the environments load conditions start
to change, the bulb recognizes a change in
temperature at the outlet piping of the evaporator
to the suction side of the compressor and
automatically adjusts the valve to maintain the
correct flow into the evaporator coil.
ROUTINE MAINTENANCE
To keep the Portable Air Conditioner unit
operating safely and efficiently, it is recommended
that a qualified service technician check the
entire system at least once a year. Check the
system more frequently depending on use and
surrounding conditions.
Filters
It is very important to keep the air filters clean.
Be sure to inspect them at least once each month
when the system is in constant operation. The
PAC4 unit typically has a cleanable air filter.
Remove the filter and use a brush to brush caked
on dust from the filter. Next, use a stream of warm
water to rinse remaining dust from the filter then
reinstall.
If the unit is equipped with disposable type air
filters, replace them with the same type and size.
NOTE:
Do not attempt to clean disposable air
filters.
Condenser Coil
Inspect the condenser coil. If the condenser coil
is dirty, clean with a stream of cold water, and
pressurized air not exceeding 50 psig, or vacuum
cleaner. Do not use hot water or steam, which can
cause excessive high pressure in the refrigerant
system. Clean the condenser coil in the opposite
direction of the airflow.
Blower and Motor Drive Components
The Evaporator and Condenser Blower Bearings
are pre-greased and sealed and require no
maintenance. The evaporator and condenser
fan motors may require oil on both bearing ends
Summary of Contents for KWV-20
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