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MCM
062519
Pump Down Cycle
WhisperKOOL’s split systems operate on a pump down cycle different from traditional air conditioners. As such, there is no wiring
between the condensing unit and evaporator unit.
WhisperKOOL units utilize a solenoid valve on the liquid line and a low-pressure switch on the suction line. When the thermostat
calls for cooling, the solenoid valve opens, permitting the flow of refrigerant. The low-pressure switch then signals the compressor
to cycle on.
When the cellar reaches the desired temperature and the thermostat is satisfied, the solenoid will close, stopping the liquid
refrigerant flow to the TXV valve. The compressor will continue to operate until most of the refrigerant on the low side boils off
and is pumped through the compressor into the condenser coil and receiver. As the suction pressure falls below the pressure
control setting, the low-pressure switch will signal the compressor to cycle off. Most of the refrigerant is now stored between the
condensing unit and receiver.
…………………………………………………………………………………………………
WARNING:
Do not utilize a ground fault interrupter, as it will prevent
the unit from drawing the necessary amperage to start the unit.
QUICK START GUIDE*
TXV Adjustments
A.
A TXV adjustment may be necessary based on ambient temperatures in the cellar and at the condensing unit.
B.
Adjust the TXV until the superheat measured at the suction line service valve is 20-30°F.
C.
Under normal operation, with the wine cellar at 55°F and the ambient temperature at 85°F, the low side pressure should be
between 28-32 PSI and the high side should be between 140-180 PSI.
*Further system operation information is available on page 31.
Liquid Line King Valve
This location is used to charge the system with liquid refrigerant
and identify the high side pressure of the system.
Calculating Subcooling
To determine the subcooling of the system, calculate the difference
between the
high side pressure of the system (converted to
temperature)
and the
temperature of the liquid line
. The temperature
of the liquid line will be taken at the outlet of the receiver.
*Saturation temp — liquid line temp
4-6°F
SUBCOOLING REQUIRED FOR WARRANTY APPROVAL
TXV
The TXV is preadjusted at the factory. If the superheat is not within
20-30° at the service valve, the TXV will need to be adjusted.
ADJUSTING THE TXV
Use a 5⁄32” hex key to remove the cap from the TXV superheat
adjustment port. With the cap removed, insert the hex key into
the superheat adjustment port. Increase superheat by turning the
hex key clockwise. Decrease superheat by turning the hex key
counterclockwise.
