Specifications

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Evacuation
Connect evacuation type four valve gauge manifold to high and low pressure service valve ports on the condensing
unit with the valve stems mid seated as when leak testing. Install service caps on valves and tighten them. Energize
the liquid line solenoid valve (make sure there is fresh oil in the vacuum pump). Connect a micron gauge directly to
the pump, blank o and start the pump to verify that it is capable of 200 micron vacuum and the gauge is capable of
reading that vacuum. Connect the micron gauge to the access valve installed in the suction line at the Evaporator Unit
(Fan Coil Unit). Remove the Schrader valve depressors from the gauge hoses to reduce restriction and connect gauges
to the suction and liquid line service valve service ports on the condensing unit. Connect the pump to the 3/8” hose
on the manifold set, start the pump and run until the micron gauge reads 200 microns.
When a 200 micron level evacuation is achieved, break the vacuum with R-134a and add enough refrigerant to
pressurize the system with a few psi of positive pressure.
Charging
Remove the vacuum pump and the micron gauge. Install a spare low pressure gauge to the access valve at the
Evaporator Unit (Fan Coil Unit). With the power o to the condensing unit, place the cylinder of R134a on a digital
scale. Admit liquid refrigerant to the system through the high pressure side,
(Liquid line service valve) until the refrigerant stops owing or until about three pounds have been added. Shut o
refrigerant ow to system.
Verify that the set point on the controller is low enough to allow the system to run continuously for 30 minutes or
more. Turn on power to the condensing unit and the compressor should start if suction pressure is above 6 psi. If the
system pumps down and the compressor shuts o, set the 5 minute time delay relay time to the lowest setting to
avoid having to wait. Add refrigerant as a vapor through the low pressure side of the system (suction service valve
port).
Observe the sight glass when the compressor starts. If bubbles are present, slowly add more refrigerant in vapor form
to the low side. The suction pressure and head pressure should increase as the sight glass clears. Check the superheat
during the charging process. If the superheat drops to 4 or 5 degrees Fahrenheit and sight glass still has bubbles, let
the unit run until the wine cellar temperature drops and approaches 55 degrees Fahrenheit. Observe the sight glass,
if bubbles are present add additional refrigerant in small increments. Let the system stabilize for about 5 minutes
and check the sight glass for bubbles before adding additional refrigerant. Once the sight glass is clear, check the
superheat at the outlet of the Evaporator Unit (Fan Coil Unit) (evaporator superheat should be between 8-12 degrees
Fahrenheit). If superheat is not between 8 and 12 degrees make an adjustment to the expansion valve. Depending
temperature, the “high side” should be approximately 175lbs, and the “low side” should be 28lbs or more to keep the
Evaporator Unit (Fan Coil Unit) from icing.
INSTALLING THE CONDENSING UNIT