Vintage Cellars Mini Ceiling Mount - Manual (Page 36)

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MCM 082814
Evacuation
Connect the evacuation type 4 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 the 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 off, 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. 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.
With the power off to the Condensing Unit, place the cylinder of R-134a on a digital scale. Admit liquid refrigerant to the system
through the high-pressure side (liquid line service valve) until the refrigerant stops flowing or until about 3 lbs have been added.
Shut off refrigerant flow to system.
Fill a wine bottle ¾ full with water between 60-75°F. Insert the bottle probe into the neck of the bottle as far as possible. (It is
important the bottle probe stopper is compressed by the neck of the bottle to ensure water will not leak out). Verify that the
bottle probe is properly installed and 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 20 psi. If the
system pumps down and the compressor shuts off, 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 4-5°F and sight glass still has bubbles, let the unit run until the wine cellar temperature drops
and approaches 55°F. 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 (evaporator superheat should be between 8-12°F). If superheat
is not between 8-12°F, make an adjustment to the expansion valve. Depending on the temperature, the high side should be
approximately 175 lbs, and the low side should be 28 lbs or more to keep the evaporator from icing.
INSTALLING THE CONDENSING UNIT
Measure Superheat
If superheat is high and bubbles are present, add more refrigerant until it is clear. If superheat is low (around 4-6°F) and bubbles
are present in the sight glass, check for liquid refrigerant entering the compressor as evidenced by cool crankcase below 100-
110°F and low discharge superheat. Adjust TXV setting in small increments to increase superheat and stop liquid from going to
the compressor. Check this before adding more refrigerant. If the temperature of the air entering the condenser is cold enough to
cause the condenser fan to cycle, block about 60% of the coil to raise the head pressure and allow time for stabilization. Reduce
blockage if the condensing temp is above 115°F Fahrenheit. Retain blockage if necessary to maintain stability for performance
test listed in the Split System Warranty Checklist. If the air is cold, below 60°F entering the condenser and the sight glass is clear;
allow the system to run for a while until the cellar cools off, then measure and record data on the Split System Warranty Checklist.
Confirm the controller is displaying the correct temperature and that the controller is not displaying an alarm. If the controller
is displaying an alarm, reference page 37 for corrective action. Confirm that the suction line is completely insulated, from TXV
to compressor. Confirm that the sight glass has no bubbles and the ambient temperature around the Condensing Unit is not
getting excessively hotter. Confirm that both king valves have been back seated and the nuts have been installed back on the
king service ports.
Insulate the 3/8” suction line with cork tape.