CellarPro AH12S Series, Manual

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V12.21
28
Evacuation, Leak Detection and Charging
Important note: The condensing unit and evaporator are shipped with a nitrogen holding charge. Please
verify positive pressure through the access valve prior to installation. If you cannot verify the holding
charge, please contact Cellarpro at 707.794.8000.
Once the piping is installed, the following steps should be performed to ensure a dry and leak-free
system:
1. The Condensing unit is pre-charged with compressor oil. To avoid moisture contamination of the oil,
do not leave the system open to atmosphere for more than 15 minutes.
2. Supply power to the Evaporator only - DO NOT connect power to the Condensing unit. Turn on the
temperature controller and set to call for cooling, which will energize and open the liquid line solenoid
valve.
3. Pressurize the system to a maximum of 150PSIG of dry nitrogen. It is important to add nitrogen
though both the high and low side access valves on the condensing unit to make sure the system is
fully pressurized. Mark the pressure and hold for a minimum of 1 hour. If the pressure holds, proceed
to the next step, otherwise locate and repair the leak and repeat this step.
4. Evacuate the system to a minimum of 500 microns. It is important to pull a vacuum though both
the high and low side access valves on the condensing unit to make sure the system is fully
evacuated. If the vacuum is achieved, proceed to the next step, otherwise locate and repair the leak
and repeat from step 4.
5. Disconnect the vacuum pump, but leave the system under vacuum . Use a charging scale to
accurately weigh in the refrigerant. Charge liquid R-134a refrigerant through the liquid service
valve according to the charge pounds indicated in the "System R-134a Charge Guidelines"
chart.
Additional refrigerant may need to be added, using the steps outlined below. DO NOT USE
REFRIGERANT WITH ADDITIVES.
6. Important: The most common causes of compressor failure are refrigerant overcharge,
adding liquid refrigerant through the suction access valve, and cold compressor starts.
In
order to assure that liquid refrigerant does not return to the compressor, adjust the charge as
necessary to maintain a MINIMUM of 20°F superheat, measured on the suction line 6 inches from
the suction valve on the condensing unit.
7. Connect power to the Evaporator and Condensing unit, and activate the system. The evaporator is
programmed with a 3 minute start up delay. After the delay, the compressor will cycle through 3
Bump Starts to protect against floodback damage, then start normally.
IMPORTANT: If the system
does not power up after the start up delay and Bump Start, verify field wiring according to the
appropriate wiring diagram. If correct, disconnect power from the system and contact Cellarpro at
707.794.8000.