Unit installation

104 IOMM ACZ/AGZ
2. Add the charge to the system through the suction shutoff valve or through the Schrader fitting on
the tube entering the evaporator between the compressor and the evaporator head.
3. The charge can be added at any load condition between 25-100% load per circuit but at least twoF
fans should be operating per refrigerant circuit if possible. The suction superheat should be in the
6°F-12°F (3.3°C-6.6°C) range.
4. Add sufficient charge to clear the liquid line sightglass and until all flashing stops in the
sightglass. Add an extra 15-20 lbs. of reserve to fill the subcooler if the compressor is operating
at 50-100% load.
5. Check the unit subcooling value by reading the liquid line pressure and temperature at the liquid
line near the filter-drier. The subcooling values should be between 6 degrees F-20 degrees F (6.6
degrees C-11.1 degrees C). The subcooling values will be highest at 75-100% load,
approximately 12 degrees F-20 degrees F (6.6 degrees C-11.1 degrees C) and lowest at 50% load,
approximately 6 degrees F-12 degrees F (3.3 degrees C-6.6 degrees C).
6. With outdoor temperatures above 60°F (15.6°C) all condenser fans should be operating and the
liquid line temperature should be within 5°F-10°F (2.8°C-5.6°C) of the outdoor air temperature.
At 25-50% load the liquid line temperature should be within 5°F (2.8°C) of outdoor air
temperature with all fans on. At 75-100% load the liquid line temperature should be within 10°F
(5.6°C) of outdoor air temperature with all fans on.
7. Overcharging of refrigerant will raise the compressor discharge pressure due to filling of the
condenser tubes with excess refrigerant.