Chapter 2: Installation
NOTE: When pulling a vacuum, the Schrader valves will unnecessarily restrict the openings, increasing the evacuation time. During the evacuation process, we recommend that you remove the Schrader valve cores with a Schrader valve removal tool and draw the vacuum through the port on the removal tool.
4.If you cannot evacuate the system below 1500 microns, close the vacuum pump isolation valve and perform a
5.If no leaks are detected after the initial vacuum, release the vacuum and pressurize the system with
6.After two hours, release the pressure. Then turn on the vacuum pump and evacuate the system a second time down to 1500 microns or less. Close the vacuum pump isolation valve and pressurize the system again with dry nitrogen and allow the system to stand for two hours as in Step #5.
7.After two hours, release the pressure. Turn on the vacuum pump and complete the process of evacuating the system, this time with a goal of achieving a
8.Replace the Schrader valve cores if you removed them during the evacuation steps. You may now introduce the refrigerant charge through the Schrader valves.
2.10.2.3 Refrigerant Charging Procedures
R410A refrigerant must be weighed in when performing the charge. Referring to Section 2.10.2.1, calculate the estimated amount of refrigerant needed for your system.
When charging a system using a blended refrigerant, it is essential that the composition of the refrigerant is maintained. To ensure correct composition, introduce the refrigerant (R410A) into the system in liquid form rather than vapor form. Cylinders that do not have dip tubes should be inverted to allow only liquid refrigerant to charge the system. Keeping the temperature of the cylinder below 85° F will help maintain the correct refrigerant composition while the cylinder is emptied.
WARNING
If refrigerant gas is released in an enclosed area, it may accumulate in low areas and near the floor, displacing available oxygen. If a major leak occurs, there is a risk of asphyxiation. In such case, the area should be immediately evacuated and ventilated. Personnel should remain away from the area until it is determined to be safe.
Initial System Charge
Follow the
1.Bleed air from hoses and break the vacuum by supplying liquid refrigerant (R410A) to the discharge port near the compressor until the pressure is equalized. This holding charge allows the low pressure switch to “hold,” enabling the compressor to operate throughout the process of charging the system.
Fine-Tuning the System Charge
Once the initial charge is completed, refrigerant will need to be added with the unit running.
CAUTION
An adequate heat load must be supplied to ensure a proper charge.
2. Disconnect the refrigerant cylinder from the discharge side of the compressor and connect it to the suction side.
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