Panasonic WU-192ME2U9 Technical Data Manual - Page 69

6. AIR PURGING Design of 2WAY VRF SYSTEM Charging additional refrigerant Use a cylinder designed for use with CCAAUUTTIIOONN R410A respectively. Pressure gauge Manifold valve Charging additional refrigerant (calculated from the liquid tube length as shown in Section "1-8. Additional Refrigerant Charge") using the liquid tube service valve. (Fig. 2-31) Valve Use a balance to measure the refrigerant accurately. If the additional refrigerant charge amount cannot be charged at once, charge the remaining refrigerant in liquid form by using the gas tube service valve with the system in cooling operation mode at the time of test run. (Fig. 2-32) Liquid 1 Finishing the job R410A (1) With a hex wrench, turn the liquid tube service valve stem counter-clockwise to fully open the valve. To avoid gas from leaking when Close 2 CCAAUUTTIIOONN removing the charge hose, make Gas tube sure the stem of the gas tube is Close turned all the way out ("BACK SEAT" position). (2) Turn the gas tube service valve stem counter-clockwise to fully open the valve. Liquid tube Open Outdoor unit 3 (3) Loosen the charge hose connected to the gas tube service Close port (5/16" (7.94mm)) slightly to release the pressure, then remove the hose. Close 4 (4) Replace the 1/4" (6.35mm) flare nut and its bonnet on the Balance gas tube service port and fasten the flare nut securely with tube an adjustable wrench or box wrench. Close This process is very important to prevent gas from leaking Fig. 2-31 from the system. (5) Replace the valve caps at both gas and liquid service valves 5 and fasten them securely. This completes air purging with a vacuum pump. The air conditioner is now ready for a test run. Open 6 Gas tube Open Liquid Close Outdoor unit 7 tube Open Close 8 Balance tube Open Fig. 2-32 2 - 53 9