Sanyo 12KS71 Installation Instructions - Page 19

05-424 KS0971-1271 12/13/05 1:28 PM Page 19 6. Air Purging Air and moisture remaining in the refrigerant system have undesirable effects as indicated below. Therefore, they must be purged completely. q pressure in the system rises q operating current rises q cooling (or heating) efficiency drops q moisture in the air may freeze and block capillary tubing q water may lead to corrosion of parts in the refrigerant system s Air Purging with a Vacuum Pump (for Test Run) (1) Check that each tube (both narrow and wide tubes) between the indoor and outdoor units have been properly connected and all wiring for the test run has been completed. Note that both narrow and wide tube service valves on the outdoor unit are kept closed at this stage. (2) Using an adjustable wrench or box wrench, remove the valve caps from the service valve on both narrow and wide tubes. (3) Connect a vacuum pump and a manifold valve (with pressure gauges) to the service port on the wide tube service valve. (Fig. 57) Indoor unit Outdoor unit Manifold valve (Exclusively for R410A) Pressure gauge Lo Hi CAUTION The service port on the wide tube service valve uses a Schrader core valve to access the refrigerant system. The valve core is similar to those used in automobile tires. Therefore, be sure to use a vacuum hose connector which has a pushpin inside. CAUTION Be sure to use a manifold valve for air purging. If it is not available, use a stop valve (field supply) for this purpose. The "Hi" knob of the manifold valve must always be kept closed. (4) With the "Lo" knob of the manifold valve open, run the vacuum pump. The operation time for the vacuum pump varies with tubing length and the capacity of the pump. The following table shows the amount of time for evacuation: Table 7 Required time for evacuation when 100 liter/h vacuum pump is used If tubing length is less than 33 ft. (10 m) If tubing length is more than 33 ft. (10 m) 10 min. or more 15 min. or more 19 Charging hose (Exclusively for R410A) Vacuum pump adapter (Exclusively for R410A) (with reverse flow prevention) Vacuum pump Fig. 57 NOTE To prevent other refrigerants from being mistakenly charged to units which use R410A, the size of the charge port on the service valve is different from the one for other refrigerant types. For servicing such as recharging, the specified charging hose, manifold and vacuum pump adapter (with reverse flow prevention) for R410A must be used. NOTE The required time in Table 7 is calculated based on the assumption that the ideal (or target) vacuum condition is around 10 mmHg abs.