Sanyo 24KHS72 Service Manual - Page 108

I Basic Functions of the Service Valves The basic functions of the service valves are given in Table 8 below. Table 8 Action Shipping Narrow Tube Service Valve (2-Way) CLOSED Wide Tube Service Valve (3-Way) O-ring Valve cap Stem Operating and test running the air conditioner Fully OPEN Fully OPEN Measuring pressure * and gas charging Air purging with a vacuum pump CLOSED * The service port on the wide tube ser- * vice valve uses a Schrader core valve to access the refrigerant system. Therefore, be sure to use a hose con- nector which has a push-pin inside. (Fig. 60a) CAUTION When opening or clos- ing the service valve Open stem, use the accessory hex wrench. Be sure to fully seat the wrench before turning the valve. Close Hex wrench Fig. 60b I Pump Down Pump down means collecting all refrigerant gas in the system back into the outdoor unit without losing any of the gas. Pump down is used when the unit is to be moved or before servicing the refrigerant circuit. Pump Down Procedure Be sure to carry out pump down with the unit in cooling mode. (1) Connect the Lo side charging hose of the manifold valve to the service port on the wide tube service valve. Hose with push-pin Service valve PUSH NOTE External diameter of service port R410A: 5/16" Fig. 60a (2) Using a hex wrench, turn the narrow tube service valve clockwise all the way to close the service valve. (Be sure to confirm that the wide tube service valve is fully open.) (3) Press the operation button and start cooling operation. (4) When the low pressure gauge reading falls to 14.2 to 7.1 psi (1 to 0.5 kg/cm2), fully close the wide tube valve stem. Then quickly stop the unit. (5) Disconnect all gauges and hoses, and replace the valve caps as they were before. 22