55• Confirm the red mark of the union (thin side) is always at lower direction after connecting piping.Vacuum dryingAfter completing the piping connection, execute vacuum drying for the connecting piping and the indoor unit.The vacuum drying must be carried out by using the service ports of both the liquid and gas side valves.10.4.5. Indoor unit drain piping• Drain piping must have down-slope (1/50 to 1/100): be sure not to provide up-and-down slope to prevent reversal flow.• During drain piping connection, be careful not to exert extra force on the drain port at the indoor unit.• The outside diameter of the drain connection at the indoor unit is 32 mm.• Be sure to perform heat insulation on the drain piping.Drain TestThe air conditioner uses a drain up motor to drain water. Use the following procedure to test the drain up motor operation.• Connect the main drain pipe to exterior and leave it provisionally until the test comes to an end.• Feed water to the flexible drain hose and check the piping for leakage.CAUTION Use two wrenches and tighten with regular torque.Flare nut fastening torque N.m (kgf.cm)ø6.35 mm 18 (180) ø12.7 mm 55 (560) ø19.05 mm 100 (1020)ø9.52 mm 42 (430) ø15.88 mm 65 (660)Liquid side piping Gas side pipingø9.52 mm ø15.88 mmPiping material: Polyvinyl chloride pipe VP-25 and pipe fittingsHeat insulation material: Polyethylene foam with thickness more than 8mm (local supply).
