10English7. DRAIN PIPING WORK(1) Carry out drain piping.Carry out drain piping so that drainage is ensured.• Select the piping diameter equal to or larger than(except for riser) that of the connection piping (polyvi-nyl chloride piping, nominal diameter 13/16 in. (25 mm),outside diameter 1-1/4 in. (32 mm)).• Install the drain piping as short as possible with down-ward inclination of 1/100 or more and without such thatair may not stagnate. (Refer to Fig. 13) (It may causeabnormal sound such as bubbling noise.)Downwardinclination of1/100 or more40-60 in.(1-1.5 m)SupportGoodWrongFig. 13CAUTIONIf drain stagnates in the drain piping, the piping may beclogged.• If sufficient downward inclination cannot be ensured,carry out upward drain piping.• Install supports at a distance of 40-60 in. (1 to 1.5 m) sothat the piping may not deflect. (Refer to Fig. 13)• Make sure to use the attached drain hose (2) and themetal clamp (1).Insert the drain hose (2) into the drain socket up to thepoint where the socket diameter becomes larger.Put the metal clamp (1) to the taped hose end andtighten the metal clamp (1) with torque 0.9-1.1 lbf·ft.(1.2-1.5 N·m).Metal clamp (1)(accessory)TapeIndoor unitDrain hose (2)(accessory)Fig. 14CAUTION• Do not tighten the metal clamp (1) with the torque morethan the specified value.The drain hose (2), the socket or the metal clamp (1) maybe damaged.• Wrap the vinyl tape around the end of the metal clamp(1) so that the sealing material (Large) (6) to be used atthe next process may not be damaged with the clampend or bend the tip of the metal clamp (1) inward asshown. (Refer to Fig. 15)Tightened partapprox. 90°Stick vinyl tape withouttearing the sealingmaterial (Large) (6).Vinyl tapeBend the tip without tearing thesealing material (Large) (6).Tightened partapprox. 90°Fig. 15