CAUTION Use two wrenches and tighten with regular torque
• The height of drain may be possible up to 750 mm. • When drain set piping, install as shown in the figure below.
Vacuum drying
After 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.
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 size piping Gas side piping
ø6.35 mm (1/4”)ø12.7 mm (1/2”)

11.2.4. 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.
• Be sure to check no air trap and to ensure smooth water flow and no abnormal.
• 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 32mm.
Piping material: Polyvinyl chloride pipe VP-25 and pipe fittings.
• Be sure to perform heat insulation on the drain piping.
Heat insulation material: Polyvinylene foam with thickness more than 8 mm (local supply).
Drain Test The 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.
• Be sure to check the drain up motor for normal operating and noise when electric wiring is complete.
• When the test is complete, connect the flexible drain hose to the drain port.
• Pour about 600-700cc of water in the drain pan of the indoor unit. (Pour from the position specified in the drawing by using a
water supply bottle or other suitable tool.)
• Press the drain pump test run on pcb to start the drain motor, and verity water drainage.
(The drain motor will automatically stop after operating for about five minutes.)
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CS-E15DB4EW CU-E15DBE / CS-E18DB4EW CU-E18DBE / CS-E21DB4ES CU-E21DBE