10. Installation
Ceiling Cassette 1-Way _ 25
Indoor Units
10.6 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 on the indoor unit.
• The outside diameter of the drain connection on the indoor
unit is 32mm.
• Be sure to install heat insulation on the drain piping.
Piping material: Polyvinyl chloride pipe 25mm
and pipe fittings
The air conditioner uses a drain pump to drain water.
Use the following procedure to test the drain pump operation:
                                                                                                     • Connect  the main  drain  pipe to the 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 pump for normal
operating and noise when electrical wiring is
complete.
                                                                • When the test is complete, connect the flexi-
ble drain hose to the drain port on the indoor
unit.
Heat insulation material: Polyethylene foam with
thickness more than 8 mm.
Drain test
CAUTION
The supplied flexible drain hose should not be curved,
neither screwed. The curved or screwed hose may
cause a leakage of water.