Daikin RR20AVAK9 Installation & Service Reference page 19

Ceiling Concealed Drain Piping Work
• To avoid damage caused by leaks and condensation, the drain pipe must be installed as shown in Figure 12.
• For best results, keep the piping as short as possible. Slant the piping at an angle to improve the flow.
• Ensure the drain pipe is securely insulated.
• It is necessary to provide a drain trap in the drain outlet to relieve pressure that exists within the unit as compared to the
outside atmospheric pressure when the unit is operating. The drain trap is to avoid the possibility of splashes or an odor.
• Keep pipes as straight as possible for easy cleaning and to prevent the accumulation of dirt and debris.
• Conduct a water drainage test after the installation is completed. Make sure that the drainage flow is smooth.
• In humid environments, use an extra drain pan to cover the entire area of the indoor unit.
Piping Works and Flaring Techniques
• Do not use contaminated or damaged copper tubing. If
any piping, evaporator or condenser has been exposed
or has been opened for 15 second or more, the system
must be vacuumed. Generally, do not remove plastic,
rubber plugs and brass nuts from the valves, fittings,
tubings and coils until it is ready for connection.
• If brazing work is required, ensure that nitrogen gas is
passed through the piping and joints while the brazing
work is being done. This will eliminate soot formation
on the inside walls of the copper tubings.
• Cut the pipe stage by stage, advancing the blade of pipe
cutter slowly. Extra force and deep cuts will cause more
distortion of the pipe and therefore, extra burrs. See Fig-
ure 13A.
• Remove burrs from cut edges of pipes with a remover,
as shown in Figure 13B. This will avoid unevenness on
the flare faces, which will cause gas leaks.
Hold the pipe on the top position and burr remover at
the lower position to prevent metal chips from entering
the pipe.
Insulate securely
Figure 12
Figure 13A
Cutting Copper Tube
1/4t
Figure 13B
Remove Burr
Figure 13C
Copper Tube
Swaging Block
19
Bottom of
the unit
Drain
trap
Do not leave in water
Unit: mm
Copper Tube
D