Daikin SkyAir FCQ18PVJU, Installation Manual

Page: 8 / 16

7 English
REFRIGERANT PIPING WORK 7.
GENERAL INSTRUCTIONS 7-1
For refrigerant pipe of outdoor units, see the installation •
manual attached to the outdoor unit.
Before refrigerant piping work, check which type of refriger-
•
ant is used. Proper operation is not possible if the types of
refrigerant are not the same.
The outdoor unit is charged with refrigerant.
•
DANGER
Refrigerant gas may produce toxic gas if it comes in contact •
with fi re such as from a fan heater, stove or cooking device.
Exposure to this gas could cause severe injury or death.
NOTE
Use a pipe cutter and fl are suitable for the type of refrigerant. •
To prevent dust, moisture or other foreign matter from •
infi ltrating the tube, either pinch the end or cover it with tape.
Do not allow anything other than the designated refrigerant
•
to get mixed into the refrigerant circuit, such as air, etc. If
any refrigerant gas leaks while working on the unit, ventilate
the room thoroughly right away.
Connecting the refrigerant pipe 7-2
When connecting the fl are nut, coat the fl are with ester oil •
or ether oil and initially tighten by hand 3 or 4 turns before
tightening fi rmly.
Ester oil or ether oil.
To prevent fl are nut cracking and gas leaking, be sure to •
use both a spanner and torque wrench together, as shown
in the drawing below, when connecting or disconnecting
pipes to/from the unit.
Torque wrench
Spanner
Pipe union
Flare nut
Refer to the Table 3 for the dimensions of fl are shape. •
Refer to the Table 3 to determine the proper tightening torque. •
Table 3
Pipe
size
(in.)
Tightening torque
(ft.lbf)
Flare
dimensions
A (in.)
Flare shape (in.)
φ
3/8 24.1-29.4 0.504-0.520
A
45
0
±2
0
R0.016-
0.031
90
0
±0.5
0
φ
5/8 45.6-55.6 0.760-0.776
NOTE
Apply ester oil or ether oil around the fl are portions before •
connecting.
The fl are nuts used must be those included with the main
•
body.
Over-tightening may damage the fl are and cause a refriger-
•
ant leakage.
Not recommended but in case of emergency
You must use a torque wrench but if you are obliged to
install the unit without a torque wrench, you may follow the
installation method mentioned below.
After the work is fi nished, make sure to check that there
is no gas leak.
When you keep on tightening the fl are nut with a spanner,
there is a point where the tightening torque suddenly in-
creases. From that position, further tighten the fl are nut the
angle shown below:
Table 4
Pipe size
(in.)
Further tightening
angle
Recommended arm length of
tool (in.)
φ
3/8 60 to 90 degrees Approx. 7 7/8
φ
5/8 30 to 60 degrees Approx. 11 13/16
Piping insulation 7-3
Execute heat insulation work completely on both sides of •
the gas pipe and the liquid pipe. Otherwise, a water leakage
can result sometimes.
The temperature of the gas pipe can reach up to approxi-
•
mately 250°F, so use insulation which is suffi ciently resistant.
Also, in cases where the temperature and humidity of the
•
refrigerant pipe sections might exceed 86°F or RH80%,
reinforce the refrigerant insulation. (13/16 in. or thicker)
Condensate may form on the surface of the insulating
material.
Check the pipe connector for gas leaking, then insulate it as
•
shown in the drawing below.
Make absolutely sure to execute heat insulation works on
•
the pipe-connecting section after checking gas leakage by
thoroughly studying the following fi gure and using the
attached heat insulating materials for fi tting. (Fasten both
ends with the clamps (accessory).)
Wrap the sealing pad (accessory) only around the insula-
•
tion for the joints on the gas pipe side.
Medium sealing
pad (11) (accessory)
(Wrap the piping union
with the sealing pad.)
Clamp (4) ×4
(accessory)
Insulation for
fitting (9) (accessory)
(for liquid line)
Insulation for fitting (8)
(accessory)
(for gas line)
Gas pipe
Liquid pipe
01_EN_3PN06240-13M.indd 7 01_EN_3PN06240-13M.indd 7 12/25/2008 5:40:06 PM 12/25/2008 5:40:06 PM