Removing And Replacing Parts; Pipe Installation; Sealing Test - Fujitsu LM Series Installation Manual

3.5. Removing and replacing parts

3.5.1. Switch cover removal
(1) Remove the tapping screws.
(2) Slide the switch cover downwards to release.
3.5.2. Installing the switch cover
(1) After inserting the hooks (2 places) on the switch cover into the hole on the outdoor
unit, slide the switch cover upwards.
(2) Replace the tapping screws.
Always use the screws as shown above.

3.6. Pipe installation

• Do not use mineral oil on a fl ared part. Prevent mineral oil from getting into the
system as this would reduce the lifetime of the units.
• While welding the pipes, be sure to blow dry nitrogen gas through them.
■ Flaring
(1) Cut the connection pipe to the necessary length with a pipe cutter.
(2) Hold the pipe downward so that cuttings will not enter the pipe and remove the
burrs.
(3) Insert the fl are nut onto the pipe and fl are the pipe with a fl aring tool.
Insert the fl are nut (always use the fl are nut attached to the indoor and outdoor
units respectively) onto the pipe and perform the fl are processing with a fl are tool.
Use the special R410A fl are tool, or the conventional (for R22) fl are tool.
When using the conventional fl are tool, always use an allowance adjustment gauge and
secure the A dimension shown in the following table.
Check if [L] is fl ared uniformly and
is not cracked or scratched.
Pipe outside diameter [in (mm)]
1/4 (6.35)
3/8 (9.52)
1/2 (12.70)
5/8 (15.88)
3/4 (19.05)
■ Bending pipes
(1) When bending the pipe, be careful not to crush it.
(2) To prevent breaking of the pipe, avoid sharp bends.
Bend the pipe with a radius of curvature of 2-3/8 in (70 mm) or more.
(3) If the copper pipe is bend the pipe or pulled too often, it will become stiff. Do not
bend the pipes more than three times at one place.
■ Flare connection
(1) Detach the caps and plugs from the pipes.
• Be sure to apply the pipe against the port on the indoor unit and the outdoor unit
correctly. If the centering is improper, the fl are nut cannot be tightened smoothly. If
the fl are nut is forced to turn, the threads will be damaged.
• Do not remove the fl are nut from the indoor unit pipe until immediately before
connecting the connection pipe.
En-6
Hook
Tapping screw
Switch cover
Hook
CAUTION
Die
A
Pipe
Dimension A [in (mm)]
Flare tool for R410A, clutch type
0 to 0.020
(0 to 0.5)
CAUTION
(2) Centering the pipe against port on the outdoor unit, turn the fl are nut with your
hand.
(3) Tighten the fl are nut of the connection pipe at the outdoor unit valve connector.
2-way valve
(liquid)
3-way valve
(gas)
(4) When the fl are nut is tightened properly by your hand, use a torque wrench to
fi nally tighten it.
Body side
Hold the torque wrench at its grip, keeping it in the right angle with the pipe, in order to
tighten the fl are nut correctly.
Flare nut [in (mm)]
1/4 (6.35) dia.
3/8 (9.52) dia.
1/2 (12.70) dia.
5/8 (15.88) dia.
3/4 (19.05) dia.
• Fasten a fl are nut with a torque wrench as instructed in this manual. If fastened too
tight, the fl are nut may be broken after a long period of time and cause a leakage of
refrigerant.
• During installation, make sure that the refrigerant pipe is attached fi rmly before
you run the compressor. Do not operate the compressor under the condition of
refrigerant piping not attached properly with 3-way valves open. This may cause
abnormal pressure in the refrigeration cycle that leads to breakage and even injury.

3.7. Sealing test

• Before operating the compressor, install the pipes and securely connect them.
Otherwise, if the pipes are not installed and if the valves are open when the
compressor operates, air could enter the refrigeration cycle. If this happens, the
pressure in the refrigeration cycle will become abnormally high and cause damage
or injury.
• After the installation, make sure there is no refrigerant leakage. If the refrigerant
leaks into the room and becomes exposed to a source of fi re such as a fan heater,
stove, or burner, it produces a toxic gas.
• Do not subject the pipes to strong shocks during the sealing test. It can rupture the
pipes and cause serious injury.
• Do not block the walls and the ceiling until the sealing test and the charging of the
refrigerant gas have been completed.
• For maintenance purposes, do not bury the piping of the outdoor unit.
To prevent gas leakage,
coat the flare surface with
alkylbenzene oil (HAB).
Do not use mineral oil.
Connection pipe
(liquid)
Connection pipe
(gas)
Flare nuts
Holding wrench
90°
Torque wrench
CAUTION
Tightening torque [lbf·ft. (N·m)]
11.8 to 13.3 (16 to 18)
23.6 to 31.0 (32 to 42)
36.1 to 45.0 (49 to 61)
46.5 to 55.3 (63 to 75)
66.4 to 81.1 (90 to 110)
CAUTION
WARNING
CAUTION