Vacuum Process; Additional Charging; Electrical Wiring - Fujitsu LM Series Installation Manual

• After connecting the pipes, perform a sealing test.
• Make sure that the 3-way valves are closed before performing a sealing test.
• Pressurize nitrogen gas to 4.15 MPa to perform the sealing test.
• Add nitrogen gas to both the liquid pipes and the gas pipes.
• Check all fl are connections and welds. Then, check that the pressure has not
decreased.
• Compare the pressures after pressurizing and letting it stand for 24 hours, and check
that the pressure has not decreased.
* When the outdoor air temperature changes 41 °F (5 °C), the test pressure changes
0.05 MPa. If the pressure has dropped, the pipe joints may be leaking.
• If a leak is found, immediately repair it and perform the sealing test again.
• After completing the sealing test, release the nitrogen gas from both valves.
• Release the nitrogen gas slowly.

3.8. Vacuum process

• Perform a refrigerant leakage test (air tightness test) to check for leaks using
nitrogen gas while all valves in the outdoor unit are closed. (Use the test pressure
indicated on the nameplate.)
• Be sure to evacuate the refrigerant system using a vacuum pump.
• The refrigerant pressure may sometimes not rise when a closed valve is opened
after the system is evacuated using a vacuum pump. This is caused by the closure
of the refrigerant system of the outdoor unit by the electronic expansion valve. This
will not affect the operation of the unit.
• If the system is not evacuated suffi ciently, its performance will drop.
• Use a clean gauge manifold and charging hose that were designed specifi cally for
use with R410A. Using the same vacuum equipment for different refrigerants may
damage the vacuum pump or the unit.
• Do not purge the air with refrigerants, but use a vacuum pump to evacuate the
system.
Refrigerant for purging the air is not charged in the outdoor unit at the factory.
(1) Remove the cap, and connect the gauge manifold and the vacuum pump to the
charging valve by the service hoses.
(2) Vacuum the indoor unit and the connecting pipes until the pressure gauge indicates
–0.1 MPa (–76 cmHg).
(3) When –0.1 MPa (–76 cmHg) is reached, operate the vacuum pump for at least
60 minutes.
(4) Disconnect the service hoses and fi t the cap to the charging valve to the specifi ed
torque.
(5) Remove the blank caps, and fully open the spindles of the 3-way valves with a
hexagon wrench [Torque: 4 to 5 lbs·ft (6~7 N·m)].
(6) Tighten the blank caps of the 3-way valves to the specifi ed torque.
1/4 (6.35)
3/8 (9.52)
Blank cap
1/2 (12.70)
[in (mm)]
5/8 (15.88)
3/4 (19.05)
Charging port cap
Use a 3/16 in (4 mm) hexagon wrench
Flare nuts
Service valve
(liquid)
Service valve
(gas)
Charging port
Charging port cap

3.9. Additional charging

When moving and installing the air conditioner, do not mix gas other than the specifi ed
refrigerant R410A inside the refrigerant cycle.
If air or other gas enters the refrigerant cycle, the pressure inside the cycle will rise to
an abnormally high value and cause breakage, injury, etc.
CAUTION
Tightening torque [lbs·ft (N·m)]
14.8 to 18.4 (20 to 25)
14.8 to 18.4 (20 to 25)
18.4 to 22.1 (25 to 30)
22.1 to 25.8 (30 to 35)
25.8 to 29.5 (35 to 40)
7 to 9 (10 to 12)
Gauge manifold
Blank caps
Vacuum pump
WARNING
• After vacuuming the system, add refrigerant.
• Do not reuse recovered refrigerant.
• When charging the refrigerant R410A, always use an electronic scales for refrigerant
charging (to measure the refrigerant by weight). Adding more refrigerant than the
specifi ed amount will cause a malfunction.
• When charging the refrigerant, take into account the slight change in the composition
of the gas and liquid phases, and always charge from the liquid phase side
whose composition is stable. Adding refrigerant through the gas pipe will cause a
malfunction.
• Check if the steel cylinder has a siphon installed or not before fi lling. (There is an
indication "with siphon for fi lling liquid" on the steel cylinder.)
Filling method for cylinder with siphon
R410A
Set the cylinder vertical and fi ll with the liquid.
Gas
(Liquid can be fi lled without turning bottom up with the
siphon inside.)
Liquid
Filling method for other cylinders
R410A
Gas Turn bottom up and fi ll with liquid.
(Be careful to avoid turning over the cylinder.)
Liquid
• Be sure to use the special tools for R410A for pressure resistance and to avoid
mixing of impure substances.
• If the units are further apart than the maximum pipe length, correct operation can not
be guaranteed.
• Make sure to back closing valve after refrigerant charging. Otherwise, the
compressor may fail.
• Minimize refrigerant release to the air. Excessive release is prohibited under the
Freon Collection and Destruction Law.
■ Gas leakage inspection
After connecting the piping, check the all joints for gas leakage with gas leak detector.

3.10. Electrical wiring

3.10.1. Conduit installation
(1) Remove the tapping screw, then remove the conduit cover.
(2) Fasten the Inter-unit wire harness and power supply to the conduit holder using
the lock nut.
(3) Connect inter-unit wire harness and power supply to the terminal.
(4) Use the tapping screw to install the conduit cover.
NOTES:
• Connector trade size for this unit is 1/2 inch. The connector can be bought at a hard
ware store. Refer to "3.10.2. Notes for electrical wiring ■ How to connect wiring to the
terminal".
• The fuse located in the outdoor unit provides power supply protection and may blow
when power is applied if the system has been incorrectly wired.
Lock nut
CAUTION
CAUTION
Power supply
Inter-unit wire harness
Conduit connector
Tapping screw
Conduit cover
En-7