Pipe Installation; Vacuum - Fujitsu AOU36RLXFZ1 Installation Manual

6. PIPE INSTALLATION - 2

6. 1. Vacuum

CAUTION
Always use a vacuum pump to purge the air.
Refrigerant for purging the air is not charged in the outdoor unit at the factory.
Refrigerant must not be discharged into atmosphere.
Use a vacuum pump, gauge manifold and charge hose for R410A exclusively. Using
the same vacuum for different refrigerants may damage the vacuum pump or the unit.
After connecting the piping, check the joints for gas leakage with gas leak detector or
soapy water.
6. 1. 1. Checking gas leakage and purging air
Gas leak checks are performed using either vacuum or nitrogen gas, so select the
proper one depending on the situation.
Checking gas leaks with vacuum:
(1) Check if the piping connections are secure.
(2) Remove the cap of 3-way valve, and connect the gauge manifold charge hoses to
the charging port of the 3-way valve.
(3) Open the valve of the gauge manifold fully.
(4) Operate the vacuum pump and start pump down.
(5) Check that the compound pressure gauge reads -0.1 MPa (500 microns), operate
the vacuum pump for 30 minutes or more in each valve.
(6) At the end of pump down, close the valve of the gauge manifold fully and stop the
vacuum pump.
(It checks that leave as it is for about 10 minutes, and a needle does not return.)
(7) Disconnect the charge hose from the 3-way valve charging port.
(8) Remove the blank caps, and fully open the spindles of the 2-way and 3-way
valves with a hexagon wrench.
[torque: 4.4 to 5.2 lbf·ft. (6 to 7 N·m)].
(9) Tighten the blank caps and charging port cap of the 2-way valve and 3-way valve
to the specified torque.
Checking gas leaks with nitrogen gas:
(1) Check if the piping connections are secure.
(2) Remove the cap of 3-way valve, and connect the gauge manifold charge hoses to
the charging port of the 3-way valve.
(3) Pressurize with nitrogen gas using the 3-way valve charging port.
(4) Do not pressurize up to the specified pressure all at once but do so gradually.
1 Increase the pressure up to 73 psi (0.5 MPa), , let it sit for about 5 minutes and
then check for any decrease in pressure.
2 Increase the pressure up to 218 psi (1.5 MPa),, let it sit for about 5 minutes
and then check for any decrease in pressure.
3 Increase the pressure up to the specified pressure (the pressure designed for
the product) and then make a note of it.
(5) Let it sit at the specified pressure and if there is no decrease in pressure then it is
satisfactory. If a pressure decrease is confirmed, there is a leak, so it is necessary
to specify the leak location and make minor adjustments.
(6) Discharge the nitrogen gas and starting removing the gas with a vacuum pump.
(7) Open the valve of the gauge manifold fully.
(8) Operate the vacuum pump and start pump down.
(9) Check that the compound pressure gauge reads -0.1 MPa (500 microns), operate
the vacuum pump for 30 minutes or more in each valve.
(10) At the end of pump down, close the valve of the gauge manifold fully and stop the
vacuum pump.
(11) Disconnect the charge hose from the 3-way valve charging port.
(12) Remove the blank caps, and fully open the spindles of the 2-way and 3-way
valves with a hexagon wrench.
[torque : 4.4 to 5.2 lbf·ft. (6 to 7 N·m)].
(13) Tighten the blank caps and charging port cap of the 2-way valve and 3-way valve
to the specified torque.
1/4 (6.35)
3/8 (9.52)
Blank cap 1/2 (12.70)
5/8 (15.88)
3/4 (19.05)
Charging port cap [lbf·ft. (N·m)]
Hexagon wrench
Charging port
Service charge hose
with valve core
Service charge hose
with valve core
Service charge hose
with valve core
Service charge hose
with valve core
Gauge manifold
Lo Hi
Service charge hose
CAUTION
Do not purge the air with refrigerants, but use a vacuum pump to vacuum the
installation! There is no extra refrigerant in the outdoor unit for air purging!
Use a vacuum pump and gauge manifold and charging hose for R410A exclusively.
Using the same vacuum for different refrigerants may damage the vacuum pump or
the unit.
Tightening torque [lbf·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)
7.4 to 8.8 (10 to 12)
Blank cap
Spindle
Charging port cap
Vacuum pump
En-12