4. Cut the refrigerant pipes coming from the indoor unit with a pipe cutter
and deburr.
5. Liquid line: use the new nut from the accessory bag.
6. Gas line: use the new nut from the accessory bag.
7. Flare the refrigerant pipes.
8. Apply refrigerant oil to the flared parts to facilitate tightening and
improve the seal.
9. Tighten the connections, observing the given tightening torques.
Tab.103
External diameter of
the pipe (mm/inch)
External diameter of
the cone fitting (mm)
Torque load (N.m)
6.35 - 1/4
17
14 - 18
9.52 - 3/8
22
34 - 42
12.7 - 1/2
26
49 - 61
15.88 - 5/8
29
69 - 82
19.05 - 3/4
36
100 - 120
5.10.5 Testing the leak-tightness of the refrigerant connections
1. Remove the protective cap from the service connection on the stop
valve.
2. Connect the pressure gauge and the nitrogen bottle to the service
connection then progressively build up the pressure in the refrigerant
connection pipes and the indoor unit to 42 bar, in 5 bar increments.
3. Check the leak-tightness of the refrigerant connections on the indoor
and outdoor units, using a leak detector spray. If leaks appear, repair
the leak and repeat the steps 1 to 3 in order and check the leak-
tightness once again.
4. Release the pressure and release the nitrogen.
5.10.6 Vacuum
Perform evacuation after checking that the refrigerant circuit is entirely free
of leaks. Evacuation is necessary to remove air and moisture from the
refrigerant circuit.
1. Connect the vacuum gauge and the vacuum pump to the service
connection.
2. Produce a vacuum in the indoor unit and the refrigerant connection
pipes.
3. Check the pressure and the vacuum according to the
recommendations table below. Refer also to local legislation.
Outdoor temperature °C
≥ 20
10
0
- 10
Vacuum pressure to
be reached
Pa
(bar)
1000
(0.01)
600
(0.006)
250
(0.0025)
200
(0.002)
Evacuation time after
reaching the vacuum
pressure
h
1
1
2
3
4. Close the valve between the vacuum gauge / vacuum pump and the
service connection.
5. Disconnect the vacuum gauge and the vacuum pump after it has shut
down.
6. Refit the protective cap of the service connection. Torque load 14-18
Nm.
Fig.199
MW-6020072-01
3
7
1/4"
3
5
6
9
9
A
Fig.200
MW-1001650-3
1
42 bar
2
Fig.201
MW-1001651-3
1
Fig.202
MW-1001662-3
6
en
5 Installation
168
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