Evacuation Of The System - Mitsubishi Electric City Multi PURY-P72TNU-A-BS Manuel D'installation

9-7-2. Insulation for the section of the pipe that goes through a wall
(1) Inner wall (concealed)
Ⓐ Ⓑ
(4) Floor (waterproof)
Ⓓ
Ⓕ
Ⓖ
Ⓑ
Ⓐ Sleeve
Ⓑ Insulation material
Ⓒ Lagging
Caulking material
Ⓓ
Band
Ⓔ
Ⓕ Waterproof layer
Ⓖ Sleeve with a flange
Ⓗ Caulk with a nonflammable material such as mortar.
Nonflammable insulation material
Ⓘ
・When caulking the gaps with mortar, cover the section of the pipe that goes through the wall with a metal sheet to prevent the insulation material
from sagging. For this section, use nonflammable insulation and covering materials. (Vinyl tape should not be used.)

9-8. Evacuation of the system

Do not purge the air using refrigerant. Use a vacuum pump to evacuate the system.
- Residual gas in the refrigerant lines will cause bursting of the pipes or an explosion.
Use a vacuum pump with a check valve.
- If the vacuum pump oil flows back into the refrigerant lines, the refrigerant oil may deteriorate and the compressor
may malfunction.
<Evacuation procedures>
① Evacuate the system from both service ports, using a vacuum pump with the service valves closed.
② After the vacuum reaches 650 Pa (0.0943 psi/5 Torr), continue evacuation for at least one hour.
③ Stop the vacuum pump and leave it for an hour.
④ Verify that the vacuum has not increased by more than 130 Pa (0.01886 psi/1 Torr).
⑤ If the vacuum has increased by more than 130 Pa, water infiltration is suspected. Pressurize the system with dry nitrogen gas up to 0.05 MPa
(7.25 psi/375 Torr). Repeat ① though ⑤ until the vacuum is increased by 130 Pa or below. If the results persist, then perform the "Triple
Evacuation" below.
<Triple Evacuation>
① Evacuate the system to 533 Pa (0.07729 psi/4 Torr) from both service ports, using a vacuum pump.
② Pressurize the system with dry nitrogen gas up to 0 Pa (0 psi/0 Torr) from the discharge service port.
③ Evacuate the system to 200 Pa (0.029 psi/1.5 Torr) from the suction service port, using a vacuum pump.
④ Pressurize the system with dry nitrogen gas up to 0 Pa (0 psi/0 Torr) from the discharge service port.
⑤ Evacuate the system from both service ports, using a vacuum pump.
⑥ After the vacuum reaches 66.7 Pa (0.09672 psi/5 Torr), stop the vacuum pump and leave it for an hour. A vacuum of 66.7 Pa must be
maintained for at least one hour.
⑦ Verify that the vacuum has not increased for at least 30 minutes.
WT09106X03
(2) Outer wall
Ⓓ
Ⓒ
Ⓐ
Ⓑ
(5) Rooftop pipe shaft
Ⓓ
Ⓑ
Ⓒ
Ⓕ
(3) Outer wall (exposed)
Ⓔ
Ⓑ
Ⓗ
(6) Protecting the penetrating parts in a fire limit zone or through a
parting wall
Ⓗ
Ⓐ
1000 1000
(39-3/8) (39-3/8)
GB-26
Ⓘ
[mm (in)]