Installing Drain Piping - Mitsubishi Electric PAC-AK52BC Installation Manual

7. Installing refrigerant piping
10~20
30~50
Fig. 7-5
Caution:
Tighten the flare nut with a torque wrench in the specified method.
Overtightening will cause the flare nut to crack and it will cause refrigerant
leakage over a period of time.
Apply refrigeration oil to the entire (Fig. 7-3) surface of the flared seat.
Basically use flared nuts fitted to the body (commercially available flared nuts
may crack).

8. Installing drain piping

Type A
11 10
Type B
11
10
11
Fig. 8-1
1.5 to 2 m 25 cm
Fig. 8-2
6
(mm)
(mm)
11
Note:
A special flare nut (optional or attached to the indoor unit) is needed to
some indoor units.
Please refer to the installation manual of outdoor unit and indoor unit for
details.
Section of connection (Fig. 7-4)
Band
Pipe covers
Tighten
Refrigerant piping
Thermal insulation for refrigerant piping
► Use the following procedures for indoor connection part which indoor
unit is not connected. (Fig. 7-5)
(1) In order to prevent refrigerant leaks, make sure that the flare nuts are tightened
according to the specified torques* in Table 3.
* Refrigerant may also leak if the flare nuts are tightened more than the speci-
fied torques.
(2) In order to prevent condensation, install the pipe covers
with the supplied bands .
Table 3
Diameters of branch box openings for
connecting indoor units (mm)
ø6.35
ø9.52
ø12.7
► Refrigerant charge:
Refer to the installation manual of the outdoor unit.
Use only R410A refrigerant (use of other refrigerants may cause troubles).
• To ensure that the drain piping has a down-gradient (greater than 1/100),
do not make traps or humps in piping.
• Install thermal insulation to prevent condensation dripping.
• Ensure that the horizontal length (not diagonal length) of drain piping does not
exceed 20 m. If the drain piping extends over a significant distance, install sup-
ports to ensure that the piping does not sag. Do not fit air bleed pipes under
any circumstances (water may exit from air bleed pipes).
• Do not fit odor traps at drain piping outlets.
• Install drain outlets in locations where odors will not present problems.
• Do not place drain piping directly in drains which may contain sulfurous gases.
• Drain piping may be installed in any direction provided the above requirements
are followed.
• Keep bends of attached drain hose to a maximum of 45°.
(1) Apply PVC adhesive (procure locally) to the drain connection on the branch
box and push the attached drain hose
go. (Fig. 8-1)
(2) Insert a hard PVC pipe (VP-16, procure locally) into the attached drain hose
and glue it together and fix it. (Fig. 8-1)
VP-16 procured locally
Thermal insulation
(3) Fit a band to the attached drain hose
(4) Ensure that the drain piping down-gradient is greater than 1/100. (Fig. 8-2)
Supports
Down-gradient greater than 1/100.
Thermal insulation
Note:
The drain hose is available in either Type A or Type B.
The installation methods are different between Type A and Type B.
and fasten them
Tightening torque
(N·m)
13 ± 2
30 ± 2
50 ± 2
onto the connection as far as it will
(Fig.8-1)