Mitsubishi Electric M Series Manual page 581

M series
7. Installing refrigerant piping
10~20
30~50
Fig. 7-4
8. Installing Drain piping
Fig. 8-1
Fig. 8-2
MULTI SYSTEM Inverter Heat Pump
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. 7-2) surface of the flared seat.
Basically use flared nuts fitted to the body (commercially available flared nuts may crack).
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 de-
tails.
Section of connection (Fig. 7-3)
Band
Pipe covers
Tighten
Thermal insulation for refrigerant piping
Refrigerant piping
Use the following procedures for indoor connection part which indoor unit
is not connected. (Fig. 7-4)
(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)
ø 6 3 . 5
ø 9 5 . 2
ø 1 2 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 supports
to ensure that the piping does not sag. Do not fit air bleed pipes under any circum-
stances (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
(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
and fasten them
Tightening torque
(N·m)
1 3 ± 2
3 0 ± 2
5 0 ± 2
onto the connection as far as it will go.
. (Fig. 8-1)
C-579