Installing Drain Piping - Mitsubishi Electric PAC-AKA51BC Installation Manual

7. Installing refrigerant piping
7/16 to 13/16
1-3/16 to 2
Fig. 7-4
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.
C Apply refrigeration oil to the entire (Fig. 7-2) surface of the flared seat.
D Basically use flared nuts fitted to the body (commercially available flared nuts
may crack).
5 ft or less
Fig. 7-5

8. Installing drain piping

Type A
11 10 11
Type B
11
10
11
Fig. 8-1
5 to 7 ft 9-7/8 inch
Fig. 8-2
6
(inch)
Support
Pipe cover
(inch)
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.
F Band 9
G Pipe covers 3456
H Tighten
J Refrigerant piping
L Thermal insulation for 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.
() In order to prevent condensation, install the pipe covers
with the supplied bands .
9
Table 3
Diameters of branch box openings for
connecting indoor units (inch, mm)
1/4, ø6.35
3/8, ø9.5
1/, ø1.7
► Refrigerant charge:
Refer to the installation manual of the outdoor unit.
Use only R410A refrigerant (use of other refrigerants may cause troubles).
Caution:
To avoid excessive strain on the branch box, support the piping with one or
more support(s) 5 ft or less from the branch box.
Refer to Fig. 7-5 as an example.
J Refrigerant piping
L Thermal insulation for refrigerant piping
• 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 66 ft. (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 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)
() Insert a hard PVC pipe (O.D. 13/16 inch, 0 mm, procure locally) into the at-
tached drain hose and glue it together and fix it. (Fig. 8-1)
0
A O.D. 13/16 inch, 0 mm procured locally
B Thermal insulation
(3) Fit a band to the attached drain hose
1
(4) Ensure that the drain piping down-gradient is greater than 1/100. (Fig. 8-)
C Supports
D Down-gradient greater than 1/100.
E 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
7 8
Tightening torque
(ft•lbs, N•m)
8-11, 13 ± 
1-4, 30 ± 
35-38, 50 ± 
onto the connection as far as it will
0
(Fig.8-1)
0