Indoor/Outdoor Units Connection Finishing And; Test Run; Flaring Work - Mitsubishi Electric MXZ-A26/32WV Installation Manual

5. INDOOR/OUTDOOR UNITS CONNECTION FINISHING AND

TEST RUN

5-1 FLARED CONNECTIONS
PIPE LENGTH AND HEIGHT DIFFERENCE
Limits A26WV
Pipe length per indoor unit 25 m max.
Total pipe length for multi-system 50 m max.
Height difference 10 m max.
No. of bends per indoor unit 25 max.
Total No. of bends for multi-system 50 max.
Refrigerant adjustment ....... If pipe length exceeds 40 m, additional refrigerant (R410A) charge is required.
(The outdoor unit is charged with refrigerant for total pipe length up to 40 m.)
Up to 40 m
Pipe length
Exceeding 40 m
20 g/m × (refrigerant piping length(m)-40)
Refrigerant to be added
Î UNIT
Indoor unit
Ç UNIT
Indoor unit
Indoor unit ı UNIT
Å UNIT
Indoor unit
• For pipe size, see the table below.
SELECTING PIPE SIZE
The diameter of connection pipes differs according to the type and capacity of indoor units. Match the diameters
of connection pipes for indoor and outdoor units according to the following table.
Model Allowable
Pipe size for indoor unit
name connection pipe size
07 Liquid pipe ø6.35 mm ø6.35 mm
09 Gas pipe ø9.52 mm ø9.52 mm
12 Liquid pipe ø6.35 mm ø6.35 mm
13 Gas pipe ø9.52/ø12.7 mm ø9.52/ø12.7 mm
Liquid pipe ø6.35 mm ø6.35 mm
18
Gas pipe ø12.7 mm ø12.7 mm
Liquid pipe ø6.35 mm ø6.35 mm
24
Gas pipe ø15.88 mm ø15.88 mm
Liquid pipe ø9.52 mm ø9.52 mm
26
Gas pipe ø15.88 mm ø15.88 mm
A32WV
25 m max.
70 m max.
10 m max.
25 max.
70 max.
No additional charge is required.
Additional charge is required.
(Refer to the table below.)
Outdoor
unit
(MXZ-A32WV)
MXZ-A32WV
Valve size for outdoor unit
Liquid pipe
Å UNIT
Gas pipe
Liquid pipe
ı UNIT
Gas pipe
Liquid pipe
Ç UNIT
Gas pipe
Liquid pipe
Î UNIT
Gas pipe
MXZ-A26WV
Valve size for outdoor unit
Liquid pipe
Å UNIT
Gas pipe
Liquid pipe
ı UNIT
Gas pipe
Liquid pipe
Ç UNIT
Gas pipe
* Connections at outdoor unit are described as unit A, B, C and D below corresponding to the indica-
tion on each valve.
• If the diameter of connection pipes does not match the diameter of pipe end connections, use optional
different-diameter joints.
• When connecting the model 12, 13 or 18 to either unit A or B for MXZ-A32WV and B or C for MXZ-A26WV,
use optional different-diameter joints MAC-A454JP because the valve size of gas pipes for the outdoor unit
is ø9.52 mm. (No need to use different-diameter joints if the diameter of the pipe is ø9.52 mm.)
• When connecting the model 07 or 09 to either unit A or B for MXZ-A32WV and A for MXZ-A26WV, use
optional different-diameter joints MAC-A455JP because the valve size of gas pipes for the outdoor unit is
ø12.7 mm.
• When connecting the model 24 to either unit A or B for MXZ-A32WV and A for MXZ-A26WV, use optional
different-diameter joints MAC-A456JP because the valve size of gas pipes for the outdoor unit is ø12.7 mm.
• Connect the model 26 to unit A only.
Use optional different-diameter joints MAC-A456JP because the valve size of gas pipes for the outdoor unit
is ø12.7 mm and PAC-493PI because the valve size of liquid pipe is ø6.35 mm.
PIPING PREPARATION
1 If you use commercially available copper pipes, use the following table for pipe specifications.
Outside diameter
Liquid pipe
Gas pipe
Gas pipe
Gas pipe ø15.88 mm
2 For insulation material, use 8 mm-thick heat-insulating expended polyethylene with a specific grarity of 0.045.
3 Ensure that the 2 refrigerant pipes are insulated to prevent condensation.
4 Refrigerant pipe bending radius must be 100 mm or more.
CAUTION:
Be sure to use the insulation of specified thickness. Excessive thickness may cause incorrect installa-
tion of the indoor unit and lack of thickness may cause dew drippage.
5-2

FLARING WORK

• Main cause of gas leakage is defect in flaring work.
ø6.35 mm
Perform flaring work correctly in the following proce-
ø12.7 mm
dure.
ø6.35 mm
ø12.7 mm
1. Pipe cutting
ø6.35 mm
• Cut the copper pipe correctly with pipe cutter.
ø9.52 mm
ø6.35 mm
2. Burrs removal
ø9.52 mm
• Completely remove all burrs from the cut cross
section of the pipe.
• Put the end of the copper pipe downward to pre-
vent burrs from dropping in the pipe.
ø6.35 mm
ø12.7 mm
3. Putting nut on
ø6.35 mm
ø9.52 mm
• Remove flare nuts attached to indoor and outdoor
ø6.35 mm
units, then put them on pipe having completed
ø9.52 mm
burr removal.
(not possible to put them on after flaring work)
6
Wall thickness
ø6.35 mm 0.8 mm
ø9.52 mm 0.8 mm
ø12.7 mm 1.0 mm
1.0 mm
Copper
pipe
No good
Good
Tilted Uneven Burred
90°
Copper pipe
Burr
Spare
reamer
Pipe cutter
Flare nut
Copper pipe