Refrigerant Piping Work; Flaring Work - Mitsubishi Electric SUHZ-SW VA series Installation Manual

5. Refrigerant piping work

A
(B)
(C)
Fig. 5-1
A
ø12.7
Fig. 5-2
b
a
90°
Fig. 5-3
b
a
c
Fig. 5-4
Fig. 5-5
A
a
b
c
Fig. 5-6
4
(A)
Indoor unit
A
Outdoor unit
B
B
Indoor unit
A
Outdoor unit
B
ø6.35
B
Copper tubes
a
Good
b
c
No good
c
d e f
Tilted
d
Uneven
e
Burred
f
Burr
a
Copper tube/pipe
b
Spare reamer
c
d
Pipe cutter
d
a
Flare nut
a
Copper tube
b
b
Flaring tool
a
e
Die
b
Copper tube
c
b
Flare nut
d
d
Yoke
e
c
5.1. Refrigerant pipe (Fig. 5-1)
► Check that the difference between the heights of the indoor and outdoor
units, the length of refrigerant pipe, and the number of bends in the pipe are
within the limits shown below.
(A) Pipe length
Models
(one way)
SUHZ-SW45 Max. 30 m
• Height difference limitations are binding regardless of which unit, indoor or out-
door, is positioned higher.
• Refrigerant adjustment ... If pipe length exceeds 7 m, additional refrigerant
(R410A) charge is required.
(The outdoor unit is charged with refrigerant for pipe length up to 7 m.)
Up to 7 m
Pipe length
Exceeding 7 m
Refrigerant
SUHZ-SW45
to be added
Piping preparation
• Refrigerant pipes of 3, 5, 7, 10 and 15 m are available as optional items.
(1) Table below shows the specifications of pipes commercially available.
Outer diameter
Model Pipe
mm
For liquid 6.35
SUHZ-
SW45
For gas 12.7
(2) Ensure that the 2 refrigerant pipes are well insulated to prevent condensation.
(3) Refrigerant pipe bending radius must be 100 mm or more.
Caution:
Using careful insulation of specified thickness. Excessive thickness prevents
storage behind the indoor unit and smaller thickness causes dew drippage.

5.2. Flaring work

• Main cause of gas leakage is defect in flaring work.
Carry out correct flaring work in the following procedure.
5.2.1. Pipe cutting (Fig. 5-3)
• Using a pipe cutter cut the copper tube correctly.
5.2.2. Burrs removal (Fig. 5-4)
• Completely remove all burrs from the cut cross section of pipe/tube.
• Put the end of the copper tube/pipe to downward direction as you remove burrs in
order to avoid burrs drop in the tubing.
5.2.3. Putting nut on (Fig. 5-5)
• Remove flare nuts attached to indoor and outdoor unit, then put them on pipe/tube
having completed burr removal.
(not possible to put them on after flaring work)
5.2.4. Flaring work (Fig. 5-6)
• Carry out flaring work using flaring tool as shown at the right.
Pipe diameter
A (mm)
When the tool for R410A is used
(mm)
Clutch type
6.35 0 - 0.5
9.52 0 - 0.5
12.7 0 - 0.5
15.88 0 - 0.5
Firmly hold copper tube in a die in the dimension shown in the table at above.
(B) Height (C) Number of
difference bends (one way)
Max. 30 m Max. of 10
No additional charge is required.
Additional charge is required.
(Refer to the table below.)
15 g × (refrigerant piping length (m) -7)
Min. wall Insulation Insulation
thickness thickness material
inch
Heat resisting
1/4 0.8 mm 8 mm
foam plastic
0.045 specific
1/2 0.8 mm 8 mm
gravity
Dimension
+0
(mm)
B
-0.4
9.1
13.2
16.6
19.7