Refrigerant Piping Work; Flaring Work - Mitsubishi Electric Mr.SLIM SLZ-KA25VAQ3 Manuel D'installation

5. Refrigerant piping work
SLZ-KA25, KA35: ø9.52
SLZ-KA50: ø12.7
Fig. 5-1
90
Fig. 5-2
Fig. 5-3
Fig. 5-4
A
Fig. 5-5
B
Fig. 5-6
A
Fig. 5-7
A Indoor unit
B Outdoor unit
ø6.35
a Copper tubes
b Good
c No good
d Tilted
e Uneven
f Burred
a Burr
b Copper tube/pipe
c Spare reamer
d Pipe cutter
a Flare nut
b Copper tube
a Flaring tool
b Die
c Copper tube
d Flare nut
e Yoke
As viewed from A
5.1. Refrigerant pipe (Fig. 5-1)
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.
Outside diameter
Model Pipe
mm inch
For liquid 6.35 1/4
SLZ-KA25
For gas 9.52 3/8
For liquid 6.35 1/4
SLZ-KA35
For gas 9.52 3/8
For liquid 6.35 1/4
SLZ-KA50
For gas 12.7 1/2
(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. 5-2)
• Using a pipe cutter cut the copper tube correctly.
5.2.2. Burrs removal (Fig. 5-3)
• 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. 5-4)
• 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. 5-5)
• Carry out flaring work using flaring tool as shown at the right.
A (mm)
Pipe diameter
(mm)
When the tool for R410A is used
Clutch type
6.35 0 - 0.5
9.52 0 - 0.5
12.7 0 - 0.5
Firmly hold copper tube in a die in the dimension shown in the table at above.
5.2.5. Check (Fig. 5-6)
• Compare the flared work with a figure in right side hand.
• If flare is noted to be defective, cut off the flared section and do flaring work
again.
a Smooth all around
b Inside is shining without any scratches
c Even length all around
d Too much
e Tilted
5.3. Refrigerant and drainage piping locations (Fig.5-7)
A Drain pipe
B Ceiling
C Grille
D Refrigerant pipe (liquid)
E Refrigerant pipe (gas)
F Water supply inlet
G Main unit
Min. wall Insulation Insulation
thickness thickness materia
0.8 mm 8 mm
Heat resist-
0.8 mm 8 mm
ing foam
0.8 mm 8 mm
plastic 0.045
0.8 mm 8 mm
specific
0.8 mm 8 mm
gravity
0.8 mm 8 mm
Dimension
+0
B (mm)
-0.4
9.1
13.2
16.6
f Scratch on flared plane
g Cracked
h Uneven
i Bad examples
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