Refrigerant Piping Work - Mitsubishi Electric MR. SLIM SLZ-M15FA Installationshandbuch

5. Refrigerant piping work
A
SLZ-M15, M25, M35: ø9.52
SLZ-M50: ø12.7
SLZ-M60: ø15.88
Fig. 5-1
b
a
90
Fig. 5-2
b
a
c
d
Fig. 5-3
Fig. 5-4
a
A
b
c
Fig. 5-5
6
A Indoor unit
B Outdoor unit
ø6.35
B
a Copper tubes
c
b Good
d e f
c No good
d Tilted
e Uneven
f Burred
a Burr
b Copper tube/pipe
c Spare reamer
d Pipe cutter
a
a Flare nut
b Copper tube
b
a Flaring tool
e
b Die
c Copper tube
b
d Flare nut
d
e Yoke
c
5.1. Precautions
For devices that use R32/R410A refrigerant
• Use alkylbenzene oil (small amount) as the refrigeration oil applied to the
flared sections.
• Use C1220 copper phosphorus for copper and copper alloy seamless pipes,
to connect the refrigerant pipes. Use refrigerant pipes with the thicknesses
specified in the table below. Make sure the insides of the pipes are clean
and do not contain any harmful contaminants such as sulfuric compounds,
oxidants, debris, or dust.
Warning:
W hen installing or relocating, or servicing the air conditioner, use only the
specified refrigerant written on outdoor unit to charge the refrigerant lines.
Do not mix it with any other refrigerant and do not allow air to remain in the
lines.
I f air is mixed with the refrigerant, then it can be the cause of abnormal high
pressure in the refrigerant line, and may result in an explosion and other haz-
ards.
The use of any refrigerant other than that specified for the system will cause
mechanical failure or system malfunction or unit breakdown. In the worst
case, this could lead to a serious impediment to securing product safety.
5.2. 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
SLZ-M15
For liquid 6.35 1/4
SLZ-M25
For gas 9.52 3/8
SLZ-M35
For liquid 6.35 1/4
SLZ-M50
For gas 12.7 1/2
For liquid 6.35 1/4
SLZ-M60
For gas 15.88 5/8
(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.
5.3. Flaring work
• Main cause of gas leakage is defect in flaring work.
Carry out correct flaring work in the following procedure.
5.3.1. Pipe cutting (Fig. 5-2)
• Using a pipe cutter cut the copper tube correctly.
5.3.2. 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.
5.3.3. 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)
5.3.4. Flaring work (Fig. 5-5)
• Carry out flaring work using flaring tool as shown at the right.
A (mm)
Pipe diameter
When the tool for
(mm)
R32/R410A is used
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.
Min. wall Insulation Insulation
thickness thickness material
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
gravity
0.8 mm 8 mm
1.0 mm 8 mm
Dimension
+0
B (mm)
-0.4
9.1
13.2
16.6
19.7