Refrigerant Piping Work - Mitsubishi Electric Mr.Slim SUZ-KA25 Manual De Instalación

5. Refrigerant piping work

(B)
(C)
Fig. 5-1
ø9.52
ø12.7
ø15.88
Fig. 5-2
90°
Fig. 5-3
Fig. 5-4
Fig. 5-5
A
Fig. 5-6
4
(A)
A Indoor unit
Outdoor unit
B
A Indoor unit
Outdoor unit
B
ø6.35
ø9.52
a Copper tubes
Good
b
c No good
d Tilted
Uneven
e
f Burred
a Burr
Copper tube/pipe
b
c Spare reamer
d Pipe cutter
a Flare nut
b Copper tube
a Flaring tool
b Die
Copper tube
c
d Flare nut
e Yoke
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)
SUZ-KA25/KA35 Max. 20 m
SUZ-KA50/KA60/KA71 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
SUZ-KA25/KA35 type 30 g × (refrigerant piping length (m) -7)
Refrigerant
SUZ-KA50/KA60 type 20 g × (refrigerant piping length (m) -7)
to be added
SUZ-KA71 type
(1) Table below shows the specifi cations of pipes commercially available.
Outside diameter
Model Pipe
mm
For liquid 6.35
SUZ-KA25
For gas 9.52
For liquid 6.35
SUZ-KA35
For gas 9.52
For liquid 6.35
SUZ-KA50
For gas 12.7
For liquid 6.35
SUZ-KA60
For gas 15.88
For liquid 9.52
SUZ-KA71
For gas 15.88
(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 specifi ed 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 fl aring work.
Carry out correct fl aring 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 fl are nuts attached to indoor and outdoor unit, then put them on pipe/tube
having completed burr removal.
(not possible to put them on after fl aring work)
5.2.4. Flaring work (Fig. 5-6)
• Carry out fl aring work using fl aring tool as shown at the right.
Pipe diameter A (mm)
(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
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. 12 m Max. of 10
Max. 30 m Max. of 10
No additional charge is required.
Additional charge is required.
(Refer to the table below.)
55 g × (refrigerant piping length (m) -7)
Min. wall Insulation Insulation
thickness thickness material
inch
1/4 0.8 mm 8 mm
3/8 0.8 mm 8 mm
1/4 0.8 mm 8 mm
3/8 0.8 mm 8 mm
Heat resisting
1/4 0.8 mm 8 mm
foam plastic
0.045 specifi c
1/2 0.8 mm 8 mm
gravity
1/4 0.8 mm 8 mm
5/8 0.8 mm 8 mm
3/8 0.8 mm 8 mm
5/8 1.0 mm 8 mm
Dimension
+0
B (mm)
-0.4
9.1
13.2
16.6
19.7