Mitsubishi Electric TRANE HVAC US NTXCKS A112 Serie Manual De Instalación página 6

5. Refrigerant piping work
NTXCKS09/12A112BA: ø9.52 (3/8")
NTXCKS15/18A112BA: ø12.7 (1/2")
Fig. 5-1
90
Fig. 5-2
Fig. 5-3
Fig. 5-4
A
Fig. 5-5
B
Fig. 5-6
5
A Indoor unit
B Outdoor unit
ø6.35 (1/4")
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
5.1. Precautions
For devices that use R410A refrigerant
• Use alkylbenzene oil (small amount) as the refrigeration oil applied to the
fl ared sections.
• Use C1220 copper phosphorus for copper and copper alloy seamless pipes,
to connect the refrigerant pipes. Use refrigerant pipes with the thicknesses
specifi ed 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:
When installing or relocating, or servicing the air conditioner, use only the
specifi ed 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.
If 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 specifi ed 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
(1) Table below shows the specifi cations of pipes commercially available.
Outside diameter
Model Pipe
mm inch
For liquid 6.35 1/4
NTXCKS09/
12A112BA
For gas 9.52 3/8
For liquid 6.35 1/4
NTXCKS15/
18A112BA
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 (4 inch) or more.
Caution:
Using careful insulation of specifi ed thickness. Excessive thickness prevents
storage behind the indoor unit and smaller thickness causes dew drippage.
5.3. Flaring work
• Main cause of gas leakage is defect in fl aring work.
Carry out correct fl aring 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 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)
5.3.4. Flaring work (Fig. 5-5)
• Carry out fl aring work using fl aring tool as shown at the right.
A (mm, inch)
Pipe diameter
(mm, inch)
When the tool for R410A is used
Clutch type
6.35, 1/4" 0 to 0.5, 0 to 1/64
9.52, 3/8" 0 to 0.5, 0 to 1/64
12.7, 1/2" 0 to 0.5, 0 to 1/64
Firmly hold copper tube in a die in the dimension shown in the table at above.
5.3.5. Check (Fig. 5-6)
• Compare the fl ared work with a fi gure in right side hand.
• If fl are is noted to be defective, cut off the fl ared section and do fl aring work again.
a Smooth all around
b Inside is shining without any scratches
c Even length all around
d Too much
e Tilted
Min. wall Insulation Insulation
thickness thickness material
0.8 mm 8 mm
(1/32 inch) (10/32 inch)
Heat resist-
0.8 mm 8 mm
ing foam
(1/32 inch) (10/32 inch)
plastic 0.045
0.8 mm 8 mm
specifi c
(1/32 inch) (10/32 inch)
gravity
0.8 mm 8 mm
(1/32 inch) (10/32 inch)
Dimension
+0
B , 1/64 (mm, inch)
- 0.4
9.1, 11/32
13.2, 17/32
16.6, 21/32
f Scratch on fl ared plane
g Cracked
h Uneven
i Bad examples