Refrigerant Piping Work - Mitsubishi Mr. Slim PEA-M160HAA Installation Manual

6. Refrigerant piping work

6.1. Refrigerant pipe
[Fig. 6-1]
ⓐ
øA
ⓐ Indoor unit
ⓑ Outdoor unit
Model
PEA-M100, 125, 140 ø15.88
PEA-M160 ø19.05
Refer to the Instruction Manual that came with the outdoor unit for the restrictions on
the height difference between units and for the amount of additional refrigerant
charge.
• For PEA-M160 model, the method of gas pipe connection is brazing connection.
* Use the pipe reducer to connect with outdoor unit PUZ-ZM160.
Avoid the following places for installation where air conditioner trouble is liable to
occur.
• Where there is too much oil such as for machine or cooking.
• Salty environment as seaside areas.
• Hot-spring areas.
• Where sulfide gas exists.
• Other special atmospheric areas.
• This unit has flared connections on both indoor and outdoor sides. [Fig. 6-1]
• Insulate both refrigerant and drainage piping completely to prevent condensation.
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
PEA-
For liquid 9.52 3/8
M100,
For gas 15.88 5/8
125, 140
For liquid 9.52 3/8
PEA-
M160
For gas 19.05 3/4
(2) Ensure that the 2 refrigerant pipes are well insulated to prevent condensation.
(3) Refrigerant pipe bending radius must be 10 cm or more.
Caution:
Using careful insulation of specified thickness. Excessive thickness prevents
storage behind the indoor unit and smaller thickness causes dew drippage.
6.2. Flaring work
• Main cause of gas leakage is defect in flaring work.
Carry out correct flaring work in the following procedure.
6.2.1. Pipe cutting
[Fig. 6-2-1]
ⓐ
90°
ⓐ Copper tubes
ⓑ Good
ⓒ No good
• Using a pipe cutter cut the copper tube correctly.
6.2.2. Burrs removal
[Fig. 6-2-2]
ⓑ
ⓐ
ⓐ Burr
ⓑ Copper tube/pipe
øB
ⓑ
A B
ø9.52
ø9.52
Min wall Insulation Insulation
thickness thickness material
0.8 mm 8 mm
Heat resisting
1.0 mm 8 mm
foam plastic
0.045 specific
0.8 mm 8 mm
gravity
1.2 mm 8 mm
ⓑ ⓒ
ⓕ
ⓓ ⓔ
ⓓ Tilted
ⓔ Uneven
ⓕ Burred
ⓒ
ⓓ
ⓒ Spare reamer
ⓓ Pipe cutter
• 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.
6.2.3. Putting nut on
[Fig. 6-2-3]
ⓐ Flare nut
ⓑ Copper tube
• 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)
• Use the flare nut included with this indoor unit.
6.2.4. Flaring work
[Fig. 6-2-4]
ⓐ
ⓑ
ⓒ
ⓐ Flaring tool
ⓑ Die
ⓒ Copper tube
• Carry out flaring work using flaring tool.
A (mm)
Pipe diameter
When the tool for R32/R410A
(mm)
is used
Clutch type
9.52 0 - 0.5
15.88 0 - 0.5
Firmly hold copper tube in a die in the dimension shown in the table at above.
• When reconnecting the detached refrigerant pipes, make sure to flare them again.
6.2.5. Check
[Fig. 6-2-5]
ⓐ ⓑ
ⓒ
ⓐ Smooth all around
ⓑ Inside is shining without any scratches
ⓒ Even length all around
ⓓ Too much
ⓔ Tilted
• 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.
6.3. Pipe connection
[Fig. 6-3-1]
• Apply a thin coat of refrigeration oil on the seat surface of pipe.
• For connection first align the center, then tighten the first 3 to 4 turns of flare nut.
• Use tightening torque table below as a guideline for indoor unit side union joint
section, and tighten using two wrenches. Excessive tightening damages the flare
section.
Copper pipe O.D. Flare nut O.D.
(mm)
ø9.52
ø15.88
ⓐ
ⓑ
A
ⓔ
ⓑ
ⓓ
ⓒ
ⓓ Flare nut
ⓔ Yoke
Dimension
+0
B (mm)
-0.4
13.2
19.7
ⓓ ⓔ ⓕ ⓖ ⓗ
ⓘ
ⓕ Scratch on flared plane
ⓖ Cracked
ⓗ Uneven
ⓘ Bad examples
Tightening torque
(mm) (N·m)
22 34 - 42
29 68 - 82
7