Installing The Refrigerant Piping - Mitsubishi Electric Mr.Slim PKA-A KA7 Manuel D'installation

4. Installing the refrigerant piping

A B
45±2°
Fig. 4-1
4.1. Precautions
4.1.1. For devices that use R410A refrigerant
• Use ester oil, ether oil, 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 to the 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
specified refrigerant (R410A) 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
hazards.
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.
Liquid pipe ø9.52 mm, 3/8 inch thickness 0.8 mm, 1/32 inch
Gas pipe ø15.88 mm, 5/8 inch thickness 1.0 mm, 3/64 inch
• Do not use pipes thinner than those specified above.
D
2-9/16
3-1/32
13/32 3-7/16
B
Fig. 4-3
C
Fig. 4-4
(inch)
C
D
A24, A30, A36
46-1/16
17-15/32 ( A )*
18-31/32 ( B )
23-1/32 ( C )
45-15/32
3-1/32
F F
3-7/16
Fig. 4-2
A
B
A
D
4.2. Connecting pipes (Fig. 4-1)
• When commercially available copper pipes are used, wrap liquid and gas pipes
with commercially available insulation materials (heat-resistant to 100 °C, 212 °F
or more, thickness of 12 mm, 1/2 inch or more).
• The indoor parts of the drain pipe should be wrapped with polyethylene foam
insulation materials (specific gravity of 0.03, thickness of 9 mm, 23/64 inch or more).
• Apply thin layer of refrigerant oil to pipe and joint seating surface before
tightening flare nut.
• Use two wrenches to tighten piping connections.
• Use refrigerant piping insulation provided to insulate indoor unit connections.
Insulate carefully.
Flare cutting dimensions
Copper pipe O.D. Flare dimensions
(mm, inch) øA dimensions (mm, inch)
ø9.52, 3/8" 12.8 - 13.2, 1/2-33/64
ø15.88, 5/8" 19.3 - 19.7, 49/64-25/32
Flare nut tightening torque
Copper pipe O.D. Flare nut O.D.
(mm, inch) (mm, inch)
ø9.52, 3/8"
ø15.88, 5/8" 29, 1-9/64
Apply refrigerating machine oil over the entire flare seat surface.
Use correct flare nuts meeting the pipe size of the outdoor unit.
4.3. Positioning refrigerant and drain piping (Fig. 4-2)
Gas pipe * Indicates the condition with accessories mounted.
Liquid pipe
Left-side piping knockout hole
Lower piping knockout hole
11-5/8 3/16
4-27/32
6-1/16
2-9/16
5-9/32
2-51/64
4.4. Refrigerant piping (Fig. 4-3)
Indoor unit
1. Remove the flare nut and cap of the indoor unit.
2. Make a flare for the liquid pipe and gas pipe and apply refrigerating machine oil
(available from your local supplier) to the flare sheet surface.
3. Quickly connect the on site cooling pipes to the unit.
4. Wrap the pipe cover that is attached to the gas pipe and make sure that the
connection join is not visible.
5. Wrap the pipe cover of the unit's liquid pipe and make sure that it covers the
insulation material of the on site liquid pipe.
6. The portion where the insulation material is joined is sealed by taping.
Site-side refrigerant piping
Unit side refrigerant piping
4.4.1. Storing in the piping space of the unit (Fig. 4-4)
1. Wrap the supplied felt tape in the range of the refrigerant piping which will be
housed within the piping space of the unit to prevent dripping.
2. Overlap the felt tape at one-half of the tape width.
3. Fasten the end portion of the wrapping with vinyl tape, etc.
Gas pipe
Liquid pipe
Indoor/outdoor connection cable
Felt tape
Tightening torque
(N·m, ft·lbs)
22, 7/8 34 - 42, 25-30
68 - 82, 49-59
Drain hose
Right-side piping knockout hole
Mount board
(inch)
G
E
7