Mitsubishi Electronics PCA-A.KA4 Installing the refrigerant piping, Precautions, Indoor unit Fig

4. Installing the refrigerant piping

	45	2	
			
0.5	A
90

Fig. 4-1

Flare cutting dimensions		in. (mm)
Copper pipe O.D.	Flare dimensions
	øA dimensions
1/4” (ø6.35)	11/32-23/64 (8.7	- 9.1)
3/8" (ø9.52)	1/2-33/64 (12.8 - 13.2)
1/2" (ø12.7)	41/64-21/32 (16.2	- 16.6)
5/8" (ø15.88)	49/64-25/32 (19.3	- 19.7)
3/4" (ø19.05)	29/32-59/64 (22.9	- 23.3)

B

			Die
			Copper pipe


	Fig. 4-2
			in. (mm)
			B
Copper pipe O.D.			Flare tool for R410A
			Clutch type
1/4” (ø6.35)		0-1/64 (0 - 0.5)
3/8" (ø9.52)		0-1/64 (0 - 0.5)
1/2" (ø12.7)		0-1/64 (0 - 0.5)
5/8" (ø15.88)		0-1/64 (0 - 0.5)
3/4" (ø19.05)		0-1/64 (0 - 0.5)

4.1. Precautions

For devices that use R410A refrigerant

• Use ester oil, ether oil or alkylbenzene oil (small amount) as the refrigera- tion 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 thick-

nesses specified in the table below. Make sure the insides of the pipes are clean and do not contain any harmful contaminants such as sulfuric com- pounds, oxidants, debris, or dust.

Warning:

When installing or moving the air conditioner, use only the specified refriger- ant (R410A) to charge the refrigerant lines. Do not mix it with any other refrig- erant and do not allow air to remain in the lines. Air enclosed in the lines can cause pressure peaks resulting in a rupture and other hazards.

	in. (mm)
	A24, 30, 36, 42
Liquid pipe	3/8" (ø9.52) thickness 1/32" (0.8)
Gas pipe	5/8" (ø15.88) thickness 3/64" (1.0)

• Do not use pipes thinner than those specified above.

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 212 °F (100 °C) or more, thickness of 1/2 in. (12 mm) or more).

•The indoor parts of the drain pipe should be wrapped with polyethylene foam in- sulation materials (specific gravity of 0.03, thickness of 23/64 in. (9 mm) or more).

•Apply thin layer of refrigerant oil to pipe and joint seating surface before tightening flare nut.

•Use 2 wrenches to tighten piping connections.

•Use refrigerant piping insulation provided to insulate indoor unit connections. In- sulate carefully.

Flare nut tightening torque

Copper pipe O.D.	Flare nut O.D.	Tightening torque
(mm, inch)	(mm, inch)	(N-m, ft.lbs)
ø6.35, 1/4	17, 43/64	14-18, 10-13
ø6.35, 1/4	22, 7/8	34-42, 25-30
ø9.52, 3/8	22, 7/8	34-42, 25-30
ø12.7, 1/2	26, 1-3/64	49-61, 35-44
ø12.7, 1/2	29, 1-9/64	68-82, 49-59
ø15.88, 5/8	29, 1-9/64	68-82, 49-59
ø15.88, 5/8	36, 1-27/64	100-120, 71-86
ø19.05, 3/4	36, 1-27/64	100-120, 71-86

Apply refrigerating machine oil over the entire flare seat surface.  Use correct flare nuts meeting the pipe size of the outdoor unit.





4.3. Indoor unit (Fig. 4-3)

Installing procedures

1.Slide the supplied pipe cover  over the gas tubing until it is pressed against the sheet metal inside the unit.

2.Slide the provided pipe cover  over the liquid tubing until it is pressed against the sheet metal inside the unit.

3.Tighten the pipe covers  and  at the both ends 3/4 in. (20 mm) with the sup- plied bands .

		 Gas tubing	 Pipe cover
		 Liquid tubing	 Press the pipe cover against the sheet metal.
		 Band	 Refrigerant tubing heat insulating material
		 Pipe cover

4.4. For twin combination

Refer to the outdoor unit installation manual.









Fig. 4-3

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