Mitsubishi Electric Mr.Slim PCA-M-HA Series Installation Manual page 7

4. Installing the refrigerant piping
A
45°±2°
Apply refrigerating machine oil over the entire flare seat surface.
Fig. 4-1
A Flare cutting dimensions
Copper pipe O.D. Flare dimensions
(mm) øA dimensions (mm)
ø6.35
ø9.52 12.6 - 13.0
ø12.7 15.8 - 16.2
ø15.88 19.0 - 19.4
ø19.05 22.9 - 23.3
B Flare nut tightening torque
Copper pipe O.D. Tightening torque
(mm)
ø6.35
ø9.52
ø12.7
ø15.88
ø19.05
A
A
B
Fig. 4-2
A (mm)
Copper pipe O.D.
Flare tool for R32/R410A
(mm)
Clutch type
ø6.35 (1/4") 1.0 - 1.5
ø9.52 (3/8") 1.0 - 1.5
ø12.7 (1/2") 1.0 - 1.5
ø15.88 (5/8") 1.0 - 1.5
ø19.05 (3/4") 1.0 - 1.5
A Gas piping (with insulation)
B Liquid piping (with insulation)
C Band 6
D Pipe cover 2
Fig. 4-3
B
Be sure to only use the flare nuts
that came with the unit.
8.6 - 9.0
Tightening angle
(N·m) (Guideline)
14 - 18 60˚ - 90˚
35 - 42 60˚ - 90˚
50 - 58 30˚ - 60˚
75 - 80 30˚ - 60˚
100 - 140 20˚ - 35˚
A Die
B Copper pipe
DE
G
E Pipe cover 3
F Press the pipe cover against the sheet metal.
G Refrigerant piping heat insulating material
4.2. Indoor unit (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 or more,
thickness of 12 mm or more).
• The indoor parts of the drain pipe should be wrapped with polyethylene foam insula-
tion materials (specific gravity of 0.03, thickness of 9 mm 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 leak detector or soapy water to check for gas leaks after connections are
completed.
• Use refrigerant piping insulation provided to insulate indoor unit connections. Insulate
carefully following shown below.
• Use correct flare nuts meeting the pipe size of the outdoor unit.
• In case of reconnecting the refrigerant pipes after detaching, make the flared part
of pipe re-fabricated.
Available pipe size
M71
Liquid side ø9.52
Gas side ø15.88
Warning:
When installing the unit, securely connect the refrigerant pipes before starting
the compressor.
Installing procedures
1. Slide the supplied pipe cover 2 over the gas piping until it is pressed against the
sheet metal inside the unit.
2. Slide the provided pipe cover 3 over the liquid piping until it is pressed against
the sheet metal inside the unit.
3. Tighten the pipe covers 2 and 3 at the both ends (15 - 20 mm) with the supplied
bands 4.
C
• After connecting the refrigerant piping to the indoor unit, be sure to test the pipe
connections for gas leakage with nitrogen gas. (Check that there is no refrigerant
leakage from the refrigerant piping to the indoor unit.)
Conduct the airtightness test before connecting the outdoor unit stop valve and the
refrigerant pipe.
If the test is conducted after the valve and pipe are connected, gas, which is used
for checking the airtightness, will leak from the stop valve and flow into the outdoor
unit, resulting in abnormal operation.
en
5