Mitsubishi Electric CITY MULTI PUMY-P112VKM6 Service Manual page 5

No. Tool name
6 Refrigerant charge base
7 Refrigerant cylinder
8 Refrigerant recovery equipment
2-2. Precautions for salt-proof type "-BS" model
Although "-BS" model has been designed to be resistant to salt damage, observe the following precautions to maintain
the performance of the unit.
• Avoid installing the unit in a location where it will be exposed directly to seawater or sea breeze.
• If the cover panel may become covered with salt, be sure to install the unit in a location where the salt will be washed
away by rainwater. (If a sunshade is installed, rainwater may not clean the panel.)
• To ensure that water does not collect in the base of the outdoor unit, make sure that the base is level, not at angle.
Water collecting in the base of the outdoor unit could cause rust.
• If the unit is installed in a coastal area, clean the unit with water regularly to remove any salt build-up.
• If the unit is damaged during installation or maintenance, be sure to repair it.
• Be sure to check the condition of the unit regularly.
• Be sure to install the unit in a location with good drainage.
2-2-1. Cautions for refrigerant piping work
New refrigerant R410A is adopted for replacement inverter series. Although the refrigerant piping work for R410A is the
same as for R22, exclusive tools are necessary so as not to mix with different kind of refrigerant. Furthermore as the
working pressure of R410A is 1.6 times higher than that of R22, their sizes of flared sections and flare nuts are different.
■ Thickness of pipes
Because the working pressure of R410A is higher compared to R22, be sure to use refrigerant piping with thickness
shown below. (Never use pipes of 0.7 mm [7/256 in] or below.)
Piping diameter and thickness
Nominal dimensions (in) Outside diameter (mm)
■ Dimensions of flare cutting and flare nut
The component molecules in HFC refrigerant are smaller compared to conventional refrigerants. In addition to that,
R410A is a refrigerant, which has higher risk of leakage because its working pressure is higher than that of other refriger-
ants.
Therefore, to enhance airtightness and strength, flare cutting dimension of copper pipe for R410A has been specified
separately from the dimensions for other refrigerants as shown below. The dimension B of flare nut for R410A also
has partly been changed to increase strength as shown below. Set copper pipe correctly referring to copper pipe flaring
dimensions for R410A below. For 1/2 and 5/8 inch pipes, the dimension B changes. Use torque wrench corresponding to
each dimension.
Dimension A
Flare cutting dimensions
Nominal dimensions (in)
Flare nut dimensions
Nominal dimensions (in)
OCH790 _5
Only for R410A
Top of cylinder (Pink)
Cylinder with syphon
1/4 6.35
3/8 9.52
1/2 12.70
5/8 15.88
3/4 19.05
Outside diameter (mm)
1/4 6.35 9.1 [11/32-23/64]
3/8 9.52 13.2 [1/2-33/64]
1/2 12.70 16.6 [41/64-21/32]
5/8 15.88 19.7 [49/64-25/32]
3/4 19.05
Outside diameter (mm)
1/4 6.35
3/8 9.52
1/2 12.70
5/8 15.88
3/4 19.05
Specifications
–
–
Thickness (mm)
R410A R22
0.8
0.8
0.8
1.0
–
Dimension B
Dimension A ( 0 ) (mm [in])
-0.4
R410A R22
13.0
16.2
19.4
– 23.3
Dimension B ( 0 ) (mm)
-0.4
R410A R22
17.0 17.0
22.0 22.0
26.0 24.0
29.0 27.0
– 36.0
0.8
0.8
0.8
1.0
1.0
9.0