Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 5

2-2-3. Service tools
Use the below service tools as exclusive tools for R410A refrigerant.
No. Tool name
1 Gauge manifold
2 Charge hose
3 Electronic weighing scale
4 Gas leak detector
5 Adaptor for reverse flow check
6 Refrigerant charge base
7 Refrigerant cylinder
8 Refrigerant recovery equipment
2-2-4. 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 7/256 in [0.7 mm] or below.)
Piping diameter and thickness
Nominal dimensions (in) Outside diameter (mm)
* Use 1/2 H or H pipes.
■ 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
OCH800A_5
Only for R410A
Use the existing fitting specifications. (UNF1/2)
Use high-tension side pressure of 768.7 psig (5.3 MPa·G) or over.
Only for R410A
Use pressure performance of 738.2 psig (5.09 MPa·G) or over.
Use the detector for R134a, R407C or R410A.
Attach on vacuum pump.
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
7/8 22.2
1 25.4
1-1/8 28.58
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 (in [mm])
R410A R22
1/32 [0.8] 1/32 [0.8]
1/32 [0.8] 1/32 [0.8]
1/32 [0.8] 1/32 [0.8]
5/128 [1.0] 5/128 [1.0]
5/128 [1.0]* 5/128 [1.0]
5/128 [1.0]* 5/128 [1.0]
5/128 [1.0]* 5/128 [1.0]
5/128 [1.0]* 5/128 [1.0]
Dimension B
Dimension A ( 0 ) (in [mm])
-0.4
R410A R22
11/32-23/64 [9.1] 32/11-23/64
1/2-33/64 [13.2] 1/2-33/64 [13.0]
41/64-21/32 [16.6] 5/8-41/64 [16.2]
49/64-25/32 [19.7] 3/4-49/64 [19.4]
– 29/32-59/64 [23.3]
[9.0]