Panasonic CU-E18CKR Service Manual page 57

5. Charging hose
- The pressure resistance of the charging hose has been
raised to match the higher pressure of R410A. The hose
material has also been changed to suit HFC use, and the size
of the fitting has been changed to match the manifold ports.
Table 8 Difference between R410A and conventional charging hoses
Working pressure
Pressureresistance
Bursting pressure
Material
6. Vacuum pump adaptor
- When using a vacuum pump for R410A, it is necessary to
install an electromagnetic valve to prevent the vacuum pump
oil from flowing back into the charging hose. The vacuum
pump adaptor is installed for that purpose. if the vacuum
pump oil(mineral oil) becomes mixed with R410A, it will
damage the unit.
7. Electric gas leak detector for HFC refrigerant
- The leak detector and halide torch that were used with CFC
and HCFC cannot be used with R410A (because there is no
chlorine in the refrigerant).
- The present R134a leak detector can be used, but the
detection sensitivity will be lower (setting the sensitivity for
R134a at 1, the level for R410A will drop to 0.6).
Fig. 4 Manifold gauge charging hose
Conventional hoses
3.4 MPa (35 kgf/cm
17.2 MPa (175 kgf/cm
NBR rubber
R410A hoses
) 5.1 MPa (52 kgf/cm
3
) 27.4 MPa (280 kgf/cm
3
HNBR rubber Nylon
coating inside
)
3
)
3