Panasonic CS-W7DKE Service Manual page 58

CS-W7DKE CU-W7DKE / CS-W9DKE CU-W9DKE / CS-W12DKE CU-W12DKE
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.
Pressure Working pressure
resistance
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).
• For detecting small amounts of gas leakage, use the
electric gas leak detector for HFC refrigerant. (Detection
sensitivity with R410A is about 23 g/year).
Table 8 Difference between R410A and conventional charging hoses
Fig. 4 Manifold gauge charging hose
Conventional hoses
3
3.4 MPa (35 kgf/cm )
3
17.2 MPa (175 kgf/cm )
NBR rubber
Fig. 5 Vacuum pump adaptor
Fig. 6 Electric gas leak detector for HFC refrigerant
58
R410A hoses
3
5.1 MPa (52 kgf/cm )
3
27.4 MPa (280 kgf/cm )
HNBR rubber Nylon coating inside