Panasonic CU-B14DBE5, Service Manual, Page: 73 / 109

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8. Electronic scale for refrigerant charging
• Because of the high pressure and fast vaporizing speed
of R410A, the refrigerant cannot be held in a liquid phase
inside the charging cylinder when charging is done using
the charging cylinder method, causing bubbles to form in
the measurement scale glass and making it difficult to
see the reading. (Naturally, the conventional R22 charg-
ing cylinder cannot be used because of the differences in
the pressure resistance, scale gradation, connecting port
size, etc.)
• The electronic scale has been strengthened by using a
structure in which the weight detector for the refrigerant
cylinder is held by four supports. It is also equipped with
two connection ports, one for R22 (7/16 UNF, 20
threads) and one for R410A (1/2 UNF, 20 threads), so it
can also be used for conventional refrigerant charging.
• There are two types of electronic scales, one for 10-kg
cylinders and one for 20-kg cylinders. (The 10-kg cylin-
der is recommended.)
Refrigerant charging is done manually by opening and
closing the valve.
9. Refrigerant cylinders
• The R410A cylinders are labeled with the refrigerant
name, and the coating color of the cylinder protector is
pink, which is the color stipulated by ARI of the U.S.
• Cylinders equipped with a siphon tube are available to
allow the cylinder to stand upright for liquid refrigerant
charging.
10. Charging orifice and packing for refrigerant cylinders
• The charging orifice must match the size of the charging
hose fitting (1/2 UNF, 20 threads).
• The packing must also be made of an HFC-resistant
material.
Fig. 7 Electronic scale for refrigerant charging
Fig. 8 Refrigerant cylinders
Fig. 9 Charging orifice and packing
11.2.3. R410A tools which are usable for R22 models
Table 9 R410A tools which are usable for R22 models
R410A tools Usable for R22 models
(1) Copper tube gauge for clearance adjustment OK
(2) Flaring tool (clutch type) OK
(3) Manifold gauge NG
(4) Charging hose NG
(5) Vacuum pump adaptor OK
(6) Electric gas leak detector for HFC refrigerant NG
(7) Electronic scale for refrigerant charging OK
(8) Refrigerant cylinder NG
(9) Charging orifice and packing for refrigerant cylinder NG