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Refrigerant Charging
Method of Charging
Execute the refrigerant charging immediately after evacuation.
R744 (CO
) shall be used and do not mix other refrigerant.
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Refrigerant shall be charged by following procedure.
(1) Preparation (Unit shall be under Vacuum mode)
– Close the vacuum valve of the manifold gauge set exclusively for CO
pump.
– Place the refrigerant cylinder on the platform scale, and remove air in the tube.
The platform scale shall be on a fl at surface and zero-point adjustment shall be performed.
(2) Initial charge (Unit shall be under Vacuum Mode)
– Check that low pressure and high pressure service ports are in Mid-position to charge refrigerant.
– Slightly open the charge valve of manifold to charge the refrigerant up to about 0.5MPa.
(3) Additional charge (Unit shall be under Normal Mode)
– Change the high pressure service port to Back seated position (close the service port).
Low pressure service port remains Mid-position.
– Set the Slide Switch (SW15) to [CONTROL]
– Turn No.1 of 8P Dip Switch (SW13) OFF. No.2 remains ON.
– Turn the Operation Switch (S1) ON and let the compressor start.
– Slightly open the valve of cylinder to let the unit suck in the refrigerant from low pressure service port.
– Continue charging until target refrigerant amount is charged (charge amount can be checked by scale).
– Close the low pressure service port to complete the charge.
(4) Charge amount
– Adequate charge amount can be calculated by the tool provided by Panasonic.
The below can be referenced in addition to above.
In the case of a freezer reach-in case = 1,260 (g) + 12 (g / m) x piping length (one-way: m)
In the case of a refrigeration showcase = 825 (g / m) x showcase length (m) + 12 (g / m) x piping length (one-way: m)
Note: 1. Do not absolutely charge liquid refrigerant from the low pressure side (low pressure service port).
2. To avoid overcharging, charging rate should be around 20 g per 5 sec.
3. If it is diffi cult to adjust refrigerant charging rate by operating the joint valve and manifold gauge set
charging valve, attach a capillary tube between the refrigerant cylinder and manifold gauge set.
4. Do not attach a capillary tube between the manifold gauge set and service piping.
5. For the method of charging refrigerant, refer to the service manual "Refrigerant Charging Operation
Procedure".
Refrigerant quantity adjustment should conform to the "Refrigerant Quantity Adjustment of Refrigeration Unit" in
the section "Adjustment during Operation".
(5) After completing refrigerant quantity adjustment, close the refrigerant cylinder valve and check that the low
pressure and high pressure service ports have been closed.
(6) Slowly open the vacuum valve or purge port of the manifold gauge set to emit the remaining refrigerant in the
service piping and manifold gauge set.
Note: Since refrigerant becomes cold when released, use caution when opening the valve for frost bite.
(7) After completing the operation, check gland nut loosening of the low pressure and high pressure service valves
and fasten them if any looseness exists. Fastening torque is 10 ± 2 N·m.
refrigerant, and separate the vacuum
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EN - 22
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