Leakage Test; Evacuation; Refrigerant Charge; Wiring Connections - Panasonic 4CW056MA01 Applications Manual

Horizontal scroll compressors
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4.5 Leakage Test

The enclosure strength test should be performed to check system leakage by means of charging pressurized
nitrogen into the system. Pressurizing should be completed step by step instead of reaching the test pressure
1) Hold 0.5MPa pressure for 5 minutes to check whether the pressure is decreasing.
2) Hold 1.5MPa pressure for 5 minutes to check whether the pressure is decreasing.
3) Record the ambient temperature and pressure when the test pressure is attained (unit design pressure).
4) Ensure the system can hold the test pressure without decreasing for 24 hours. If pressure decreasing
occurs in any step, leakage points should be checked and repaired immediately.
1) Never use refrigerant, oxygen, dry air, combustible and toxic gas as the test medium to avoid the risk of
fire or explosion.
Charge the test gas both from the gas line and liquid line of the system simultaneously .
The design pressure should be in the scale of the pressure gauge .
4) Pressure may change

4.6 Evacuation

The system must be evacuated by a vacuum pump to remove the residual moisture and un-condensable gas.
It is essential to connect the vacuum pump to both the high-pressure side and low-pressure side
simultaneously to ensure that the system is completely evacuated.
It is necessary to confirm the vacuum degree of the system after removing the vacuum pump from the system.
Sufficient vacuum degree means:
30 seconds after removing the vacuum pump
24 hours after removing the vacuum pump
Please select proper size of vacuum pump according to the above vacuum degree requirements.
Do not use compressor as a vacuum pump and NEVER energize the compressor under vacuumed conditions.

4.7 Refrigerant Charge

It is recommended that system charging be done using the weighted charge method, by adding liquid
refrigerant to the condenser outlet side of system. Only gas refrigerant can be charged to compressor suction
tube. Charging at the high and low pressure side of a system with gas simultaneously at a controlled rate is
also acceptable. Do not exceed the manufacturer's charge amount limit and NEVER charge liquid at suction
side of compressor.
The excessive refrigerant charged in system will result in dilution of oil and lack of lubrication on sliding parts,
in severe cases liquid refrigerant flooding back to compressor and compressor failure will occur.

4.8 Wiring Connections

PANASONIC scroll compressors will only compress gas in the counterclockwise direction when viewed from
the top. Since single phase motors start and run in only one direction, reverse rotation is not a major
consideration. Three phase motors will start and run in either direction, depending on the phase angles of the
supplied power. This requires care during installations to ensure the compressor is operating in the proper
as the ambient temperature changes.
below 1.0Torr
below 7.6Torr


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