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Notes for Maintenance of Air Conditioning System

1.When handling refrigerant the following precautions must be observed
Do not handle refrigerant in an enclosed area or near an open flame.
Always wear eye protection.
Be careful that liquid refrigerant does not get in your eyes or on your skin.
(1)If liquid refrigerant gets in your eyes or your skin:
Do not rub.
Wash the area with a lot of cool water.
Apply clean petroleum jelly to the skin.
Go immediately to a physician or hospital for professional treatment.
Do not attempt to treat yourself.
2.When replacing parts on refrigerant line
Recover the refrigerant into the refrigerant recovery machine for reuse.
Insert a plug immediately in disconnected parts to prevent entry of moisture and dust.
Do not leave a new condenser or receiver/dryer, etc, lying around with the plug removed.
Discharge nitrogen gas from the charging valve before removing the plug from the new compressor. If the nitrogen gas is not discharged first, compressor oil will spray out with the nitrogen gas when the plug is removed.
Do not use a burner for bending or lengthening tubes.    
3.When tightening connecting parts
Apply a few drops of compressor oil to O-ring fittings for easy tightening and to prevent leakage of refrigerant gas.
Tighten the nut using two opened wrenches to avoid twisting the tube.
Tighten the O-ring fittings or the bolted type fittings to the specified torque.
4.When handling refrigerant container
The container must never be heated.
Containers must be kept below 40°C (104°F).
When warming the container with warm water, be careful that the valve on top of the container is never immersed in the water, as the water may permeate into the refrigeration circuit.
Empty containers must never be re-used.
5.When A/C is on and refrigerant gas is being replenished
If there is not enough refrigerant gas in the refrigeration circuit, oil lubrication becomes insufficient and compressor burnout may occur, so take care to avoid this.
If the valve on the high-pressure side is opened, refrigerant flows in reverse and causes the service can to rupture, so only open and close the valve on the low-pressure side.
If the refrigerant container is inverted and refrigerant is charged in a liquid state, the liquid will be compressed and the compressor will break down, so the refrigerant must be charged in a gaseous state.
Be careful not to charge too much refrigerant gas, as this causes trouble such as inadequate cooling, poor fuel economy, engine overheating, etc.
6.When using halide torch leak detector
Since an open flame is used, there is a danger of igniting explosive gas. The surrounding area should first be checked for the presence of inflammable or explosive materials before using this detector.
Although the R-12 refrigerant is nontoxic, it becomes toxic once it is exposed to an open flame. For this reason, if the color of the flame in the detector changes, be particularly careful not to inhale the gas emitted by the detector.