General Refrigerant Handling Precautions
1. R-134a refrigerant is highly volatile. Contact with a drop of refrigerant on the skin can cause local frostbite. Gloves must be worn when working with refrigerant.
2. Use goggles to protect your eyes and gloves to protect your hands. If refrigerant gets into your eyes, rinse immediately with water.
3. The R-134a refrigerant tank is under high pressure Do not store the tank in a place where it can be exposed to high temperatures. Storage temperature should not exceed 52°C.
4. Check the tightness of the system with an electronic leak detector. Remember that R-134a refrigerant releases highly toxic phosgene gas when exposed to an open flame.
5. Use only the specified brand of oil to charge the R-134a refrigerant circuit. The use of other brands of oils may cause system failure.
6. Since PG oil strongly absorbs moisture from the surrounding air, the following precautions should be observed:
When removing any parts of the refrigerant circuit, plug the openings immediately to prevent moisture from entering.
When installing refrigerant circuit parts, remove the hole plugs immediately before installing the parts.
Connect all pipes and hoses as soon as possible to prevent moisture from entering the air conditioning system.
Use only the specified brand of compressor oil from a sealed container.
7. In case of accidental leakage of refrigerant from the system, ventilate the work area before continuing work.
Precautions for Replacing Air Conditioning Parts
1. It is forbidden to loosen the connections of parts before draining the refrigerant from the system.
2. To prevent moisture from entering, immediately close open parts with caps or plugs.
3. Remove protective plugs only immediately before installing the part.
4. When connecting fittings of parts, be sure to install new o-rings, having previously applied refrigerant or oil to the fitting and seal.
Maintenance of pipeline and connections
When using a moisture-free refrigerant and recommended lubricants, the internal surfaces of the cooling system components will maintain chemical resistance. Excessive levels of dirt, moisture or air can impair the chemical resistance of the internal surfaces and eventually cause malfunctions or serious damage.
Precautions to be observed
1. If it is necessary to depressurize the cooling system, prepare in advance all the tools and spare parts that will be required to perform system maintenance so that the system is in a depressurized state for the strictly necessary time.
2. Plug or plug all piping and connections immediately after disconnecting them to prevent dirt and moisture from entering.
3. All pipelines and other elements of vehicle systems stored in the spare parts warehouse must be hermetically packed until they are ready for use, or their openings must be closed with plugs.
4. Do not bend molded piping elements of the system to fit in place When servicing refrigeration units, use piping elements of the required shape.
5. All fixtures, including the refrigerant charge manifold, pressure gauge manifold, and inspection hoses, must be clean and dry.
When servicing the system
Note.
- Equipment used to remove HFC-134a refrigerant (R-l34a) from air conditioning systems must be certified and meet the requirements of UL and SAEJ2210.
- In the event of an accidental release of refrigerant, ventilate the room before resuming work.
- Additional health and safety information can be obtained from the refrigerant and oil manufacturers.
Attention.
- Vapors of oil or refrigerant used in the air conditioning system may cause eye or nasal irritation.
- Be careful when connecting maintenance equipment.
- Do not inhale refrigerant or vapors.
Creating a vacuum in the system
1. In case of system depressurization. for example, during installation or repair, it must be evacuated using a system for draining, recycling and charging with R-134a refrigerant (If the system has been open for several days, it is necessary to replace the receiver-drier and evacuate the air for several hours).
2. Connect the R-134a refrigerant drain, recovery and charge system to the high and low pressure ports according to the manufacturer's instructions.
3. After about 10 minutes, verify that the low pressure gauge shows a vacuum below 93.3 kPa. If vacuum cannot be obtained, this indicates a leak in the system. Partially charge the system and test it for leaks.
4. Remove the low pressure valve from the low pressure service port.
Charging the system with refrigerant
1. Connect the R-134a Drain, Recycle, and Charge System to the high pressure port as shown and in accordance with the manufacturer's instructions.
2. Add the same amount of new refrigerant oil to the system as was previously drained. Use only recommended refrigerant oil. Charge the system with the required amount of R-134a refrigerant. Overfilling the system with refrigerant can damage the compressor.
System leak test
In all cases, when a refrigerant leak is suspected or work is being done to disconnect components or loosen connections, perform a system leak test using an electronic leak detector.
Note. In order to properly use the electronic leak detector, it is recommended to read its instructions.
1. Check the tightening torque of the pipe connections. When loosening, tighten the connections to the specified torque. Use a leak detector to check for gas leaks.
2. If the leak persists after tightening the joint, discharge the system, disconnect the joint and check the sealing surfaces for damage. Even slightly damaged connection parts must be replaced.
3. Check the amount of compressor oil and top up if necessary.
4. Charge the system and check for leaks. If no leaks are found. Perform a vacuum purge and charge the system.
Compressor oil
Technical characteristics of oils
1. The HFC-134a system uses synthetic (PG) compressor oil, and in the R-12 system - mineral. These two types of oils should not be mixed.
2. Brand of compressor oil (PG) varies depending on the compressor model. Use only the brand of oil specified for this compressor model.
Oil Handling
1. Do not allow moisture, dust, metal particles, etc. to enter the oil.
2. Do not mix oils of different brands.
3. When the oil is exposed to air for a long time, the moisture content in it increases. After refueling and adding oil, immediately close the container tightly (HFC-134a system compressor oil absorbs moisture very quickly).
4. Compressor oils should only be stored in metal containers. Storage of oils in plastic containers is prohibited.
Compressor oil level check
Oil for lubricating the compressor during its operation circulates in the system. Whenever parts of the system are replaced or a large amount of refrigerant leaks, add oil to restore its original amount.
Filling the compressor with oil
Oil and refrigerant have similar properties. During normal operation, part of the oil circulates in the system along with the refrigerant. Before checking the oil level in the system or replacing any elements of the system, it is necessary to turn on the compressor for a while to ensure that the oil is charged. This procedure is performed in the following order:
1. Open all doors and engine hood.
2. Start the engine; turn the air conditioner switch to the ON position (ON) and set the fan motor control knob to the position corresponding to the maximum speed.
3. Leave the compressor running for 20 minutes at 800.1000 rpm to power the system.
4. Stop the engine.