Refrigerant: Service Precautions

Safety Precautions
The following safety precautions have to be observed for these cooling aids (additional laws may apply for different countries).

Safety precautions for handling of refrigerant

The subassemblies and lines of the air conditioner are filled with the following refrigerant:
1,1,1,2 Tetrafluorethane (CF3-CH2F or CH2F-CF3)

This refrigerant is commonly known as R-134a, H-FKW 134a, SUVA 134a and KLEA 134a (in the USA different names may apply as well).

Refrigerant R-134A replaces the refrigerant R-12 which is reported to have harmful effects on the ozone layer of the earth's atmosphere.

R-134a and R-12 systems are similar in design but there are very important differences in the refrigerants, lubricating oils, service equipment and A/C system components.

If it is necessary to open the refrigerant circuit during service work, discharge the refrigerant circuit first. Avoid contact with liquid refrigerant or refrigerant gases. If refrigerant should escape although all safety caution were observed, do not inhale refrigerant/air mixture.

Always wear hand and eye protection (gloves and goggles) when working around the A/C refrigerant system and switch on existing exhaust/ventilation systems.

Reason:
Unprotected body parts may freeze under intensive impact of refrigerant aid.

WARNING:
Equipment must be approved!
- Always use an Underwriter's Laboratory (UL) approved refrigerant recovery/recycling/recharging unit such as Kent-Moore ACR(4), or equivalent, whenever discharging an R-134a A/C system.
Technicians must be trained!
- As of January 1, 1992 any person who services a motor vehicle air conditioner MUST, by law, be properly trained and certified and use approved refrigerant recycling equipment. Technicians must complete an EPA approved recycling course to be certified.
- State and Provincial governments may have additional requirements regarding air conditioning servicing. Always comply with state and local laws.
Use refrigerant with care!
- The A/C system is filled with refrigerant which is under pressure.
- The refrigerant must not come in contact with your skin.
- It is recommended to have an eye-flushing bottle available.
- If liquid refrigerant has come in contact with your skin and eyes, immediately flush with cool water for 15 minutes.
- Afterward apply eye drops and consult a doctor immediately, even when the eyes are not hurting.
- The doctor must be informed, which type of refrigerant caused the freezing.

Although refrigerant is not flammable, smoking, welding or soft or hard soldering is not permitted in a room aerated with refrigerant.

Reason:
The refrigerant gas is chemically split via the high temperature of the open flame or via the hot body. Breathing poisoning refrigerant vapors leads to irritated eyes, nose and throat.

Discharge refrigerant circuit
The refrigerant must be discharged using an air conditioning service station and should not be released into the environment. The discharged refrigerant will be locally recycled or sent to an recycling facility or to the manufacturer (different or additional laws may apply in USA). To discharge refrigerant.

Reason:
If refrigerant R-134a is released into the environment, it may enhance the green house effect.

NOTE:
- Compared to R-12, R-134a has a substantially lower green house effect.
- Because R-134a does not contain chlorine atoms, the major catalyst in ozone depletion, R-134-a has no ozone depletion potential. The ozone depletion in the upper atmosphere is only initiated by splitting carbon-chlorine bonds (e.g. properties of R-12)

After discharging the air conditioner, disconnect harness connector from A/C Compressor Regulator Valve -N280- or High Pressure Sensor -G65-.

Reason:
The A/C Compressor Regulator Valve -N280- is not activated and the compressor runs at idle. This compressor is constructed in such a way, that the components are lubricated at idle via an internal oil circuit (as long as enough oil is in compressor).

Work on refrigerant circuit
Work on refrigerant system should only be carried out in a well ventilated area (workshops). Make sure that with in 5 meters circumference are no working-pits, basement staircases or shafts. Switch on existing/ventilation systems when working on the refrigerant system.

WARNING:
You need good ventilation!
- Switch on existing exhaust/ventilation systems when working on the refrigerant system.
- Work in a well ventilated area because refrigerants are heavier than air, displace oxygen and may cause suffocation in areas of poor air circulation, like under the car.
- Avoid breathing refrigerant vapors. Exposure may irritate eyes, nose and throat.
- Always wear hand and eye protection (gloves and goggles) when working around the A/C refrigerant system.
- Do not expose any component of the A/C system to high temperatures (above 80 degrees C/176 degrees F) or open flames. Excessive heat will cause a pressure increase which could burst the system.

Reason:
Refrigerant is colorless, odorless and heavier than air and therefore displaces oxygen. Should refrigerant escape although all safety precautions were observed, a danger of suffocation exists in non vented rooms and work pits.

NOTE: The escaping refrigerant/air mixture should not be inhaled, but should be sucked out via an existing exhaust ventilation system.

Do not attempt repair on a pressurized air conditioning systems by soldering, brazing or welding. This also applies to welding and soldering work on the vehicle, which may cause components of the climate control system may heat up.

Reason:
A high positive pressure occurs in the system when heating, this can lead to an explosion.

Corrective action:
Discharge A/C refrigerant system

NOTE: Always replace damaged and/or leaking A/C system components. Do not attempt repair by soldering, brazing or welding.

Immediately plug open connections on A/C system when servicing the system.

Reason:
Moisture enters the A/C system and components when system is opened for longer periods of time. An A/C system that has been open for a longer period of time cannot be filled again without replacing components of the system.

Paint work on vehicles with A/C systems
Surface temperatures of 80 degrees C should not be exceeded in the drying-oven or the pre-warm zone during the paint job.

Reason:
A high positive pressure occurs in the system when heating, this can lead to an explosion.

WARNING:
Refrigerant containers are under pressure!
- Keep refrigerant containers stored below 50 degrees C (122 degrees F) and never drop any from high places. DO NOT warm refrigerant containers with an open flame. If refrigerant needs to be warmed, place the bottom of the tank in warm water.
- Keep refrigerant away from open flames because poisonous gas will be produced if it burns. Do not smoke when refrigerants are present for the same reason.
- Electric welding near refrigerant hoses causes R-134a to decompose from ultraviolet light. Discharge system before electric welding.
- Pressurized R-134a refrigerant in the presence of oxygen may form a combustible mixture. Never introduce compressed air into any closed R-134a container (full or empty), A/C component or piece of service equipment.
- DO NOT exceed the maximum rated capacity of refrigerant containers. Never fill a container to more than 60% of its gross weight rating (for example, 18 lb. in a 30 lb. container.) Without sufficient room for expansion of R-134a (gas cushion), the container could explode when the temperature rises causing serious injury.
- Do not steam clean condensers or evaporators. Use only cold water or compressed air.

CAUTION:
Do not mix refrigerants!
- R-12 and R-134a refrigerants are NOT compatible. Never add R-12 refrigerant to an R-134a system or R-134a refrigerant to an R-12 system. If the refrigerants are mixed, total system contamination will occur and compressor failure may result.
- Refrigerant oils used for the R-134a system and R-12 system are NOT compatible. Use only the specified synthetic oil (Polyalcylene Glycol/PAG) for the R-134a refrigerant system. DO NOT use R-12 system oil in an R-134a system or R-134a system oil in an R-12 system. If the refrigerant oils are mixed, system contamination will occur and compressor failure may result.
PAG oil absorbs moisture!
- R-134a refrigerant system oil (PAG oil) absorbs moisture very rapidly. Moisture combines with the refrigerant to form acids which will damage the system. Use only the specified oil from a sealed container and ALWAYS re-seal the oil container immediately after use. DO NOT use oil if it has become contaminated with moisture or if container has been left open.
- Immediately plug open connections on A/C components to prevent dirt and moisture contamination. Likewise, DO NOT remove new component from packaging until ready to install. Immediately tighten component connections after installation.
Do not mix equipment or components!
- Always use separate refrigerant recovery/recycling/recharging servicing equipment for R-12 and R-134a systems. DO NOT use one piece of equipment for both R-12 and R-134a systems. The residual traces of refrigerant will contaminate and damage the equipment. Servicing equipment includes recovery/recycling/recharging unit, charging station, vacuum pump, manifold gauges, etc.
- DO NOT use R-12 servicing equipment on R-134a systems or R-134a equipment on R-12 systems or damage to both the vehicle A/C system and servicing equipment may result. Use only equipment designed to meet Society of Automotive Engineers (SAE) standards.
- R-134a and R-12 systems use different size service fittings. NEVER use adapters to convert an R-12 fitting to R-134a size or R-134a fitting to R-12 size.
- R-134a and R-12 A/C components including compressor, hoses, O-rings, evaporator, condenser, receiver-dryer, etc. are NOT interchangeable. Components of the R-134a system are identified by lettering "R-134a" or by a green label (or stripe). In addition, a label on the evaporator housing (below plenum chamber) identifies which type of refrigerant is used. Use only the correct system component for each refrigerant type.
Do not repair components!
- Always replace damaged and/or leaking A/C system components. Do not attempt repair by soldering, brazing or welding.
- Work area must be extremely clean when working on A/C system components.
- Use only tools, equipment and parts specified for use with R-134a.
- Switch on existing exhaust/ventilation systems when working on the refrigerant system.
Use only approved equipment!
- Discharge A/C system using refrigerant recovery/recycling/recharging unit Kent-Moore ACR4, or equivalent, before removing any A/C system component.
- After emptying A/C refrigerant, disconnect power supply from A/C pressure switch -F129- and high pressure sensor -G65- to prevent accidental compressor operation with A/C system discharged.
- Always replace O-rings, DO NOT reuse. Use only the correct size and type of O-rings specified for use with R-134a refrigerant. Lubricate O-ring with R-134a refrigerant oil before installing.
- Always reinstall sealing cap(s) over A/C service valve(s).