Technician Safety Information
A/C System (R-134a), Safety Measures
- The subassemblies and lines of the air conditioner are filled with tetrafluoroethane also known as refrigerant R-134a.
- Refrigerant R-134a replaces the refrigerant R-12 which is reported to have harmful effects on the earth's ozone layer.
- 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.
WARNING!
- Always use an Underwriter's Laboratory (UL) approved refrigerant recovery/recycling/recharging unit such as Kent-Moore ACR4, or equivalent, whenever discharging an R-134a A/C system.
- As of January 1, 1992 any person who services a motor vehicle air conditioner MUST, by law, be properly trained and certified and use approve 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.
- A/C system is filled with refrigerant which is under pressure.
- Refrigerant must not come in contact with your skin.
If liquid refrigerant has come in contact with your skin or eyes:
- Do not rub skin or eyes
- Immediately flush with cool water for 15 minutes
- Rush to a doctor or hospital
- Do not attempt to treat yourself
- 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 °C / 176 °F) or open flames. Excessive heat will cause a pressure increase which could burst the system.
- Keep refrigerant containers stored below 50 °C (122 °F) and never drop from high places. DO NOT warm refrigerant containers with an open flame. If refrigerant needs to be warmed, place bottom of tank in warm water.
- Keep refrigerant away from open flames because poisonous gas will be produced if it burns. Do not smoke when refrigerant 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 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!
- 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 (Polyalkylene 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.
- 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 reseal 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.
- 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 R12 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-drier, 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 fray) identifies which type of refrigerant is used. Use only the correct system component for each refrigerant type.
- 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.
- 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 clutch -N25- (e.g. unplug connector from A/C refrigerant low pressure switch -F73-) 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 refrigerant - oil before installing.
- Always reinstall cap(s) over A/C service valve(s).