Heating and Air Conditioning: Service Precautions
Safety Precautions For Climate Control System And Handling Of Refrigerant R-134a
The subassemblies and lines of the air conditioner are filled with 1.1.1.2 Tetrafluorethan (CF3-CH2F or CH2F-CF3) filled.
This refrigerant is currently known as R134a, H-FKW 134a, SUVA 134a and KLEA 134a (different names may apply to different countries.
Safety precautions
The following safety precautions have to be observed for these cooling aids (additional laws may apply for different countries)
Empty (evacuate) refrigerant circuit first if the refrigerant circuit has to be opened during service, the refrigerant must not come in contact with your skin. If refrigerant should escape although all safety precautions 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!
Make sure 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 use eye drops and consult a doctor immediately, even if the eyes are not hurting.
The doctor must be informed, which type of refrigerant caused the freezing.
If other body parts came in contact with refrigerant although all safety precautions were observed, flush body parts immediately for at least 15 minutes with cold water.
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 creating a poisonous gas. Breathing poisoning refrigerant vapors leads to irritated eyes, nose and throat.
Drain refrigerant circuit
The refrigerant must be drained using an air conditioning service station and should not be released into the environment. The drained refrigerant will be locally recycled or is send to an environment-recycling place to the manufacturer (different or additional laws may apply in USA).
Reason:
If refrigerant R134a is released into the environment, it enhances the green house effect.
NOTE:
- Compared to R12, R134a 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 R12)
After draining the refrigerant circuit, interrupt the voltage supply to A/C Clutch -N25- or A/C Compressor Regulator Valve -N280-. For this, depending on vehicle equipment disconnect harness connector of A/C Pressure Switch -F129-/High Pressure Sensor -G65- or disconnect harness connector on compressor (to -N25-/to -N280-)
Reason:
Disconnecting the voltage supply prevents accidental compressor operation via -N25- with the A/C system discharged.
The A/C Compressor Regulator Valve -N280- is not activated and the compressor runs at idle. This compressor is built in such 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 properly ventilated workshop. Ensure that within 5 meters circumference there are no working-pits, basement staircases or shafts. Switch on existing/ventilation systems when working on the refrigerant system.
Reason:
The exiting refrigerant is colorless, odorless and heavier than air and therefore displaces oxygen. Should refrigerant escape although all safety precautions were observed, a previously unrecognizable danger of suffocation exists in non vented rooms and working 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 filled air conditioning systems by soldering, brazing or welding. This pertains also for welding and soldering work on the vehicle, in the event that parts 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 of the system.
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 was opened for longer period of time. An A/C system that was 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 ° 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 of the system.