Tesla Model S: Air Conditioning System Precautions - General

The air conditioning system contains fluids and components which could be potentially hazardous to the technician or the environment if not serviced and handled correctly. The following guidelines are intended to alert the technician to potential sources of danger and emphasize the importance of ensuring the integrity of the air conditioning operating conditions and components fitted to the vehicle.

Where necessary, additional specific precautions are detailed in the relevant sections of this Manual which should be referred to prior to commencing repair operations.

The refrigerant used in the air conditioning system is R134a or R1234yf.

Warning: Refrigerant is a hazardous liquid and when handled incorrectly can cause serious injury. Suitable protective clothing, consisting of face protection, heat-proof gloves, rubber boots and apron or waterproof overalls, must be worn when carrying out operations on the air conditioning system.

Remedial actions

Warning: Due to its low evaporating temperature, refrigerant must be handled with care. Refirgerant splashed on any part of the body will cause immediate freezing of that area.

If an accident involving refrigerant should occur, conduct the following remedial actions:

• If liquid refrigerant enters the eye, do not rub it. Gently run large quantities of eye wash over affected eye to raise the temperature. If an eye wash is not available, cool, clean water may be used to flush the eye. After rinsing, cover the eye with a clean pad and seek immediate medical attention.
• If liquid refrigerant is splashed onto the skin, run large quantities of water over the affected area to raise the temperature. Implement the same action if the skin comes in contact with discharging cylinders. Wrap the contaminated body parts in blankets (or similar materials) and seek immediate medical attention.

Observe the following precautions when handling components used in the air conditioning system:

• Air conditioning units must not be lifted by their hoses, pipes or capillary lines.
• Hoses and lines must not be subjected to any twist or stress; the efficiency of the system will be impaired by kinks or restrictions. Ensure that hoses are correctly positioned before tightening couplings, and ensure that all clips and supports are utilized.
• Completed assemblies must be checked for refrigeration lines touching metal panels. Any direct contact of components and panels may transmit noise and so must be eliminated.
• The appropriate torque wrench must be used when tightening refrigerant connections to the stipulated value. An additional wrench must be used to hold the union to prevent twisting of the pipe when tightening connections.
• All protective plugs must remain in place to seal the component until immediately prior to connection.
• Ensure components are at room temperature before uncapping, to prevent condensation of moisture from the air that enters it.
• Components must not remain uncapped for longer than 15 minutes. In the event of a delay, the caps must be fitted.
• When disconnecting, immediately cap all air conditioning pipes to prevent ingress of dirt and moisture into the system.
• The receiver/drier contains desiccant which absorbs moisture. It must be positively sealed at all times. A receiver/drier that has been left uncapped must not be used.
• The receiver/drier should be the last component connected to the system to ensure optimum dehydration and maximum moisture protection of the system.
• Use alcohol and a clean, lint-free cloth to clean dirty connections.
• Ensure that all new parts fitted are suitable for use with the specified refrigerant.

Always carry out the following procedure before connecting any hose or pipe:

1. All refrigeration fittings require oiling with the recommended refrigerant oil before installation. Refer to General Information > Fluids and Capacities > Fluids.
2. When connecting refrigeration fittings, ensure that the O-ring is positioned correctly. Push the joint together until the O-ring disappears before attempting to tighten the nut. The nut should start by hand; if a wrench is required then the joint is misaligned. Tighten the joint to the torque shown.
3. The refrigeration system must be kept clean and capped at all stages. At no time must any hoses be left open to atmosphere as the oil in the system is hygroscopic (absorbs moisture). The connection to the drier should only be completed just prior to commissioning (or at least the system should be vacuumed to keep the system dry so any moisture generally in the pipe work does not affect the oil or 'wet' the receiver drier).
4. Keep the lid on oil containers such that a small amount can be dispensed at any time and then at the end of the week, the whole can is disposed of to avoid using contaminated oil. Oil containers kept to lubricate O-rings should not be used to top up oil in systems due to potential contamination.

Use the HVAC machine to perform a leak test after a major repair has been completed.

Refrigerant oil

The compressor contains a lubricant, which has greater electrical insulating properties than the A/C lubrication oil normally used for standard mechanical belt driven A/C pumps. It is important that the compressor is kept upright at all times to retain the lubricant in the compressor's sump.

Caution: Use of the incorrect oil may affect the dielectric strength of the motor and potentially cause an internal short circuit as well potentially affecting the bearing life.

Caution: Refrigerant oil easily absorbs water and must not be stored for long periods. Do not pour unused refrigerant oil back into the container.

Compressor

A new compressor is sealed. Ensure that no foreign material is allowed to enter the compressor.

Caution: Do not remove the cap(s) until immediately prior to connecting the air conditioning pipes to the compressor. Foreign material entering the compressor is likely to cause significant damage requiring replacement.

Rapid refrigerant discharge

If the air conditioning system is involved in accident damage and the system is punctured, the refrigerant will discharge rapidly. The rapid discharge of refrigerant will also result in the loss of most of the oil from the system. The compressor must be removed and all the remaining oil in the compressor drained and refilled as instructed in the air conditioning section of this manual.

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