Engine, Starting With Empty Refrigerant Circuit When Necessary
There is a risk of damaging the A/C compressor if the engine runs when the refrigerant circuit is not filled. Refer to REFRIGERANT CIRCUIT or REFRIGERANT CIRCUIT, DISCHARGING [R1234yf] .
- An A/C compressor without an A/C Clutch -N25- is always driven when the engine is running. Therefore the engine may only be started when the refrigerant circuit has been properly assembled.
- For example, if the refrigerant lines are not connected to A/C compressor, the A/C compressor may heat up so much when the engine is running that the A/C compressor will be damaged by internal heat generation.
- If possible, only start the engine when the refrigerant circuit is filled.
- Do not start the engine while evacuating the refrigerant circuit or when the refrigerant circuit is evacuated. Refer to REFRIGERANT CIRCUIT, EVACUATING WITH A/C SERVICE STATION [R134a] or REFRIGERANT CIRCUIT, EVACUATING [R1234yf] .
- The engine should not be run for longer than absolutely necessary.
The A/C compressor has an "internal oil circuit" to ensure that the A/C compressor is not damaged when the refrigerant circuit is empty. There must be a residual amount of refrigerant oil in the A/C compressor for this.
Do not start the engine while evacuating or when the refrigerant circuit is evacuated (the A/C compressor could become damaged). Refer to A/C SYSTEM, STARTING AFTER CHARGING REFRIGERANT CIRCUIT / A/C SYSTEM, GENERAL INFORMATION or A/C SYSTEM, STARTING AFTER CHARGING REFRIGERANT CIRCUIT / A/C SYSTEM, OPERATING AFTER CHARGING [R1234yf] .
The A/C compressor on the version without a A/C Clutch -N25- is always driven by the belt pulley. To prevent damage when the compressor is idling, it is lubricated by an "Internal oil circuit".
The A/C compressor has an "internal oil circuit" to ensure that the A/C compressor is not damaged when the refrigerant circuit is empty. The prerequisite for the internal lubrication is a residual amount of refrigerant oil in the A/C compressor and there is no vacuum in the refrigerant circuit.
The engine may only be started when the refrigerant circuit is installed correctly. For example; if the refrigerant lines are not connected to the A/C compressor, when the engine is running the A/C compressor may heat up (via internal heat generation) so much that the A/C compressor will be damaged.
A/C Compressor Regulator Valve -N280- is not activated when the refrigerant circuit is empty and the A/C compressor without solenoid coupling idles with the engine. Since there is no refrigerant in the circuit, the required refrigerant oil for lubricating the A/C compressor is not supplied.
If it is necessary to start the engine on a vehicle with an A/C compressor without a A/C Clutch -N25- with an empty refrigerant circuit.
- The refrigerant circuit must be fully assembled.
- There must be no vacuum in the refrigerant circuit.
- If the A/C compressor was removed: At least a quarter of the prescribed refrigerant oil amount must be in the A/C compressor.
- Do not let the engine speed go above 2, 500 RPM.
- The engine should not be run for longer than absolutely necessary (for example, to move the vehicle into the workshop area).
If only the refrigerant was evacuated (the A/C compressor was not removed), it is guaranteed that there is enough refrigerant oil in the A/C compressor to continue lubricating the A/C compressor for a short operating period due to the design of the refrigerant circuit.