Compressor

Compressor

A 7-cylinder swash plate (adjustable) compressor is used for the air conditioning system. The capacity is 160 cm3 at 100% output.

Refrigerant oil capacity = 195 ± 15 cm3 ND8







Function

The compressor output varies between 5% and 100%. Changing the swash plate setting (the angle of incidence changes in relation to the drive axle) results in a change in the flow rate and output. The higher the cooling power required, the greater the suction pressure.

The piston stoke is controlled on the basis of the high pressure/low pressure ratio. The control valve in the compressor is membrane-driven via the suction pressure and connects the high-pressure side with the crankcase chamber. The crankcase chamber pressure is determined by the high and low pressure at the control valve and by an internal throttle bore. The inclination of the swash plate depends on the crankcase chamber pressure which is regulated by the control valve. This pressure control eliminates the need to cycle the compressor clutch.

Air Conditioning Compressor Control

The compressor is switched on by the DME via a relay at least 8 seconds after the engine starts. This relay is located in relay holder 2.

The following conditions cause the air conditioning compressor to switch off:
- Temperature conditions
- At outside temperatures <37.4° F. (3° C.) (see also section "Temperature sensor for fresh air intake"), the compressor is switched off. The control unit only allows the compressor to be switched on again at 38.3° F. (3.5° C).
- At coolant temperatures > 244° F. (118° C.), the compressor is switched off; at <239° F. (115° C.) it is switched on again.

- Pressure conditions
At coolant pressures less than 29 psi (2 bar) (low pressure) and > 406 psi (28 bar) (high pressure), the compressor is switched off.

- Kickdown condition (acceleration)
At a pedal travel > 92% (shortly before pedals end postion), the compressor is shut down for 6 seconds when the pedal is held in position for less than 6 seconds, or for a maximum of 9 seconds when the pedal is held in position for > 6 seconds). Classic full-load cut-off is not incorporated.

Condenser

The condensers of the air conditioning system are installed together with the radiators in space-saving configuration on the left and right sides at the front end of the vehicle (see also section "Refrigeration circuit").

Receiver Dryer

The receiver dryer is installed in the fresh air chamber at front left, next to the battery. The pressure relief valve (see arrow) for the cooling system is also located here.







Expansion Valve and Additional Components