Component Description For Electric Refrigerant Compressor - GF83.55-P-2110RFH

Model 205.012/013/047/053/054/147/212/213/247/253, 253.311/354/911/954/99 

Shown on engine 651, model 205.012/212 

Courtesy of MERCEDES-BENZ USA

Shown on engine 274, model 205.047/147/247, 253.354/954 

Courtesy of MERCEDES-BENZ USA

Location 

On model 205, model 253 (except 253.99), the electric refrigerant compressor is located on the left side of the engine. On model 253.99, the electric refrigerant compressor is located on the left below the air filter housing.

Task 

The electric refrigerant compressor is responsible for intake and compression of the refrigerant. The speed of the electric refrigerant compressor is controlled steplessly from 700 to 9000 rpm depending on the evaporator temperature.

The climate-control, control unit (N22/1) actuates the electric refrigerant compressor via the climate control LIN 2 (LIN B8-2).

Pressing the "OFF" button or the "A/C" button on the climate control operating unit (N58/1) switches off the electric refrigerant compressor.

The other functions of the automatic air conditioning are still available.

However, a cool-down below the current outside temperature is not possible.

Switching on the electric refrigerant compressor can also be requested by the high-voltage battery cooling function or the pre-entry climate control function.

High-voltage battery cooling system function:

The battery management system control unit (N82/2) sends the request to switch on the electric refrigerant compressor via hybrid CAN (CAN L), powertrain control unit (N127), chassis FlexRay (Flex-E), electronic ignition lock control unit (N73) and interior CAN (CAN B) to the climate control, control unit.

Pre-entry climate control function:

The electronic ignition lock control unit transmits the status of the central locking via the interior CAN to the climate control, control unit. The climate-control, control unit then initiates the pre-entry climate control.

The powertrain control unit sends the request to switch on the pre-entry climate control via the chassis FlexRay, electronic ignition lock control unit, and interior CAN to the climate control, control unit. The climate-control, control unit then initiates the pre-entry climate control.

The electric refrigerant compressor is switched off depending on the outside temperature and after an accident. If the outside temperature is below -10°C, the electric refrigerant compressor is generally switched off.

The electric refrigerant compressor is diagnosed using the diagnostic tester.

Courtesy of MERCEDES-BENZ USA

Structure 

The control unit of the electric refrigerant compressor controls the rpm of the electric motor and the amount of refrigerant. The electric motor drives the spiral compressor. This consists of two intertwined spirals, one of which is permanently connected to the housing while the second rotates in a circle in the first one. The spirals here form several increasingly smaller chambers within the coils. In these chambers, the refrigerant compressed in this manner reaches the center, where it then exits compressed.