Component description for electric refrigerant compressor - GF83.55-P-2110FLH

MODEL 212.095/098/298 

Shown on ENGINE 651 

Fig 1: Electric Refrigerant Compressor - Shown On Engine 651

Courtesy of MERCEDES-BENZ USA

Location 

The respective refrigerant compressor is located on the engine.

Task 

The electric A/C compressor is responsible for intake and compression of the refrigerant. The speed of the electric A/C compressor is continuously regulated as a function of the evaporator temperature from n= 700 up to 9000 RPM.

The automatic climate control control and operating unit (N22/7) transmits the switch-on request to the electric refrigerant compressor via interior CAN (CAN B), front SAM control unit with fuse and relay module (N10/1), chassis CAN (CAN E) (up to 28.2.13) or chassis CAN 1 (CAN E1) (ab 1.3.13), CDI control unit (N3/9) (with diesel engine) or ME-SFI [ME] control unit (N3/10) (with gasoline engine) and hybrid CAN (CAN L).

Pressing the "OFF" button or the "A/C" button on the automatic air conditioning control and operating unit also switches off the electric A/C compressor. The other functions of the automatic climate control 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 system function. To this end, the battery management system control unit (N82/2) transmits the request to switch on via the hybrid CAN to the electric refrigerant compressor.

The electric refrigerant compressor is diagnosed using the diagnostic tester.

Fig 2: Electric Refrigerant Compressor Components

Courtesy of MERCEDES-BENZ USA

Body 

The electric refrigerant compressor control unit regulates the rotational speed of the electric motor and the quantity 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. The compressed refrigerant then enters these chambers up to the center, where it then exits compressed.