Compressor HVAC: Description and Operation

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

Component Identification:

Location
The electric refrigerant compressor is located at the bottom left on the engine.

Task
The electric refrigerant compressor control unit is responsible for the intake and compression of the refrigerant.
The electric refrigerant compressor's speed is regulated infinitely by the AAC control unit (N22/1), within the speed range of 700 to 9000 rpm, depending on the evaporator temperature.
The AAC control unit sends the switch on request to the central gateway control unit (N93) via the interior CAN. The latter routes the request to the ME control unit via the chassis CAN (CAN E). The ME control unit then actuates the electric refrigerant compressor via the drive train sensor CAN (CAN I).

Pressing the "OFF" button (without code (228) Stationary heater) or the OFF/Residual heat button (N72/1s38) (with code (228) Stationary heater) on the upper control panel control unit (N72/1) switches off the electric refrigerant compressor.
The electric refrigerant compressor can also be switched off on the front central control unit (A40/9). This is accomplished by activation of "AC-OFF" in the central menu of the climate control in the COMAND display (A40/8) (without code (867) SPLITVIEW) or in SPLITVIEW display (A40/10) (with code (867) SPLITVIEW). The other functionalities of the automatic air conditioning continue being available. However, a cool-down below the current outside temperature is not possible.

Design
The electric refrigerant compressor consists of the following three main groups:
- Control unit (1)
- Electric motor (2)
- Spiral compressor (3)

The electric refrigerant compressor control unit regulates the speed the electric motor and the refrigerant quantity. 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 is rotated in a circle in the first one. In doing so the spirals touch each other several times and form several increasingly smaller chambers within the spirals. The compressed refrigerant then enters these chambers up to the center, where it then exits compressed.

The familiar R134a refrigerant compressor oil is used as the refrigerant compressor oil.