Condensation sensor, component description

W42.10-1210-11

Location

B76 Condensation sensor

Depending on the vehicle equipment the condensation sensor (B76) is either installed on the single-chamber compressed-air reservoir (5.01) which is used as a constant pressure reservoir or on the single-chamber compressed-air reservoir (5.01), which is located at the lowest point.

W42.10-1211-82

Task

The condensation sensor (B76) records the condensation water yield in the compressed-air system.

Design

1 Brass tip

2 Temperature sensor

3 Heating element

4 Brass housing

5 Drain valve

6 Key button

B76 Condensation sensor

Function

After switching on the ignition the heating element (3) heats up the brass tip (1). The heating element (3) needs approx. approx.
75 s to reach operating temperature. During this time the message "no condensation water" is output in the maintenance system (WS).

The heat of the brass tip (1) located in the air is measured by the temperature sensor (2) and passed on to the maintenance system (WS). If there is too much condensation water in the single-chamber compressed-air reservoir (5.01) and if the measuring tip (1) is surrounded by water, then the heat of the brass tip (1) is dissipated by the water due to the good thermal conductivity of the water and operating temperature drops. The temperature sensor (2) measures the reduced operating temperature and after a reaction time of approx. 90 s to 120 s passes this on to the maintenance system (WS). The message "condensation water" is displayed in the instrument (INS).

By pressing the key button (6) the drain valve (5) is opened and the condensation water is pushed out of the single-chamber compressed-air reservoir (5.01) due to the excess pressure.

 Once the condensation water is drained the driver can reset the message "condensation water" in the maintenance system (WS) in the "maintenance "menu using the steering wheel buttons.