Brush Monitoring - Linde E25 Service Training

Section 2.6
Page 88
2.6.12

BRUSH MONITORING

In trucks up to series 6/95 a brush monitoring system was used in which the brush wear switch (maker) was
connected to a brush monitor which, in turn, was connected to the combined instrument.
Brush monitoring from series 7/95
A switching contact is installed on each of the positive and negative brushes in the motor (traction and pump
motors).
All four switching contacts are connected in series and to battery negative on one side. When one brush is
worn down to 60 % of its original length, the pressure spring touches the switching contact, thus cutting off
the battery negative signal at the combined instrument.
The lamp in the combined instrument is illuminated and signals the wear of a motor brush. Even if only a
brief triggering of the switching contact at a motor brush occurred, this information will remain stored until
the key switch is turned off. To identify the motor with the brush wear, the motor number is shown in the LCD
display.
1 RH traction motor 1M1
2 LH traction motor 1M2
3 Pump motor 2M1
The motor number and the elapsed service hours are displayed alternately.
Service Training
Pressing Spring
Switching
Contact
Pressing Spring
Switching
Contact