5
TEBS E
braking system
42
Parameter setting
The LSV data is entered via tab 3, Brake data.
Generally, the definition of a linear characteristic is sufficient.
In special cases a special characteristic can be defined by means of an additional
characteristic point.
By default, three values are preset:
Application range Wear range
Transition range
(optional)
Stability range
Pressure at the yellow coupling head
(Control pressure or nominal value)
p ≤ 0.7 bar 0,7 bar < p ≤ 2.0 bar 2,0 bar < p
≤ 4,5 bar 4,5 bar < p ≤ 6.5 bar
Calculated deceleration of the vehicle 0 % at 2 bar: 12,6 % at 4.5 bar: 37 % at 6.5 bar: 56,5 %
The braking pressure level control is adapted proportionally to the measured vehi-
cle load.
The aim is to achieve a deceleration of 55 % during all loading conditions and
when the pressure at the yellow coupling head (control pressure or nominal value)
is 6.5 bar.
Pressure sensor for hydraulic suspension
The pressure sensor has to be selected based on the pressures that occur. The
signal output must be linear between 0.5 and 4.5 V.
Hydraulic Pressure: 0 bar = 0.5 V
Maximum system pressure = 4.5 bar
Various manufacturers supply matching pressure sensors, such as WIKA (Model
894.24.540 with measuring range of hydraulic pressure 25 to 1000 bar) or Hydac
(pressure transducers HDA4400, range of measurement 250bar).
Next to the pressure range, the pin assignment on the electrical port must be
checked.
Example
Hydraulic bellows pressure ‘unladen’ = 50 bar
Hydraulic bellows pressure ‘laden’ = 125 bar
The pressure input for the TEBS E LSV parameters ‘laden’ and ‘unladen’ is sought
after.
Default
Search for hydraulic pressure sensor, which corresponds with the measuring range
from 125 bar.
‘Hydraulic’ pressure sensor: 0 to 250 bar => 0.5 to 4.5 V
WABCO standard EBS pressure sensor ‘pneumatic’ as comparison value: 0 to
10 bar => 0.5 to 4.5 V
Calculation
Range of measurement 250 bar: WABCO standard EBS pressure sensor 10 bar =
25 bar
Parameter value for bellows pressure ‘laden’ => 125 bar / 250 bar * 10 bar = 5 bar
Parameter value for bellows pressure ‘unladen’ =>
50 bar / 250 bar * 10 bar = 2 bar
Conversion of the hydraulic pressure into the pneumatic reference
pressure is carried out in the TEBS E Diagnostic Software and simpli-
fies the setting of parameters.
Deviations in the calculation of the parameter values are also pro-
duced by rounding or down within the binary numeric system.
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