GF43.30-W-3000A | Braking torque limitation as a result of coolant temperature, function | 9.9.96 |
MODELS 375.4, 944, 950, 952, 953, 954 with CODE (BA9) Voith R115 secondary retarder
Operating procedure
1 The retarder control unit receives information about the coolant temperature through the coolant temperature sensor.
2 If, during a retarder brake application, the coolant temperature increases to the temperature limit range, the control current to the retarder proportioning valve is regulated back linearly for a short time. The actuating pressure is limited and thus the retarder braking torque is limited.
3 Finally, if the coolant temperature is regulated to a constant value, i.e. if the measured temperature is lower than the permissible maximum temperature, the actuating pressure is continually increased (max. until no more adaptation is active). In the opposite case the actuating pressure is lowered continuously (down to zero in an extreme case).
4 The braking torque and the resultant heat reduce until an equilibrium results between the retarder braking energy occurring and the heat which can be dissipated via the vehicle cooling system.
The permanent brake indicator lamp flashes while braking torque limitation as a result of coolant temperature is effective.