Bosch rexroth MBT, Manual

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13.13.2 Excessive temperature of motor housing
State The housing temperature of the motor rises to unusually high values.
Damage to motor or machine by restarting af‐
ter excessive motor temperature!
CAUTION
⇒ Liquid-cooled motors may not be restarted or supplied with cold coolant
immediately after a failure of the cooling system or an increase in motor tem‐
perature Risk of damage!
⇒ Wait until the motor temperature has dropped under +40 °C before the re‐
start
Possible causes 1. Failure or malfunction in the cooling system.
2. The original machining cycle has been changed.
3. The original motor parameters have been changed.
4. Motor bearings are worn or defective.
Measures for 1. Check the cooling system. Clean or rinse the cooling circuit as required.
Contact the machine manufacturer in the case of a cooling system fail‐
ure.
2. Check the sizing of the drive for changed requirements. Stop operation
in case of overload. Risk of damage!
3. Restore the original parameters. Check the sizing of the drive if require‐
ments have been changed.
4. Contact the machine manufacturer.
13.13.3 High motor temperature values, but housing temperature is normal
State The diagnostic system of the machine shows unusually high winding temper‐
ature values via display or operator software. However, the temperature of
the motor housing is normal.
Possible causes 1. Wiring error or cable break in sensor cable.
2. Diagnostic system defective.
3. Failure of the winding temperature sensor (PTC).
Measures for 1. Check the wiring and connection of the temperature sensor according to
the interconnection diagram.
2. Check the diagnostic system at the controller or the control unit.
3. Check the resistance value of the temperature sensor using a multime‐
ter.
●
Shut down the system and wait until the discharging time has
elapsed.
● Disconnect the connection of the temperature sensor at the con‐
troller. Set the measuring device to resistance measurement mode
and connect the wire pair to the measuring device (this also checks
the sensor line). Check values according to the characteristic
curves in chapter 9.8 "Motor temperature monitoring" on page
277 .
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Commissioning, operation and maintenance
MBT High Synchronous Torque Motors
Bosch Rexroth AG R911298798_Edition 08