100 °C. When the housing temperature exceeds 100 °C, overtemperature
shutdown takes place.
Above 200% of the continuous torque at standstill an I
2
t limitation
starts. It
limits the temperature of winding and electronics to the safe working range.
In standstill (turning shaft n < ~ 60 min
-1
), the current is limited in a more re‐
strictive way, due to the concentration of losses in one phase. For bigger mo‐
tors, the continuous torque at standstill can be less than 200% of the continu‐
ous torque at standstill 60 K.
The limitation starts at 100% of thermal drive load. To have reserve capacity
(e.g., for dynamic processes or increased friction), the drive system should
not be dimensioned with more than 80% of thermal drive load. The drive load
should be checked during the initial commissioning.
See also "P-0-0141, Thermal drive load"
k
Overload ratio
A)
Turning shaft n > ~ 60 min
-1
B)
Standstill n < ~ 60 min
-1
Fig. 7-22:
Example of current limitation
To determine the resulting torque or current limitations, additional‐
ly take the motor current limitations into account. See "KSM02
characteristics" or for KMS02 the data sheet of the motor used.
7.2.4
Motor temperature
Since the electronics is thermally connected to the motor housing, the amplifi‐
er temperature is the most important load variable. This temperature is meas‐
ured and can be read as parameter "S-0-0384, Amplifier temperature". It is
slightly higher than the housing temperature and should not exceed 100 °C.
Operation under rated conditions causes temperature rise of 60 K.
If 105 °C are exceeded, the motor temperature warning is generated; after 30
seconds, power is switched off.
The product of the square of the current and the time results in a constant
Bosch Rexroth AG
DOK-INDRV*-KCU02+KSM02-PR03-EN-P
224/337
Rexroth IndraDrive Mi Drive Systems with KCU02 KSM02, KMS02/03, KMV03, KNK03
Notes on project planning
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