Speed-Dependent Current Limitation - Siemens SINAMICS Series Operating Instructions Manual

Descriptions of functions

10.22 Speed-dependent current limitation

● PT1000
Approx. 840 Ω up to approx. 2980 Ω at -40 °C to +550 °C
Positive temperature coefficient, almost a linear characteristic
● NTC thermistor K227/S1/1.8 kΩ/KER
Approx. 200 Ω at 190 °C to 1.8 kΩ at 100 °C
Figure 10-71 Characteristic K227
10.22 Speed-dependent current limitation
Speed-dependent current limitation protects the DC motor's commutator and brushes at high
speeds.
The settings required for this (p50104 to p50107) must be taken from the motor rating plate.
Additionally, the maximum operating speed of the motor (p50108) must be entered; this must
match the actual maximum operating speed.
The actual maximum operating speed is determined as follows:
● Using p2000 in cases where the actual speed value comes from an incremental encoder
● Using p50741 in cases where the actual speed value comes from an analog tachometer
● Using p50115 in the case of operation without a tachometer
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SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A