Siemens SINAMICS V20 Operating Instructions Manual page 100

Commissioning via the built-in BOP
5.6 Function commissioning
Motor overheat
For compound braking, regenerative braking is superimposed on the DC braking (braking
along a ramp). This means that components of the kinetic energy of the motor and motor
load are converted into thermal energy in the motor. This can cause the motor to overheat if
this power loss is too high or if the brake operation takes too long!
Note
The compound braking depends on the DC link voltage only (see threshold in the above
diagram). This will happen on OFF1, OFF3 and any regenerative condition. Compound
braking is deactivated, if:
• flying start is active
• DC braking is active.
Dynamic braking
Dynamic braking converts the regenerative energy, which is released when the motor
decelerates, into heat. An internal braking module or an external dynamic braking module,
which can control an external braking resistor, is required for dynamic braking. The converter
or the external dynamic braking module controls the dynamic braking depending on the DC
link voltage. Contrary to DC and compound braking, this technique requires that an external
braking resistor is installed.
For more information about the dynamic braking module, see Appendix "Dynamic braking
module (Page 367)".
98
WARNING
SINAMICS V20 Converter
Operating Instructions, 10/2019, A5E34559884-012