Electrically Braking The Motor; Dc Braking - Siemens SINAMICS G120D Operating Instructions Manual

Advanced commissioning
7.8 Application-specific functions
7.8.3

Electrically braking the motor

Braking with the motor in generating mode
If the motor brakes the connected load electrically, it will convert the kinetic energy of the
motor to electrical energy. The electrical energy E released on braking the load is
proportional to the moment of inertia J of the motor and load and to the square of the speed
n. The motor attempts to pass the energy on to the inverter.
7.8.3.1

DC braking

DC braking is used for applications without regenerative feedback into the line supply, where
the motor can be more quickly braked by impressing a DC current than along a braking
ramp.
Typical applications for DC braking include:
● Centrifuges
● Saws
● Grinding machines
● Conveyor belts
Function
NOTICE
Motor damage caused by overheating
The motor can overheat if it is braked for long periods of time or frequently using DC
braking. This may damage the motor.
• Monitor the motor temperature.
• If the motor gets too hot during operation you must select another braking method or
With DC braking, the inverter outputs an internal OFF2 command for the time that it takes to
de-energize the motor p0347 - and then impresses the braking current for the duration of the
DC braking.
240
give the motor more time to cool down.
Converter with control units CU250D-2
Operating Instructions, 04/2015, FW V4.7.3, A5E34261542B AB