Electrically Braking The Motor; Electrical Braking; Dc Braking - Siemens SINAMICS G110M Operating Instructions Manual

8.20

Electrically braking the motor

8.20.1

Electrical braking

Overview
Braking with the motor in generator operation
If the motor brakes the connected load electrically, it converts the kinetic energy of the motor
into electrical energy. The electrical energy E released when 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 transfer the energy on to the converter.
A differentiation is made between mechanically braking and electrically braking a motor:
• Mechanical brakes are generally motor holding brakes that are closed when the motor is at
a standstill. Mechanical operating brakes that are closed while the motor is rotating are
subject to a high wear and are therefore often only used as an emergency brake.
If your motor is equipped with a motor holding brake, then you should use the converter
functions to control the motor holding brake, see Section Motor holding brake (Page 230).
• The motor is electrically braked by the converter. An electrical braking is completely wear-
free. Generally, a motor is switched off at standstill in order to save energy and so that the
motor temperature is not unnecessarily increased.
8.20.2

DC braking

Overview
DC braking is used for applications where the motor must be actively braked, but where the
converter is neither capable of energy recovery nor does it have a braking resistor.
Typical applications for DC braking include:
• Centrifuges
• Saws
• Grinding machines
• Conveyor belts
DC braking is not permissible in applications involving suspended loads, e.g. lifting equipment/
cranes and vertical conveyors.
Distributed converter for SIMOGEAR geared motors
Operating Instructions, 10/2020, FW V4.7 SP13, A5E31298649B AL
Advanced commissioning
8.20 Electrically braking the motor
311