Dc Braking - Siemens SINAMICS G120 Operating Instructions Manual

6.25.1

DC braking

DC braking is used for applications where the motor must be actively stopped; however, neither
an inverter capable of energy recovery nor a braking resistor is available.
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.
Function
NOTICE
Motor overheating as a result of DC braking
The motor will overheat if you use DC braking too frequently or use it for too long. This may
damage the motor.
● Monitor the motor temperature.
● Allow the motor to adequately cool down between braking operations.
● If necessary, select another motor braking method.
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.
The DC-braking function is possible only for induction motors.
4 different events initiate DC braking
DC braking when falling below a starting speed
Converter with the CU230P-2 Control Units
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257946B AE
Advanced commissioning
6.25 Electrically braking the motor
Requirement:
p1230 = 1 and p1231 = 14
Function:
1. The motor speed has exceeded the starting
speed.
2. The inverter activates the DC braking as
soon as the motor speed falls below the
starting speed.
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