Dc Braking - Siemens SINAMICS G120 Operating Instructions Manual

Advanced commissioning
6.19 Electrically braking the motor
6.19.1

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
Function
NOTICE
Motor damage caused by overheating during 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
304
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.
Converter with the CU240B-2 and CU240E-2 Control Units
Operating Instructions, 01/2017, FW V4.7 SP6, A5E34259001B AD