Advanced commissioning
6.16 Electrically braking the motor
Converter with the control units CU240D-2
216
Operating Instructions, 04/2018, FW V4.9 SP10, A5E34262100B AF
6.16.1
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
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.