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94 Program features
Motor speed
Reference
21.09
Note:
•
DC hold is only available in speed control in DTC motor control mode (see page
26).
•
The function applies the DC current to one phase only, depending on the
position of the rotor. The return current will be shared between the other
phases.
Post-magnetization
This feature keeps the motor magnetized for a certain period (parameter 21.11)
after stopping. This is to prevent the machinery from moving under load, for
example before a mechanical brake can be applied. Postmagnetization is activated
by parameter 21.8. The magnetization current and time are set by parameters
and 21.11.
Note: Post-magnetization is only available in speed control in DTC motor control
mode (see page 26), and only when ramping is the selected stop mode (see
parameter 21.3).
Continuous magnetization
A digital signal, such as a user bit in the fieldbus control word, can be selected to
activate continuous magnetization. This can be especially useful in processes
requiring motors to be stopped (for example, to stand by until new material is
processed), then quickly started without magnetizing them first.
DC hold
t
t
21.10
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