Siemens SINAMICS S150 NEMA, Operating Instructions Manual

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Functions, monitoring and protective functions
9.3 Drive functions
Enclosed Drives
Operating Instructions, 12/2018, A5E36652151A
523
9.3.5 Automatic restart function
Description
The automatic restart function automatically restarts the converter after an undervoltage or a
power failure. The alarms present are acknowledged and the drive is restarted automatically.
The drive can be restarted using:
● The standard procedure starting from standstill, or
● Starting the drive with the flying restart function.
For drives with low moments of inertia and load torques that allow the drive to come to a
standstill within a matter of seconds (e.g., pump drives operating against a pressure
head), then starting from standstill is recommended.
Note
Drives with high moments of inertia
The flying restart function can also be activated for drives with large moments of inertia (such
as fan drives). This enables you to switch to the motor that is still rotating.
WARNING
Unexpected movement of the motor during automatic restart
If p1210 is set to values > 1, the motor can be restarted automatically without the need to
issue the ON command.
In the event of prolonged power failures and when the automatic restart function is
activated (p1210 > 1), the drive may have been at a standstill for a long time and
mistakenly considered to have been switched off.
For this reason, entering the area around the drive when it is in this condition can cause
death, severe injury or material damage.
•
Observe the general safety instructions.
•
Ensure that the EMERGENCY STOP functions are always fully functional.