Lenze 8400 TopLine - Manual (Page 264)

5 Motor control (MCTRL)
5.10 Parameterisable additional functions
264
Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
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5.10.4 Flying restart function
The flying restart circuit for asynchronous motors uses a simple motor model which requires
knowledge of the motor stator resistance RS and the rated motor current.

Tip!
In association with the flying restart function, we recommend information provided in this
documentation on the following topic:
 Automatic DC-injection braking (Auto-DCB) ( 268)

Note!
• Currently, the flying restart circuit is only available for asynchronous motors. (A flying
restart circuit for synchronous motors is in preparation.)
• For a correct functioning of the flying restart circuit, we recommend to perform a
parameter identification first.  Automatic motor data identification ( 141)
• The flying restart function works safely and reliably for drives with great centrifugal
masses.
• Do not use the flying restart function if several motors with different centrifugal
masses are connected to a controller.
• After the controller is enabled, the motor can start for a short time or reverse when
machines with low friction and low mass inertia are used.
• The flying restart function serves to identify max. field frequencies up to ±200 Hz.
• When power-adapted standard asynchronous motors are used (rated motor power
approximately corresponds to the rated inverter power), a motor parameter
identification is not required.
• On drive systems with feedback, you do not need to use the flying restart function
because the synchronisation to the speed detected by the feedback is always carried
out in a jerk-free manner.
• Especially in case of very high power, very high mass inertia and a mains voltage
higher than 440 V, an overvoltage in the DC bus may be caused temporarily. Using a
brake resistor may avoid this behaviour.
• From version 15.00.00 , frequency can be set as a remedy in C00989 which is added
to the found flying restart frequency.
Here, the setting in C00989 has to be increased in small steps up to double the slip
frequency until the behaviour does not occur anymore.