Automatic Restart And Flying Restart; Flying Restart - Switching On While The Motor Is Running - Siemens SINAMICS G120 Operating Instructions Manual

9.9.4

Automatic restart and flying restart

9.9.4.1 Flying restart – switching on while the motor is running
If you switch on the motor while it is still running, then with a high degree of probability, a
fault will occur due to overcurrent (overcurrent fault F07801). Examples of applications
involving an unintentionally rotating motor directly before switching on:
● The motor rotates after a brief line interruption.
● A flow of air turns the fan impeller.
● A load with a high moment of inertia drives the motor.
After the ON command, the
"flying restart" function initially
synchronizes the inverter output
frequency to the motor speed
and then accelerates the motor
up to the setpoint.
If the inverter simultaneously drives several motors, then you must only use the "flying
restart" function if the speed of all of the motors is always the same (group drive with a
mechanical coupling).
Table 9- 44
Parameter Description
P1200
Table 9- 45
Parameter Description
P1201
P1202
P1203
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB
Basic setting
Flying restart operating mode (factory setting: 0)
0 Flying restart is locked
1 Flying restart is enabled, look for the motor in both directions, start in direction of
setpoint
4 Flying restart is enabled, only search in direction of setpoint
Advanced settings
Flying restart enable signal source (factory setting: 1)
Defines a control command, e.g. a digital input, through which the flying restart function
is enabled.
Flying restart search current (factory setting 100 %)
Defines the search current with respect to the motor magnetizing current (r0331), which
flows in the motor while the flying restart function is being used.
Flying restart search speed factor (factory setting 100 %)
The value influences the speed with which the output frequency is changed during the
flying restart. A higher value results in a longer search time.
If the inverter does not find the motor, reduce the search speed (increase p1203).
9.9 Application-specific functions
Functions
219