Siemens Sinamics S120 Function Manual page 200

Vector control
4.20 Flying restart
Figure 4-29
When the flying restart (p1200) function is active, the drive may still be accelerated by the
detection current despite the fact that it is at standstill and the setpoint is 0!
For this reason, entering the area around the drive when it is in this condition can cause
death, serious injury, or considerable material damage.
Note
With induction motors, the demagnetization time must elapse before the flying restart
function is activated to allow the voltage at the motor terminals to decrease otherwise high
equalizing currents can occur when the pulses are enabled due to a phase short-circuit.
Flying restart in encoderless operation for long cables
As a rule, it is important to consider the cable resistance. The cable resistance is required for
calculation of the thermal motor model.
Enter the cable resistance in parameter p0352 before you carry out motor identification. Set
parameter p1203[0...n] to at least 300%. This operation can take a little longer than for the
factory setting (100%). Flying restart for long cables is optimized by changing the flying
restart algorithm.
Note
Flying restart for long cables
Use a trace recording to check and optimize the flying restart function. If necessary, optimize
the settings of parameters p1202 and p1203.
198
ON
Flying restart, example of induction motor with encoder
WARNING
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Drive functions