Converter Control; Switching The Motor On And Off - Siemens SINAMICS G120 Operating Instructions Manual

9.2

Converter control

9.2.1

Switching the motor on and off

After switching on the supply voltage, the converter normally
goes into the "Ready to start" state. In this state, the converter
waits for the command to switch-on the motor:
 The converter switches on the motor with the ON command.
 After the OFF1 command, the converter brakes the motor with
Converter states and commands for switching the motor on and off
In addition to the OFF1command, there are other commands that are used to switch off the
motor:
● OFF2 - the converter immediately switches off the motor without first braking it.
● OFF3 - this command means "quick stop". After an OFF3 command, the converter brakes
The following diagram shows the internal sequence control of the converter when switching
the motor on and off.
Figure 9-2
SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB
The converter changes to the "Operation" state.
the ramp-down time of the ramp-function generator. The
converter switches off the motor once standstill has been
reached. The converter is again "ready to start".
the motor with the OFF3 ramp-down time. After reaching standstill, the converter switches
off the motor.
The command is frequently used for exceptional operating situations where it is
necessary to brake the motor especially quickly, e.g. when it involves collision protection.
State overview of the converter
Functions
9.2 Converter control
161