Siemens SINAMICS G120 Operating Instructions Manual page 10

Table of contents
9.6 Motor control ............................................................................................................................. 185
9.6.1 V/f control .................................................................................................................................. 185
9.6.1.1 Characteristics of U/f control ..................................................................................................... 186
9.6.1.2 Selecting the U/f characteristic ................................................................................................. 187
9.6.1.3 Optimizing with a high break loose torque and brief overload .................................................. 188
9.6.2 Vector control ............................................................................................................................ 190
9.6.2.1 Properties of the sensorless vector control............................................................................... 190
9.6.2.2 Select motor control .................................................................................................................. 191
9.6.2.3 Re-optimize the speed controller .............................................................................................. 191
9.7 Protection functions................................................................................................................... 194
9.7.1 Inverter temperature monitoring................................................................................................ 194
9.7.2 Motor temperature monitoring using a temperature sensor...................................................... 195
9.7.3 Overcurrent protection .............................................................................................................. 198
9.7.4 Limiting the maximum DC link voltage...................................................................................... 199
9.8 Status messages....................................................................................................................... 200
9.9 Application-specific functions .................................................................................................... 200
9.9.1 Functions that match the application ........................................................................................ 200
9.9.2 Unit changover .......................................................................................................................... 200
9.9.2.1 Unit changeover ........................................................................................................................ 200
9.9.2.2 Changing over the motor standard ........................................................................................... 202
9.9.2.3 Changing over the unit system ................................................................................................. 202
9.9.2.4 Changing over units for the technology controller .................................................................... 203
9.9.2.5 Changing of the units with STARTER....................................................................................... 204
9.9.3 Braking functions of the inverter ............................................................................................... 205
9.9.3.1 Comparison of electrical braking methods................................................................................ 205
9.9.3.2 DC braking ................................................................................................................................ 207
9.9.3.3 Compound braking.................................................................................................................... 210
9.9.3.4 Dynamic braking ....................................................................................................................... 212
9.9.3.5 Motor holding brake .................................................................................................................. 214
9.9.4 Automatic restart and flying restart ........................................................................................... 219
9.9.4.1 Flying restart - switching on while the motor is running ........................................................... 219
9.9.4.2 Automatic switch-on .................................................................................................................. 220
9.9.5 PID technology controller .......................................................................................................... 224
9.9.5.1 Overview ................................................................................................................................... 224
9.9.5.2 Setting the controller ................................................................................................................. 224
9.9.5.3 Optimizing the controller ........................................................................................................... 226
9.10 Fail-safe function Safe Torque Off (STO) ................................................................................. 228
9.10.1 Functional description ............................................................................................................... 228
9.10.2 Prerequisite for STO use........................................................................................................... 229
9.10.3 Commissioning STO ................................................................................................................. 229
9.10.3.1 Commissioning tool................................................................................................................... 229
9.10.3.2 Password................................................................................................................................... 230
9.10.3.3 Resetting the safety function parameters to the factory setting................................................ 230
9.10.3.4 Interconnecting the "STO active" signal.................................................................................... 232
9.10.3.5 Setting the signal filter............................................................................................................... 232
9.10.3.6 Setting forced dormant error detection ..................................................................................... 236
9.10.3.7 Activate settings ........................................................................................................................ 237
9.10.3.8 Checking the assignment of the digital inputs........................................................................... 238
9.10.3.9 Acceptance test......................................................................................................................... 240
9.11 Switchover between different settings ...................................................................................... 245
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SINAMICS G120C frequency converter
Operating Instructions, 03/2012, FW V4.5, A5E02999804B AB