It System; Requirements For The Protective Conductor - Siemens SINAMICS G120C Operating Instructions Manual

4.9.1.3

IT system

In an IT line system, all of the conductors are
insulated with respect to the PE protective
conductor – or connected to the PE protective
conductor through an impedance.
There are IT systems with and without transfer
of the neutral conductor N.
Operating the converter on an IT line system
• Converters with integrated line filter:
– Operation on IT line systems not permissible.
• Converter without line filter:
– Operation on all IT line systems permissible.
Behavior of the converter when a ground fault occurs
You must install an output reactor if the converter is to remain operational even when a ground
fault occurs at the converter output. This output reactor prevents an overcurrent trip or damage
to the converter.
4.9.2

Requirements for the protective conductor

Overview
A high leakage current flows through the protective conductor in converter operation. The
protective conductor of the converter must not be interrupted for safe touch protection in
converter operation.
This primarily results in requirements for the minimum conductor cross-section of the
protective conductor.
No restriction applies to the length of the protective conductor for touch protection.
However, short protective conductors are advantageous for EMC-compliant installation.
SINAMICS G120C Converters
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK
4.9 Connect the line supply, motor and braking resistor
Installing
67