Converter Operation On A Grounded Network - Siemens 1LA8 Operating Instructions Manual

Electrical connection
6.5 Connecting the auxiliary circuits
Measures to further reduce bearing currents
To specifically reduce and prevent damage caused by bearing currents, you must consider
the system as a whole, which comprises the motor, converter, and driven machine. The
following precautions help to reduce bearing currents:
● In the overall system, set up a properly meshed grounding system with low impedance for
● Use the common-mode filter (damping cores) at the converter output. The Siemens sales
● Limit the rise in voltage by using output filters. This dampens the harmonic content in the
6.5.6.4

Converter operation on a grounded network

NOTICE
Damage resulting from protective conductor currents
When the machine is operated on a converter with current limiter, but without ground-fault
monitoring, protective conductor currents of up to 1.7 times the external conductor current
can arise if there is a ground fault on the output side. Neither the PE conductors of normally
rated multi-core connecting cables nor the PE connecting points of normal terminal boxes
are suitable for this purpose. Material damage can result.
● Use an appropriately sized PE conductor.
● Connect the PE conductor to the grounding terminal on the motor enclosure.
82
high-frequency currents.
representative is responsible for selection and dimensioning.
output voltage.
Note
Converter documentation
The operating instructions for the converter are not part of this documentation. Refer also
to the configuration information for the converter.
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 05/2014