Insulated Bearings When Operating The Converter - Siemens SIMOTICS FD 1LN1 Operating Instructions & Installation Instructions

Preparations for use
4.21 Converter operation
● If the cable shield is connected as described, then it ensures the specified equipotential
● If the cable shield is not connected due to special secondary conditions, or not adequately
Overall system design
To specifically reduce bearing currents, you must consider the system as a whole, which
comprises the motor, converter, and driven machine. The following measures support you
when reducing bearing currents and help to avoid damage:
● In the overall system, set up a properly meshed grounding system with low impedance.
● Use the common-mode filter (damping cores) at the converter output. The Siemens sales
● Limit the rise in voltage by using output filters. Output filters dampen the harmonic content
Note
Converter documentation
The operating instructions for the converter are not part of this documentation. Refer also to the
configuration information for the converter.
4.21.4

Insulated bearings when operating the converter

If the machine is operated from a low-voltage converter, insulated bearings are fitted at the NDE
and an insulated encoder with insulated bearings (option).
Comply with the plates on the machine relating to bearing insulation and possible bridges.
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bonding between the motor enclosure and converter. A separate RF equipotential bonding
conductor is then not necessary.
Concentric copper or aluminum shield
connected, then the specified equipotential bonding is not provided. In this particular case,
use a separate RF equipotential bonding conductor:
– Between the motor enclosure and protective ground rail of the converter.
– Between motor enclosure and driven machine
– Use braided flat copper straps or high-frequency cables with finely-stranded conductors
for the separate RF equipotential bonding cable.
– Ensure that the contacts are established over a large area.
representative is responsible for selection and dimensioning.
in the output voltage.
Steel armor
SIMOTICS FD 1LN1
Operating Instructions 01/2019