Siemens HT-direct User Manual

Transport, installation and assembly
3.9 Connecting the ground conductor
A5E01083943A AB
48 Siemens AG Operating Instructions 2.02 1FW4
the protective grounding bar of the converter. On the motor end for example, this can be
done using EMC screw joints at the cable entry ports. On the converter end, you can use
EMC-shielded clips, for example.
● In the overall system, set up a properly meshed grounding system with low impedance for
high-frequency currents.
● No potential difference between the motor, converter, and working machine.
– Use the symmetrical, shielded connection cable
– Connect the cable shielding at both ends on a wide area (360° contact)
– Use the equipotential bonding cables between the motor and the driven machine,
between the motor and the converter, inside the motor, between the terminal box and
the RF grounding point on the motor housing
– Use a separate RF equipotential bonding cable between the motor housing and the
driven machine
– Use a separate RF equipotential bonding cable between the motor housing and the
protective grounding bar of the converter
● Use the common-mode filter (damping cores) at the converter output. The Siemens sales
representative is responsible for selection and dimensioning.
● Limit the rise in voltage by using output filters. This dampens the harmonic content in the
output voltage.
● Use the motor reactors.
● Give preference to an IT system with an insulated neutral point
Note
Operating instructions for the frequency converter
The operating instructions for the frequency converter are not part of this documentation.
Parallel PE conductor
In the case of current-limited converters without ground fault monitoring, PE 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. It is then
necessary to route a sufficiently dimensioned parallel protective conductor. You can connect
this to the grounding terminal on the motor housing. [ID 838.01]
3.9 Connecting the ground conductor
Connecting to the motor
The cross-section of the motor ground conductor must comply with the installation and
erection regulations, for example in accordance with IEC/EN 60204-1, for phase conductor
cross-sections greater than 35 mm
2
, with a minimum of 50% of the cross-section of the
phase conductor.

Siemens HT-direct Specifications

General

Brand	Siemens
Model	HT-direct
Category	Engine
Language	English