Zone Concept Within The Converter Cabinet - Siemens SINAMICS G130 Engineering Manual

Installation examples using typical SINAMICS chassis units and SINAMICS cabinet units will illustrate how these
rules can be applied in practice.

Zone concept within the converter cabinet

The most cost-effective method of implementing interference suppression measures within the converter cabinet is to
ensure that interference sources and potentially susceptible equipment are installed separately from each other. This
must be taken into account already during the planning phase.
The first step is to determine whether each device used is a potential source of interference or potentially susceptible
equipment:
•
Typical sources of interference include frequency converters, braking units, switched-mode power supplies,
and contactor coils.
•
Typical potentially susceptible equipment includes automation devices, encoders and sensors, as well as
their evaluation electronics.
Following this, the entire converter cabinet has to be divided into EMC zones and the devices have to be assigned to
these zones. The example below illustrates this zone concept in greater detail.
Division of the converter cabinet / drive system into different EMC zones
Inside of each zone, certain requirements apply in terms of interference emissions and interference immunity. The
different zones must be electromagnetically decoupled. One method is to ensure that the zones are not positioned
directly next to each other (minimum distance app. 25 cm). A better, more compact method, however, is to use
separate metallic housings or separation plates with large surface areas. Cables within each zone can be unshielded.
Cables connecting different zones must be separated and must not be routed within the same cable harness or cable
channel. If necessary, filters and/or coupling modules should be used at the interfaces of the zones. Coupling
modules with electrical isolation are an effective means of preventing interference from spreading from one zone to
another. All communication and signal cables leaving the converter cabinet must be shielded. For longer, analog
signal cables isolating amplifiers should be used. Sufficient space for bonding the cable shields must be provided,
EMC Installation Guideline
Engineering Information
SINAMICS Engineering Manual - May 2008
© Siemens AG
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