Emc Compliant Connection; Avoiding Electromagnetic Interference; Emc-Compliant Cabinet Design - Siemens SINAMICS G120P Hardware Installation Manual

4.2

EMC compliant connection

4.2.1

Avoiding electromagnetic interference

Only the concurrent use of filtering, grounding and shielding ensure an installation in
accordance with the EMC requirements.
The next sections cover all of the most important rules for the installation of inverter and
drive systems.
4.2.2

EMC-compliant cabinet design

The most cost-effective method of implementing interference suppression measures within
the control 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.
EMC-zone concept within the control cabinet
The control cabinet has to be divided into EMC zones and the devices within the control
cabinet have to be assigned to these zones. The example below illustrates this zone concept
in greater detail.
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 / 9.84
in). 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 cabinet must be shielded. For longer,
analog signal cables isolating amplifiers should be used. Sufficient space for bonding the
cable shields must be provided, whereby the braided cable shield must be connected to the
cabinet ground with excellent electrical conductivity and with a large contact area.
Differences in the ground potential between the zones must be avoided to ensure that
impermissible, high compensating currents are kept away from the cable shields.
Power Module PM230, IP20 / Push through
Hardware Installation Manual, 03/2012, A5E03448282B AA
Connecting
4.2 EMC compliant connection
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