Emc-Compliant Drive Installation (Installation Instructions) - Siemens SINAMICS DCM Operating Instructions Manual

If all the control components in the plant or system (such as PLCs) demonstrate a level of
interference immunity that is suitable for industrial applications, then it is not necessary for
every drive to adhere to limit value "A1".
Non-grounded networks
Non-grounded networks (IT systems) are used in some branches of industry in order to
increase the availability of the plant. In the event of a ground fault, no fault current flows and
the plant can continue with production. If RFI suppression filters are brought into the
equation, however, a fault current does flow in the event of a ground fault, which may cause
the drives to shut down or the RFI suppression filter to potentially be destroyed. For this
reason, the product standard does not define any limit values for these networks. From an
economical perspective, any necessary EMC conformance measures should be taken on the
grounded primary side of the supply transformer.
EMC planning
If two devices are not electromagnetically compatible, you can reduce the interference
emission level of the source of interference or increase the interference immunity of the
potentially susceptible equipment. Sources of interference are generally power electronics
devices with high power consumption; reducing their interference emission levels requires
complex filters. Potentially susceptible equipment usually refers to controlgear and sensors,
including their evaluation circuit. There is less work involved in increasing the interference
immunity of inefficient devices, meaning that – economically speaking – increasing
interference immunity is generally a more favorable option for industrial applications than
reducing the interference emission level.
In industrial applications, EMC between devices should be based on a carefully-balanced
combination of the interference emission and interference immunity levels.
The most cost-effective measure that can be put in place to achieve EMC conformance is to
physically separate sources of interference and potentially susceptible equipment – provided
that you have taken this option into account during the planning stage of your machine/plant.
In the first instance, it is necessary to determine whether each device used is a potential
source of interference or potentially susceptible equipment. Within this context, converter
units and contactors, for example, can be counted as sources of interference. While
examples of potentially susceptible equipment include PLCs, encoders and sensors.
The components in the control cabinet (sources of interference and potentially susceptible
equipment) must be physically separated, by means of partition plates if necessary, or by
installing them in metal enclosures.
6.1.2

EMC-compliant drive installation (installation instructions)

General information
Not only are drives operated in a wide variety of environments, but the electrical components
used (controllers, switch mode power supplies, and so on) can also differ widely with respect
to interference immunity and interference emission levels, meaning that all installation guide-
lines of any kind can offer is a practical compromise. For this reason, EMC rules do not need
to be implemented to the letter in all cases, provided that measures are tested on a case-by-
case basis.
SINAMICS DCM Control Module
Operating Instructions, 12/2018, A5E34888669A
6.1 Instructions for EMC-compliant drive installation
Connecting
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