Basic Rules; Regulations - Siemens SIMATIC RF300 System Manual

RF300 system planning
4.7 EMC Directives
EMC measures usually consist of a complete package of measures, all of which need to be
implemented in order to ensure that the plant is immune to interference.
Note
The plant manufacturer is responsible for the observance of the EMC guidelines; the plant
operator is responsible for radio interference suppression in the overall plant.
All measures taken when setting up the plant prevent expensive retrospective modifications
and interference suppression measures.
The plant operator must comply with the locally applicable laws and regulations. They are
not covered in this document.
4.7.3

Basic rules

It is often sufficient to follow a few elementary rules in order to ensure electromagnetic
compatiblity (EMC).
The following rules must be observed:
Shielding by enclosure
● Protect the device against external interference by installing it in a cabinet or housing.
● Use metal plates to shield against electromagnetic fields generated by inductances.
● Use metal connector housings to shield data conductors.
Wide-area ground connection
● Bond all passive metal parts to chassis ground, ensuring large-area and low-HF-
● Establish a large-area connection between the passive metal parts and the central
● Don't forget to include the shielding bus in the chassis ground system. That means the
actual shielding busbars must be connected to ground by large-area contact.
● Aluminium parts are not suitable for ground connections.
Plan the cable installation
● Break the cabling down into cable groups and install these separately.
● Always route power cables, signal cables and HF cables through separated ducts or in
● Feed the cabling into the cabinet from one side only and, if possible, on one level only.
● Route the signal cables as close as possible to chassis surfaces.
● Twist the feed and return conductors of separately installed cables.
88
The housing or enclosure must be connected to the chassis ground.
impedance contact.
grounding point.
separate bundles.
System Manual, 11/2009 - Zwischenstand 17.09.2009, A5E01642529-04
SIMATIC RF300