User's Manual

Planning the RF300 system
4.5 Guidelines for electromagnetic compatibility (EMC)
SIMATIC RF300
System Manual, 07/2016, C79000-G8976-C345-0x
101
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 direct
ives; 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 compl
y with the locally applicable laws and regulations. They are
not covered in this document.
4.5.3
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.
The housing or enclosure must be connected to the chassis ground.
● Use metal plates to shield against electromagnetic fields generated by inductances.
● Use metal connector housings to shield data conductors.
Wide-area ground connection
● Plan a meshed grounding concept.
● Bond all passive metal parts to chassis ground, ensuring large-area and low-HF-
impedance contact.
● Establish a large-area connection between the passive metal parts and the central
grounding point.
● 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
separate bundles.
● Feed the cabling into the cabinet from one side only and, if possible, on one level only.