Installation and commissioning SET DATAEAGLE X-treme IO 2730
Connections to
EMC earth
Housing for
sources of
interference
Protective earth
conductor
Control cabinet
wiring
Chapter 6 – Tips and Tricks
Design all connections with EMC earth as short as possible
and as extensive as possible. Pay attention that all metallic
housings have good contact to the galvanized mounting
surface.
Pay attention that all electronic or electric parts which should
be considered as possible source of HF interferences are
installed in a closed metallic housing.
Run the protective earth conductors of the individual system
components star-shaped towards the potential equalization
rail. Thereby you avoid that interferences are injected by PE
loops which act as antennas. Unfavourable earth protection
connections and loops may bridge EMC measurements and
will make them inefficiently.
Pay unconditional attention to a separation of N (neutral
conductor) and PE (earth protection) inside the control
cabinet. Measure with a clamp-on ammeter if equalizing
currents flow across the PE control cabinet cable. Here, no
currents should flow permanently.
In case of very disturbed ambient conditions, as they can oc-
cur for example in industrial halls with induction furnaces, we
recommend the PE-free construction. As the radio modem is
only supplied with 24V DC, earthing is not mandatory. If a
ring current flows over the screen during a direct measure-
ment (to be measured with a current clamp), galvanic isola-
tion should be provided via a 100nF /230V X capacitor. The
capacitor has a low resistance to high-frequency interference
levels but prevents ring currents.
