User's Manual

4 – 5
EMC Directives
D101583 0207 BL ident
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undertaken during system design save expensive modifications and
elimination of interference at a later date.
Fundamentals for EMC protection
The following elementary rules relating to electromagnetic
compatibility (EMC) must be observed:
 Shielding by a housing
Protect the device from external sources of interference by the
installation in a switch cabinet or housing. The cabinet or the
housing must be included in the connection to earth.
Shield the electromagnetic fields from inductances by partition
panels of devices. Use shielded data transmission cables with
metallic connector housings.
 Large area ground connections
Connect all inductive metal parts over a large area and use a low
resistance for radio frequencies. Establish a large area
connection between the inactive metal parts and the central
earthing point.
Integrate the shield earth into the earthing concept, i.e. the end
of the shield must be connected to a large area to earth.
 Planning of the cable routes
Divide the cables into power groups and lay them separately.
Lay the high power cables and the data cables in separate ducts
or bundles.
Introduce the entire cabling into the cabinet only from one side
and on a single level when possible.
Lay the data cables as close to earthed surfaces as possible.
Twist the incoming and outgoing cables of individually laid
conductor pairs.
In many cases an independent cable guidance for the bus cable
is already provided. Ideally this should also be used for laying the
data cables between read-write heads and interface modules.
 Shielding of cables
Shield the data transfer cables and apply the shield on gateway
side. Shield the analogue cables and apply the shield at one end,
e.g. on the drive unit.
Always apply the cable shields at the entry to the switch cabinet
to a large area on the grounding bar and attach them with fixing
clamps.