Electromagnetic compatibility (EMC) means the ability of an electrical
device, to function error free in an electromagnetic environment
without being interfered respectively without interfering the environ-
ment.
The components of VIPA are developed for the deployment in indus-
trial environments and meets high demands on the EMC. Neverthe-
less you should project an EMC planning before installing the compo-
nents and take conceivable interference causes into account.
Electromagnetic interferences may interfere your control via different
ways:
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Electromagnetic fields (RF coupling)
n
Magnetic fields with power frequency
n
Bus system
n
Power supply
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Protected earth conductor
Depending on the spreading medium (lead bound or lead free) and
the distance to the interference cause, interferences to your control
occur by means of different coupling mechanisms.
There are:
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galvanic coupling
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capacitive coupling
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inductive coupling
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radiant coupling
In the most times it is enough to take care of some elementary rules
to guarantee the EMC. Please regard the following basic rules when
installing your PLC.
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Take care of a correct area-wide grounding of the inactive metal
parts when installing your components.
– Install a central connection between the ground and the pro-
tected earth conductor system.
– Connect all inactive metal extensive and impedance-low.
– Please try not to use aluminium parts. Aluminium is easily oxi-
dizing and is therefore less suitable for grounding.
n
When cabling, take care of the correct line routing.
– Organize your cabling in line groups (high voltage, current
supply, signal and data lines).
– Always lay your high voltage lines and signal respectively data
lines in separate channels or bundles.
– Route the signal and data lines as near as possible beside
ground areas (e.g. suspension bars, metal rails, tin cabinet).
n
Proof the correct fixing of the lead isolation.
– Data lines must be laid isolated.
– Analog lines must be laid isolated. When transmitting signals
with small amplitudes the one sided laying of the isolation may
be favourable.
– Lay the line isolation extensively on an isolation/protected
earth conductor rail directly after the cabinet entry and fix the
isolation with cable clamps.
– Make sure that the isolation/protected earth conductor rail is
connected impedance-low with the cabinet.
– Use metallic or metallised plug cases for isolated data lines.
What does EMC mean?
Possible interference
causes
Basic rules for EMC
VIPA System SLIO FM 050
Basics and Assembly
Installation guidelines
HB300 | FM | 050-1BA00 | GB | 15-11
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