Handheld Terminal
CE Conformity, Directives and Standards
User's Manual, Version: 1.3
151
© KEBA 2007
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Ignition impulses of fluorescent lamps
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Switching procedures on inductive electrical circuits
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Contact bounces when closing or opening make-and-break contacts
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Voltage fluctuations on heavy load switching procedures
There is a series of test standards for the above listed sources of interfer-
ence, intentionally or unintentionally caused by technical systems, which
simulate this interference:
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IEC 61000-4-3 High Frequency Electromagnetic Field Immunity Test
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IEC 61000-4-4 Electrical Fast Transient / Burst Immunity Test
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IEC 61000-4-6 Test of Immunity to Conducted Disturbances, Induced
by High Frequency Fields
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IEC 61000-4-8 Power Frequency Magnetic Field Immunity Test
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IEC 61000-4-11 Voltage Dips, Short Interruptions and Voltage Varia-
tions Immunity Test
All the international Standards listed here are also available as European
Standards. The Product Standard IEC 61131-2 demands testing to these
Standards and also defines the severity level.
14.3.1.4 Technical systems as interference sinks
In the case of functional interference, EMC problems first arise at interfer-
ence sinks. The following interference sinks can be identified dependent on
the degree of immunity to electromagnetic influences:
Immunity Interference
sinks
max
min
Transformers
Circuit breakers, contactors
Relays
Power transistors
Transistor circuits
Integrated switching circuits
Control systems without integrated switching circuits are unthinkable and
would therefore not be sufficiently immune without suitable EMC measures.
14.3.1.5 Coupling paths
The transfer of interference signals from an interference source to an inter-
ference sink can take place via various coupling paths.