Technical Systems As Sources Of Interference; Technical Systems As Interference Sinks - Festo CDSA-D3-RV Operating Instructions Manual

Appendix: Electromagnetic compatibility
15.1.3

Technical systems as sources of interference

Technical systems can act as sources of interference. The malfunctions can be intentional or uninten-
tional. Electromagnetic energy is frequently used for material processing.
Periodic malfunctions:
– Ignition pulses from internal combustion engines
– Sparking from commutator motors
– Electromagnetic fields from induction furnaces, arc welding devices, microwave devices,...
– Pulse currents from frequency converters and switching power supplies
– Electromagnetic fields from radio and telecommunications equipment
Accidental malfunctions:
– Ignition pulses from fluorescent lamps
– Switching operations in inductive circuits
– Contact bounce when closing or opening switching contacts
– Voltage fluctuations during switching operations with large loads
There are a number of test standards for the sources of interference listed above for intended and
unintentional interference caused by technical systems:
– IEC 61000-4-3 Test of interference immunity to high-frequency electromagnetic fields
– IEC 61000-4-4 Test of interference immunity to fast transient disturbances / burst
– IEC 61000-4-6 Test of interference immunity to conducted disturbances, induced by high-fre-
quency fields
– IEC 61000-4-8 Test of interference immunity to magnetic fields with energy-related frequencies
– IEC 61000-4-11 Test of the interference immunity to voltage dips, brief interruptions and voltage
fluctuations
All of the international standards listed here are also available as European standards. The product
standardIEC 61131-2 requires tests in accordance with these standards and specifies the severity
level.
15.1.4

Technical systems as interference sinks

EMC problems only occur when there are malfunctions in the interference sinks. Depending on the
level of immunity to electromagnetic interference, the following interference sinks can be identified:
Immunity to interference
Maximum
é
Minimum
Tab. 33 Immunity to interference and interference sinks
Control systems are unthinkable without integrated circuits and would therefore not be sufficiently
immune from interference without suitable EMC measures.
Festo — CDSA-D3-RV — 2020-08
Interference sinks
Transformers
Branch-circuit protective devices, contactors
Relays
Power transistors
Transistor circuits
Integrated circuits
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