Siemens SIMATIC Ident RF340R02 System Manual page 113

The EMC measures are applied to all three components, in order to prevent malfunctions
due to interference. When setting up a plant, the manufacturer must take all possible
measures in order to prevent the occurrence of interference sources:
● Only devices fulfilling limit class A of VDE 0871 may be used in a plant.
● Interference suppression measures must be introduced on all interference-emitting
devices. This includes all coils and windings.
● The design of the system must be such that mutual interference between individual
components is precluded or kept as small as possible.
Information and tips for plant design are given in the following sections.
Interference sources
In order to achieve a high level of electromagnetic compatibility and thus a very low level of
disturbance in a plant, it is necessary to recognize the most frequent interference sources.
These must then be eliminated by appropriate measures.
Table 4- 65
Interference source
Contactors,
electronic valves
Electrical motor
Electric welding device
Power supply unit, switched-
mode
High-frequency appliances
Transmitter
(e.g. service radio)
Ground or reference potential
difference
Operator
Power cable
High-voltage cable
SIMATIC RF300
System Manual, 07/2017, C79000-G8976-C345-07
Interference sources: origin and effect
Interference results from
Contacts
Coils
Collector
Winding
Contacts
Transformer
Circuit
Circuit
Antenna
Voltage difference
Static charge
Current flow
Voltage difference
4.5 Guidelines for electromagnetic compatibility (EMC)
Effect on the interference sink
System disturbances
Magnetic field
Electrical field
Magnetic field
Electrical field
Magnetic field, system disturbance,
transient currents
Electrical and magnetic field, system
disturbance
Electromagnetic field
Electromagnetic field
Transient currents
Electrical discharge currents, electrical
field
Electrical and magnetic field, system
disturbance
Electrical field
Planning the RF300 system
113