Electromagnetic Compatibility - Siemens SIMATIC RS 485 Manual

Technical data
6.1 General technical data
6.1.2

Electromagnetic Compatibility

Definition
Electromagnetic compatibility (EMC) is the ability of an electrical installation to function
satisfactorily in its electromagnetic environment without interfering with that environment.
The S7-300 modules also satisfy requirements of EMC legislation for the European domestic
market. Compliance of the S7-300 system with specifications and directives on electric
design is prerequisite.
Pulseshaped disturbance
The table below shows the EMC compatibility of S7 modules in areas subject to pulse-
shaped disturbance.
Pulse-shaped disturbance
Electrostatic discharge
according to IEC 61000-4-2
Burst pulses (high-speed
transient disturbance)
to IEC 61000-4-4.
High-energy single pulse (surge) to IEC 61000-4-5
External protective circuit required
(refer to operating instructions SIMATIC S7-300, CPU 31xC and CPU 31x:
Installing (http://support.automation.siemens.com/WW/view/en/13008499)
in Chapter "Lightning and overvoltage protection")


Additional measures
When connecting an S7-300 system to the public network, always ensure compliance with
Limit Value Class B to EN 55022.
30
asymmetric coupling
symmetric coupling
Test voltage
Air discharge: ± 8 kV
Contact discharge ± 4 kV
2 kV (power supply lines)
2 kV (signal lines > 3 m)
1 kV (signal lines < 3 m)
2 kV (power supply lines)
DC with protective elements
2 kV (signal/ data line only > 3 m),
with protective elements as required
1 kV (power supply lines) DC with
protective elements
1 kV (signal/ data line only > 3 m),
with protective elements as required
corresponds with degree
of severity
3
2
3
3
3
RS 485 Repeater
Manual, 02/2011, A5E03382072-01