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System Assembly, Construction and Connection
Overall Information (valid for complete AC500 Product Family) > EMC-Conforming Assembly and Construction
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Rout signal cables and data cables separately from the power cables.
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Lay signal and data cables close to earthed surfaces.
2.4.4.3
Cable Shields
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Use only shielded data cables. The shield should be earthed at both ends.
A cable shield only earthed at one end can only protect from capacitively coupled interfer-
ence and low-frequency disturbances (50 Hz hum).
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Avoid parasitic currents flowing through the cable shields.
This can be done by installing current-carrying equipotential bondings.
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Use only cables with braided shields.
Foil shields are not robust enough, cannot be contacted well and have poor HF properties.
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Use only metallic or metal-plated plugs for shielded data cables.
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Use only shielded cables for analog signals.
For small signals earth the shield only at one end.
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Earth the cable shield directly with a clip when entering the switch-gear cabinet.
Do not cut the shield until the cable reaches the module connected.
2.4.4.4
Switch-Gear Cabinet
Connections
The connections between the switch-gear cabinet, the mounting plates, the PE bar and the
shield bar must have a low impedance.
Earthing
Earth the switch-gear cabinet doors with short and highly flexible conductors.
Illumination
Only use filament lamps (bulbs) or fluorescent tubes with interference suppression.
For supplying
Use the mains socket which is located inside the switch-gear cabinet.
the PC
Ä Chapter 2.5.2.1 "Switchgear Cabinet Assembly" on page 1196
2.4.4.5
Reference Potential
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Provide a uniform reference potential in the entire installation and earth all electrical appli-
ances if possible.
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Route your earthing conductors in a star configuration so that no earth loops can occur.
2.4.4.6
Equipotential Bonding
The Installation of equipotential bondings are necessary if there are present or expected poten-
tial differences between parts of your application.
1188
Separate cable ducts or cable bundles.
The distance should be 20 cm or greater.
The connection between the PE bar and the shield bar must have a low impe-
dance.
3ADR010121, 13, en_US
2019/04/17
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