Lenze PCM 310 PCMatic Slot Controller - Handbuch (Seite 48)


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The following points should be observed when constructing a switching enclosure:
•
Divide the switching enclosure into EMC zones.
•
Separate individual EMC zones as well as possible (galvanically, spatially).
•
Construct separate potential interrelationship systems:
- analogue zone
→
star-shaped
- digital zone
→
intermeshed
- power zone
→
star-shaped
•
Restrict to a minimum level any galvanic coupling between the different
potential interrelationship systems:
→
only connect them at one central point (Potential equalisation point)
•
All conductive, inactive metal parts should be earthed.
3.2. Wiring/Shielding
3.2.1. Wiring categories and their installation
Wiring and cables are grouped into various categories on the basis of their emission of interference
and sensitivity to interference.
Wiring categories
•
Network and power supply wiring
•
Digital loading signals, e. g. digital PLC outputs, etc.
•
Digital information signals, e. g. Fieldbus, etc.
•
Analogue signal wiring
Installation of wiring
The wiring in each of the different categories should be routed separately in the enclosure. Cables of
different wiring categories should be routed through different cable channels and wiring looms. In
addition, care should be taken to ensure the largest possible separation between the individual cable
channels and wiring looms. Analogue signal wiring and cables for digital information signals must be
performed with insulation.
If particular sources of interference are located in the enclosure (e. g. contacts, transformers, switching
transformers, motors), all analogue signal wiring and digital information signals should be installed
sufficiently far away (> 1 m). If necessary, separating sheets of metal must be included, and these
must be metallically connected to the enclosure over a large area.
The incoming and outgoing conductors of digital signals should be installed parallel to each other and
with the smallest possible separating distance, possibly even being twisted together.
To exploit as far as possible the reductive effects of large surfaces, cables should always be installed
as close as possible to these surfaces (enclosure wall, separating sheets, etc.).