Lenze EPM−T9XX Modular system - Manual (Page 157)

Wiring according to EMC
7
Electrical installation
7.1
L
7.1−1 EDSPM−TXXX−9.0−11/2009
7.1 Wiring according to EMC
General notes
·
The electromagnetic compatibility of the I/O system IP20 depends on the type and accuracy of the installation. Special attention should be
paid to:
– Assembly
– Shielding
– Earthing
·
Any other installation set−ups require the system to be checked for compliance with the EMC limit values for assessment of conformity with
the EMC Directive. This for instance applies to the following:
– Use of unshielded cables
·
Responsibility for compliance with the EMC Directive is with the user.
– It can be assumed, if the following measures are observed, that no EMC problems will arise during operation and that the EMC Directive
and / or the EMC Act, respectively, is complied with.
– Operating devices near the system that do not meet the CE standard in terms of disturbance immunity EN 61000−4−2, may cause
electromagnetic interference to these devices by the decentralised I/O system IP20.
Assembly
·
Connect DIN rail to earthed mounting plate:
– Mounting plates with conductive surfaces (zinc−coated or stainless steel) allow permanent contact.
– Painted plates are not suitable for installation in accordance with the EMC.
·
If you use several mounting plates:
– Connect the mounting plates electrically with a surface as large as possible (e.g. with copper bands).
·
When laying the cables, ensure spatial separation from signalling and mains cables.
·
Route the cables as close as possible to the reference potential. Freely suspended cables act like aerials.
Shielding
·
If possible, use only cables with braids.
·
The shield coverage should be in excess of 80%.
·
Data lines for serial coupling always require metallic or metallised plugs. Connect the shield of the data line to the plug housing.
·
Use metal cable clamps to attach the braids.
·
Connect shield to shield rail inside the switchgear cabinet.
·
Connect the shields of analog control cables at one end (either to the sensor or as closely as possible to the analog module input).
Earthing
·
Earth all metallically conductive components with suitable cables from a central earthing point (PE bar).
·
Comply with the minimum cross−sections defined in the safety instructions:
– It is not the cable cross−section that is decisive for EMC, but instead the cable surface and large−surface contact.