Siemens S5-155U System Manual page 37

Principles of Installation of Systems for EMC
3 - 8
• • Provide the line shields with a large-area connection to a
shield/protective conductor bar immediately after the cabinet inlet,
and secure the shields with cable clamps. Route the grounded
shield as far as the module without interruption, but do not connect
the shield there again.
• • Ensure that the shield/protective ground bar has a low-impedance
connection to the cabinet.
• • Use metal or metallized connector cases for shielded data lines.
Employ special EMC measures for particular applications
(see Section 3.3.4).
• • Fit quenching elements to all inductances which are not controlled
by SIMATIC S5 modules.
• • Use incandescent bulbs for illuminating cabinets, and avoid
fluorescent lamps.
Create a standard reference potential; ground all electrical
apparatus if possible (see Sections 3.4 and 3.5).
• • Use specific grounding measures. Grounding of the control system
is a protective and functional measure.
• • System parts and cabinets with central controllers and expansion
units should be connected to the ground/protective conductor
system in star configuration. This serves to avoid the creation
of ground loops.
• • In the case of potential differences between system parts and
cabinets, install equipotential bonding conductors of sufficient
rating.
System Manual
C79000-B8576-C199-03