Example Of Rack And Wall Mounting For Emc - Siemens S5-135U/155U System Manual

3.2.3

Example of Rack and Wall Mounting for EMC

To operate your control system in a low-interference environment whilst
observing the permissible ambient conditions (see "Technical
Specifications"), you can mount the programmable controllers on racks or
directly on walls.
Picked-up interference should be given a path to large metal surfaces. You
should therefore secure standard sectional rails, shield and protective
conductor bars to metal structural elements. For wall mounting in particular,
installation on reference potential surfaces made of sheet steel has proved
advantageous.
When installing shielded cables, provide a shield bar for connecting the cable
shields. The shield bar can also be the protective conductor bar.
Ensure the following for rack and wall mounting:
Connection to
P. Ground: 10 mm
Figure 3-3 Wall Mounting of an S5-135/155U PLC
System Manual
C79000-G8576-C199-06
Suitable contacting aids should be used on painted and anodized metal
parts. Use special contact washers or remove the insulating protective
layers.
Provide large-area, low-impedance metal-to-metal connections when
securing the shield/protective conductor bar.
AC conductors must be covered.
Installation Guidelines
Reference Potential
Surface
Shielded Signal
Line
Cable Clamp for
Shield Contact
Shield/Protective
Conductor Bar
3-11