Shielding Measures With Power Lines - Siemens SIROTEC Planning Manual

Wiring and Shielding
6.2.3

Shielding measures with power lines

Shield connection – control side
All line shields must be inserted in relation to the control extensively and as close
as possible to the respective terminal. For components which do not have any
special shield connection, the contacting must be performed by means of pipe
clamp or indentation bars on the blank assembly wall of the control cabinet. In any
case, it must be ensured that the free line between the shield connection point and
the terminal is as short as possible.
For the contacting of the shield of the shielded lines, shield connection plates are
generally available with prepared clamp contacting and assembly points for brake
clamps.
Shield connection – motor side
If the motor is equipped with a brake, then the shield of the brake feed line must be
applied to both sides with the shield of the power line.
If there is no shield connection possibility on the motor side, a screw connection
must be attached in the terminal connection box with the possibility of an extensive
link shield – motor housing.
Basically shielded execution
A metal channel with an electrically extensively contacting cover can also be used
for the motor and mains supply line. Ensure a double-sided extensive link of the
shield/cable duct to the appropriate components (converter module, motor).
!
Warning
Unused cores of power lines (e.g. brake cores) and their shields must be installed
on at least one side to an earthed housing potential in order to discharge the
loads arising due to capacitive overcoupling.
Negligence can result in the presence of hazardous contact voltages on the
unearthed shields and cores.
6-40
EMC Installation Guideline – Planning Guide (EMV) – 03.2004 Edition
© Siemens AG, 2004. All rights reserved