Siemens NXPLUS C Installation And Operating Instructions Manual page 99

Installation
Connect the shields to earth potential - with high electrical conductivity and all around as far
as possible. Protect the contact surfaces from corrosion in case of humidity (regular
condensation).
When laying cables into the switchgear assembly, separate the control, signaling and data
cables and other lines with different signal and voltage levels, e.g. by laying them on separate
racks or riser cable routes.
Corresponding to the different shield designs, there is a number of methods to perform
connection. The planning department or site management determines which of the methods
will be used, taking EMC requirements into account. The preceding points should always be
taken into account.
The shield is connected to cables or wires with clamps contacting all around. If low demands
are placed on EMC, it is also possible to connect the shield directly to earth potential (combine
or twist the shield wires) or via short cable connections. Use cable lugs or wire-end ferrules at
the connecting points.
Always keep the connecting leads of the shields as short as possible (< 10 cm).
If shields are used as protective earth conductors at the same time, the connected plastic-
insulated lead must be marked green/yellow over its entire length. Non-insulated connections
are inadmissible.
802-9081.9 • INSTALLATION AND OPERATING INSTRUCTIONS • NXPLUS C • Revision 11 99/293