Siemens SIROTEC Planning Manual page 21

Equipotential bonding by equipotential bonding lines
If no meshed connection is possible via the cabinet housing between control
components and the central earthing bar (e.g. because of a control cabinet with an
insulated rear panel), the equipotential bonding can also be provided between
components and the central earthing bar by means of equipotential bonding lines
(see Section 4.2, Fig. 4-2).
Points to bear in mind:
•
Create the potential connections in a star shape. The neutral point of the
equipotential bonding lines may be:
central earthing bar or
–
separate equipotential bonding bus (see Section 4.2, Fig. 4-2).
–
•
Equipotential bonding lines of power components such as drives, machines,
load power supply units, relay adjusting parts, etc., are basically connected to
the central earthing bar. A jointly equipotential bonding line for power and non-
power components may not be used.
•
If the equipotential bonding is performed on power parts with analog regulation
by means of the equipotential bonding lines, then:
The electronic earth must be connected only with the NC equipotential
–
bonding terminal.
The SL terminal must be connected to the central earthing bar.
–
•
The line lengths of the equipotential bonding lines must be as short as
possible.
• Cross-section of the equipotential bonding lines ≥ 10mm
© Siemens AG, 2004. All rights reserved
EMC Installation Guideline – Planning Guide (EMV) – 03.2004 Edition
Equipotential Bonding
2
Cu.
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