Siemens SINAMICS S120 Manual page 374

Cabinet design and EMC for components, Blocksize format
10.7 Protective connection and equipotential bonding
Functional equipotential bonding
For EMC reasons, the shield of the motor cable should be connected through a large surface
area both at the Power Module as well as at the motor.
The drive line-up must be arranged on a common bright mounting plate in order to comply
with the EMC limit values. The mounting plate must be connected to the protective conductor
connection of the control cabinet through a low impedance. It simultaneously serves as a
functional equipotential bonding surface. This means that no additional functional
equipotential bonding is required within the drive line-up.
If a single, bare metal mounting plate is not available, then equally good functional
equipotential bonding must be established using cable cross-sections as listed in the table
above or, as a minimum, with the same conductivity.
When mounting components on standard mounting rails, the data listed in the table apply. If
only smaller connection cross-sections are permissible at the components, then the largest
possible cross-section should be used, e.g. 6 mm
to distributed components located outside the control cabinet.
Copper cables with appropriate cross-sections (> 2.5 mm²) must be used for the functional
equipotential bonding of PROFIBUS nodes.
NOTICE
Component destruction as a result of high leakage currents
The Control Unit or other PROFIBUS and/or PROFINET nodes can be destroyed, if
significant leakage currents flow via the PROFIBUS or PROFINET cable.
• Use a functional equipotential bonding conductor with a cross section of at least 10 mm²
No functional equipotential bonding conductors are required for PROFIBUS inside a control
cabinet. For PROFIBUS connections between different buildings or parts of buildings, a
functional equipotential bonding must be routed in parallel to the PROFIBUS cable. The
following cross-sections must be observed in accordance with IEC 60364-5-54:
● Copper 6 mm²
● Aluminum 16 mm²
● Steel 50 mm²
Additional information about equipotential bonding for PROFIBUS can be found at:
http://www.profibus.com/fileadmin/media/wbt/WBT_Assembly_V10_Dec06/index.html
Note
Non-observance of the above guidelines on functional equipotential bonding can lead to
faults on the fieldbus interfaces or to malfunction of the devices.
Note
PROFINET
For installation guidelines and information of protective grounding and equipotential bonding
for all PROFINET types and topologies, refer to DOWNLOADS at:
http://www.profibus.com
374
between components of an installation that are located at a distance from each other.
for SMC. These requirements also apply
2
Manual, (GH6), 07/2016, 6SL3097-4AL00-0BP5
AC Drive