Siemens SINAMICS S120 System Manual page 182

Cabinet design and EMC
12.5 Protective connections and equipotential bonding
Electric shock due to high leakage currents caused by an interrupted external protective
conductor
Drive components conduct high discharge currents via the protective conductor. When the
protective conductor is interrupted, touching live components can result in electric shock,
which can lead to death or serious injuries.
• Ensure that the external protective conductor complies with at least one of the following
Functional equipotential bonding with protective conductor connection
The mounting plate, which is connected with the protective conductor connection of the control
cabinet through a low impedance connection, simultaneously serves as the function
equipotential bonding surface. This means that no additional functional equipotential bonding
is required within the drive line-up.
When installing components on standard mounting rails, the data listed in the table also apply
to the functional equipotential bonding. If only smaller conductor cross-sections are permissible
on components, the largest cross-section must be used (e.g. 6 mm
requirements also apply to distributed components located outside the control cabinet.
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
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
180
WARNING
conditions:
– It is laid protected against mechanical damage.
– For an individual conductor, it has a cross-section of at least 10 mm² Cu.
– As a core of a multi-core cable, it has a cross section of at least 2.5 mm² Cu.
– It has a parallel, second protective conductor with the same cross-section.
– It corresponds to the local regulations for equipment with increased leakage current.
Cables routed in control cabinets or enclosed machine enclosures are considered to be
1)
adequately protected against mechanical damage.
1)
for TM31 and SMC). These
2
High Frequency Drive
System Manual, 10/2020, 6SL3097-5AH10-0BP0