Cable Shielding And Routing - Siemens SINAMICS S120 Manual

Cabinet design and EMC Booksize

12.8 Cable shielding and routing

12.8 Cable shielding and routing
In order to comply with the EMC requirements, certain cables must be routed apart from
other cables and from certain components. To satisfy EMC requirements, the following
cables must be used with shields:
● Line supply conductors from line filter via line reactor to Line Module
● All motor cables (if necessary, including cables for motor holding brake)
● Cables for "fast inputs" of the Control Unit
● Cables for analog direct voltage/current signals
● Signal cables for sensors
● Cables for temperature sensors
Supplementary conditions
● Alternative measures (e.g. routing behind mounting plates, suitable clearances) can also
be used provided they have similar results. This excludes measures that relate to the
design, installation, and routing of motor power cables and signal cables.
● If unshielded cables are used between the line supply connection point and line filter,
make sure that no interfering cables are routed in parallel.
● Power and signal cables must always be routed separately. For this purpose, it is
practical to arrange the various cables according to cable groups. Cables belonging to a
group can be combined in a bundle. The various cable groups must be routed with the
necessary clearance between them. A minimum clearance of 20 cm has proven itself in
practice. As an alternative, shielding plates with the appropriate contacts at several
locations can be used between the cable bundles.
● All cables inside the cabinet must be routed as closely as possible to parts connected
with cabinet ground, such as a mounting plate or cabinet wall. Ducts made of sheet steel
or cables routed between steel sheets (e.g. between the mounting plate and back wall)
should provide adequate shielding.
● All cables must be kept as short as possible, to minimize the antenna effect.
● Signal and power cables may cross each other (if absolutely necessary), but must never
be routed closely to one and other in parallel over longer distances.
● Signal cables must be routed with a minimum clearance of 20 cm from strong magnetic
fields (motors, transformers). Alternatively, shield plates with the appropriate contacts at
several locations along their length can be used to provide the appropriate clearance.
● Cables for the 24 V supply should be treated just like signal cables.
● Avoid, where possible, routing unshielded cables, connected to the drive line-up, in the
immediate vicinity of noise sources, e.g. transformers. Signal cables (shielded and
unshielded) connected to the drive line-up must be laid at a great distance from strong
external magnetic sources (e.g. transformers, line reactors). In both cases, a distance of
≥ 300 mm is usually sufficient.
734
Booksize Power Units
Manual, (GH2), 07/2016, 6SL3097-4AC00-0BP8