Cable Shielding And Routing - Siemens SINAMICS S120 Combi Manual

12.6

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 full EMC requirements, the following cables
must be used with shields:
● Line supply cables from the line filter via the line reactor to the S120 Combi Power
Module
● All motor cables (if necessary, including cables for motor holding brake)
● Cables for analog direct voltage/current signals
● Signal cables for sensors
● Cables for temperature sensors
Supplementary conditions
● Alternative measures (e.g. laying behind mounting plates, suitable clearances) can also
be used provided they have similar results. This excludes measures that relate to the
design, installation, and laying of motor power cables and signal cables.
● If unshielded cables are used between the line supply connection point and the line filter,
make sure that no interference-emitting 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 laid as closely as possible to parts connected with
cabinet ground, such as a mounting plate or cabinet panel. Ducts made of sheet steel or
cables laid between steel sheets (e.g. between the mounting plate and rear panel) 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 be 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.
SINAMICS S120 Combi
Manual, 11/2017, 6SL3097-4AV00-0BP7
Cabinet design and EMC
12.6 Cable shielding and routing
291