Siemens S120 Manual page 421

Alternatively, the cable shields can be connected to them metal mounting plate using pipe
clamps and serrated rails. The cable length between the shield contact point and the
terminals for cable conductors must be kept as short as possible.
Shield connection plates and shield connection kits with pre-prepared clip contacts are
available for connecting the shields of power cables used for Power Modules.
All cables inside the cabinet must be connected as closely as possible to parts connected
with cabinet ground, such as a mounting plate or cabinet wall. Ducts made of sheet steel or
routing cables between between steel sheets (e.g. between the mounting plate and back
wall) should provide adequate shielding.
Avoid, where possible, routing non-shielded 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.
Routing 24 V cables
When routing 24 V cables, the following must also be observed:
● A maximum of one conductor pair may be bundled together.
● 24 V conductors must be routed separately from other cables and conductors that could
● 24 V cables must never be routed parallel to power cables.
● 24 V cables as well as power cables should be routed to the components so that they
Conditions of use for 24 V cables
● Ambient temperature 55 °C
● Limit conductor temperature, ≤ 70° C for operation with the rated load current
● Cable length max.:
AC Drive
Manual, (GH6), 04/2014, 6SL3097-4AL00-0BP4
conduct the operating current.
never cover ventilation slots
– 10 m for the 24 V supply cables
– 30 m for signal lines without additional connections
Cabinet design and EMC for components, Blocksize format
10.4 Cable shielding and routing
421