Siemens SINAMICS G120 Operating Instructions Manual page 68

Installing
4.6 Connecting inverters in compliance with EMC
● Equip the following devices with interference suppression elements:
– Coils of contactors
– Relays
– Solenoid valves
– Motor holding brakes
Interference suppression elements are RC elements or varistors with AC coils and free-
wheeling diodes or varistors for DC coils.
Connect the interference suppression elements directly at the coil.
Cable routing and shielding
● Rout all inverter power cables (line supply cables, cables between the braking chopper
and the associated braking resistance as well as the motor cables) separately from signal
and data cables. Keep the minimum clearance to 25 cm. If the cables can not be
separated use metal partitions with a good connection to the mounting plate.
● Rout the cables from the line supply to the line filter separately away from the following
cables:
– Cables between the line filter and converter
– Cables between the braking chopper and the associated braking resistor
● Signal and data cables as well as filtered line supply cables may only cross non-filtered
● Keep all cables as short as possible.
● Rout signal and data cables and the associated equipotential bonding always in parallel
with the smallest possible clearance between them.
● Use shielded motor cables.
● Route the shielded motor cable separately away from the cables to the motor
temperature sensors (PTC/KTY).
● Shield signal and data cables.
● Connect shields at both ends to the grounded enclosures through a good electrical
connection and through a large surface area.
● Connect cable shields as close as possible to where the cable enters the cabinet.
● Use EMC shield bars for power cables.
Use the shield support elements provided in the converter for signal and data cables.
● Do not interrupt the cable shields by intermediate terminals.
● Use appropriate EMC clamps for the cable shields.
The EMC clamps connect the cable shield to the EMC shield bar or the shield support
element through a large conductive area.
68
– Motor cables.
power cables at right angles.
Converter with the CU250S-2 Control Unit (vector)
Operating Instructions, 06/2013, FW V4.6, A5E31759476B AB