Siemens SINAMICS DCM Operating Instructions Manual page 62

Connecting
6.1 Instructions for EMC-compliant drive installation
In order to ensure electromagnetic compatibility (EMC) in your control cabinets in rugged
electrical environments and adhere to the standards required by the relevant legislating
body, the EMC rules listed below should be followed during the construction and design
stages.
Rules 1 to 10 apply on a general level. Rules 11 to 15 must be followed in order to fulfill
interference emission standards.
Rules for EMC-compliant installation
1
2
3
4
5
6
7
8
9
60
Connect all metallic parts of the control cabinet to one another over a flat area with good
conductivity (not paint against paint!). Use contact or scratch washers if necessary. The
cabinet door must be connected to the cabinet using the shortest possible ground strips
(at the top, center, and bottom).
Contactors, relays, solenoid valves, electromechanical operating hours counters, etc., in
the cabinet and – where applicable – in neighboring cabinets – must be provided with
quenching combinations such as RC elements, varistors, and diodes. These must be
connected directly at the appropriate coil.
Whenever possible, guide signal cables
Unshielded cables in the same circuit (outgoing/incoming conductors) must be twisted
where possible, or the area between them minimized, to prevent unnecessary frame
antennae.
Connect spare wires to the cabinet ground
shielding effect.
Avoid unnecessary cable lengths in order to keep coupling capacities and inductances
low.
Crosstalk is generally reduced if the cables are laid close to the control cabinet ground.
Do not, therefore, route cables freely around the cabinet, but lay them as close as
possible to the cabinet enclosure/mounting plates. This also applies to spare cables.
Signal and power cables must be physically separated (to prevent coupling paths).
Minimum clearance: You should aim for a minimum of 20 cm.
If it is not possible to physically separate the encoder and motor cables, the encoder
cable must be decoupled either using a metal partition or by laying it in a metal conduit.
The partition or metal conduit must be grounded at several points.
Ground the shields of digital signal cables at both ends (source and destination),
ensuring maximum contact area and good conductivity. In the event of poor
equipotential bonding between the shield connections, run an additional equalizing
conductor with a cross-section of at least 10 mm² parallel to the shield for the purpose of
reducing the shield current. Generally speaking, the shields may also be connected to
the cabinet enclosure (ground)
outside the control cabinet.
Foil shields should be avoided as they are are at least 5 times less effective than
braided shields.
into the cabinet at one level only.
1)
at both ends. This achieves an additional
2)
at several points, and connected at several points
2)
Operating Instructions, 12/2018, A5E34888669A
SINAMICS DCM Control Module