Emc Guidelines; Avoiding Electromagnetic Interference; Connections And Interference Suppression; Cabling - Siemens SINAMICS G120P Hardware Installation Manual

Connecting

4.9 EMC guidelines

4.9 EMC guidelines
4.9.1

Avoiding electromagnetic interference

Only the concurrent use of filtering, grounding and shielding ensure an installation in
accordance with the EMC requirements.
The next sections cover all of the most important rules for the installation of inverter and
drive systems.
4.9.2

Connections and interference suppression

All connections should be made so that they are permanent. Screwed connections on
painted or anodized metal components must be made either by means of special contact
washers, which penetrate the isolating surface and establish a metallically conductive
contact, or by removing the isolating surface on the contact points.
Contactor coils, relays, solenoid valves, and motor holding brakes must have interference
suppressors to reduce high-frequency radiation when the contacts are opened (RC elements
or varistors for AC currentoperated coils, and freewheeling diodes for DC current-operated
coils). The interference suppressors must be connected directly on each coil.
4.9.3

Cabling

Cables
● All cable lengths must be minimized (excessive cable lengths must be avoided).
● Signal and data cables, as well as their associated equipotential bonding cables, must
always be routed in parallel and with as short a distance as possible.
● Spare wires for signal and data cables must be grounded at both ends to create an
additional shielding effect.
● All power cables (line supply cables, as well as motor cables) must be routed seperately
from signal and data cables. The minimum distance should be approximately 25 cm.
● The power cable between inverter and motor must be shielded. A symmetrical, 3-wire,
three-phase cable should be used here. Shielded cables with symmetrical three-phase
conductors (L1, L2, and L3) and an integrated, 3-wire, and symmetrically arranged PE
conductor are ideal for this purpose.
● The shielded power cable to the motor must be routed separately from the cables to the
motor temperature sensors (PTC/KTY), since the latter two are treated as signal cables.
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Hardware Installation Manual, 11/2014, A5E35319202B AA
PM230 Power Module IP55