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JetMove 203-230
Fig.2: Shielding of SUB-D connectors in conformity with EMC standards.
Jetter AG
Shielded cables must be used for the following lines:
Analog lines, data lines, motor cables coming from inverter drives (servo
output stage, frequency converter), lines between components and
interference suppressor filter, if the suppressor filter has not been placed
at the component directly .
Shield both sides of the cable.
Unshielded wire ends of shielded cables should be as short as possible.
The entire shield must be drawn behind the isolation, and then be
extensively clamped under a flat earthed strain relief.
If male connectors are used:
The shield (impedance shielding) must, in its entire perimeter, be drawn
behind the shielding clamp of the metallised connector housing,
respectively of the EMC gland bushing, its greatest possible surface area
being clamped under a strain relief.
Only use metallised connectors, e.g. SUB-D with metallised housing.
Make sure that the strain relief is directly connected with the housing here
as well (see Fig. 2).
What to do, if the shield cannot be fixed to the connector, e.g. if the signal
has been connected to terminal screws:
Shield and cable strap must be connected with low impedance to earthed
surfaces. Earthing must be done in a way that keeps the unshielded part of
the signal lines as short as possible (see Fig. 3).
1.4 Instructions on EMI
19
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