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Observe the following provisions for an electromagnetically compatible setup of
your drive system:
1.
As user you must ensure that the HF impedance between frequency inverter,
filter and ground is as small as possible.
•
Take care it that the connections are metallic and have the largest possible
areas (zink-plated mounting plates)
2.
Conductor loops act like antennas, especially when they encompass large
areas. Consequently:
•
Avoid unnecessary conductor loops
•
Avoid parallel arrangement of „clean“ and interference-prone conductors
3.
Lay the motor cable and all analog and digital control lines shielded.
•
You should allow the effective shield area of these lines to remain as large as
possible; i.e., do not move the shield further away than absolutely
necessary.
•
With compact systems, if for example the frequency inverter is
communicating with the steering unit, in the same control cabinet connected
at the same PE-potential, the screen of control lines should be put on, on
both sides with PE. With branch systems, if for example the communicating
steering unit is not in the same control cabinet and there is a distance
between the systems, we recommend to put on the screen of control lines
only on the side of the frequency inverter. If it is possible, direct in the cable
entry section of the steering unit. The screen of Motor cabels always must be
put on, on both sides with PE.
•
The large area contact between shield and PE-potential you can realise with
a metal PG screw connection or a metallic mounting clip.
•
Use only copper mesh cable (CY) with 85% coverage
•
The shielding should not be interrupted at any point in the cable. If the use of
reactors, contactors, terminals or safety switches in the motor output is
necessary, the unshielded section should be kept as small as possible.
•
Some motors have a rubber gasket between terminal box and motor housing.
Very often, the terminal boxes, and particularly the threads for the metal PG
screw connections, are painted. Make sure there is always a good metallic
connection between the shielding of the motor cable, the metal PG screw
connection, the terminal box and the motor housing, and carefully remove
this paint if necessary.
4.
Very frequently, interference is coupled in through installation cables. This
influence you can minimize:
•
Lay interfering cables separately, a minimum of 0.25 m from cables
susceptible to interference.
•
A particularly critical point is laying cables parallel over larger distances. If
two cables intersect, the interference is smallest if they intersect at an angle
of 90°. Cables susceptible to interference should therefore only intersect
motor cables, intermediate circuit cables, or the wiring of a rheostat at right
angles and never be laid parallel to them over larger distances.
5.
The distance between an interference source and an interference sink
(interference-threatened device) essentially determines the effects of the
emitted interference on the interference sink.
•
You should use only interference-free devices and maintain a minimum
distance of 0.25 m from the drive.
