Operating Manual – Digital Frequency Converter
Page 4 of 14
09/99 R0048GB.doc
Antriebstechnik GmbH
1.1 Information on EMC
In order to guarantee electromagnetic compatibility (EMC) in your switch cabinets in an
electrically raw environment, the following EMC rules are to be observed during construction
and set-up:
♦
All metallic parts of the switch cabinet are to be connected flatly and in a well-conducting
manner (not lacquer on lacquer!). If necessary, use contact or scraper wafers. The
cabinet door is to be connected with as short a circuit as possible via the metal powder
tapes (upper, middle, lower).
♦
Signal lines and power cables are to be laid separate from each other in order to avoid
coupling intervals. Minimum distance: 20 cm:
♦
Signal lines should be led to the cabinet from only one level, if possible.
Unshielded lines from the same electrical circuit (outgoing and return circuit) are to be
transposed, if possible.
♦
Contactors, relays and magnetic valves in the switch cabinet, if necessary in the adjacent
cabinets, are to be wired with quench combinations, e.g. with RC elements, varistors,
diodes.
♦
The screens from signal lines are to be laid two-way (source and target), large-area and
well-conducting to a ground
1
. In case of poor potential equalization between shielded
connections, an additional balancing network of at least 10 mm² must be laid parallel to
the screen to reduce the screen current.
♦
Wiring is not to be laid freely in the cabinet, but should rather lead as tightly as possible
to the cabinet frame or to installation plates. This also applies to reserve cables. At least
one end of them must lie grounded, but preferably both (additional shield effect).
♦
Unnecessary wire lengths are to be avoided. Coupling capacities and coupling
inductances are thereby kept small.
♦
The screen from leads, such as resolver or incremental director cables, must be laid to
the frame grounding. Approximately 2 cm of the insulation is to be removed in the area
where the cable is to be led into the frame in order to expose the braided cable. The
braided cable may not be damaged while removing the insulation. The cable is to be led
at the position where the insulation has been removed by grounded terminals or taut
supports.
cable
taut support
1
Generally all metallic conducting parts which can be connected to a protective conductor,
such as cabinet frames, motor frames, foundation grounding, etc. are designated as a
ground.
