Chapter 2: SAFETY
Page 10 of 30
Operating Manual FU3AM-03
2.8 Information on EMC
In order to warranty electromagnetic compatibility (EMC) in your switch cabinets in an elec-
trically 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 cabi-
net 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 separated 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 suppressor combinations, e.g. with RC elements, varistors
or diodes.
♦
The braiding 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 braiding to reduce the 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 be grounded, but preferably both (additional shield effect).
♦
Unnecessary wire lengths are to be avoided. Coupling capacities and coupling induct-
ance’s are thereby kept small.
♦
The braiding from leads, such as resolver or incremental tachometer 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 sup-
ports.
cable
clamping y
ok
e
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.
