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FCM 300:
FCM 300:
FCM 300:
FCM 300:
FCM 300:
Physical connection
The PROFIBUS is connected to the bus line via X100,
terminals 1 and 2.
It is recommended to use a master with a galvanic
isolated bus driver and with over voltage protection
(e.g. zenerdiode).
EMC precautions
The following EMC precautions are recommended to
obtain interference free operation of the PROFIBUS
network. Additional information on EMC can be found
in the design guide on the FC motor (MG.03.Bx.02).
Please also consult the manual of the PROFIBUS
master for further installation guidelines.
If the PROFIBUS cable has to cross a motor and
brake resistor cable they must cross each other at
an angle of 90°.
-
Connection of the cable screen
The screen of the PROFIBUS cable must always
be connected to ground at both ends, that means
the screen must be connected to ground in all
stations connected to the PROFIBUS network. It
is very important to have a low impedance
ground connection of the screen, also at high
frequencies.This can be obtained by connecting
the surface of the screen to ground, for example
by means of a cable clamp or a conductive cable
gland.
The FC motor Series is provided with different
clamps and brackets to enable a proper ground
connection of the PROFIBUS cable screen. The
screen connection is shown in the following
drawing.
MG.90.A2.02 – VLT is a registered Danfoss trademark
FCM 300 PROFIBUS / VLT 2800 PROFIBUS
Relevant national and local regulations, for
example regarding protective earth
connection, must be observed.
-
Cable routing
The PROFIBUS communication cable must be
kept away from motor and brake resistor cables to
avoid coupling of high frequency noise from one
cable to the other. Normally a distance of 200 mm
is sufficient, but it is generally recommended to
keep the greatest possible distance between the
cables, especially where cables are running in
parallel over long distances.
-
Earth connection
It is important that all stations connected to the
PROFIBUS network are connected to the same
earth potential. The earth connection must have a
low HF (high frequency) impedance. This can be
achieved by connecting a large surface area of the
cabinet to earth, for example by mounting the FC
motor on a conductive rear plate.
Especially when having long distances between
the stations in a PROFIBUS network it can be
necessary to use additional potential equalizing
cables, connecting the individual stations to the
same earth potential.
Connecting the bus line
7
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