Physical Connection; Protective Measures For Emc; Cable Connection Fcm 300; Connection Of The Cable Screening - Danfoss VLT 5000 Operating Instructions Manual

Physical connection

The PROFIBUS option card will be connected to the
bus line (data line) at terminals 62 and 63. Data line
"B" (TxD/RxD-P) will be connected to terminal 62 and
data line "A" (TxD/RxD-N) to terminal 63. A master
with a voltaically insulated bus driver and overvoltage
protection (e.g. Z diode) is recommended.

Protective measures for EMC

It is recommended to carry out the following protective
measures for EMC in order to ensure a trouble-free
operation of the PROFIBUS network. Additional notes
concerning the subject of EMC can be found in the
project manual for the VLT 5000 series (MG.50.Cx.yy)
and in the manual for the Profibus master.
NB!:
The applicable national and local regulations,
for example with respect to protective
earthing, must be observed.

Cable connection FCM 300

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.
If the PROFIBUS cable has to cross a motor and
braking resistance cable, it should occur at a 90° angle.

Connection of the cable screening

The shielding of the PROFIBUS cable always needs
to be of a large-area, low-impedance type on both
sides. As a matter of principle, the screen should be
put up with a large area and low impedance at all
PROFIBUS stations. It is very important to have an
earth connection with low impedance even at high
frequencies. This can be achieved by connecting the
shield surface to earth, for example with the help of
a cable bow or a conductive cable connector.
The frequency converter is equipped with various
terminals and supports in order to provide a flawless
shielding of the PROFIBUS cable. The shield
connection is shown in the following diagram.
MG.90.G1.02 - VLT is a registered Danfoss trademark
VLT® 5000/ 5000 FLUX/ 6000 HVAC/
8000 AQUA PROFIBUS

Earthing

It is important to connect all stations linked to the
PROFIBUS network to the same earth potential. The
earthing must have a low high-frequency impedance.
This can be achieved by connecting a protective
housing surface which is as large as possible to
earth, for example by mounting the frequency
converter to a conductive rear wall.
Especially in the case of large distances between the
stations of a PROFIBUS network, the additional use of
potential equalization cables to connect the individual
stations to the same earth potential may be necessary.

Bus connection

62 = RxD/TxD-P red cable
63 = RxD/TxD-N green cable
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