Connection Of The Cable Screen; Vlt 2800 Earth Connection; Devicenet Connection - Danfoss VLT 5000 Operating Instructions Manual

Connection of the Cable Screen

The screen of the DeviceNet 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 DeviceNet 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. VLT
frequency converter Series are provided with different
clamps and brackets to enable a proper ground
connection of the DeviceNet cable screen. The
screen connection is shown in the drawing.

VLT 2800 Earth Connection

It is important that all stations connected to the
DeviceNet 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
ground, for example by mounting the VLT frequency
converter on a conductive rear plate. Especially
when having long distances between the stations
in a DeviceNet network it can be necessary to use
additional potential equalizing cables, connecting the
individual stations to the same earth potential.

DeviceNet Connection

It is essential that the bus line be terminated properly.
A mismatch of impedance may result in reflections
on the line that will corrupt data transmission.
The DeviceNet Option Card is provided with a
pluggable screw connector.
By using a pluggable screw connector as a splice
between two trunk lines, removal of devices will
not sever the network. Strain relief, if required,
must be provided by the developer. In current
installations of this type of connector, the strain
relief is attached to the product.
8
®
VLT 5000/ 5000 FLUX/ 6000 HVAC/
8000 AQUA DeviceNet
NB!:
Wires should not be installed while the
network is active. This will prevent problems
such as shorting the network supply or
disrupting communications.
MG.50.H4.02 - VLT is a registered Danfoss trademark