Examples Of How Shielding Can Be Connected - Bartec BAT VGA pro Manuel D'installation

Operator´s manual for BAT VGA pro
Version 1.1
3.5.7

Examples of how shielding can be connected

Connection of shielding at both ends of the cables linking the controller and display terminal:
Controller
Generally, connection of the shielding at both ends results in optimum damping of all interference frequencies. This
method is to be recommended when there is good equipotential bonding between the individual units. In such cases it is
possible to make use of the controller's voltage supply cable even if this is not electrically isolated.
Connection of shielding at one end only of the cables linking the controller and display terminal:
Controller
Connection of the shielding at one end only is recommended when there is inadequate equipotential bonding, or none at
all. In such cases an electrically isolated power supply unit must be used.
If the shielding were connected at both ends, the equipotential bonding current would flow to point A and this must be
avoided at all costs, as the resultant interference pulses could be passed on to the devices via the data cable. When
shielding is connected at one end only it must be on the side that has the lowest resistance earth connection.
Before the equipment goes into service the directions from the controller manufacturer regarding proper assembly and
operation must be read carefully. They should then be applied taking full account of the recommendations we make here.
E_BMS00680_Rev7.doc • Operator´s manual for BAT VGA pro • Revision 7 / Status: 29. January 2004 • Technical data subject to change
Shielding
Earth
Shielding
Difference in potential
Display terminal
Display terminal
Earth
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