Assembling and Installing Systems
A-35
AutomationSystem S7-400 Hardwareand Installation
A5E00850741-01
Shielding and Grounding under Industrial Conditions
If the monitor and programmable controller are operated under harsh industrial
conditions, you must observe the following:
On the side of the programmable controller:
•Connect the cable shields in the cabinet to the shielding busbar immediately
behind the cable inlet. The following points are important:
-- Strip the video cables without damaging the conductors.
-- Secure the outer braided shield with the largest possible area to the
shielding busbar of the programmable controller (for example, secure the
shielding with metal straps or cable clamps).
•Provide large-area contact between the shielding busbars and the frame or
cabinet wall.
•Connect the shielding busbar to the central grounding point of the cabinet.
On the side of the monitor:
•Isolate electronic ground and chassis ground from each other.Proceed as
follows:
-- Remove the jumper on the monitor to separate the two potentials.
-- Install a contact protection on the video sockets, because with isolated
grounding, a shock--hazardvoltage of more than 40 V may develop in this
area.
!Caution
There is a risk of personal injury.
Shock-hazard voltages may be present at the video sockets of the monitor.
Insulate the sockets.
•Connect the ground clamp of the monitor to the chassis ground.
•Connect the cable shields to the ground clamp of the monitor as follows:
Proceed as follows:
-- Strip the outer cable insulation of the video cables in the region of the ground
clamp of the monitor,without damaging the braided shield.
-- Secure the outer braided shield over a large area to the ground clamp of the
monitor.