Pilz PSSnet GW1 MOD-CAN - Manual (Page 13)

Safety
Operating Manual PSSnet GW1 MOD-CAN
1002693-EN-02
13
Shielding
Interference currents must be diverted to cable shields via shield bars.
In doing so you must ensure the following:
} Connect the shields with low impedance to the shield bar or earth bar.
} Use cables with braided screening, with a minimum cover area of 80 %.
} When laying cables without equipotential bonding or using foil shields: Connect the
shield at one end.
} If possible, use metal or metallised plugs to connect cables for serial data transfer. Al-
ways refer to the regulations relating to the fieldbus systems.
} If the shield is not to be connected at the end of the cable, it must have no connection
to the connector housing.
} If the shield is to be connected, connect it to the shield bar at the point where the cable
enters the cabinet, without making a break in the cable. Use metal cable clamps which
cover the shield over a wide surface area. Route the shield as far as the units, but do
not connect it to the units.
Digital inputs and outputs do not need shielded cables.
However, if the connection cables have a shield, it should be connected at one end.
Analogue inputs and the incremental encoder inputs on speed monitors should always be
connected using shielded cables.
Lighting in the control cabinet
Use low interference panel lighting for inside the control cabinet.
Testing the EMC-compliance of an installation
You can use the list below to check that the installation of the Gateway is EMC-compliant.
Check Measures Done
Are there areas with a high
probability of interference?
(e.g. computers running,
process control areas, dis-
tribution cabinets, cable
casing, frequency convert-
ers, hand-held radios etc.).
EMC protection in these areas should be planned
with particular care.
Are areas where comput-
ers are running or areas
such as process control
rooms sufficiently shielded
from electromagnetic cou-
pling?
If necessary shield the whole area.
Does the cable layout take
into account the principles
of EMC compliance?
Some important points: Lay cables close to earth,
keep clear of other electrical equipment, keep ca-
bles in ducts separate from other parts of the in-
stallation, keep cables as short as possible, avoid
multiple crossovers.
Is the supply voltage free
of interference?
Supplies with interference voltages should be fit-
ted with a mains filter.
3.1.1.4
3.1.1.5
3.1.1.6