I-Data POLARIS Panel PC 19.1" - Manual (Page 18)

User manual
POLARIS Panel PC 19.1'' and Panel PC 15''
Version 2.00
Page 18 of 46
E_BMS790_POLARIS_PanelPC_19+15_Rev1.doc • User manual for POLARIS Panel PC 19.1" and 15" • Revision 1 / Status: January, 3 rd , 2006 • Technical data subject to change
3.3.2 Interference
suppression
Certain basic measures must be taken to ensure freedom from interference when the POLARIS Panel PC are installed:
■
Interference voltages injected into the unit via power and signal cables and static charges
caused by contact are to be conducted to earth (e.g. grounding screw terminal fixed to the back
of the unit). This earthing point must be connected to the PE conductor by means of the
shortest possible low resistance copper conductor or must be integrated in the equipotential
bonding. If this point is not observed, the measures taken to suppress interference and
preclude damage to the device effectively will be impaired.
■
The installation point should be as far as possible away from fields of electromagnetic
interference. This is especially important if there are frequency converters in the vicinity. Under
certain circumstances it will be advisable to set up partitions to isolate the POLARIS Panel PC
from interference.
■
If inductive unit are fitted in the vicinity (e.g. contactor, relay or solenoid coils), especially if they
are powered from the same source, protective circuits (e.g. RC elements) must be installed.
■
Power supply and data cables must be laid so as to avoid interference. This can, for example,
be achieved by avoiding laying such cables in close proximity to high current carrying cables.
3.3.3 Shielding
■
Only cables with braided shielding should be used
(recommended cover density > 80%).
■
Sheet shielding should not be used.
■
Generally, connection of the shielding at both ends results in optimum damping of all
interference frequencies.
■
Connection of the shielding at one side only may be more advisable if a difference in
potential exists and no equipotential bonding cable can be laid.