Electromagnetic compatibility (EMC)
Installation Manual PNOZmulti Installation Manual
1002265-EN-02
14
3.3
Testing the EMC-compliance of an installation
You can use the list below to check that the installation of the control systems PNOZmulti
and PNOZmulti Mini is EMC-compliant.
Check
Action
Done
Are there areas with a high
probability of interference?
(e.g. computers running,
process control areas, distri-
bution cabinets, cable cas-
ing, frequency converters,
hand-held radios etc.)
EMC protection in these areas should be
planned with particular care.
Are areas where computers
are running or areas such as
process control rooms suffi-
ciently shielded from electro-
magnetic coupling?
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 cables in ducts separate from other parts
of the installation, keep cables as short as pos-
sible, avoid multiple crossovers
Is the supply voltage free of
interference?
Supplies with interference voltages should be
fitted with a mains filter.
EMC characteristics of indi-
vidual units / all units tested
once installed?
Test EMC characteristics under operating con-
ditions, e.g. while hand-held radios are in use,
or HF frequency generators are close by. Test
static discharge with operating personnel, test
mutual interference between units under differ-
ent operating conditions.
Earthed parts connected
correctly?
Most important are the connections between
the units, racking bars, earth conductors and
shield bars; inactive metal parts should be con-
nected over a wide surface area and earthed at
a central point; with insulated metal: Remove
insulation or use special contact fixings; protect
the connection from corrosion; connect the cab-
inet doors to the body of the cabinet using
earthing straps
Cable groups laid separ-
ately?
Separate cables into groups. Supply and signal
leads should be laid separately
Are the shields connected
correctly?
Use shielded cables for analogue and data
leads; use metallic plugs; connect cable shields
to shield bar at point of entry to cabinet; con-
nect cable shields over a wide surface area and
with low impedance
Equipotential bonding car-
ried out?
If the installation extends over a wide area:
Equipotential bonding cables should be laid.
Are inductive loads
switched?
Sufficient fuse protection should be provided
with inductive loads
