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Appendix E
EU Directives
A–5
European Union Directives
DL05, DL205 and DL305 AC
powered base power supplies
require extra mains filtering to
comply with the EMC Directive
on conducted RF emissions.
All PLC equipment has been
tested with filters from
Schaffner, which reduce
emissions levels if the filters
are properly grounded (earth
ground). A filter with a current
rating suitable to supply all
PLC power supplies and AC
input modules should be
selected. We suggest the
FN2010 for DL05/DL205
systems and the FN2080 for
DL305 systems. DL405
systems do not require extra
filtering.
Earth
Terminal
Fused
Terminals
Filter
Transient
Suppressor
To AC
Input
Circuitry
Schaffner
FN2010
L
N
NOTE: Very few mains filters can reduce problem emissions to negligible levels. In
some cases, filters may increase conducted emissions if not properly matched to the
problem emissions.
In order to comply with the fire risk requirements of the Low Voltage and Machinery
Directive electrical standards EN 61010–1, and EN 60204–1, by limiting the power
into “unlimited” mains circuits with power leads reversed, it is necessary to fuse both
AC and DC supply inputs. You should also install a transient voltage suppressor
across the power input connections of the PLC. Choose a suppressor such as a metal
oxide varistor, with a rating of 275VAC working voltage for 230V nominal supplies
(150VAC working voltage for 115V supplies) and high energy capacity (eg. 140
joules).
Transient suppressors must be protected by fuses and the capacity of the transient
suppressor must be greater than the blow characteristics of the fuses or circuit
breakers to avoid a fire risk. A recommended AC supply input arrangement for Koyo
PLCs is to use twin 3 amp TT fused terminals with fuse blown indication, such as
DINnectors DN–F10L terminals, or twin circuit breakers, wired to a Schaffner FN2010
filter or equivalent, with high energy transient suppressor soldered directly across the
output terminals of the filter. PLC system inputs should also be protected from voltage
impulses by deriving their power from the same fused, filtered, and surge-suppressed
supply.
A heavy-duty star earth terminal block should be provided in every cubicle for the
connection of all earth ground straps, protective earth ground connections, mains
filter earth ground wires, and mechanical assembly earth ground connections. This
should be installed to comply with safety and EMC requirements, local standards, and
the requirements found in IEC 1000–5–2.The Machinery Directive also requires that
the common terminals of PLC input modules, and common supply side of loads driven
from PLC output modules should be connected to the protective earth ground
terminal.
AC Mains Filters
Suppression and
Fusing
Internal Enclosure
Grounding