AutomationDirect DL105, User Manual

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EU
Directives
Appendix
F
F--5
European Union Directives
DL105 PLC User Manual, 3rd Edition
Basic EMC Installation Guidelines
The simplest way to meet the safety requirements of the Machinery and Low Voltage
Directives is to house all control equipment in an industry standard lockable steel
enclosure. This normally has an added benefit because it will also help ensure that
the EMC characteristics are well within the requirements of the EMC Directive.
Although the RF emissions from the PLC equipment, when measured in the open
air, are well below the EMC Directive limits, certain configurations can increase
emission levels. Holes in the enclosure, for the passage of cables or to mount
operator interfaces, will often increase emissions.
DL105, 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 to negligible 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 DL105/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 neglegible levels. In
some cases, filters may increase conducted emissions if not properly matched to the
problem emissions.
I
n 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.
Enclosures
AC Mains Filters
Suppression and
Fusing