DRIVES AND CONTROLS | EMC COMPLIANCE
WORKING IN HARMONY
In many industrial environments,
ensuring the stability of drive
controllers is sometimes
overlooked. However, according to
Mark Checkley, sales and managing
manager, KEB Automation, an EMCcompliant
(electromagnetic
compatibility) drive
assembly with
efficient control
cabinet and
suppression
system is
the basis for
ensuring
the safe
and reliable
operation of
machines and
equipment. It
can also extend
the life of certain
components.
The operation
of variable speed
drives with intermediate
voltage circuits can
put stress on the mains
and motor, which
can be optimised
using additional
measures
Manufacturers and operators are
required to implement the installed
drive systems to achieve electrical
compliance with the limits – for
emissions – and requirements – for
fault-free operation – set out in the
relevant European and International
standards and regulations. Utilising
some components can lead to
additional advantages besides
compliance.
To ensure the stability and safety of drive
assemblies, OEMs and machine builders
must ensure drives comply with specific
EMC requirements.
For power drive
systems (i.e. inverter
and motor viewed in
terms of a drive),
the product
standard is EN
61800-x, with EN
61800-3 being
the relevant
EMC standard.
The technical
standard sets out
the requirements for
a specific environment.
EN61000-6-x applies to machine
builders and sets out the general
EMC requirements for use either
in a public low-voltage grid or an
industrial grid/network.
“When selecting a drive,”
Checkley explains. “It is sensible to
check what range of accessories the
drives supplier can offer. Whilst some
of these accessories can be sourced
from other Third Party suppliers, it is
often better to deal with a supplier that
can provide everything from a single
source, so the items are optimised to
suit their own specific drives (or even
designed in-house for their drives)
and therefore more likely to meet
the specific requirements of your
application.”
He adds, the operation of variable
speed drives with intermediate
voltage circuits can put stress on
the mains and motor, which can be
optimised using additional measures,
depending on the place of use and
the type of application. An EMCcompliant
drives assembly may
therefore include several accessories
and interference suppression
components for the mains- and motorrelated
optimisation of operating
conditions. The most common
suppression components and their
functions are:
MAINS SUPPRESSION
“Mains chokes optimise the harmonics
to the mains power supply that
SEPTEMBER 2019 | WWW.EUREKAMAGAZINE.CO.UK 39
/WWW.EUREKAMAGAZINE.CO.UK