This protection scheme usually used for distribution cabinets. Devices using this protection principle may not be
installed Zone 0.
Intrinsically safe equipment and intrinsically safe parts of
the associated equipment are divided into protection levels:
ia (for zones and 2), (for zones and 2), and ic
(only for zone 2). Increased safety is
achieved reducing the current load and raising the isolation
properties and maintaining clearance and creepage distances
above the value industrial application. These connections are known ignition gaps.
A typical application area are control and display circuits with
low voltage and current.5
IECEx scheme
The IECEx scheme international certification scheme for
products which meet the requirements the international
standards, e.
The enclosure must therefore stable enough ensure
that not deformed destroyed the pressure created.
The surrounding possibly explosive atmosphere can enter the
enclosure and will produce internal explosion during the
equipment’s lifespan.
Increased safety e
No sparks and surface temperature limited
to safe level
Increased safety for products where
there are sparks produced during normal
operation case failure.Technicalappendix
W
W.
A Certificate Conformity (CoC) refers test report
(Ex Test Report ExTR) and assessment the quality
assessment report from the manufacturer (QAR).
The standards used for the production the test report
correspond almost entirely the harmonised standards in
Europe.iecex.
Protection concepts
The zoning described above provides the basis for the
selection the type ignition protection. the technical committee TC31’s IEC standards.
The certificates awarded this scheme are published the
IECEx website (www.
They can viewed online and printed out.g. The methods that achieve
intrinsic safety mean that important that not only the devices
installed direct contact with the explosive atmosphere are
constructed correctly, but also the electrical devices which
they are connected. rms).
Intrinsically safe i
Limited safe level ignition energy
Intrinsic safety for products where electrical
energy which flows into the product, is
stored the product, not sufficient to
ignite the surrounding explosive atmosphere. A. So, example,
in the ATEX applicable areas, only ignition protection devices
meeting for Zone (highest probability explosive
atmosphere being present) are allowed.com) electronic certificate.
IECEx scheme
.
All connections the enclosure are sized that they
cannot transmit explosion from inside the surrounding
atmosphere. The highest voltage
permitted for this protection scheme (D.C.
Pressure-resistant encapsulation
Limits the explosion the inside the enclosure
Pressure-resistant encapsulated enclosures are
designed for devices where sparks are
generated which have hot surfaces which
are source ignition during normal
operation. The surface
temperature the relevant parts limited to
a value below the ignition temperature. Similarly, industrial components for use potentially
explosive atmospheres are often made suitable encapsulating
them pressure-resistant enclosure which otherwise could
not used. Recent standards were initially adopted IEC
standards.
This also applies fault conditions.
For this sort ignition protection the explosion groups apply
(IIA, IIB, IIC).C
