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 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.
The standards used for the production the test report
correspond almost entirely the harmonised standards in
Europe. These connections are known ignition gaps.5
IECEx scheme
The IECEx scheme international certification scheme for
products which meet the requirements the international
standards, e.
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.g. Recent standards were initially adopted IEC
standards. The highest voltage
permitted for this protection scheme (D.
A Certificate Conformity (CoC) refers test report
(Ex Test Report ExTR) and assessment the quality
assessment report from the manufacturer (QAR).
A typical application area are control and display circuits with
low voltage and current.
Protection concepts
The zoning described above provides the basis for the
selection the type ignition protection.
The surrounding possibly explosive atmosphere can enter the
enclosure and will produce internal explosion during the
equipment’s lifespan. A.
The enclosure must therefore stable enough ensure
that not deformed destroyed the pressure created.com) electronic certificate.
This protection scheme usually used for distribution cabinets.
This also applies fault conditions. So, example,
in the ATEX applicable areas, only ignition protection devices
meeting for Zone (highest probability explosive
atmosphere being present) are allowed.C.C.
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. rms). The surface
temperature the relevant parts limited to
a value below the ignition temperature.Technicalappendix
W
W. Similarly, industrial components for use potentially
explosive atmospheres are often made suitable encapsulating
them pressure-resistant enclosure which otherwise could
not used.
The certificates awarded this scheme are published the
IECEx website (www. Increased safety is
achieved reducing the current load and raising the isolation
properties and maintaining clearance and creepage distances
above the value industrial application.
For this sort ignition protection the explosion groups apply
(IIA, IIB, IIC).
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).
All connections the enclosure are sized that they
cannot transmit explosion from inside the surrounding
atmosphere. Devices using this protection principle may not be
installed Zone 0.iecex.
IECEx scheme
. the technical committee TC31’s IEC standards.
They can viewed online and printed out
