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Spark gaps in ex areas – easy installation and testing thanks to coaxial connection technology

The EXFS Coaxial Connection Box by DEHN is the ideal solution for integrating
electrically conductive parts in ex areas like, for instance, the insulating joints of
pipelines, in the lightning equipotential bonding.
This effectively protects those electrically conductive parts in ex areas which
cannot be directly interconnected against lightning induced surges.
The benefits for the user, above all, during installation, maintenance and testing
are significant. The Coaxial Connection Box is installed above the ground so that
the regular inspection of the integrated EXFS 100 can be conducted outside the
ex area. There is also no need to disconnect cables or remove insulation when
testing. What is more, mounting is simple because DEHN includes all fixtures and
assembly accessories in the scope of delivery.
The Coaxial Connection Box serves to protect insulating

The Coaxial Connection Box serves to protect insulating joints mounted underground
or to bridge them in cathodically protected pipe sections. The connection between the
insulating joint and the connection box forms a coaxial connection cable. The
protective effect is up to three times higher than with a conventional connection of
comparable length. The Coaxial Connection Box, therefore, has the advantage that the insulation strength of the insulating joint is not exceeded, even with longer connection cables. The EXFS 100 used here is approved according to the ATEX guideline 2014/34/EU, IECEx, UL and Inmetro. The low sparkover voltage of this spark gap has proven its worth, especially with functionally isolated parts of an installation which only have a low insulation strength with each other. With a maximum lightning impulse current of 100 kA (10/350), the EXFS 100 also fulfils the criteria of class H, the highest lightning current carrying capability according to DIN EN 62561-3 “Lightning Protection System Components (LPSC). Requirements for isolating spark gaps”.


The functionality of such protective systems is checked at the inspection intervals laid
down for the system, for example, every 2 years in compliance with DIN EN 62305-3 or
every 3 years in accordance with DIN EN 60079-17 (VDE 0165 part 10-1). The DEHN Coaxial Connection Box makes it easy to inspect and exchange the ex spark gap EXFS 100 outside the hazardous area without the need for any excavation work.


Advantages in a nutshell:

  • Simple inspection and replacement of the spark gap outside the ex area
  • Protective solution tested by the manufacturer – suitable for all classes of LPS
  • No disconnection of cables and removal of insulation for inspection purposes
  • Up to three times lower voltage drop on the connection cable than with a
    conventional connection cable
  • Version for lightning equipotential bonding in hazardous areas according to IEC
    62305
  • Simple to mount – All fixtures and assembly accessories are included in the scope
    of delivery
Petra Raab

Petra Raab ⎟ Head of External Communications

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