It is a DEHNventil ACI.

The no-worries solution from DEHN:
When work safety meets easy compliance with standards, it is DEHNventil ACI.

The prewired DEHNventil ACI combined arrester (Type 1 + Type 2 + Type 3) provides safety in and at the supply point of the low-voltage main distribution board - this makes the innovative ACI technology (Advanced Circuit Interruption) available for the first time in the type 1 arrester class.

Innovative detailed solutions such as an automatic disconnection function with visual display of voltage disconnection, 3-sided module replacement options or a connection cross-section of 16 mm² Cu that is always the same ensure maximum safety - in terms of occupational safety, standards and also the reliable operation of your system.


Technical details

All benefits at a glance

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Innovative installation concept for safer work

An automatic, electrical disconnection function of the protection module in the event of a fault means that the module can be replaced safely during system operation and in compliance with industrial safety regulations. The dead protection module can also be removed from the side or front. This enables safe replacement in any installation situation.

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Compliance with standards made easy

The absence of a back-up fuse and direct mounting on an earthed top hat rail or busbar make it easy to comply with the cable length of max. 0.5 m prescribed by IEC 60364-5-53
of max. 0.5 m.

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Reliable dimensioning
– times three

Forget about time-consuming dimensioning of backup fuses, selectivity and cross-sectional area. The new DEHNventil ACI already has an integrated switch/spark gap combination which is precisely adapted to the arrester. This means: no backup fuse, no errors in dimensioning and always the same cross-section of only 16 mm² of copper.

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Convenient installation

The compact system solution not only offers maximum flexibility, but also freedom when positioning and connecting the surge arrester. The integrated switch spark gap saves valuable installation space and enables flexible mounting on top-hat rails, busbars or control cabinet walls.


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High system availability

The safe disconnection of the protection module from the power supply means that the system can continue to operate seamlessly even when servicing is required. The maintenance can be carried out during operation. This minimises costly downtimes. In addition, the DEHNventil ACI also offers the usual outstanding performance parameters in operation (100 kA of lightning current carrying capability / 100 kA of short-circuit current capability) with the best possible protection (Type 1+2+3 certification with terminal device protection).

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Quick, easy and safe maintenance

An electrical status indication via remote signalling is integrated in the DEHNventil ACI as standard. In the event of a fault, the disconnection function isolates the protection module from the base module and thus safely from the power supply. This is visually indicated on all four sides of the arrester, providing safety for maintenance personnel.

Product features at a glance

For maximum system availability: DEHNventil ACI

DEHN has stood for innovation and technical progress for over 100 years and has created space-saving system solutions for modern surge protection with its CI and ACI arresters. CI stands for Circuit Interruption and means that an optimally dimensioned fuse is already integrated in the SPD. With the ACI (Advanced Circuit Interruption) technology introduced in 2018, this fuse has been replaced by a switch-spark gap combination. These and other innovative features make the DEHNventil ACI the simplest and safest solution. Overview of our arrester classes:


The "no-worries solution" from DEHN

ACI technology: For maximum safety in the switchgear cabinet

No more time-consuming dimensioning! Our Type 1 and Type 2 arresters with ACI technology have an integrated switch/spark gap combination. This completely eliminates the conventional backup fuse. This provides certainty, enables flexible installation and raises system availability to a new level.

The DEHN ACI technology


  • Peak-level reliability and system availability
  • Reliable dimensioning and space savings due to the elimination of the separate backup fuse
  • Long service life thanks to high TOV withstand capability and zero leakage current
  • Easy installation due to a smaller cross-sectional area
To ACI technology

Module replacement video

Product versions

Available end of 2024


DEHNventil ACI M TNS 264 (FM)

Four-pole, spark-gap-based, Type 1 + Type 2 + Type 3 DEHNventil ACI M TNS combined arrester as per EN 61643-11 with integrated ACI switch/spark gap. Maximum system availability due to RADAX Flow follow current limitation. Capable of protecting terminal equipment.

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DEHNventil ACI M TNC 264 (FM)

Three-pole, spark-gap-based, Type 1 + Type 2 + Type 3 DEHNventil ACI M TNC combined arrester as per EN 61643-11 with integrated ACI switch/spark gap. Maximum system availability due to RADAX Flow follow current limitation. Capable of protecting terminal equipment.

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Flyer DEHNventil ACI The prewired, Type 1+2+3 combined arrester with ACI technology .pdf 0.3 MB

Got any questions about the new DEHNventil ACI?

We are ready to answer your questions on the new DEHNventil ACI.
Call us on +49 9181 906 1462 or write us an email [email protected]. We look forward to hearing from you!