Surge protection in switchgear cabinets without an external backup fuse
Less planning. More space. Greater operational safety with DEHN's ACI technology.
The reliable way to protect your power distribution system without the need for an external backup fuse. With DEHN's ACI technology, you can reduce complexity, save space and increase system availability.
Challenges in switchgear cabinets
Switchgear cabinets combine demanding requirements with limited space:
- Additional backup fuses require space
- Design and selectivity make planning more complex
- Additional components increase the protection level
- Fault currents are not always detected in time
Conventional approaches work, but they are labour-intensive and are not ideally suited to all operating conditions.
The solution: ACI technology for surge protection in switchgear cabinets
Advanced Circuit Interruption (ACI) technology integrates overcurrent protection into the SPD itself, eliminating the protection gap.
- No external backup fuse
- No additional wiring
- No complex coordination
The protection concept becomes simpler, more compact and more robust.
Typical applications in switchgear cabinets
ACI offers particular advantages in applications with high demands in terms of availability, space and planning:
Industrial plants
Stable processes require reliable protection without unscheduled downtimes.
Power distribution
Compact and well-organised switchgear cabinet solutions are crucial.
Charging infrastructure (AC/DC)
High load dynamics and TOV risks present additional challenges.
Battery systems and DC applications
Stable protection concepts for varying operating conditions.
Building technology
Limited space in the distribution cabinet requires efficient solutions.
Why DEHN ACI makes financial sense
Materials, time and availability are key in switchgear cabinets.
ACI reduces complexity and operating costs throughout the lifecycle:
No external backup fuse necessary
Less wiring and fewer components
No selectivity or backup fuse dimensioning
Fewer failures due to quick disconnection
No leakage currents, less ageing
How you benefit in the switchgear cabinet
Which solution is right for your application?
The choice depends on your application:
When ACI makes most sense
Choose ACI if:
- Space is limited in the switchgear cabinet
- Planning and installation needs to be carried out quickly
- TOV risks exist, for example loss of neutral
- High system availability is required
- Sensitive electronics need protecting
When conventional solutions still make sense
Standard SPDs with a backup fuse are suitable:
- If there are specific structural constraints
- If existing protection concepts are to remain in use
FAQs
The protection gap refers to the range within which fault currents are too high for the internal disconnector in the SPD, but too low for the external backup fuse. The SPD could become a fire hazard.
ACI uses an integrated switching unit to close the protection gap. Under normal conditions, this prevents leakage currents (galvanic isolation) and immediately interrupts both high and low fault currents without any mechanical time delay.
Among other things, ACI offers a consistently low protection level, zero leakage current for a longer service life, high TOV withstand and reliable failure behaviour. It also makes planning and installation simpler, as no external backup fuse is required.
ACI is ideal where space is limited in the distribution board, where networks are unstable, where there are high TOV risks, where simple installation and planning is desired, and where a consistently low protection level must be ensured for sensitive terminal equipment.
The integrated switching unit in ACI devices is dimensioned to safely handle prospective short-circuit currents of up to 50 kA for the Type 2 and 100 kA for the Type 1 version.
Find the right solution for your switchgear cabinet now
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