The new DEHNventil ACI M TNS 264 FM is a Type 1 surge arrester based on its ACI (Advanced Circuit Interruption) technology.
The pre-installed DEHNventil ACI M TNS 264 FM (Type 1 + 2 + 3) combination surge arrester provides protection at the low-voltage switchboard's point of supply.
Conventional overcurrent protection systems, such as fuses or circuit breakers, are only partially suitable for protecting surge protective devices (SPDs), as required by IEC 60364-5-53:2001/A2:2015, since they can trip unintentionally in response to lightning currents or transient impulses.
The maximum backup fuse specified for the SPD does not reliably protect against residual currents of several tens or hundreds of amps, which can cause thermal overloads.
With its innovative ACI technology, DEHN takes a completely new approach: the classic overcurrent protection concept is replaced by the integration of a powerful circuit breaker/spark arrester combination directly into the surge protection device.
In addition to providing overcurrent protection, this solution offers galvanic isolation under normal conditions. This eliminates leakage currents and significantly increases resistance to temporary power-frequency (TOV) surges.
This technology offers numerous advantages for designers and installers:
Reduced planning effort,
elimination of sizing errors,
greater operational safety,
simplified calculations and selectivity criteria, and
reliable protection on the power supply side.
In addition to setting new standards in Type 2 applications and in the direct current (DC) sector, ACI technology plays a fundamental role in protecting the incoming side of the installation, especially in Type 1 surge arresters.
This is where high short-circuit currents and complex network conditions converge. The IEC 60364-5-53:2001/A2:2015 standard requires that surge protection be installed as close as possible to the system's power supply point.
In practice, this is complicated because the connecting cables must not exceed 0.5 meters to avoid inductive voltage drops.
The DEHNventil ACI M TNS 264 FM (Type 1+2+3) modular combined surge arrester simplifies this implementation:
Integrated ACI technology eliminates the need for backup fuses.
It can be mounted directly on DIN rails or grounding bars.
A conductor cross-section of 16 mm² Cu is always sufficient.
Even in the event of a fault, the integral current is so low that the connecting cable does not suffer thermal overload.
The disconnect function allows for safe module replacement during operation, from either the side or the front, using insulated tools.
