Disassembling DG M 275 ACI, for highest system availability – DEHNguard ACI

DEHNguard M TT ACI 275 FM
Modular surge arrester with Advanced Circuit Interruption (ACI) for TT and TN-S systems (3+1 configuration).
Part No. 952341 DG M TT ACI 275 FM
GTIN 4013364376632, Customstariff No.: 85363030, Grossweight: 455g

DEHNguard DG M TT ACI 275 FM (952 341)


Basic circuit diagram DG M TT ACI 275 FM

DEHNguard M TNS ACI 275 FM
Modular surge arrester with Advanced Circuit Interruption (ACI) for TN-S systems.
Part No. 952440 DG M TNS ACI 275 FM
GTIN 4013364376625, Customs tariff No.: 85363030, Gross weight: 450g

DEHNguard DG M TNS ACI 275 FM (952 440)


Basic circuit diagram DG M TNS ACI 275 FM

DEHNguard DG MOD ACI 275 – No. 952 524

DEHNguard DG MOD ACI 275 - No. 952 524

DEHNguard DG MOD H A NPE – No. 952 083

DEHNguard DG MOD H A NPE - No. 952 083

DEHNguard modular with Advanced Circuit Interruption (Safe Dimensioning)

  • New technology “Advanced Circuit Interruption” (ACI) integrated with the protection module, consists of a switch/spark gap combination
  • Due to ACI technology, no external backup fuse required
  • Small connection cross-sections (6 mm² Cu) absolutely sufficient *)
  • TOV withstand also at 440 V (AC)
  • High system reliability, no tripping of 32 A gG fuses
  • Zero leakage current due to galvanic isolation by ACI switch unit
  • Energy coordination with other arresters of the Red/Line product family
  • Vibration and shock-tested according to EN 60068-2

*) All live conductors should be wired so that they inherently short-circuit and earth fault-proof

ACI: The highest level of safety

Equipped for the future: Surge protection with ACI technology

The new ACI Technology – Advanced Circuit Interruption – improves the safety of your electrical systems.

New: The switch/spark gap combination in type 2 arrester DEHNguard ACI makes upstream fuses superfluous. As a backup fuse is no longer required, you save time, space, and material.

A further bonus: you eliminate possible configuration errors made when selecting and dimensioning a suitable backup fuse.

Reduce expenses and make your system safe!

For the highest possible availability – to keep your system up and running

The switch/spark gap combination in DEHNguard ACI is connected in series with a varistor. At the end of the service life of the ACI surge arrester, any fault current is interrupted by the varistor through the switch/spark gap combination connected in series and reduced to such an extent that not even the smallest fuses in the system are tripped.

This means much greater availability and operational safety for the system in comparison with standard type 2 arresters with external fuses.

Standard solutionCI technologyACI technology
Safe dimensioning
Smaller connection cross-section – only 6mm2 always sufficient
Longer service life due to TOV withstand and zero leakage current
Monitoring overcurrent protection
More space in the switchgear cabinet
No external backup fuse needed
Thermo Dynamic Control
Protective effect of a type 2 arrester

Technical data

SPD according to EN 61643-11 / IEC 61643-11type 2 / class II
Energy coordination with terminal equipment (≤ 10 m)type 2 + type 3
Nominal a.c. voltage (UN)230 / 400 V (50 / 60 Hz)
Max. continuous operating voltage (a.c.) [L-N] (UC)275 V (50 / 60 Hz)
Max. continuous operating voltage (a.c.) [N-PE] (UC)255 V (50 / 60 Hz)
Nominal discharge current (8/20 µs) [L-N] (In)20 kA
Nominal discharge current (8/20 µs) [N-PE] (In)80 kA
Voltage protection level [L-N] / [N-PE] (UP)≤ 1.5 / ≤ 1.5 kV
Voltage protection level [L-N] / [N-PE] at 5 kA (UP)≤ 1,5 / ≤ 1,5 kV
Follow current extinguishing capability [N-PE] (Ifi)100 Arms
Response time [L-N] (tA)≤ 100 ns
Response time [N-PE] (tA)≤ 100 ns
Additional external fusenot required
Short-circuit withstand capability (ISCCR)25 kArms
Temporary overvoltage (TOV) [L-N] (UT) – Characteristic440 V / 120 min. – withstand
Temporary overvoltage (TOV) [N-PE] (UT) – Characteristic1200 V / 200 ms – withstand
Operating temperature range (TU)-40 °C … +80 °C
Operating state / fault indicationgreen / red
Number of ports1
Cross-sectional area (min.)1.5 mm2 solid / flexible
Cross-sectional area (max.)35 mm2 stranded / 25 mm2 flexible
For mounting on35 mm DIN rails acc. to EN 60715
Enclosure materialthermoplastic, red, UL 94 V-0
Place of installationindoor installation
Degree of protectionIP 20
Capacity4 module(s), DIN 43880
Type of remote signalling contactchangeover contact
Switching capacity (a.c.)250 V / 0.5 A
Switching capacity (d.c.)250 V / 0.1 A; 125 V / 0.2 A; 75 V / 0.5 A
Cross-sectional area for remote signalling terminalsmax. 1.5 mm2 solid / flexible