DEHN DG M TNC ACI 275 FM Type 2 Surge Arrester, 3-Pole, 275 V AC, with Remote Signalling

In industrial facilities and commercial buildings with TN-C power distribution, protecting sensitive electronics from transient overvoltages is critical. The DEHN DG M TNC ACI 275 FM surge arrester is a Type 2 device designed for installation at the main distribution board or sub-distribution boards to safeguard three-phase systems. It features a 3-pole configuration for TN-C networks (3+1 circuit) and a maximum continuous operating voltage of 275 V AC. With ACI technology, the arrester includes an integrated backup fuse, eliminating the need for a separate fuse and simplifying installation. The FM version provides a remote signaling contact (potential-free changeover) for remote monitoring of the arrester status. The device is DIN rail mountable (35 mm) and has a compact, red thermoplastic housing (UL 94 V-0). It offers a nominal discharge current of 20 kA (8/20 µs) and a maximum discharge current of 40 kA (8/20 µs), with a voltage protection level of ≤1.5 kV and a response time of ≤25 ns. The arrester is suitable for ambient temperatures from -40 °C to +80 °C and has an IP20 degree of protection. Connectable conductor cross-sections range from 1.5 to 35 mm² (solid) and 1.5 to 25 mm² (flexible). Optical fault indication is provided by a green/red flag. The device complies with EN 61643-11 and IEC 61643-11.

Key specifications

• Type 2 surge arrester according to EN 61643-11
• Network configuration: TN-C (3+1 circuit), 3-pole
• Maximum continuous operating voltage (Uc): 275 V AC
• Nominal discharge current (In) (8/20 µs): 20 kA
• Maximum discharge current (Imax) (8/20 µs): 40 kA
• Voltage protection level (Up): ≤ 1.5 kV
• Response time (tA): ≤ 25 ns
• Integrated backup fuse (ACI technology)
• Remote signaling contact (FM) for status monitoring
• DIN rail mounting (35 mm)
• Degree of protection: IP20
• Operating temperature range: -40 °C to +80 °C
• Housing material: thermoplastic, red, UL 94 V-0
• Connectable conductor cross-section: 1.5 - 35 mm² (solid), 1.5 - 25 mm² (flexible)
• Optical fault indication: green/red flag
• Standards: EN 61643-11, IEC 61643-11

Why choose it

The DEHN DG M TNC ACI 275 FM offers reliable protection for three-phase TN-C systems with a compact design and integrated backup fuse, reducing installation time and component count. The remote signaling contact enables proactive maintenance by alerting you to arrester status changes, while the robust thermoplastic housing ensures durability in demanding environments.

Ideal use cases

• Main distribution boards in industrial plants
• Sub-distribution boards in commercial buildings
• Protection of sensitive electronic equipment in TN-C networks
• Applications requiring remote monitoring of surge protection status

Good to know

The arrester is designed for DIN rail mounting and has an IP20 rating, suitable for installation in distribution enclosures. The ACI technology eliminates the need for a separate backup fuse, simplifying wiring and reducing space requirements. The green/red flag provides clear visual indication of the arrester status.