DEHN DEHNguard MP TT 275 FM Type 2 Surge Arrester, 4-Pole, 275 V AC, DIN Rail Mount, with Remote Signalling Contact 942315

The DEHNguard MP TT 275 FM stands out with its modular 4-pole design that integrates both varistor and spark-gap protection in a single compact unit, making it a reliable choice for TT and TN systems where space and performance are critical. It combines high discharge capacity with a fast response time and includes a remote signalling contact for easy monitoring.

Highlights

• Type 2 surge protective device for TT and TN systems
• 4-pole (3+1) configuration with protection paths L-N, N-PE, and L-PE
• Max continuous operating voltage 275 V AC, nominal discharge current 20 kA, max discharge current 40 kA
• Voltage protection level ≤ 1.3 kV at In, response time < 25 ns
• Potential-free changeover contact for remote status indication
• Mounts on 35 mm DIN rail, IP20, operating temperature -40 °C to +80 °C

In daily use

Installed in distribution boards, the DEHNguard MP TT 275 FM protects electrical installations from transient overvoltages caused by switching operations or indirect lightning effects. Its compact thermoplastic housing (UL 94 V-0) and DIN rail mounting simplify integration, while the remote signalling contact allows integration into building management systems for proactive maintenance.

Full specifications

• SPD type: Type 2 / Class II
• System configuration: TT and TN systems
• Max. continuous operating voltage (Uc): 275 V AC
• Nominal discharge current (In) (8/20 µs): 20 kA
• Max. discharge current (Imax) (8/20 µs): 40 kA
• Voltage protection level (Up) at In: ≤ 1.3 kV
• Voltage protection level (Up) at 5 kA: ≤ 1.1 kV
• Response time (tA): < 25 ns
• Number of poles: 4-pole (3+1 configuration)
• Protection paths: L-N, N-PE, L-PE
• Remote signalling contact: Yes (potential-free changeover contact)
• Mounting type: 35 mm DIN rail
• Degree of protection: IP20
• Operating temperature range: -40 °C to +80 °C
• Housing material: Thermoplastic, UL 94 V-0
• Protection technology: Varistor-based (L-N), Spark gap (N-PE)
• Short-circuit withstand capability (Isccr): 50 kA (with max. 250 A gG backup fuse)

Final note

Engineered for reliability in demanding electrical environments, the DEHNguard MP TT 275 FM delivers robust surge protection with the convenience of remote monitoring.