DEHN DG MD TT 275 Type 2 Surge Arrester 4-Pole with Remote Signalling 943315

Protect TT and TN-S power systems from transient overvoltages with the DEHN DG MD TT 275. This Type 2 surge arrester diverts surge currents safely to ground, preventing damage to connected equipment and reducing downtime caused by lightning or switching events.

Who is it for

Electrical installers and panel builders who need reliable surge protection for low-voltage power distribution in residential, commercial, or industrial settings. It is suitable for main distribution boards and sub-distribution boards where a 4-pole, 3+1 configuration is required.

Main features

• Type 2 surge protective device for TT and TN-S systems
• Nominal discharge current (In) of 20 kA (8/20 µs) and maximum discharge current (Imax) of 40 kA
• Voltage protection level (Up) ≤ 1.2 kV for effective equipment protection
• Integrated thermal disconnector and visual status indication (green/red)
• Floating changeover contact (FMFM) for remote signalling of device status
• DIN rail mountable, 4-pole (3+1) design
• Operating temperature range from -40 °C to +80 °C

Specifications

• SPD type: Type 2
• System configuration: TT and TN-S
• Nominal voltage (Un): 230 / 400 V AC (50/60 Hz)
• 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): ≤ 1.2 kV
• Follow current extinguishing capability (If): 25 kA rms
• Response time (tA): < 25 ns
• Number of poles: 4 (3+1)
• Mounting type: 35 mm DIN rail
• Degree of protection: IP20
• Connection cross-section: 1.5 - 35 mm² solid / 1.5 - 25 mm² stranded
• Short-circuit withstand capability (Isccr): 50 kA rms
• Remote signalling: floating changeover contact
• Visual status indication: green (OK) / red (fault)
• Housing material: thermoplastic, red

Tips

Install the DEHN DG MD TT 275 close to the incoming supply to minimise cable lengths and improve protection. Check the visual indicator regularly and integrate the remote signalling contact into your building management system for proactive maintenance alerts.