DEHN DG MP TT 275 Type 2 Surge Protection Device 3+1 (942310)

With a maximum discharge current of 40 kA and a voltage protection level of ≤1.5 kV, this DEHNguard MP surge protection device safeguards TT and TN-S systems against transient overvoltages. The 3+1 configuration combines varistor technology for L-N protection with a spark gap for N-PE, ensuring comprehensive protection for three-phase power supplies.

Overview

The DEHN DG MP TT 275 is a Type 2 surge protective device (SPD) designed for installation in low-voltage power distribution systems. It features a nominal voltage of 230/400 V AC and a maximum continuous operating voltage of 275 V AC, making it suitable for standard mains applications. The device mounts on a 35 mm DIN rail and includes a visual status indicator and remote signaling contact for easy monitoring.

What stands out

• High discharge capacity: 20 kA nominal (8/20 µs) and 40 kA maximum (8/20 µs).
• Low voltage protection level: ≤1.5 kV at nominal discharge current, ≤1.2 kV at 5 kA.
• Fast response time: less than 100 ns.
• Integrated thermal disconnect with green/red status indication.
• Potential-free changeover contact for remote signaling.
• Compact DIN-rail housing made of red thermoplastic, UL 94 V-0.

Technical details

• Type: Type 2 surge protective device (SPD) per EN 61643-11 / IEC 61643-11.
• System: 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) at In: ≤1.5 kV.
• Voltage protection level (Up) at 5 kA: ≤1.2 kV.
• Response time (tA): <100 ns.
• Number of poles: 3+1 (3-phase + N).
• Protection modes: L-N, N-PE.
• Technology: Varistor (MOV) with N-PE spark gap.
• Thermal disconnect: Yes, with visual status indicator (green/red).
• Remote signaling contact: Yes (potential-free changeover contact).
• Mounting: 35 mm DIN rail.
• Housing material: Thermoplastic, red, UL 94 V-0.
• Degree of protection: IP20.
• Operating temperature range: -40 °C to +80 °C.
• Standards: IEC 61643-11 / EN 61643-11.

Our verdict

The DEHNguard MP TT 275 is a robust and reliable Type 2 SPD for three-phase TT and TN-S systems. Its high discharge capacity, low protection level, and comprehensive monitoring features make it a solid choice for protecting sensitive equipment from surges.