DEHN DSH ZP B2 LSG A TT 2 DSH ZP B2 LSG A TT 255 Surge Arrester Combination Type 1+2 (909131)

With a lightning impulse current of 25 kA per pole (50 kA N-PE) and a voltage protection level of ≤ 1.5 kV, the DEHN DSH ZP B2 LSG A TT 2 DSH ZP B2 LSG A TT 255 is a spark-gap-based surge protective device for TT and TN-S earthing systems.

Overview

This 2-pole combination arrester integrates Type 1 and Type 2 protection in a single DIN-rail mountable unit. It is rated for a nominal voltage of 230/400 V AC and a maximum continuous operating voltage of 255 V AC, making it suitable for 50/60 Hz networks.

What stands out

• High lightning impulse current: 25 kA (L-N/PE) and 50 kA (N-PE) per IEC 61643-11
• Low voltage protection level: ≤ 1.5 kV for both L-N/PE and N-PE paths
• Follow current extinguishing capability: 50 kA rms
• Short-circuit withstand: 50 kA rms with maximum 160 A gG backup fuse
• Fast response time: ≤ 100 ns
• Wide operating temperature range: -40 °C to +80 °C
• Compact 2-pole design for 35 mm DIN rail

Technical details

• SPD type: Type 1 + Type 2 (Class I + II)
• Earthing systems: TT, TN-S
• Nominal voltage (Un): 230 / 400 V AC (50/60 Hz)
• Max. continuous operating voltage (Uc): 255 V AC
• Lightning impulse current (Iimp) (10/350 µs): 25 kA (L-N/PE), 50 kA (N-PE)
• Nominal discharge current (In) (8/20 µs): 25 kA (L-N/PE), 50 kA (N-PE)
• Voltage protection level (Up): ≤ 1.5 kV
• Follow current extinguishing capability (Ifi): 50 kA rms
• Short-circuit withstand capability (Isccr): 50 kA rms
• Max. backup fuse: 160 A gG
• Response time (tA): ≤ 100 ns
• Operating temperature range: -40 °C to +80 °C
• Mounting: 35 mm DIN rail
• Degree of protection: IP20
• Number of poles: 2
• Protection technology: Spark gap based
• Standards: IEC 61643-11 / EN 61643-11
• Housing material: Thermoplastic, UL 94 V-0

Our verdict

The DEHN DSH ZP B2 LSG A TT 255 delivers robust surge protection with high discharge capacity and low residual voltage, ideal for main distribution boards in TT and TN-S systems.