Finder 7P.03.8.255.S007 Combined Arrester Type 1+2 for Three-Phase TN-C Networks

The Finder 7P.03.8.255.S007 stands out by combining Type 1 and Type 2 surge protection in a single DIN-rail module, eliminating the need for separate arresters in three-phase TN-C systems. Its 255 V continuous operating voltage and 21 kA total impulse current make it suitable for installations where high-energy lightning currents and switching surges must be handled by one compact device.

Highlights

• Combined Type 1+2 arrester for three-phase TN-C networks
• Nominal discharge current 20 kA, impulse current 7 kA per pole
• Low voltage protection level < 1.5 kV
• DIN rail mounting, IP20 protection

In daily use

Installed at the service entrance or main distribution board, the 7P.03.8.255.S007 protects all three phases against transient overvoltages. Its metal oxide varistor technology responds in less than 100 nanoseconds, keeping the residual voltage below 1.5 kV. The thermoplastic housing is rated UL 94 V-0, and the unit accepts conductors up to 35 mm² for secure connections.

Full specifications

• SPD type: Type 1 + Type 2 combined arrester
• Network configuration: 3-phase TN-C
• Nominal voltage (Un): 230/400 V AC
• Maximum continuous operating voltage (Uc): 255 V AC
• Nominal discharge current (In): 20 kA (8/20 µs)
• Impulse current (Iimp) per pole: 7 kA (10/350 µs)
• Total impulse current (Iimp total): 21 kA (10/350 µs)
• Voltage protection level (Up): < 1.5 kV
• Response time (tA): < 100 ns
• Operating temperature range: -40°C to +80°C
• Protection degree: IP20
• Mounting type: DIN rail (EN 60715)
• Number of poles: 3 (L1, L2, L3)
• Technology: Metal oxide varistor (MOV)
• Remote signaling contact: No
• Housing material: Thermoplastic, UL 94 V-0
• Max. conductor cross-section: 35 mm² (solid/stranded)
• Short-circuit withstand capability (Isccr): 50 kA (with external fuse)

Final note

For three-phase TN-C installations, this combined arrester reduces component count and simplifies wiring while providing both lightning current and surge protection in one unit.