Finder 7P.04.8.255.S012 Type 1+2 Combined Surge Arrester for 3-Phase TN-S and TT Networks, 4-Pole, 255 V AC

The Finder 7P.04.8.255.S012 combines Type 1 and Type 2 surge protection in a single DIN-rail mounted device, specifically engineered for three-phase TN-S and TT power distribution systems. Its 4-pole (3P+N) configuration and high discharge capacity make it suitable for service entrance and sub-distribution boards where both lightning current and switching surge protection are required.

Highlights

• Combined Type 1+2 arrester for 3-phase TN-S and TT networks
• 4-pole (3P+N) design with 255 V AC maximum continuous operating voltage
• Impulse current (10/350 µs) of 12.5 kA per pole and nominal discharge current (8/20 µs) of 20 kA
• Voltage protection level below 1.5 kV for both L-N and N-PE paths
• Visual status indication and remote signaling contact for monitoring

In daily use

Installed on a 35 mm DIN rail, the arrester provides reliable protection against transient overvoltages. The green/red flag gives immediate visual status, while the changeover contact allows integration into building management or alarm systems. Its compact thermoplastic housing meets UL 94 V-0 flammability rating.

Full specifications

• Arrester type: Type 1+2 combined surge arrester
• Network compatibility: 3-phase TN-S, 3-phase TT
• Number of poles: 4 (3P+N)
• Max. continuous operating voltage (Uc): 255 V AC
• Nominal discharge current (In) (8/20 µs): 20 kA
• Impulse current (Iimp) (10/350 µs): 12.5 kA
• Voltage protection level (Up): < 1.5 kV (L-N, N-PE)
• Follow current extinguishing capability (Ifi): 100 A rms
• Response time (tA): < 25 ns
• Operating temperature range: -40 to +80 °C
• Mounting type: DIN rail (EN 60715)
• Degree of protection: IP20
• Status indication: visual (green/red flag), remote contact
• Remote signaling contact: 1 CO (changeover), max. 0.5 A / 250 V AC
• Standards compliance: EN 61643-11
• Max. backup fuse: 160 A gG
• Housing material: thermoplastic, UL 94 V-0
• Connection cross-section: 1.5 - 35 mm² (solid/stranded)

Final note

Designed for critical power distribution, this arrester ensures continuous protection with minimal maintenance, backed by clear visual and remote status signals.