Finder 7P.03.8.255.S012 Type 1+2 Surge Arrester for 3-Phase TN-C Networks (7P038255S012)

Combined Type 1+2 surge arrester with 21 kA total impulse current (10/350 µs) for three-phase TN-C networks, providing robust protection for low-voltage power distribution systems.

Overview

The Finder 7P.03.8.255.S012 is a DIN-rail mounted surge protective device designed to safeguard electrical installations against transient overvoltages caused by lightning strikes and switching operations. It combines Type 1 and Type 2 protection in a single unit, making it suitable for main distribution boards where both high-energy impulse currents and lower-energy surges must be diverted.

What stands out

• Handles impulse currents up to 7 kA per pole (10/350 µs) and total 21 kA, meeting demanding Type 1 requirements.
• Nominal discharge current of 20 kA per pole (8/20 µs) for effective surge suppression.
• Voltage protection level below 1.5 kV ensures sensitive downstream equipment is not exposed to damaging residual voltages.
• Follow current extinguishing capability of 50 kA rms allows safe operation in high short-circuit current installations.
• Visual status indication (green/red) provides immediate health monitoring.

Technical details

• Network configuration: 3-phase TN-C
• Nominal voltage (Un): 230/400 V AC
• Maximum continuous operating voltage (Uc): 255 V AC
• Protection mode: L-PEN
• Response time: < 100 ns
• Operating temperature range: -40 to +80 °C
• Mounting: DIN rail (EN 60715), 4 modules wide (70 mm)
• Degree of protection: IP20
• Connection: screw terminals, max conductor 35 mm² rigid / 25 mm² flexible
• Short-circuit withstand capability: 50 kA

Our verdict

A high-performance surge arrester engineered for three-phase TN-C systems, delivering reliable protection with clear status indication and robust electrical specifications.