Finder 7P.04.8.255.S007 – 7P Series Surge Protection Devices

Why Choose the Finder 7P.04.8.255.S007 Type 1+2 Surge Protection Device?

The Finder 7P.04.8.255.S007 is a combined Type 1+2 surge protection device (SPD) designed to protect three-phase electrical installations against lightning-induced surge currents and transient overvoltages. Part of the Finder 7P Series, this surge arrester combines lightning current discharge and overvoltage limitation in a single assembly, helping protect electrical distribution systems and connected equipment.

Designed for 230 V AC TN-S and TT electrical networks, the Finder 7P.04.8.255.S007 features a 3+1 protection configuration incorporating three varistor protection paths and a spark-gap protection element. The device provides a 7.5 kA lightning impulse current rating per protection path using the 10/350 µs waveform, together with a 20 kA nominal discharge current using the 8/20 µs waveform.

Engineered for installation on a 40 mm busbar system, this combined surge arrester is particularly suited to main electrical distribution assemblies and pre-metering installations where permitted by local regulations. Its replaceable protection modules, optical status indication and 1.5 kV voltage protection level support effective surge protection and straightforward maintenance.

Key Advantages

• Combined Type 1+2 protection: Provides lightning current discharge and transient overvoltage protection in one device.
• 7.5 kA lightning impulse capability: Designed to discharge lightning impulse currents using the 10/350 µs test waveform.
• 20 kA nominal discharge current: Supports protection against transient surge currents using the 8/20 µs waveform.
• 1.5 kV voltage protection level: Helps limit transient overvoltages reaching downstream electrical equipment.
• TN-S and TT compatibility: Suitable for specified three-phase, five-conductor AC distribution systems.
• 3+1 protection arrangement: Combines varistor-based phase protection with spark-gap technology.
• 40 mm busbar mounting: Designed for integration into compatible busbar-based distribution assemblies.
• Replaceable protection modules: Simplifies servicing following end-of-life indication.
• Optical status indication: Provides local visual indication of protection module condition.
• Leakage-current-free design: Supports reliable operation in the intended electrical installation.
• IP20 enclosure protection: Suitable for installation inside appropriately rated electrical distribution cabinets.
• Wide operating temperature range: Suitable for demanding indoor electrical installation environments.

Key Features

• Finder 7P Series surge protection device.
• Combined Type 1+2 SPD classification.
• Three-phase TN-S and TT system compatibility.
• 3+1 surge protection configuration.
• 230 V AC nominal system voltage.
• 255 V AC maximum continuous operating voltage (Uc).
• 7.5 kA lightning impulse current (Iimp), 10/350 µs.
• 20 kA nominal discharge current (In), 8/20 µs.
• 1.5 kV voltage protection level (Up).
• 1.5 kV L-N protection level.
• 1.5 kV N-PE protection level.
• Four conductors excluding protective earth.
• 40 mm busbar mounting arrangement.
• Three-module mounting width.
• Replaceable surge protection modules.
• Optical protection status indication.
• Module retention system.
• IP20 ingress protection.
• −40 to +80 °C operating temperature range.
• No integrated backup fuse.
• No remote signalling contact.

Combined Lightning and Transient Overvoltage Protection for Three-Phase Installations

Electrical distribution systems can be exposed to transient overvoltages caused by lightning activity and switching events. These surges may damage sensitive electrical equipment, disrupt industrial processes or reduce the service life of connected devices. The Finder 7P.04.8.255.S007 Type 1+2 surge arrester is designed to provide coordinated lightning current discharge and overvoltage limitation at the electrical installation's incoming distribution point.

The 3+1 protection configuration is suitable for specified TN-S and TT systems, with varistor-based protection for the phase conductors and spark-gap protection between neutral and protective earth. The device is designed for use at the transition between lightning protection zones, including LPZ 0 and LPZ 1, where installation conditions require a combined Type 1+2 SPD.

Its 40 mm busbar mounting arrangement supports integration into compatible distribution equipment, while the replaceable modules and optical condition indicators simplify inspection and servicing. Selection and installation should account for the earthing arrangement, prospective fault current, required upstream protection, conductor routing and coordination with downstream surge protection devices. Installation must be performed by a suitably qualified electrician in accordance with applicable regulations and manufacturer instructions.

Typical Applications

• Three-phase TN-S electrical distribution systems.
• Three-phase TT electrical distribution systems.
• Main electrical distribution boards and switchgear assemblies.
• Incoming electrical supply surge protection.
• Compatible 40 mm busbar distribution systems.
• Commercial building electrical infrastructure.
• Industrial electrical distribution cabinets.
• Pre-metering surge protection installations where permitted.
• Lightning protection zone transition points.
• Electrical installations requiring combined Type 1 and Type 2 protection.
• Industrial automation and control system supply protection.
• Building services and electrical infrastructure protection.