Why Choose the Finder 7P.25.8.275.0020 Type 2 Three-Phase Surge Protection Device?
The Finder 7P.25.8.275.0020 is a professional four-pole Type 2 surge protection device (SPD) designed to protect three-phase electrical installations against transient overvoltages caused by induced lightning surges and electrical switching operations. Part of the trusted Finder Series 7P, this DIN rail-mounted surge arrester provides protection for three-phase TN-S electrical distribution systems with separate neutral and protective earth conductors.
Engineered for standard 230/400 V AC three-phase electrical systems, the Finder 7P.25.8.275.0020 features a 275 V AC maximum continuous operating voltage (Uc), a 20 kA nominal discharge current (In) and a 40 kA maximum discharge current (Imax), measured using an 8/20 µs surge waveform. Its 1.2 kV voltage protection level (Up) helps limit transient overvoltages reaching connected equipment when the SPD is correctly selected, installed and coordinated with the electrical system.
The device incorporates four replaceable metal oxide varistor protection modules and integrated visual status indicators to simplify inspection and maintenance. Its compact four-module DIN rail construction, IP20 protection rating and wide operating temperature range make it suitable for industrial distribution boards, commercial electrical installations and three-phase automation systems. The 7P.25.8.275.0020 is the version without a remote signalling contact, making it a practical choice where local visual inspection is sufficient.
Key Advantages
- Type 2 surge protection helps protect electrical equipment against induced lightning surges and switching transients.
- Four-pole 3P+N configuration provides surge protection for three-phase TN-S electrical systems.
- Suitable for 230/400 V AC three-phase installations commonly used in commercial and industrial electrical distribution.
- 275 V AC maximum continuous operating voltage supports correct operation on compatible mains supplies.
- 20 kA nominal discharge current provides substantial surge-handling capability.
- 40 kA maximum discharge current supports protection against higher-energy transient events.
- 1.2 kV voltage protection level helps limit residual surge voltage.
- Four metal oxide varistor protection elements provide surge protection between L1, L2, L3, N and protective earth.
- Replaceable varistor cartridges support straightforward maintenance without replacing the complete SPD assembly.
- Visual protection status indicators enable quick identification of cartridges requiring replacement.
- Compact four-module DIN rail format saves installation space inside electrical distribution boards.
- 35 mm DIN rail mounting supports convenient installation in standard electrical enclosures.
- −40 to +80 °C operating temperature range supports demanding industrial environments.
- IP20 protection rating for installation inside suitable electrical cabinets.
Key Features
- Finder Series 7P surge protection device.
- 7P.25 four-pole Type 2 SPD configuration.
- Three-phase plus neutral protection for TN-S systems.
- Four metal oxide varistor (MOV) protection elements.
- 230/400 V AC nominal three-phase system voltage.
- 275 V AC maximum continuous operating voltage (Uc).
- 350 V DC maximum continuous operating voltage characteristic.
- 20 kA nominal discharge current (In) using an 8/20 µs waveform.
- 40 kA maximum discharge current (Imax) using an 8/20 µs waveform.
- 1.2 kV voltage protection level (Up).
- 1.2 kV neutral-to-earth voltage protection level.
- Replaceable varistor protection cartridges.
- Optical varistor status indication for identifying protective elements requiring replacement.
- No integrated remote signalling contact on this model.
- 35 mm DIN rail mounting in accordance with EN 60715.
- Four modular spacing units with approximately 71.8 mm overall width.
- IP20 ingress protection rating.
- −40 to +80 °C operating temperature range.
- 50 kA short-circuit current rating (Isccr) under specified installation conditions.
- Maximum associated backup fuse of 160 A, subject to manufacturer's coordination requirements.
- IEC/EN 61643-11 Type 2 surge protection classification.
Technical Specifications
- Manufacturer: Finder
- Series: 7P Surge Protection Devices
- Model: 7P.25.8.275.0020
- Product type: Three-phase Type 2 surge protection device
- SPD classification: Type 2
- Number of poles: 4 (3P+N)
- Electrical configuration: Three-phase plus neutral
- Suitable earthing arrangement: TN-S
- Protection arrangement: L1-PE, L2-PE, L3-PE and N-PE
- Protection technology: Four metal oxide varistors (MOV)
- Nominal system voltage (Un): 230/400 V AC
- Nominal phase-to-neutral voltage: 230 V AC
- Maximum continuous operating voltage (Uc), AC: 275 V AC
- Maximum continuous operating voltage, DC characteristic: 350 V DC
- Nominal discharge current (In): 20 kA (8/20 µs)
- Maximum discharge current (Imax): 40 kA (8/20 µs)
- Voltage protection level (Up): 1.2 kV
- Neutral-to-earth voltage protection level: 1.2 kV
- Short-circuit current rating (Isccr): 50 kA, subject to specified installation conditions
- Maximum associated backup fuse: 160 A, subject to manufacturer coordination requirements
- Integrated short-circuit protection: No
- Integrated backup fuse: No
- Protection elements: Replaceable varistor cartridges
- Local status indication: Optical varistor status indicators
- Integrated remote signalling contact: No
- Mounting method: DIN rail
- DIN rail size: 35 mm
- DIN rail standard: EN 60715
- Installation space: 4 modular spacing units
- Overall width: Approximately 71.8 mm
- Maximum rigid conductor cross-section: 35 mm²
- Maximum flexible conductor cross-section: 25 mm²
- Ingress protection: IP20
- Operating temperature: −40 to +80 °C
- Applicable standard: IEC/EN 61643-11
- Typical installation location: LPZ 1 / LPZ 2 boundary or higher protection zone
- EAN / GTIN: 8012823398150
Reliable Type 2 Surge Protection for Three-Phase TN-S Systems
Three-phase electrical installations can be exposed to transient overvoltages caused by lightning activity, switching operations, inductive loads and disturbances within the electrical supply network. Although these voltage spikes are often extremely short, they can damage electronic equipment, interrupt industrial processes and reduce the reliability of connected electrical systems.
The Finder 7P.25.8.275.0020 Type 2 surge arrester is designed to help protect compatible 230/400 V AC three-phase TN-S systems. Its four-pole configuration provides protection for the three phase conductors and neutral relative to protective earth, helping limit transient voltages across the electrical installation.
The device uses metal oxide varistor technology, which responds to transient overvoltages by becoming conductive and diverting surge current through the intended protective path. With a 20 kA nominal discharge current, 40 kA maximum discharge current and 1.2 kV voltage protection level, the SPD provides defined surge protection characteristics for properly designed electrical distribution systems.
The Finder 7P.25.8.275.0020 is particularly suitable for installation in three-phase distribution boards where Type 2 protection is required downstream of the main electrical supply or as part of a coordinated surge protection arrangement. It is typically installed at the boundary between lightning protection zones LPZ 1 and LPZ 2, or at a higher protection zone, depending on the overall electrical installation design.
Effective surge protection depends on more than the SPD rating alone. The installation must also account for the earthing arrangement, upstream protective devices, connection lengths and coordination with any other surge protection devices. Installation should be carried out by a qualified electrical professional in accordance with Finder's instructions and applicable electrical regulations.
Replaceable Varistor Modules for Convenient Maintenance
Surge protection devices are exposed to repeated transient events throughout their operating life. Over time, these events can degrade the protective elements, eventually requiring replacement to maintain effective surge protection.
The Finder 7P.25.8.275.0020 incorporates four replaceable varistor cartridges, allowing maintenance personnel to replace individual protection elements without changing the complete SPD base, provided the base remains serviceable and the correct replacement modules are used.
Each protective element includes optical status indication. A red indication in the status window identifies a varistor cartridge requiring replacement, helping maintenance teams assess the condition of the installed SPD during routine inspections.
This model is supplied without a remote signalling contact. It is therefore well suited to installations where local inspection of surge protection status is sufficient and external monitoring through a building management system or PLC is not required.
Typical Applications
- 230/400 V AC three-phase TN-S electrical distribution systems.
- Industrial electrical distribution boards and switchgear assemblies.
- Commercial building three-phase electrical installations.
- Industrial automation and PLC control cabinets.
- Manufacturing equipment and machinery electrical supplies.
- Motor control centres and industrial process installations.
- Building services electrical distribution systems.
- Electrical installations exposed to induced lightning surges.
- Three-phase power systems requiring protection against switching transients.
- Industrial and commercial facilities using separate neutral and protective earth conductors.
- DIN rail-mounted surge protection in electrical distribution enclosures.
- Maintenance-friendly electrical installations using replaceable SPD cartridges.
