- Nexans and Epsilon Composite successfully validate CORECHECK monitoring technology on TenneT’s 380 kV transmission network in the Netherlands.
- Industry-first deployment enables utilities to verify the integrity of composite-core conductors after installation, reducing project risk and improving quality assurance.
- Milestone strengthens Nexans’ position as a trusted partner delivering innovative solutions for Europe’s grid modernisation and energy transition.
Nexans, a global leader in sustainable electrification, has successfully completed the world’s first field validation of CORECHECK, an innovative composite-core monitoring technology developed and integrated in collaboration with Epsilon Composite. Successfully deployed on a 380 kV transmission line operated by Dutch transmission system operator TenneT, the technology enables utilities to verify the structural integrity of composite-core overhead conductors throughout transport, installation and commissioning.
The milestone supports TenneT’s long-term programme to increase transmission capacity while accelerating the energy transition. As part of its 2045 strategy, TenneT is deploying High Temperature Low Sag (HTLS) conductors, including Nexans’ High Voltage Composite Reinforced Conductor (HVCRC), to upgrade existing overhead lines and deliver greater network capacity without the need for significant new infrastructure.
As electricity grids across Europe come under increasing pressure from renewable generation, electrification and growing demand, utilities are increasingly turning to advanced composite-core conductors to maximise transmission capacity. Until now, however, there has been no practical and reliable field method to verify that composite cores have remained undamaged throughout transportation, handling and installation.
CORECHECK detects internal defects within the composite core using a breakdown voltage test that takes advantage of the insulating properties of the conductor’s glass fibre outer layer. The test is designed for use in the field, requires minimal operator training and can typically be completed by a single technician in approximately five minutes per conductor without disrupting installation schedules.
Utilities are looking for ways to increase network capacity quickly while maintaining the highest levels of reliability. By integrating CORECHECK into our HVCRC solution, we are providing customers with a practical way to verify conductor integrity throughout the installation process. This gives utilities and contractors greater confidence that critical transmission infrastructure has been installed correctly and is ready to perform throughout its operational lifetime.
Overhead lines Sales Director, Nexans
Epsilon Composite – a long-standing Nexans partner in advanced overhead conductors – is proud to have successfully developed CORECHECK, an innovative system for monitoring composite core integrity, supporting safer and faster grid modernization. This first successful in-field deployment on Tennet’s grid definitely marks a key milestone for our companies.
Managing Director, Epsilon Composite
During the TenneT project, conductor integrity was verified at every key stage of the project lifecycle, including after manufacture of the composite core by Epsilon Composite, following conductor stranding by Nexans, upon delivery to site and after installation by the engineering contractor. Testing was successfully completed under challenging field conditions, including strong winds, dense fog, heavy rain and sub-zero temperatures, while also demonstrating compatibility with complex transmission environments containing nearby energised circuits.
The CORECHECK procedure takes approximately five to ten minutes per conductor, so around 15 minutes for each phase. We remained on schedule because the test integrates smoothly into the installation process while providing verification of conductor integrity.
Overhead line Engineer, TenneT
Beyond providing a simple pass or fail assessment, CORECHECK delivers full traceability throughout the project by recording operator identification, conductor batch information and measurement results for every test performed. This creates a comprehensive quality record for utilities and contractors while supporting greater accountability across complex infrastructure projects.
The successful deployment further strengthens Nexans’ portfolio of overhead line (OHL) solutions designed to support Europe’s energy transition. By combining advanced conductor technologies with innovative quality assurance tools, Nexans helps utilities modernise transmission networks more efficiently while reducing project risk and increasing confidence in long-term network performance.
A technical paper detailing the project and field validation results will be presented at CIGRE Paris 2026, building on the technology principles first introduced at the 2024 conference.
Learn more about Nexans’ OHL solutions, visit our dedicated page.
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