High Voltage (HV) engineering and cable services

Safe, compliant and expertly delivered high‑voltage asset management

James Fisher delivers trusted, innovative solutions that make high‑voltage operations safer, more sustainable and more efficient across offshore wind and energy infrastructure. Our HV specialists provide end‑to‑end support across installation, termination, testing, fault response and long‑term asset management.

With proven capability across 11–400kV networks, we help operators maintain HV integrity, optimise performance and reduce the risk of unplanned outages through proactive engineering and robust safety processes.

As part of James Fisher’s fully integrated high voltage capability, our engineering teams contribute to safe and coordinated offshore operations throughout the asset lifecycle.

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Why James Fisher?

Over 9,000 HV terminations successfully completed worldwide

Full high‑voltage capability up to 400kV

Industry‑leading response times for HV fault investigation and repair

Complete high‑voltage cable termination, testing and fault response solutions

James Fisher’s termination and testing services ensure correct fitment, protection, minimum bend radius compliance and full system integrity for high‑voltage assets. We support connector installation from 11kV to 220kV and deliver complete fibre optic termination and configuration.

Our emergency fault and response services include live condition monitoring, asset integrity inspections, strategic spares management and rapid mobilisation for cable fault investigation and repair. We can help you minimise downtime and protect revenue.

This comprehensive testing programme covers sheath testing, OTDR, conductor resistance checks, VLF testing, damped AC withstand testing and full electrical integrity assessment - supporting safe energisation, recommissioning and long‑term reliability.

We also deliver comprehensive cable care programmes, including risk planning, readiness and rapid fault repair. With predictive monitoring and SCADA‑based insights, you can gain improved control over cable health and performance throughout the lifecycle.