Restoring Transformer Termination Integrity with LoviSil: A Modern Solution for Ageing PILC Networks

Published 28 Nov 2025

Restoring transformer termination integrity with LoviSil

When a major site recently experienced a fault on an 11kV transformer termination, the challenge was clear: restore the system quickly, safely and without the expense/disruption of full PILC cable replacement.

Upon investigation, engineers discovered that a void had formed within the pitch insulation of the termination box: an all-too-common issue in legacy installations. Although the termination assembly had failed, the underlying PILC cable remained structurally sound and fully capable of continued service.

Instead of replacing the cable, the team opted for a smarter, more efficient approach: upgrade only the insulation system using the proven LoviSil liquid-silicone technology.

Thorne & Derrick are the UK’s specialist distributors for Lovink Enertech: LoviSil, PILC cable jointing solutions and MV termination systems; supporting utilities, DNOs, industrial sites and contractors with market-leading products.

The LoviSil Solution: Upgrading Without Replacing

1. Removing the Old Pitch/Bitumen Medium

All degraded insulation compound was safely extracted from the termination box, exposing a clean cavity ready for refurbishment.

2. Introducing LoviSil Liquid Silicone

The housing was refilled using LoviSil, a premium liquid-silicone medium designed for high-integrity insulation in MV applications.

Performance Advantages of LoviSil

Enhanced Insulation Performance

LoviSil delivers superior dielectric strength, helping reduce the likelihood of future failure.

Full Void-Free Insulation

The silicone compound flows into every internal space, eliminating air gaps that can lead to partial discharge (PD) and premature breakdown.

Compatible with Legacy PILC Installations

Because the system works seamlessly with the paper insulation of PILC cables, engineers avoided a costly and disruptive network decommissioning.

Long-Term Breakdown Resistance

LoviSil maintains integrity under thermal and electrical stress, offering a modern, robust alternative to historical insulation materials.

Why This Matters for Utilities & Network Operators

This project highlights an increasingly important theme in today’s power networks: extending the life of legacy infrastructure using modern materials and smarter engineering choices.

By retaining the original PILC cable and upgrading only the termination insulation, the client achieved:

• Significant cost savings

• Reduced downtime and site disruption

• Improved long-term network reliability

• A future-proofed termination assembly

Lovink Enertech products are proven in service worldwide for network resilience, ease of installation, and long-term reliability.

Thorne & Derrick provide expert technical support, fast delivery and comprehensive stock availability for the complete Lovink range from medium voltage straight joints to high voltage transition solutions.