RTV-Coated C8-2550 Ceramic Post Insulator for HVDC Air-Core Dry-Type Reactors
The study “Manufacturing & Qualifying RTV-Coated C8-2550 Ceramic Post Insulator for HVDC Air-Core Dry-Type Reactors” was authored by Markku Ruokanen (Quality and R&D Director, Insulator Technology Group), Radoslav Strenk (Electrical Engineer, ITG), and Klaus Pointner (Senior Expert Coils and Systems, Trench Austria GmbH), and presented at the INMR World Congress 2025, in Panama.
It examines how modern HVDC transmission—driven by the global energy transition, increasing converter station requirements, and demanding pollution environments—creates the need for highly robust ceramic post insulators enhanced with RTV silicone coatings. The study’s key objective was to design, manufacture and fully qualify an RTV-coated C8-2550 ceramic post insulator for a 500 kV HVDC air-core dry-type reactor, ensuring superior mechanical strength, creepage performance, and pollution resistance.
The authors conclude that factory-applied RTV coatings deliver superior adhesion, uniformity, and long-term performance compared to field application. With the new IEC TS 63432 standard, RTV-coated ceramic insulators are set to become a preferred solution for demanding HVDC applications requiring high rigidity, strong mechanical support, and reliable pollution performance.
The full study can be found here: