Are your composite insulators compliant with IEC 62217 Edition 3:2025?
With the latest revision of IEC 62217 introducing updated acceptance criteria and new mandatory testing requirements, railway infrastructure operators, OEMs, and contractors must now ensure that their insulation systems meet an even higher benchmark for long-term reliability, safety, and environmental performance.

Are you aware of the latest changes to the standard?
Are your current insulators fully compliant with the new mandatory test requirements?
And most importantly — are your products proven to perform under real-world railway operating conditions?
At Mosdorfer Rail, we are actively testing and validating our composite insulators in accordance with the latest IEC 62217 Edition 3:2025 requirements, ensuring our solutions continue to meet the evolving demands of modern rail electrification infrastructure.
Compliance with these updated standards delivers significant operational and commercial benefits, including:
- Simulation of real-world ageing conditions
- Verification of long-term material reliability
- Reduced risk of in-service failure
- Increased international acceptance and credibility
- Improved lifecycle performance and lower maintenance costs
Our composite railway insulators are available across a wide voltage range including:
- 750 V DC
- 3 kV DC
- 15 kV AC
- 25 kV AC
In addition, we provide bespoke, tailor-made insulation solutions engineered to meet project-specific requirements across railway, metro, tram, and electrified transport systems.
All Mosdorfer Rail insulators are designed and tested in accordance with key international railway and insulation standards including:
- EN 50119
- EN 50124
- EN 62621
- EN 61109
Our insulators utilise an HTV silicone over-moulded housing design manufactured in a single continuous piece. This construction fully encapsulates the critical triple point — the interface between the end fitting, silicone housing, and FRP core rod — creating a moisture-impervious sealing system that significantly enhances long-term reliability.
The housing material is manufactured from HTV silicone rubber, also known as High Consistency Rubber (HCR), selected specifically for its superior pollution performance and long-term hydrophobic properties in harsh railway environments.
Hydrophobicity transfer test
The silicone housing is chemically bonded directly to the FRP core, creating an interface where the adhesive bond strength exceeds the cohesive strength of the silicone itself. This provides exceptional long-term electrical and mechanical stability while minimising the risk of moisture ingress or interface degradation over time.
Our FRP cores are manufactured using boron-free E-CR glass fibres combined with a specialised epoxy resin system. This construction provides excellent resistance to acid attack and brittle fracture, ensuring long-term mechanical integrity and dependable operational performance even in demanding environmental conditions.
To ensure the highest level of quality assurance and international compliance, our insulators are independently tested in ISO 17025 accredited laboratories, validating both electrical and mechanical performance against recognised global standards.
Key Benefits of Mosdorfer Rail Composite Insulators
- Cast and forged fittings suitable for all railway applications
- Eight-point circumferential crimping for enhanced mechanical integrity
- High strength-to-weight ratio
- Cost-efficient lifecycle performance
- Multiple assembly and configuration variants available
- Intelligent fitting designs enabling a wide range of cantilever geometries
- Excellent pollution and environmental resistance
- Long-term mechanical and electrical reliability
As railway electrification systems continue to evolve, selecting fully compliant, future-ready insulation technology is critical to ensuring network reliability, operational safety, and reduced maintenance intervention.
At Mosdorfer Rail, we combine advanced materials engineering, rigorous testing, and decades of railway expertise to deliver insulation solutions designed for the next generation of rail infrastructure.
If you would like to learn more about our IEC 62217 Edition 3:2025 compliant composite insulators or discuss your project requirements, our team would be pleased to support you.
This article was originally written by Mosdorfer Rail.