Composite Insulators

Long rod insulators - Composite technology up to 800 kV

Siemens Energy composite long rod insulators – Type 3FL - combine the highest levels of electrical insulation and mechanical tensile strength in a compact, lightweight one-piece housing design with two different sealing options depending on the customer requirements. All 3FL long rod insulators are designed and tested in compliance with the latest versions of IEC 61109, ANSI 29.11, ANSI 29.12 and CSA C411.4-16. 

Product features

Product features of long rod insulators

  • Voltage Class (Um): 72.5 kV – 800 kV
  • Mechanical Class (SML): 70 kN – 630 kN
  • For suspension and tension application
  • ECR Glass (boron free) brittle fracture resistant FRP rod (hydrolysis- and acid-resistant)
  • HTV silicone rubber with hydrophobicity transfer mechanism for highest pollution performance
  • Direct injection silicone molding process prevents partial-discharges
  • Forged steel end fittings according to IEC 61466-1 and ANSI C29.2
  • Integrated grading ring reduces electrical field stress
  • Also available in combination with line hardware and line surge arrester

Housing insulator designs

Also available in combination with overhead line hardware and line surge arresters.

Downloads, support and services

Our services for you

You can find details on our long rod insulators and information about our services here.

Please contact us if you have any questions or need assistance


Performance meets durability

Thanks to their superior design and reduced weight, 3FL long rod insulators are especially suitable for overhead compact-line applications. We will gladly help you find the ideal solution for your requirements.