The importance of electrical insulation in charging systems for electric vehicles

April 15, 2024

The spread of electric vehicles is growing rapidly globally, driven by incentive policies and increased environmental awareness. As a result, the charging infrastructure is expanding and evolving technologically to support this transition towards sustainable mobility. However, to ensure user safety and reliability of charging systems, a fundamental aspect not to be overlooked is electrical insulation.

What is electrical insulation and what is it used for

Electrical insulation consists of interposing non-conductive materials between live parts and those accessible to people or other system components. The main purpose is to prevent accidental contact with live elements, which could cause electric shock, short circuits, or fires. In addition, good electrical insulation helps to:

  • Reduce current leakage and energy losses
  • Protect components from electrical and thermal stress
  • Increase the life span and reliability of the system
  • Comply with safety standards and required certifications

In charging systems for electric vehicles, characterized by high power levels (up to 350 kW for ultra-fast stations), insulation plays a crucial role in preventing failures and accidents.

Critical components to be electrically insulated

Within a charging station or column, the main components that require adequate electrical insulation are:

  1. Connection cables: must have insulating sheaths resistant to wear, chemical and atmospheric agents, and high temperatures generated during charging.
  2. Connectors and sockets: contact surfaces must be protected by insulating enclosures to avoid direct contact with live parts. Materials such as silicone rubbers and epoxy resins are often used.
  3. Transformers and power converters: require class H insulation systems, with materials such as aramid paper, polymeric films, and insulating varnishes to withstand high temperatures.
  4. Electrical panels and protection devices: must be constructed with self-extinguishing and flame-retardant insulating materials, such as polyester and polycarbonate.

Standards and certifications for electrical insulation

To ensure the safety and quality of charging systems, electrical insulation must comply with specific international standards, including:

  • IEC 61851: general standard on conductive charging systems for electric vehicles
  • IEC 62196: standard on plugs, socket-outlets, vehicle connectors and inlets
  • IEC 60664: standard on insulation coordination for equipment within low-voltage systems

Moreover, insulating materials must be tested and certified according to recognized standards, such as UL, VDE, CEI, to verify their dielectric, thermal, and mechanical performance.

Choosing the right insulating materials

To achieve effective and long-lasting electrical insulation in charging systems, it is essential to select high-quality insulating materials suitable for the specific conditions of use. Some of the main materials employed are:

  • Silicone rubbers: excellent thermal and aging resistance, maintaining flexibility and insulating properties over time.
  • Epoxy resins: high dielectric strength, mechanical resistance, and dimensional stability, ideal for encapsulating components.
  • Polymeric films (e.g., Nomex, Mylar, Kapton): combine lightness, flexibility, and excellent insulating properties, suitable for class H.
  • High-density insulating papers and laminates: offer electrical, thermal, and mechanical resistance, often used in transformers and windings.

At Guerzoni SRL, we specialize in the production and distribution of flexible insulating materials for electrical applications, including charging systems for vehicles. Thanks to partnerships with leading manufacturers and strict quality controls, we offer a wide range of insulation solutions, customizable according to customer needs.


In conclusion, electrical insulation plays a key role in the safety, efficiency, and reliability of charging systems for electric vehicles. Designers, installers, and maintainers must pay the utmost attention in choosing certified insulating materials and qualified suppliers to ensure compliance with industry standards and best practices.

Do not hesitate to contact us for technical advice on the most suitable insulating materials for your needs and to discover the innovative solutions that Guerzoni SRL offers for the electric charging infrastructure.

Meta title: Electrical insulation in charging systems for electric vehicles | Guerzoni SRL

Meta description: Electrical insulation is fundamental for the safety and efficiency of charging systems for electric vehicles. Discover the most suitable insulating materials, the standards to comply with, and Guerzoni SRL’s offer for the e-mobility sector.

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