IEC 60674-3-7:2023

Overview

IEC 60674-3-7:2023 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies the requirements for fluoroethylene-propylene (FEP) films used for electrical insulation. Part of the broader IEC 60674 series on plastic films for electrical purposes, this second edition updates the original 1992 publication through technical revisions, including unifying the title within the series and updating normative references. FEP films defined by this standard are flexible, self-supporting plastic films offering high-performance electrical insulation properties.

This standard addresses the dimensions, classification, electric strength, thermal endurance, burning characteristics, and roll characteristics of FEP films, ensuring users and manufacturers have clear guidelines to achieve consistent quality for electrical insulation applications.

Key Topics

• Scope and Classification
  IEC 60674-3-7 applies specifically to FEP films intended for electrical insulation and categorizes them into three types:

  • Type 1: General purpose FEP films
  • Type 2: Surface treated films for heat sealability and cementability
  • Type 2A: One side treated
  • Type 2B: Both sides treated

• Material Requirements
  The films must be made from FEP copolymer and must comply with general requirements as per IEC 60674-1. Type 2 films require specialized surface treatment to enhance bonding and sealing capabilities.

• Dimensions and Thickness
  Film thickness ranges are defined to ensure uniformity and applicability:

  • Type 1: 12.7 µm to 508 µm
  • Type 2: 12.7 µm to 127 µm
    Thickness measurement methods conform to the related testing protocols described in IEC 60674-2:2016.

• Electrical and Physical Properties
  Important properties such as electric strength (AC test), thermal endurance, and burning characteristics are outlined with specific test criteria. These evaluations ensure that films meet performance levels necessary for reliable electrical insulation.

• Roll Characteristics
  Guidelines for roll dimensions, windability, sag, joins, and cores are addressed to facilitate manufacturing, handling, and application processes.

Applications

Fluoroethylene-propylene (FEP) films conforming to IEC 60674-3-7:2023 are primarily used as insulating materials in electrical and electronic equipment. Due to their excellent dielectric strength, chemical resistance, and high thermal endurance, applications include:

• Insulation for wires and cables, particularly in demanding environments
• Protective barriers in transformers and motors
• Surface treatments enabling heat sealing make these films suitable for layered insulation systems
• Enclosures and components exposed to high voltage or harsh chemical exposure, benefiting from FEP’s durability

By complying with this standard, manufacturers ensure product consistency and performance suitable for safety-critical electrical insulation applications.

Related Standards

• IEC 60674-1: Definitions and general requirements for plastic films for electrical purposes - foundational for understanding plastics’ classification and quality metrics.
• IEC 60674-2: Methods of test for plastic films used in electrical applications - details the testing methodologies referenced in IEC 60674-3-7 for thickness, electric strength, and other properties.
• IEC 60757: Code for designation of colours - used for standardized color coding in film identification.

Together, these standards provide a comprehensive framework enabling manufacturers, test labs, and users to maintain consistent quality and safety in electrical insulation films.

By following IEC 60674-3-7:2023, industry professionals can confidently select FEP insulation films that meet internationally recognized performance criteria, promoting safety, reliability, and efficiency in electrical engineering applications.