IEC 60331-2:2018

Overview

IEC 60331-2:2018 is an International Electrotechnical Commission standard that defines a test method for circuit integrity of electric cables under fire with mechanical shock. The method applies to cables with an overall diameter not exceeding 20 mm and rated voltage up to and including 0,6/1,0 kV (600 V/1 000 V). The test simulates a fire environment at a temperature of at least 830 °C combined with a shock event to verify that cables can maintain electrical continuity under extreme fire conditions.

Keywords: IEC 60331-2, circuit integrity, fire with shock, electric cables, 830 °C, 0.6/1.0 kV

Key Topics and Requirements

• Scope and applicability
  • Intended for electric power and control cables (≤ 600 V/1 000 V) and can be used, by agreement, for higher voltages up to 1,8/3 (3,3) kV with suitable fusing.
  • Extended to include metallic data/telecom and optical fibre cables; however, specific continuity-checking and reporting details for those cable types are not provided in this part.
• Test environment and apparatus
  • Fire source producing at least 830 °C, mounted relative to a standard test wall and specimen mounting arrangement.
  • Mandatory use of mass flow meters/controllers for accurate control of fuel and air delivery to the burner.
  • Annex A specifies verification procedures for the burner and control system.
• Specimen preparation and mounting
  • Limits on overall diameter (≤ 20 mm) and defined methods for mounting and bending radius of samples to ensure repeatable results.
• Continuity checking and failure criteria
  • Detailed continuity checking arrangements, specific point of failure definition and electrical connections are given for power/control cables up to 600 V/1 000 V.
• Test procedure, reporting & marking
  • Requirements for the test sequence, shock application, test report content and optional cable identification marking to indicate compliance.

Keywords: burner verification, mass flow controllers, continuity checking, test report, cable marking

Practical Applications and Who Uses This Standard

• Cable manufacturers use IEC 60331-2 to design and validate fire-resistant cables and to support product claims of circuit integrity under fire with shock.
• Independent test laboratories adopt the method to perform standardized cable fire/shock tests and issue test reports for certification and procurement.
• Specifiers, procurement and safety engineers (buildings, tunnels, transport systems, industrial plants) reference the standard to select cables for emergency circuits, fire detection, alarm and safety-critical power/control systems.
• Certification bodies and compliance teams use the documented procedure and reporting requirements to assess conformity and to allow optional marking on compliant cable products.

Keywords: cable testing, fire-resistant cables, emergency circuits, safety-critical cables

Related Standards

• IEC 60331 series (other parts): Part 1 (larger diameter cables), Part 3 (metal enclosure tests), and associated parts (11, 21, 23, 25) that address alternative apparatus and procedures for different cable types and test conditions.