IEC 60331-1:2018

Overview

IEC 60331-1:2018 - Tests for electric cables under fire conditions - Part 1 defines a standardized test method for circuit integrity under fire with mechanical shock. The procedure applies to cables with an overall diameter exceeding 20 mm and rated voltage up to and including 0,6/1,0 kV (600 V / 1 000 V). The standard targets reliable assessment of whether power, control, metallic data/telecom and optical fibre cables can maintain circuit continuity when exposed to a flame at at least 830 °C combined with shock. Annex A gives the burner and control-system verification method and optional cable marking rules identify compliance.

Key technical topics and requirements

• Scope and applicability: Power and control cables ≤ 0.6/1.0 kV; includes metallic data/telecom and optical fibre cables (note: specific test details for data/telecom and optical fibre are not provided in this part).
• Test environment and apparatus: Defined test ladder and mounting arrangements for large-diameter cables, burner/venturi configuration and positioning, and shock-producing device requirements.
• Burner control and verification: Mandatory use of mass flow meters/controllers for accurate fuel and air flow control; Annex A describes burner verification and temperature measurement.
• Specimen preparation and mounting: Detailed mounting methods for single-core and multicore cables, including modifications for cables with large bending radii and single cores without concentric metal layers.
• Continuity checking and fusing: Continuity arrangements and fuse selection for cables rated up to 600 V/1 000 V; procedure can be extended up to 1,8/3 (3,3) kV by mutual agreement between manufacturer and purchaser using suitable fuses.
• Test procedure and reporting: Defined flame and shock application, acceptance criteria for circuit integrity, retest rules and an improved list of required information in the test report.
• Optional marking: Requirements for an identification mark that can be applied to indicate compliance.

Practical applications

IEC 60331-1 is used to demonstrate cable performance for:

• Emergency power and life-safety circuits in buildings, tunnels and transport systems
• Critical industrial and utility control wiring
• Large-diameter power and control cables in infrastructure projects
• Situations where fire plus mechanical shock (e.g., collapse, impacts) may threaten circuit integrity

Who should use this standard

• Cable manufacturers and R&D teams for product development and compliance testing
• Independent test laboratories performing fire/shock circuit-integrity tests
• Specifiers, consultants and safety engineers writing procurement and performance requirements
• Authorities having jurisdiction and certification bodies evaluating fire performance claims

Related standards

• IEC 60331 series (Part 2 for diameter ≤ 20 mm, Part 3 for metal enclosures)
• IEC 60331-11, -21, -23, -25 (related apparatus and procedures)
• IEC Guide 104 (group safety publication status)

Keywords: IEC 60331-1:2018, circuit integrity, fire test, 830 °C, electric cables, large-diameter cables, mass flow controller, burner verification, cable fire performance.