IEC 60332-3-22:2018

Overview

IEC 60332-3-22:2018 specifies a Category A test method for assessing vertical flame spread of vertically mounted bunched wires or cables - including electrical and optical fibre cables - under defined fire conditions. Intended primarily for type approval testing, the procedure evaluates flame propagation on cables mounted on a test ladder to achieve a nominal total volume of 7 l/m of non‑metallic material, with a 40-minute flame application. This edition (2018) clarifies mounting details and explicitly includes optical fibre cables.

Key topics and technical requirements

• Test scope: Vertical flame spread of bunched cables (Category A) for high volumes of non‑metallic material.
• Test sample configuration: Cables mounted on the front of a test ladder (standard or wide ladder depending on conductor cross‑section and number of pieces).
• Volume target: Nominal total non‑metallic material volume of 7 l/m of test sample.
• Flame application: 40 minutes using ribbon‑type propane burners (per IEC 60332-3-10 apparatus).
• Mounting rules:
  • Cables with a conductor cross‑section > 35 mm² are mounted in a spaced configuration (standard or wide ladder as required).
  • Cables with conductors ≤ 35 mm² and optical fibre cables are mounted touching (array in contact) on a standard ladder.
• Evaluation: Flame spread measured as the extent of damage (char and consumed material) along the sample. Annex B contains recommended performance criteria; Annex A gives guidance on cable selection for type approval.
• Edition changes: 2018 revision emphasizes applicability to optical fibre cables and refines ladder mounting procedures to improve repeatability and reproducibility.

Practical applications and users

Who uses IEC 60332-3-22:

• Cable manufacturers performing type approval and product development for flame-retardant cables.
• Independent testing laboratories and conformity assessment bodies conducting fire performance tests.
• Specifiers, consultants and safety engineers writing procurement or compliance requirements for buildings, industrial installations, transportation, and data centers.
• Regulatory authorities and standards committees referencing cable flame spread behaviour in safety regulations.

Why it matters:

• Demonstrates a cable’s ability to limit vertical flame spread in bunched installations.
• Supports product certification, risk assessment, and procurement decisions where grouped cable fire performance is critical.

Related standards

• IEC 60332-3-10 (apparatus for vertical bunched-cable tests)
• Other parts of IEC 60332 series: 3-21 (Category A F/R), 3-23 (Category B), 3-24 (C), 3-25 (D)
• IEC 60695-4 (fire testing terminology)
• IEC 60811 series (non‑metallic material test methods)

Keywords: IEC 60332-3-22, vertical flame spread test, bunched cables, Category A, optical fibre cable fire testing, cable type approval, ladder mounting, flame spread measurement.