Fire Zone Diagram of Flame-retardant Cables: Ignition and Upward Flame Spread

Qiyuan Xie, Tai Gong, Xinyan Huang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)


Electrical cable is a common fire risk and hazard, and once ignited, a cable fire can spread to other rooms and floors by following the direction and location of cables. This work investigated the ignition and upward flame spread over the 1-m long cable under a growing heat flux. Results showed that the flame-retardant cables could be easily ignited by a small flame after a weak irradiation (5 kW/m2) if preheated to 70°C. As the external radiation increases, the cable surface temperature increases, and the upward flame spread rate increases significantly. Once the cable surface reaches 240°C, piloted ignition can be achieved. With the combined effect of external heating (> 18 kW/m2) and smoldering, auto-ignition could be achieved once the cable sheath reaches 500 °C. Moreover, flame-retardant cable fire is intense with severe melting, dripping, swelling, and cracking. The falling cracks and dripping flow can form a pool fire to increase the fire hazard. Finally, a new fire-zone diagram with the surface temperature and critical mass flux was proposed to quantify the cable fire hazard. This work provides important information about fire behaviors of the flame-retardant cable under a real fire scene and may guide the design of fire-resistant cables. Graphical abstract: [Figure not available: see fulltext.].

Original languageEnglish
Pages (from-to)2643-2659
Number of pages17
JournalFire Technology
Issue number5
Publication statusPublished - 13 Mar 2021


  • Fire hazard mapping
  • Fire spread
  • Growing fire heating
  • PVC/PE cable
  • Transient heat flux

ASJC Scopus subject areas

  • General Materials Science
  • Safety, Risk, Reliability and Quality


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