Abstract: In June 2017 a new European regulation (Construction Product Regulation) became effective Subsequently, it became mandatory in Europe for all cables to be rated for their ability to resist fire before they can be used permanently in buildings. The test procedures are described in the European (Cenelec) standards EN 50399 (CPR tests) and the classification of the cables is defined in the standard EN 13501-6. The corresponding CPR classes of cables are mainly determined by measuring their vertical flame spread (FS), heat, and smoke release parameter. The tests will be performed by certified independent test laboratories (Notified Bodies). To be able to characterize the newly developed Flame Retardant cables, a brand new burn chamber was installed in the Corning cable development facility at the Corning Technology Center Berlin (CTCB). Intensive burn testing started in 2015. From the beginning a reference cable was used for the characterization of the burn chamber conditions. Especially, the vertical flame spread (FS) was monitored since it is very sensitive against any changes in the operating as well as environmental conditions. Comparative round robin tests in European test labs were performed which showed a systematically lower average flame spread in the order of 0.4 m, measured on the reference cable. However, test results achieved in other newly installed chambers confirmed a higher flame spread comparable to that measured at the beginning in our chamber. Long term monitoring (2015 – 2022) of the FS in our chamber revealed a gradual decrease of the flame spread by approx. 0.2 m. The following paper will prove that the observations mentioned above can be explained by a gradual change of the emissivity of the inner walls of the burn chamber by “aging.” The most prominent aging effect is the coverage of the originally shiny metall surfaces by a black soot.
About the Presenter: Hariom Bhargava received his master’s degree in mechanical engineering from Indian Institute of Technology (IIT), Bombay in 2017. He joined Mahindra & Mahindra Limited as Senior Engineer in 2017. Since 2019, he works at Corning Research Center India as a Scientist and models flow and thermal processes for various Corning businesses.
This technical paper was originally presented at last year’s IWCS Cable & Connectivity Industry Forum. Do you have research to present at the 2024 Forum? Abstracts will be accepted through April 5, 2024. Click here to view suggested topics and submission criteria.