Topical issues of aging during operation and prediction of fire hazard of cable products including in fire protection systems
Authors: Смелков Г.И. , Боков Г.В. , Варламкин А.А. , Грузинова О.И. 
Published: September 2023

В соответствии со статистическими данными кабельные изделия (линии и электропроводки) ежегодно занимают верхнюю строчку в перечне пожарной опасности основных видов электротехнической продукции. Особую опасность представляют пожары на объектах в системах противопожарной защиты, поэтому актуальность проблемы по изучению и снижению пожарной опасности кабельных изделий (КИ) не вызывает сомнений. Весьма очевидным является и тот факт, что пожарная опасность КИ в значительной степени связана со старением электроизоляции, которое, в свою очередь, зависит от условий эксплуатации и срока службы КИ. В статье рассматриваются результаты исследований, которые направлены на поиск критериев, свидетельствующих об «отказном» (прекращение эксплуатации) и пожароопасном уровне старения изоляции кабелей на объекте.

Ensuring the fire safety of cable lines and electrical wiring in Russia is traditionally the most acute and urgent problem among all types of electrical installations. This is also confirmed by the statistical data given in the article which show that in 2022 out of more than 60,000 “electric fires” in the country, 68 % are associated with cable lines and electrical wiring. Direct damage from these fires amounted to 78.9 %, and the number of people killed 57.8 %. The article deals with a very important scientific and applied problem of searching physical and chemical indicators that characterize the “failure” (for further operation of cables) state caused by the aging of insulating materials of cable products, in order to use them (indicators) for the prevention of accidents and fires in power networks. The search was carried out using experimental and analytical methods for determining the critical state of insulation (sheaths), based either on the assessment of changes in their mechanical properties (elasticity, tensile strength, etc.), or (for PVC materials) – on the critical value of the concentration of the plasticizer in the sample structure. The method given in the paper for determining the predicted service life of cable products which indirectly characterize their fire hazard, has scientific and applied significance. The calculation is carried out on the basis of the Arrhenius equation using experimentally determined values of the activation energy of insulating materials during their aging, as well as taking into account the data obtained during accelerated thermal tests. The article presents generalized results of research and analysis of literature data on the insignificant effect of the aging process on modern fire-resistant insulating materials used for the manufacture of fire-resistant cables for fire protection systems. In cable products for general industrial purposes with insulation and sheaths made of PVC-compounds, mechanical properties deteriorate significantly during aging (loss of elasticity, brittleness, etc.), while combustibility and, consequently, the rate of combustion spread (due to desorption of the plasticizer) – decreases..