Assessing the reaction to fire of cables by a new bench‐scale method

Abstract

Summary The recently approved EU Construction Products Regulation (CPR) applies to cables as construction products. The difficulty of predicting the fire performance of cables with respect to propagation of flame and contribution to fire hazards is well known. The new standard EN 50399 describes a full‐scale test method for the classification of vertically mounted bunched cables according to CPR. Consideration of the material, time, and thus cost requires an alternative bench‐scale fire test, which finds strong demand for screening and development purposes. The development of such a bench‐scale fire test to assess the fire performance of multiple vertically mounted cables is described. A practical module for the cone calorimeter is proposed, simulating the fire scenario of the EN 50399 on the bench scale. The efficacy of this module in predicting full‐scale CPR test results is shown for a set of 20 different optical cables. Key properties such as peak heat release rate (PHRR), fire growth rate (FIGRA), and flame spread are linked to each other by factors of around 5. In a case study, the bench‐scale test designed was used to investigate the influence of the main components on the fire behaviour of a complex optical cable. Copyright © 2016 John Wiley & Sons, Ltd.

Fire behaviour of electrical cables in cone calorimeter: Influence of cables structure and layout

“…Hence the role of the inner components should not be neglected. Gallo et al [34] used a new test based on the cone calorimeter equipment where the cone heater was replaced by a burner and a portion of cable tray in vertical position was tested. They evidenced that the HRR curve of the entire cable can be predicted from the curve of its different components.…”

Fire tests at reduced scale as powerful tool to fasten the development of flame-retarded material: Application to cables

“…During the past years, Gallo et al 12,13 investigated the possibility to evaluate the fire performances of optical cables in a bench-scale test instead of the EN 50399 apparatus. In these studies, a cone calorimeter hood was used in order to evaluate the flame spread and HRR behavior of optical cables.…”

Degradation of flame retardance: A comparison of ethylene‐vinyl acetate and low‐density polyethylene cables with two different metal hydroxides

“…A bench scale method, our cable module for the cone calorimeter designed for faster and cheaper cable screening, 40 was utilized to investigate the fire properties of a vertically mounted bundle of cables. It provides simultaneous measurements of real vertical flame spread, heat release, flaming droplets, smoke emission and visibility, which differed from the results from the horizontal fire test in the cone calorimeter.…”

“…A bench scale fire test to assess the fire performance of multiple vertically mounted cables was selected, 40 which offered a simple, low‐cost cable module to be placed in the cone calorimeter (FTT, Fire Test Technology, East Grinstead, UK). In accordance with the study on this bench scale method, 40 the cable module replaced the common cone heater, sample holder and balance. The output of the gas burner (130 mm in width) was set to 5 kW.…”

“…Although the cone calorimeter is a powerful tool to study fire behavior, and thus also the degradation of flame retardancy, [37][38][39] the plate-like geometry of cablebased specimens and their horizontal orientation seem to be disadvantages, as it is difficult to access the cables properly in order to study their burning behavior. By modifying standard cone calorimeter equipment, 40 a tailored bench scale reaction to fire test was developed to test the fire properties of cable bundles mounted vertically. The proposed alternative bench scale fire test is designed for faster and cheaper cable screening than the established largescale fire tests for cables, combining the advantages of advanced testing with low cost.…”