Irregular Low-Voltage Electrical Cables

Abstract

In emerging economies, it is common to find products that do not comply with established norms, for example, low-quality production, material, counterfeit, etc., in the market where users are motivated by the low price, especially in times of economic crisis. With regards to products for electrical installations, there is no difference. Most notably, several products do not comply with the standards in the wire and cable market. Many manufacturers seek to reduce costs and improve margins by using cheaper raw materials. This is mainly observed in reducing the volume of copper used in the conductors, causing overheating, increasing electrical losses, and reducing the service life, increasing the risk of fires of electrical origin. Brazil has had an independent entity for over 29 years, which monitors the market - Qualifio - Brazilian Association for the Quality of Electrical Wires and Cables. In this study, 136 cable samples collected by Qualifio were used and submitted to tests according to Brazilian Association of Technical Standards - ABNT NBR 6814: Electrical wires and cables - Electrical resistance test. The results showed that 32% of the collected wires and cables presented electrical resistance above the maximum allowed for those nominal cross-sections. In some cases, the resistance was three times higher than the upper limit established in the standard. Cables with a nominal area of 1.5 mm2, 2.5 mm2 4 mm2 and 6 mm2 were analyzed.