An improved methodology for periodic verifications of low-voltage electrical installations

This paper presents improved measures for the prevention of electrical fires and electric shock. Based on extensive study of the current standards and literature, as well as on the analysis of the results of long-lasting experimental work (2011–2022), original and comprehensive questionnaires specifically designed for periodic verifications of low-voltage electrical installations in buildings are proposed, related to visual inspection, functionality checks and thermal imaging inspection. The questionnaires overcome the disadvantages of incomplete regulations and currently used safety procedures in this field, ensuring thorough safety assessments, facilitating verification activities, maximizing operator’s efficiency and preventing some of the necessary activities to be overlooked. The questionnaires can be applied broadly, because they can easily be adapted for use in residential buildings, schools and hotels, as well as modified to be applied in other facilities and countries with different standards and practices. Novelties and scientific and technical contributions of this research mainly refer to the introduction of the questionnaires eliminating the shortcomings of traditional checklists. They are also related to the questionnaire contents and the novel, detailed and systematic methodology applied for achieving a logical order for inspection tasks, as well as to the importance of including thermal imaging inspection of distribution cabinets as a mandatory requirement. Specific aspects of periodic verifications of low-voltage electrical installations in three contemporary areas (photovoltaic systems, battery energy storage systems and electric vehicle charging stations) are given special attention.