Infrared thermography in energy audit of electrical installations

Abstract

Subject reviewEnergy Audit of Electrical Installations is an integral part of the overall energy audit of complex technical systems, and infrared thermography is one of the non-destructive testing (NDT) methods for that type of analysis of power distribution subsystems. During the energy audit of the power subsystem by means of a thermal camera, it is necessary to carry out some additional measurements of electrical quantities which are often not performed easily. The paper provides an overview of the standards in the field of thermography and safety criteria of electrical installations based on a thermal image and measured electrical parameters. As a practical example, an analysis of an electric power distribution subsystem of large complex industrial consumers is presented.The procedure of the audit and decision making for future maintenance is described in detail. Recommendations of corrective actions in the maintenance procedure based on the absolute temperature criterion and the delta-T criterion under consideration of the measured load are given as well. Keywords: electrical power installations; fault rating; thermography Infracrvena termografija u energetskom pregledu električnih instalacijaPregledni članak Energetski pregled elektroenergetskih sustava sastavni je dio energetskog pregleda složenih tehničkih sustava, a infracrvena termografija jedna je od nezaobilaznih nedestruktivnih metoda ovakve vrste analize elektroenergetskih podsustava. Prilikom energetskog pregleda elektroenergetskog sustava termokamerom potrebno je provesti dodatna mjerenja električnih veličina što se često ne može izvesti na jednostavan način. Rad daje pregled standarda na području termovizije i kriterija ispravnosti elektroenergetskih instalacija na osnovu termograma uzimajući u obzir izmjerene električne veličine. Na praktičnom primjeru velikog složenog industrijskog potrošača prikazan je detaljan postupak analize i donošenja suda o ispravnosti instalacija kao i preporuka korektivnih radnji u postupku održavanja.