Measurements of electric and magnetic fields due to the operation of indoor power distribution substations

In this paper, the electric and magnetic fields with a frequency of 50 Hz, caused by the operation of indoor power distribution substations of 20/0.4 kV, are examined. First, the results of previous relevant research studies as well as the reference levels for safe general public and occupational exposure given in the guidelines of the International Commission on Non-Ionizing Radiation Protection are presented. Next, basic data for standardized indoor power distribution substations used in Greece, where the measurements have been carried out as well as a brief description of the field measurement instruments used are given. The results of the electric- and magnetic-field measurements in indoor power distribution substations of all the standardized nominal power ratings in the town of Xanthi, Greece, accompanied by relevant tables and diagrams follow. After the evaluation of these results, according to international guidelines, final conclusions are set out concerning safe public and occupational exposure to the above-mentioned fields.