Common test methods for insulating and sheathing materials of electric and optical cables. Part 4-1. Methods specific to polyethylene and polypropylene compounds. Resistance to environmental stress cracking. Measurement of the melt flow index. Carbon black and/or mineral filler content measurement in polyethylene by direct combustion. Measurement of carbon black content by thermogravimetric analysis (TGA). Assessment of carbon black dispersion in polyethylene using a microscope
United power system and isolated power systems. Relay protection and automation. Automatic emergency control of electric power systems. Device for unloading automation during short circuits. Short circuit severity fixation device. Norms and requirements