Ключевые слова: background, black, cable, chain, construction, contour, cord, distribution, electrical, electricity, energy, engineering, graphic, icon, icons, illustration, illustrations, industrial, industry, intermediate, light, lightning, line, lined, mark, monochrome, network, outline, pole, post, set, sign, signs, single, supply, support, symbol, technology, transformer, volt, voltage, watt, white, wire,