| abstract |
ABSTRACT An electrical conductor is provided with an electrical insula-tion surrounding the conductor, in the form of an organic polymer containing at least 10 per cent by volume of a powdered filler in the form of chromium oxide, iron oxide with an intrinsic resistivity of 104-108 ohm m, metal phthalo-cyanine, or a mixture of at least two substances of these kinds. The filler in superficially located parts of the insulation protects the underlying parts of the insulation against degra-dation caused by corona. The chromium oxide and metal phtha-locyanine preferably have an intrinsic resistivity of 104-108 ohm m and the insulation preferably a resistivity in excess of 1010 ohm m. The conductor may, inter alia, be used in windings and coils for electrical machines. |