electrical insulation

Insulation ( insulation also ) is a non-or weakly conductive material to hindrance of the ( electric ) current flow between live and non- voltage-carrying conductive parts and the environment (persons, things, substances) in electrical engineering. Of insulator insulators or insulation are made ( eg in cables ).

In everyday life, the concept of insulation is often used technical terminology wrong for insulating materials designed to discourage energy or mass transfer, such as heat ( thermal insulation ), sound (sound ) or water vapor (eg paints ) and water ( structural waterproofing ).

Electrical insulating materials

Electrical insulating materials have a high electrical resistivity ( Ω · cm min. 1010 ) and are therefore non-conductor. Furthermore, they are characterized by a high dielectric strength and low water absorption. Other requirements are depending on the scope of mechanical strength and resistance to environmental influences.

Other features include a high tracking resistance and thermal resistance. The thermal stability is given by insulation classes.

One of the first technically used electrical insulating mid-19th century, gutta-percha, the dried milk of the domestic space in the Malay Guttaperchabaumes, which was used in the nascent telegraph lines. Today Isolierstoffe are primarily various plastics, technical ceramics, oil-impregnated special papers and glass. The latter insulating materials find application primarily in the high voltage range.

Examples

  • Technical ceramics, such as: Steatite, porcelain ( insulators, current feedthroughs )
  • Alumina ceramic
  • Polyethylene or PE (coaxial cable, telephone and network cables, high voltage cables )
  • Polyvinyl chloride or PVC (cable)
  • Polytetrafluoroethylene or PTFE ( high-stress, low-loss cable and components, high frequency insulators )
  • Polyester (PES ) and polycarbonate (PC) (cables, capacitors, insulation for winding wires )
  • Hard paper ( PCB base material ), phenolic (housing and terminals)
  • Hard tissue (electric motors and generators )
  • Epoxy resin ( potting, envelopes ) and epoxy resin - fiber composites ( PCB base material )
  • Melamine resin ( amino resin )
  • Polyurethane resin (paints, casting components, insulation for winding wires )
  • Silicone elastomers ( composite insulators, coatings for ceramic insulators )
  • Silicone oil
  • Chlordiphenyl ( no longer allowed)
  • Transformer oil in circuit breakers, power transformers, power capacitors, oil filled cables.

Supra insulator effect

Analogous to the superconductor, there are at temperatures close to absolute zero the effect that the electrical resistance of some ( Supra ) insulators increases by several orders of magnitude. This may increase until complete disappearance of electrical conductance, such materials are also called Supra insulator (English superinsulator ).

Electrical conductor Insulation system FR-2 Digital Object Identifier
419341
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