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Public-images-osm logo.svg cables
Number of electrically separated, individual or bundled, power-carrying conductors in a power line or cable Edit this description in the wiki page. Edit this description in the data item.
Group: power
Used on these elements
should not be used on nodesmay be used on waysshould not be used on areasshould not be used on relations (except multipolygon relations)
Useful combination
Status: de facto

Power lines (power=line) or cables (power=cable) are often composed of as many conductors as electrically separated poles or phases they carry. This key is intended to describe how many conductors we see in them.
In OSM, cables relates to conductors.

Power lines conductors may be individual (IEC ref 466-10-19) or bundled (IEC ref 466-10-20). See wires=* about this particular point.

Some power lines may hold several independent systems called circuits which share the same supports. cables=* doesn't care about them and count every conductor of the power lines. Independent circuits may be described with relations and counted with circuits=*.

Usually on terrestrial power systems, alternative current circuits are composed of 3 phases (cables=3) and direct current circuits are composed of 2 poles (cables=2).
We don't count earth wires, intended to prevent lightnings to disrupt overhead lines, as conductors.

Some particular situations should be noted however:

  • Some circuits use only one or two conductors, including:
    • single-phase or split-phase AC circuits for:
      • single wire earth return (SWER) medium voltage lines sometimes used in rural areas,
      • supply to electric railroads (e.g., German traction power network),
      • street lighting,
      • small end customers (such as individual households).
    • terminal branches of the 3-phase distribution grid that carry only 2 of the phases for an immediate connection to a small set of end customers.
  • Do not include cables that do not carry power, such as:
    • protective ground cables (also called earth wires),
    • passive loop cables (to reduce the magnetic field),
    • telephone or other communications cables

See also

  • circuits=* Number of electrical circuits of power line or cable connection.
  • wires=* Number of wires in conductors bundles of a power line or cable.
  • cable_number=* Number of cables supporting simple-suspension/Tibetan style bridges