Tag:power=line
 power = line
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| Description |
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High-voltage power lines used for power transmission, usually supported by towers or pylons 
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| Rendering in OSM Carto |
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| Group: power |
| Used on these elements |
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| Useful combination |
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| Status: de facto |
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A power line or overhead line (![[W]](/w/images/2/24/Wikipedia-16px.png "Wikipedia"){kind=small}
Overhead power line, IEC 466-01-02) is a structure consisting of electrical conductors carried by towers (pylons), or poles. Power line conductors are normally uninsulated, with the insulation provided by air, but may have insulation in the case of smaller lines.
- For underground or underwater power cables, use power=cable.
- For telephone, communications, and data lines, use communication=line.
Classification
OpenStreetMap divides power lines into two categories: lines and minor lines. This distinction helps general-purpose map renderers decide which lines are appropriate to display at each zoom level. This distinction is based on the visual prominence of the line and is inherently somewhat subjective.
As a general rule, if a line is mainly carried by towers (pylons), it's a power=line, and if it's mainly carried by smaller poles it's a power=minor_line. Some editors have a validation rule to check this, but it is common to see minor lines with occasional towers, which will cause these validation rules to generate a false positive.
Very high-voltage lines at more than 150 kV, or which form part of a transmission network, should always be tagged as power=line.
How to map
Draw a single 
way for all circuits connected to one power tower and add the tags below.
| Key | Value | Comment | Recommendation |
|---|---|---|---|
| power | line minor_line |
power=line for larger lines carried on towers. power=minor_line for smaller lines. Use construction:power=line or construction:power=minor_line for power lines under construction. |
Mandatory |
| voltage | <operating voltage> | The nominal voltage at which the line is operated, in volts. May be semicolon-separated if there are multiple voltages. | Recommended |
| cables | <number of conductors> | The number of phase conductors carried by this power line. Usually a multiple of 3 (6, 9, 12). Sometimes there may be a thin earth/ground conductor - this should not be included in the number. |
Recommended |
| circuits | <number of circuits> | The number of separate electrical circuits carried by this power line. For common 3-phase systems, this is usually the number of conductors divided by 3. | Recommended |
| operator operator:wikidata |
<line operator> | The organisation which operates the power line | Recommended |
| owner owner:wikidata |
<line owner> | The organisation that owns the power line | Optional |
| wires | <wire bundle per conductor> | The number of wires which form each conductor. Often there are 2 or 4 individual wires per conductor bundle to increase capacity. | Optional |
| frequency | <operating frequency> | The frequency in Hertz which the power line operates at. Not required if the line is operating at the country's normal grid frequency. May be semicolon-separated if there are multiple frequencies. | Optional |
| name | <name> | The name of this power line | Optional |
| ref | <reference> | The reference of this power line | Optional |
| line | bay, busbar or substation | The function of a power line within a power=substation. | Optional |
| layer | <number> | If power lines cross each other without connecting, a layer can be provided | Optional |
If two lines connect in mid-air at a crossing point without any ground support, use power=connection on the node connecting them.
Towers and poles (supports)
The structures that support a power line should usually be tagged with 
power=tower or power=pole. Lines may also terminate on a power=portal inside a power=substation, or a power=terminal at a connection with a building.
Lines carrying multiple voltages or frequencies
If a line has multiple circuits at different voltages, they should be listed individually, separated by semicolons. For example, if there are two circuits at 66 kV and one at 33 kV, the line should be tagged as:
If there are also multiple frequencies (only in the case of HVDC or traction power), the frequency=* tag should also be semicolon separated. In this case, the frequency=* tag should have the same number of semicolon-separated items as the voltage=* tag. For example, for a line carrying 220 kV and 110 kV at 50 Hz, as well as 110 kV at 16.7 Hz for traction power:
If a power line is technically designed for another voltage than it's operated, it was suggested that this may be tagged with construction:voltage=*, however this conflicts with the meaning of construction:*=*.
See also the discussion at power routing proposal.
Lifecycle
In general, it's recommended to use lifecycle prefixes for power infrastructure, and we encourage data consumers to support these.
Power lines under construction
If a power line is under construction and is not currently operational, it should be tagged with construction:power=line (and not power=line). It's not recommended to add power lines to OpenStreetMap until construction has started on the ground.
Open Infrastructure Map shows power lines with the construction: prefix.
Disused & demolished power lines
In some cases, disused power lines may still be energised. If this is the case, they should be tagged normally.
If a power line is de-energised but has not been removed, it should be tagged with disused=yes, not with the disused: lifecycle prefix. This is because the line is still physically present, and should be rendered on general-purpose maps which aren't expected to understand lifecycle prefixes.
If a power line has been removed but is still visible in common OSM aerial imagery layers, it's recommended to use the demolished:power=line lifecycle prefix so that other mappers don't re-add it. Once aerial imagery has updated, these objects should be removed - OSM is not a historical map.
Examples
| Picture/description | Tags | OSM Carto | Open Infrastructure Map |
|---|---|---|---|
Electricity pylon and power lines
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power=line wires=double cables=6 circuits=2 operator=(operator-name) voltage=380000 |
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Three conductors correspond to one circuit (except traction power lines and high voltage direct current/HVDC). Every circuit has one voltage=* level on which it operate.
Rendering
In addition to the default OSM Carto rendering, the following maps also show power infrastructure:
- Open Infrastructure Map
- Power Grid Map
- Electricity grid map (Europe only)
- Maperitive power line rule set for rendering power lines, cables and substations in Maperitive.
See also
- Power_networks and associated local projects.
- Classification of power lines.
- Power transmission refinement proposal
- usage=transmission