Tag:power=circuit
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Description |
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Arrangement of connected physical lines involved in the same connected power system. ![]() ![]() |
Group: power |
Used on these elements |
Requires |
Useful combination |
See also |
Status: approved![]() |
Tools for this tag |
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A power circuit is defined by 601-02-28 IEC60050 definition. These are the actual paths the electricity follows through power grids.
It represents the longest continuous portion of a power grid between circuit breakers, which are typically located within substations. Circuit breakers isolate electrical faults occurring on a given circuit to avoid the propagation of the fault to other circuits and prevent power grids failure.
A circuit mapped with power=circuit
is composed of as many power line sections as necessary that are used to be mapped as power=line
, power=minor_line
, power=cable
or power=line_section
on OpenStreetMap.
It has been reviewed in power routing and power circuits routing proposals.
Power routing in OSM
Tagging similar to transportation routes
Another approach has been used at first modelling power circuits as transportation routes with route=power
and is now discouraged. You can refer to its own page for more information.
Tagging power circuits with a relation
Power line routes are not similar to transportation routes. Power lines have exactly two end point and have no "stops" in the middle. The beginning and the end (source and consumer of energy) of the line may exchange sometimes (e.g. in case of emergency switching). A power line may have T-shape connection to another one, but it is not an intermediate stop, it is a beginning of the other line. Also there are no traveling things like buses, passengers or travelers as in "common" routes. A traveling of electrons is rather physical abstraction, and it is not so simple as "small moving balls".
The relation for power circuits must be able, ideally, to tag splitting of phases to individual towers and gathering of them together; T-shaped circuits connections; supporting structures when part of wire does not transmit electricity but only acts as a holding device.
Among other issues, a special relation will help us not to confuse, when we make a map of transportation routes. Because a map of traveling routes and a map of power lines are different kinds of maps. In case of special relation for power lines a software will not have to fetch the values of route=*
(is it equal to "power" or not?) but may rely on a type=power
only.
So the structure of this relation is very different from structure of a route relation. That is why we should not tag power circuits with type=route
+ route=power
.
How to map
Circuits can be deducted by looking at power lines from ground or on aerial imagery. A circuit is first of all a metallic continuation of conductors between substations. Mappers only have to follow the cables and stop as the conductor they follow end in a substation (more particularly connected to circuit breakers inside) to survey a given circuit.
Looking in details at particular points will help, particularly the towers which has got line_management=*
, areas with power=substation
or nodes with switch=circuit_breaker
.
Doing so will allow mappers to connect the dots and finally the substations with their neighbors.
Readable labels or colours plates on towers can also help to know which substations are reachable by the given circuit passing by the tower.
Read more about circuits identification plates in UK.
Public documentation with valid license could help to solve undefined situations. Such knowledge should always be verifiable on ground.
There is no trunk and branch

This section relates on circuits with more than two ends.
Some models sometimes define a multi-tenant circuit as a trunk line and one or several branch lines. Such a distinction isn't relevant as the trunk line may be any valid combination of line sections linking two substations through the given circuit. Nothing but the geometry of lines allows to set the trunk line as the one which goes on without change in its direction (if applicable).
We'd be better defining only line sections which converge on tapping points and join them in a proper circuit relation.
If and only if a given section is composed of several segments, an intermediate relation could be used to group properties like cables=*
and frequency=*
for the good.
Otherwise, when a section is composed of a single segment, this segment () can be directly involved as a member of the circuit relation with role section.
Why aren't we prompted for capacity in MW?
Public communication often deals with actual power line capacity in MW as the amount of power that could flow in the power line without damage.
Such values aren't constant and vary due to seasons and upon operational conditions. They're sometimes restricted in a given time period (i.e 4 000 MW during 10 minutes) as to not overheat and finally destroy the power conductors.
We shouldn't add this value to OSM, despite interesting, as it won't be accurate and lead to wrong interpretation.
Tagging
Relation
This relation represent an electrical connection between two or more facilities, with dedicated and permanent properties and involving power line sections, substations and sometimes tap points.
Key | Value | Comment | Recommendation |
---|---|---|---|
type |
power |
This is a power relation | Mandatory |
power |
circuit |
This relation represents a power circuit | Mandatory |
topology |
linear or branched |
Nature of power circuit topology | Recommended |
voltage |
<Operating voltage> | The voltage at which the circuits operates, in volts | Recommended |
frequency |
<Operating frequency> | The frequency at which the circuits operates, in Hertz | Recommended |
cables |
<Circuit's cables> | The amount of cables involved by the circuit | Recommended |
ref |
<Reference> | The circuit's reference | Optional |
name |
<Name> | The circuit's readable name | Optional |
operator operator:wikidata |
<Company name> | The company in charge of circuits operation | Optional |
wikidata |
<Link Qid> | The wikidata item related to significant power lines, often interconnections between countries | Optional |
Please avoid duplicating wires=*
on circuits relations at it only relates to physical lines members. Using this key is strongly discouraged.
Members
The relation combines one or more line sections, 0 or more tap points and two or more substations in which the circuits originates and ends.
Member's role | Member's type | Count | Member | Description |
---|---|---|---|---|
section | ![]() ![]() |
one or more | line , minor_line , cable or line_section
|
A section of the power circuit |
tap | ![]() |
none or more | Power line tap, related to line_management=branch
|
A node at which several sections connect to form a tap point |
substation | ![]() ![]() |
two or more | Substation | A substation in where the circuit starts / ends |
Early circuits relations has been created with following former roles. They are kept here for sake of documentation but shouldn't be used anymore.
Retreive data
Exploring circuits relation may not be easy from an editor.
It is possible to retrieve existing defined circuits in OpenStreetMap with the following Overpass query (for instance in France but feel free to adapt the wikidata code):
area["wikidata"="Q212429"]->.france;
relation(area.france)["type"="power"]["power"="circuit"]->.circuits;
.circuits >->.circuitsMembers;
way.circuitsMembers["power"!="substation"];
out geom; // Simple sections as osm ways
way.circuitsMembers["power"="substation"];
out center; // Substations polygons as points
.circuits >>->.complexMembers;
relation.complexMembers["power"="substation"];
out center; // Subtations multipolygons as points
relation.complexMembers["power"="line_section"]->.sections;
.sections; >->.sectionsMembers;
way.sectionsMembers;
out geom; // Line members of line_section relations
.sections out body; // Sections members list
.circuits out body; // Circuits members list
{{style:
/* Substations */
area[power=substation][substation=transmission]{width:3;color:#FFD800;fill-color:#FFD800;fill-opacity:0.2;}
node[power=substation]{symbol-size:6; fill-color:#FFD800; color:#FFD800; }
/* Power lines */
way[power=line],way[power=cable]{width:3;color:#ABABAB;}
/* Relations */
relation[power=line_section] way{dashes:1,10,1,10;}
/* Tap points */
relation[power=circuit] node {symbol-size:3; fill-color:#000000; color:#000000;}
}}
Examples
General example

The following drawing illustrates a connection of the substation "H" with two other substations: "K" and "T".
At the substation "H" both of the circuits run on the same towers (line segment 1), then split (the segments 2 and 3). Then the phases of the circuit "H—T" split (4,5,6) and then gather together again (line 7).
Tagging relations
Relation | Relation's tags | Relation's members, in the following order |
---|---|---|
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type=power power=circuit cables=3 ref=H-K topology=linear
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type=power power=circuit cables=3 ref=H-T topology=linear
|
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Tagging ways and polygons:
Way | ![]() |
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---|---|---|---|---|---|---|---|---|---|---|
Tags | power=substation ref=H
|
power=substation ref=K
|
power=substation ref=T
|
cables=6 circuits=2
|
cables=3 circuits=1
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cables=3 circuits=1
|
cables=1 circuits=1 phase=L1
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cables=1 circuits=1 phase=L2
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cables=1 circuits=1 phase=L3
|
cables=3 circuits=1
|
A linear circuit with two ends

This circuit is said linear because it links two substations with no tap point.
However, it runs over 5 different line sections and you will observe that the wires
changes along its path.
As the circuit only have two ends, it is possible to directly involve line segments in the circuit relation.
Key | Value | Comment |
---|---|---|
type |
power |
This is a power relation |
power |
circuit |
This relation represents a power circuit |
topology |
linear |
This power circuit is linear with 2 ends |
voltage |
400000 | The voltage at which the circuits operates, in volts |
frequency |
50 |
Alternative public grids are operated at 50Hz in western Europe |
cables |
3 | It's 3-phase without neutral power circuit |
ref:FR:RTE |
CORNIL71M.LAN | The circuit's French reference |
ref:EU:ENTSOE_EIC |
17T-FR-00000066P | The circuit's European reference |
name |
Cornier-Montagny les Lanches 1 | The circuit's readable name |
operator |
RTE | French transmission grid is operated by RTE in France |
Sections A to F are power=line
ways and will get the section role. Substations are power=substation
members with the role substation.
This circuit is currently described in 5459750 5459750.
The difficulty to produce an accurate model of the actual power path with the physical lines knowledge only appears clearly.
A more complex circuit with sections as single segment

This circuit involves 3 line sections and 1 tap point to link 3 substations together.
All 3 sections are composed of 1
power=line
segment, so no additional power=line_section
is required.
It is still possible to involve the ways as circuit relation members and section role.
Key | Value | Comment |
---|---|---|
type |
power |
This is a power relation |
power |
circuit |
This relation represents a power circuit |
topology |
branched |
This power circuit has 3 ends so form a branched topology. 3 substation members are expected |
voltage |
225000 | The voltage at which the circuits operates, in volts |
frequency |
50 |
Alternative public grids are operated at 50Hz in western Europe |
cables |
3 | It's 3-phase without neutral power circuit |
name |
Grandval-Lanau-Rueyres 1 | The circuit's readable name |
operator |
RTE | French transmission grid is operated by RTE in France |
Sections A to C are power=line
ways and will get the section role. Substations are power=substation
members with the role substation and tower #1 will be member with role tap.
This circuit is currently described in 5465785 5465785.
The most complex circuit with sections as relations

This circuit involves 3 line sections and 1 tap point to link 3 substations together.
The northern section is mapped as a relation as it involves 3 different segments, with different tags that can't be merged into a single one.
Two remaining sections are involved in the circuit relation as ways and get the section role.
Here is the circuit relation:
Key | Value | Comment |
---|---|---|
type |
power |
This is a power relation |
power |
circuit |
This relation represents a power circuit |
topology |
branched |
This power circuit has 3 ends so form a branched topology. 3 substation members are expected |
voltage |
225000 | The voltage at which the circuits operates, in volts |
frequency |
50 |
Alternative public grids are operated at 50Hz in western Europe |
cables |
3 | It's 3-phase without neutral power circuit |
name |
Saint Auban-Salignac-Sisteron 1 | The circuit's readable name |
operator |
RTE | French transmission grid is operated by RTE in France |
Here is the section C relation:
Key | Value | Comment |
---|---|---|
type |
power |
This is a power relation |
power |
line_section |
This relation represents a power line section |
voltage |
225000 | The voltage at which the section operates, in volts |
cables |
3 | It's 3-phase without neutral power section |
operator |
RTE | French transmission grid is operated by RTE in France |
ref:FR:RTE |
SISTEL61ZSAL6 | The French identifier of the power line section |
Sections A and B are power=line
ways and will get the section role. Section C is a power=line_section
relation and will get the section role.<
Substations are power=substation
members with the role substation and tower #1 will be member with role tap.
This circuit is currently described in 5977379 5977379.