conductor
2.2.2. A current conductor is a device intended for the transmission and distribution of electrical energy, consisting of uninsulated or insulated conductors and related insulators, protective coverings, branch devices, supporting and load-bearing structures.
2.2.3. Depending on the type of conductors, current conductors are divided into flexible (when using cables) and rigid (when using rigid busbars).
A rigid current conductor up to 1 kV manufactured in factories and supplied in complete sections is called a busway.
Depending on their purpose, busways are classified as follows:
mainline busways, mainly intended for connecting distribution busways and power distribution points, panels, and individual powerful electrical receivers;
distribution busways, mainly intended for connecting electrical receivers;
trolley busways, intended for supplying movable electrical receivers;
lighting circuits, intended for powering luminaires and electrical receivers of small power.
2.2.4. A current conductor with a voltage above 1 kV that extends beyond the limits of one electrical installation is called an extended circuit
Source: "Rules for the Design of Electrical Installations (PUE). Sixth Edition" (approved by the Main Technical Administration, State Energy Supervision of the Ministry of Energy of the USSR 05.10.1979) (edition from 20.06.2003)