EP0116044B1

EP0116044B1 - Distributing bus-bar

Info

Publication number: EP0116044B1
Application number: EP83900991A
Authority: EP
Inventors: Rolf CEDERSTRÖM
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-03-24
Filing date: 1983-03-16
Publication date: 1990-11-22
Anticipated expiration: 2003-03-16
Also published as: FI71032B; FI841582A0; NO834324L; WO1983003494A1; EP0116044A1; DE3382010D1; SE435004B; FI841582A; FI71032C; SE8201887L

Abstract

An electric power distributing bus-bar or cable comprising a carrying line (10) and electric conductor parts (11-15). The carrying line (10) and the conductor parts (11-15) are disposed in a common electrically insulated jacket (16) and the electric conduction capacity of the carrying line (10) is adapted to and preferably similar to that of each one of the conductor parts so that the carrying line (10) may be used as a complementary conductor.

Description

The present invention relates to a distributing bus-bar, particularly for electric power distribution, comprising a plurality of insulated electric conductors and a through-going carrying line.
In SE-C-186 596 a hanging cable has been- proposed for electric power distribution, communication, signalling or controlling, which comprises a carrying line and a jacket carried thereby. The jacket is tube shaped and houses electric conductors. The characterizing feature of this known hanging cable is that the electric conductors are movable with respect to each other and with respect to the jacket which permits the conductors to be axially moved with respect to the carrying line.
The tube shaped jacket may be made from conducting material, such as metal, or from insulating material, e.g. a thermoplastic material such as nylon or the like. The carrying line is preferably embedded in the wall of the tube which may be thin-walled around the rest of its periphery. To meet the demands this hanging cable may be designed for 1-phase or 3-phase power distribution, or for communication, signalling or control over the desired number of conductors. If not only the insulated electric conductors are introduced into the tube during the manufacture but also one or more pulling wires the advantage is achieved that an already finished installation may be completed by one or more conductor parts. If desired it is also possible to replace electric conductors by others in an already finished installation. Further, the following advantages are gained.
It is very easy to control the tension of the carrying line and to completely avoid that the electric conductors take up tensile loads. Both the carrying line and the electric conductors can, by taking up openings in the tube shaped jacket, easily be made accessible for attachment to poles and for connection to service lines or branch lines. If the electric conductors of e.g. power distribution lines are parallel disposed individually insulated conductors, i.e. without a uniting winding, stranding or the like, the conductors may very easily be separated to permit mounting or connecting clamps. If the tube is made from insulating material it affords a protection against disturbances if cables for different purposes come into contact with each other. A hanging cable of standard dimensions may be used for varying numbers of electric conductors and also for several conductor dimensions which facilitates the store holding.
Thus, hanging cables of the above described type have a plurality of advantageous properties and accordingly they have come to a widespread use.
Cables of the general type with which the present invention is concerned are known from e.g. US-A-3.267.201 and DE-A-633.140. However, in use these cables suffer from the drawback that the carrying line thereof is not useful as a complementary conductor to be coupled in parallel with any one of the other conductors to double the conductivity of such conductor for special purposes.
The present invention has aimed at providing a distributing bus-bar which has at least some of the advantageous properties that are inherent with the just described cables and which beyond those has some installation technical and economical advantages.
To the just mentioned end there is provided according to the present invention a distribution bus-bar comprising a carrying line and electric conductor parts, particularly adapted to be used within a five-conductor system, in which bus-bar the carrying line runs separate from the conductor parts and extends straight lined, as is known per se, whereas the conductor parts are jointly spirally wound, and in which the carrying line and the conductor parts are disposed in a common electrically insulated jacket, in which the conductor parts are mutually freely and separably disposed, which distributing bus-bar or cable is characterized in that both the carrying line and the conductor parts consist of an aluminium alloy, and that the electric conduction capacity of the carrying line is identical to that of each one of the conductor parts, so that the carrying line is useful as a parallel coupled complementary conductor for 0- or earth function.
Preferably both the electric conductor parts and the complementary conductor part consist of few- threaded aluminum conductors, e.g. of the kind which is commercially available under the Trade Mark "Ductalex", but also solid conductors may be used.
The invention will be disclosed in more details below with reference had to the accompanying drawing.

Fig. 1 is a perspective view of a portion of a distribution bus-bar according to the invention;
Fig. 2 shows a cross-section of the distributing bus-bar.

The embodiment of the hanging cable shown as an example in the drawing comprises a carrying line 10 and a plurality of electric conductor parts 11,12,13,14and 15, which are disposed in a common electrically insulating jacket 16. The jacket portion 16A which surrounds the carrying line 10 and the jacket portion 16B which surrounds the electrical conductor parts 11-15 are separated from each other by means of a web 16C so that there is a good possibility to affix the distributing bus-bar in case this is to be used e.g. as a hanging cable. In the example shown the carrying line 10 and each one of the conductor parts 11-15 has its own insulation, so as is indicated e.g. by the insulation 10A, 13A and 15A.
Each one of the conductor parts may have a conductor area of e.g. 25 mm² and may consist of a 7-threaded aluminum alloy, e.g. of the kind which is sold under the Trade Mark "Ductalex". The conductor part insulation 13A, 15A may consist of PVC and have a thickness of 1,3 mm. The carrying line may similarly consist of a 7- threaded aluminum conductor with a conductor area of e.g. 25 mm² and the conductor insulation consists similarly of PVC of a thickness of 1,3 mm. The jacket 16 consists of PVC and has a thickness of 1,2 mm.
The conductor parts are preferably color marked so they are easy to identify, e.g. one part green/yellow, one part blue, one part brown and remaining parts black with one of the blacks parts also marked with the figure 1.
The distributing bus-bar according to the invention is useful with special advantages for illuminating systems within industries, department stores, athletic halls, excercise tracks and underground rooms. It is also very useful in the power distribution technique, e.g. within small factories, farm service houses, work shop hotels and various kinds of service operations. At building sites the distributing bus-bar according to the invention is particularly useful in temporary electric systems, particularly at elongated building sites, such as bridge buildings, culvert buildings and in staircases for electric power distribution between different planes.
It should be mentioned that the increasing use of electric discharge lamps motivates an increased attention to the losses which occur due to the overtunes in the power net which are inherent with such light sources. Also other cases which cause overtunes in the power net require due attention. The dimensioning of the zero- conductor is of importance for a low power consumption. The invention permits a considerable increase of the conduction capacity of the zero-function as compared to that of the other phase conductors by parallel coupling of the zero conductor and the carrying conductor 10, whereby uneven load problems, e.g. due to overtunes, are avoided.
Elongated systems are normally limited by the fact that the so-called tripping condition must be met. Due to the possibility of parallel coupling of the protective conductor and the carrying conductor 10, the last mentioned one then serving as a complementary conductor, when using the bus-bar according to the present invention the system may be given properties which permit very elongated installations. In other words, with the electrical security remaining unchanged, it will be possible to increase the length of the wiring or it is possible to decrease the voltage between accessible parts and earth.
Depending on the organisation of the power distribution net and other local conditions sometimes a so called potential equalisation may be required, particularly in certain industrial applications having a so called "free zero-point". To that end it normally happens that a separate conductor is installed which may be difficult to identify within a system. For the same purpose it is instead possible according to the invention to use the carrying line 10, which thereby serves as a complementary protective conductor and has the advantage that it always follows the power supplying conductor parts. Due to its mechanical binding to the distributing bus-bar or cable this conductor is always easy to identify.
It should be mentioned that the individual conductor parts of the distributing bus-bar according to the invention must not necessarily be continuosly cabled around each other. Instead they may be cabled back and forth (SZ-cabling) and of course it would also be possible to permit one of the parts or several of them to run purely parallel to the other, cabled parts.

Claims

A distributing bus-bar or cable comprising a carrying line (10) and electric conductor parts (11-15), particularly adapted to be used within a five-conductor system, in which bus-bar the carrying line (10) runs separate from the conductor parts (11-15) and extends straight lines, as is known per se, whereas the conductor parts are jointly spirally wound, and in which the carrying line (10) and the conductor parts (11-15) are disposed in a common electrically insulated jacket (16), in which the conductor parts (11-15) are mutually freely and separably disposed, characterized in that both the carrying line (10) and the conductor parts (11-15) consist of aluminium alloy, and that the electric conduction capacity of the carrying line (10) is identical to that of each one of the conductor parts (11-15), so that the carrying line (10) is useful as a parallel coupled complementary conductor for 0- or earth function.