WO2005039016A1

WO2005039016A1 - Electric installation

Info

Publication number: WO2005039016A1
Application number: PCT/SE2004/001494
Authority: WO
Inventors: Leif NORLÈN
Original assignee: Norlen Leif
Priority date: 2003-10-15
Filing date: 2004-10-15
Publication date: 2005-04-28
Also published as: SE0302726D0; SE0302726L

Abstract

A mains distribution network has a hierarchic structure simplifying the work for installing it. From a central at a fuse box (11), only one line extends that is successively at nodes (13.1.1, 13.1.1, 13.3.1, 13.4.1) divided in branching lines. At nodes and endpoints (13.2.2, 13.4.2) remotely controllable elements are provided including actuator units and measuring units. The controllable elements can receive values of the maximum current allowed to pass in the line in which the respective controllable element is connected, and they can, by operating the actuator unit, disconnect the power supply through the line if required. The controllable elements can be interconnected to form a data network such as a local area network. In the data network signals can be transmitted on lines of the mains network. The local intelligence provided by the controllable elements gives an enhanced safety against overheating and an increased safety for persons since electric outlet boxes do not have to carry any electric voltage until a connection to a power requiring device is made.

Description

ELECTRIC INSTALLATION RELATED APPLICATION This application claims priority and benefit from Swedish patent application No. 0302726-5, filed October 15, 2003, the entire teachings of which are incorporated herein by reference. TECHNICAL FIELD The present invention is concerned with electrical distribution networks, primarily electrical distribution networks for and in small units, such as large and small private homes, apartments and offices in apartment buildings, i.e. networks for distribution of electrical power to various electrically powered devices, often known as mains networks or heavy current networks having a voltage between phase and ground in the magnitude of 230 - 260 V, i.e. a voltage that is dangerous to human beings. BACKGROUND The advantage, and really the great advantage, of the present method of making installations of electrical distribution networks in small units is that this method is established and well tried-out. This implies that there are many skilful craftsmen in this field. The work is to a very high degree a handicraft. Looking at other construction activity, the manual work at the construction place is being more and more decreased. Instead, there is a move towards prefabrication performed in factories and assembly work at the construction place. In fact, there are today three fields in construction work that still are very much craftsmen oriented, these fields being plumbing, electrician work and painting.

Some of the drawbacks associated with the handicraft method of today of making electrical installations include among other things:

- The installation is a handicraft and the achieved quality depends on the handicraft skill of the craftsman.

- The installation work takes long time and has to a very high extent to be coordinated with other construction work at the construction place. - The functionality in the electrical distribution network is very low and is limited mainly to distributing electrical current within the electrical installation. Functions for monitoring and control are basically lacking.

- Components included in the electric distribution network have a low degree of prefabrication

- Only a few and strongly limited monitoring and security functions are provided. As appears from Fig. 1, which is a schematic picture of electrical distribution networks of today for private homes, apartments, offices, etc., after the main fuses, not shown, the security functions of the electrical distribution networks are carried out in one or several fuse boxes 11. All connected devices, such as lamps, switches, etc., that are to be secured in the same group, have their electrical cables installed to be connected to the same fuse in the fuse box. This means that the total length of the installed electrical cables is very large and that the installation of the cables partly is complicated.

Before the cables are installed, pipes usually have to be installed to accommodate the cables. The published French patent application 2 704698 discloses a conventional electrical distribution network having a main control point for an electrical device and parallel, secondary control points for controlling the power supply to the same electrical device. U.S. patent 4,418,333 also discloses a conventional electrical distribution network having a central control unit and slave control units at every terminal for connecting power consuming devices. The communication between the control units is made via the cables in the electrical distribution network. SUMMARY OF THE INVENTION It is an object of the invention to provide a network for distributing electrical current for powering various devices, the network having increased security, particularly increased security against overheating at short-circuits. It is another object of the invention to provide a network for distributing electrical current for powering various devices, the network having an easy installation and even requiring only a rninimum amount of manual work. It is another object of the invention to provide a network for distributing electrical current for powering various devices, which network can in an easy way be extended. It is another object of the invention to provide a network for distributing electrical current for powering various devices, the network having extended control functions for the connected devices. The problem that the invention intends to solve is how the installation work of today in installing mains distribution networks can be simplified and how such a mains distribution network can be provided with various added functions, in particular functions for achieving increased security, for supervision of the network and for communicating signals. Generally thus, such an electrical distribution network for distributing mains power is built to have a hierarchical structure, also called a tree structure. From a central terminal, at which the electrical distribution network is connected to a power source or to an external distribution cable, and at which the electrical distribution network receives power, extends only one cable of a first level. The cable of the first level is ramified at a node of a first level into branching cables of a second level. Every branching cable of the second level extends further to an endpoint for connecting manually operated actuator devices such as switches or energy consuming devices or to a node of a second level. For each node of the second level, in the same way, branching cables of a third level extend to different devices or to a node of a third level. This ramifying at nodes of the third level is continued a required number of levels or steps, until all devices or terminals are connected to the electrical distribution network. Then, the path of distributing electrical power from the central terminal to every endpoint extends only through nodes and in particular not through any endpoint. Thus, for example switches for illumination are not directly connected to illumination points but only to nodes. In the electrical distribution network at at least one node and at at least one terminal controllable elements, also called control elements, can be provided, that each one includes an electronically controllable actuator unit and/or a measuring unit connected in the cable incoming to the node or terminal point, respectively, or in a cable going out from the node. Then, the controllable elements can be arranged to receive signals having values of maximum current or power that is allowed to flow in the cable, in which the controllable element has an actuator unit and a measuring unit connected. The controllable elements can then compare received values to values of current or power respectively measured by the measuring unit and control the actuator element to interrupt the power supply through the cable, if a received value is lower than a measured value. Advantageously, the controllable elements are interconnected to form a control network for communicating control signals. The control network can be the type local area network, i.e. a digital network, and can communicate control signals in the same electrical conductors that are used in the electrical distribution network to conduct electrical current to various devices. All or some of the units in an installation of an electrical distribution network, in particular those parts which one desires to control digitally, such as wall outlet boxes, dimmers, switches, terminals or outlet points for permanently installed electrical equipment etc., can thus be exchanged by or replaced with units, which can be controlled by electronic signals and have the same functionality as previously, or these units can be supplemented with electronically controllable elements. The modified devices and the controllable elements include preferably a communication module to allow communication, in a control network or a local data network, with other devices or elements in the electrical distribution network or for communication with other units or devices, this giving new functions integrated in the electrical distribution network. The local data network can also have allow communication with other networks, such as general purpose networks, for instance the Internet. Furthermore, the modified devices and the controllable elements advantageously include a computer module or processor used to control and monitor the function of the respective device/element, and to handle, forward and receive messages and to perform additional control and monitoring functions in the electrical distribution network. The functions of the devices/elements are then controlled by the computer module or processor using e.g. circuit breakers built into the respective device/element and monitoring functions can be performed by sensors/measuring units for sensing various conditions in the electrical distribution network. The electrical distribution network as proposed herein has several advantages compared to presently used electrical distribution networks and at the same time a number of disadvantages or problems associated with the presently used electrical distribution networks are removed or reduced. The electrical distribution network can in the usual way be centrally secured using main fuses.

After this securing, the central unit of the electrical distribution network, or alternatively one of a plurality of central units in large installations, can be connected. Through this central unit/these central units all electric power is supplied from the outside to the electrical distribution network and the supply of power can further be combined with a control network or a data network, in which signals in the preferred way are transferred in the same cables as those used for the supply of power to various devices/equipment. Any further securing is not required in the electrical distribution network, if controllable elements according to the description above are used. The computerized monitoring or control and the securing in the data network can then accomplish this function. A sufficient and very good security is obtained in this way in the electrical distribution network and as stated above, the installation of cables can advantageously be made as a pure tree structure, this minimizing the length of the cables and also to a high extent making it easier to extend or expand the electrical distribution network. The cables in the electrical distribution network can in the ordinary way include insulated cables having three, four or five individual electrical conductors, i.e. conductors for both ground, zero and needed phases. In addition possible separate signal cables can be included. The cables are advantageously shielded to reduce the electrical fields and generally electromagnetic emission from the cables. Special variants of shielded cables and shielded connectors/ramification nodes can be manufactured to substantially eliminate the electrical fields in sensitive environments. This implies that the coupling work in the installation of the electrical distribution network can to a high extent be simplified and that the risk for mistakes is reduced. Connectors/ramification nodes can be permanently mounted to the cables, which are delivered in fixed lengths. Variants of connectors and cables can be provided at the installation place to allow that cables for special needs are produced. Advantageously, the cables have modularized connectors that allow ramifications having preserved supplying capability for electric current and that preserve the functionality of the data network. The ramification nodes can contain digital control functions, which can vary between different nodes depending on the requirements. In principle all switching-off and switching-on of devices that consume electrical power can be obtained using control in the data network and by monitoring consumed power. It implies, among other things, that it can be achieved that no outlet boxes for electric current carry a voltage, until a switching-on operation has been performed or an electrically powered device has been connected to the outlet box. It can be accomplished using switches and also by a checking operation against the device, the connector of which is attached to the electrical outlet box. In suitable ramification points power consumption can be monitored and an automatic interruption can occur if the power consumption is too large. If a connected electrical device is prepared to include a suitable electrical control function, the device can inform the data network about its power need and then, in a ramifying point, such information can be collected and supervised for highest security. In some ramifying points sensors for measuring the temperature in the electrical cables for supplying the mains current can be installed, this being used to interrupt the supply of power in the case of a maximum temperature being exceeded to prevent fire at bad electrical contacts/shortcircuits. Due to the reduced length of cables required in a tree structure, the installation of the electrical distribution network in a house can be mainly done, after the house has been finished or after a repair of the house has been finished. If the electrical distribution network is combined with suitable moulding strips that can protect the electrical cables, only a minimum of installation work is required that has to be performed before the rest of the construction work is finished. Every node, i.e. ramification point, in the electrical distribution network can be equipped with intelligence to control and monitor the electrical distribution network. The controlling and monitoring functions can be implemented in a control network/digital network and these functions control the consumption/supply of electrical power in the electrical distribution network. It is achieved by the method that the data network controls switching the current on and off in various nodes and also by performing power monitoring and other kinds of monitoring such as measuring increased temperatures and measuring electrical resistance to discover bad electrical contact. All intelligent ramification points and terminal points can communicate with each other and can automatically or manually be given addresses and then the data network can be automatically configured. This implies for instance, that a switch can be placed anywhere in the electrical distribution network totally independently of the power consuming device/devices that are to be controlled/monitored. Also, it implies that external communication can be used to influence, control and monitor the function of the electrical distribution network. For instance, a circuit breaker/switch for connecting/disconnecting can be externally connected via Bluetooth or the Internet. Of course, a control network or data network for communicating signals and superposed on an electrical distribution network can be used for every type of distribution network. Such a control or data network can then have communication channels running in parallel with or in the cables. If the communication channels pass in the cables, such a communication channel typically includes a high frequency signal superposed on the electrical current used for supply of power. It is particularly advantageous that the communication channels in the control or data network are interconnected to form a closed loop. In nodes in the electrical distribution network, where at least three cables are interconnected, interconnection boxes can be provided. They can include interconnection devices for the communication channels, in such a way that for each of the cables connected to the node there is one communication channel incoming to the node and one communication channel going out from the node. Furthermore, advantageously a communication channel incoming to the node associated with one of the cables connected to the node can be connected to only one communication channel going out from the node associated with another of the cables connected to the node. The endpoints can in a similar way include interconnection devices for connecting a communication channel incoming to an endpoint to a communication channel going out from the endpoint. The same is valid for adapted power consuming devices that can also include interconnection devices for connecting a signal communication channel incoming to the power consuming device to a signal communication channel going out from the power consuming device. This function can for example be built into a connector plug for connecting the power consuming device to the electrical distribution network. Such a plug or the power consuming device can also contain an element forwarding a value of maximum current or power to a controllable element connected in the electrical distribution network. Generally, the electrical distribution network as described herein intends to make the electrical installation work to a high extent an assembly work, at the same time as the finished installation can be given a strongly increased functionality. In particular, the proposed electrical distribution network has among other things the following qualities and advantages:

- Due to a higher degree of prefabrication for the components in the electrical distribution network the handicraft part of the installation work necessary for the network is significantly reduced, this resulting in a higher quality, lower installation costs and much faster installation work at the construction place,

- The coordination with other work at the construction place is much easier and the installation of the electrical distribution network can to a higher degree than now be done after the major part of the rest of other construction work has been finished. - Easy installation.

- Minimum of cables.

- Security functions such as fire protection, improved protection against piercing through the cable by nails, minimizing electrical fields and monitoring of supplied power in the electrical distribution network can be provided. - Many new functions can be obtained in the electrical distribution network including monitoring functions and supervision, these functions among other thins including: a. Security monitoring of supplied power in an arbitrary point or node in the electrical distribution network. b. Power monitoring at any level. c. Connectors/External connection points are not "live", i.e. they do not carry any voltage. d. Complex functions in the electrical distribution network for switching devices on and off in the electrical distribution network, such as time dependent control functions. e. Connection of alarm functions f. Detailed monitoring of the electrical distribution network, g. Easier expansion of the electrical distribution network, h. That the electrical distribution network can be used for data communication Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or can be learned by practice of the invention. The objects and advantages of the invention can be realized and obtained by means of the methods, processes, instrumentalities and combinations particularly pointed out in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS While the novel features of the invention are set forth with particularly in the appended claims, a complete understanding of the invention, both as to organization and content, and of the above and other features thereof can be gained from and the invention will be better appreciated from a consideration of the following detailed description of non-limiting embodiments presented hereinbelow with reference to the accompanying drawings, in which:

- Fig. 1 is a principle picture of an electrical distribution network as presently used, - Fig. 2 is a principle picture of an electrical distribution network having a tree structure,

- Fig. 3 is a perspective view of an apartment/private home including an electrical distribution network as presently used,

- Fig. 4 is a perspective view of an apartment/private home including an electrical distribution network having a tree structure, - Fig. 5a is a block diagram of a controllable element for connection at for instance an outlet box,

- Fig. 5b is a block diagram of a controllable element similar to Fig. 5a for a double outlet box, but also for use as a ramification box,

- Fig. 5c is a block diagram of a controllable element for connection at a manual switch,

- Fig. 5d is a block diagram of similar to Fig. 5c of an alternatively designed controllable element, - Fig. 6 is a block diagram of a local area network arranged parallel to the cables of an electrical distribution network,

- Figs. 7a, 7b and 7c are schematics showing different branching cases in a node,

- Fig. 8 is a schematic showing how a loop in local data network runs in parallel with the cables in an electrical distribution network, - Fig. 9a is a schematic of a ramification point having dropping units and adding units and signal lines to accomplish a loop in a local data network,

- Fig. 9b is a schematic similar to Fig. 9a for a ramification point having more mcoming and outgoing conductors, - Fig. 9c is a block diagram of a ramification point according to Fig. 9a,

- Fig. 9d is a block diagram similar to Fig. 9c of a ramification box having a built-in controllable element and dropping units and adding units and signal lines to accomplish a loop in a local area network according to Fig. 9b,

- Fig. 10a is a block diagram of an outlet box having a built-in controllable element and functions to accomplish a loop in a local area network,

- Fig. 10b is a block diagram similar to Fig. 10a of a simplified built-in controllable element, and - Fig. 10c is a block diagram of a controllable element mounted in a plug belonging to a device intended for connection to an electrical distribution network. DETAILED DESCRIPTION Fig. 1 is a principle view of a currently used electrical distribution network for supplying mains power in a small house or apartment including only one central fuse box 11. Main fuses can be located in an exterior cabinet, not shown. All units 13 or generally all connection points and terminals, which are required or used for supplying power to various devices, such as lamps, switches, wall outlet boxes etc., are shown as substantially filled circles and have cables installed directly connected to the fuse in the central box, to which the unit belongs. Every unit thus belongs to one fuse group. The direct connection with the central fuse box results in that the total length of all required cables is very large and that the cable installation work also partly is relatively complicated. Usually, in the installation work there must be first installed insulated protection pipes and thereafter the electrical cables are mounted in these pipes, usually several single-core cables in each pipe. In Fig. 2 is shown how the units 13 of Fig. 1 instead can be connected to the central fuse box 11 with a hierarchical installation of cables, that can also be called an installation of cables having a tree structure. From the central fuse box one outgoing cable extends to the units, to a first unit 13.1, that is located in a first hierarchical level and can be some connection or coupling point. From the first unit two cables are branched off to second units 13.2.1, 13.2.2 of a second hierarchical level. These second units can be terminal points, compare item 13.2.2, from which no more cables extend, or be intermediate units, compare item 13.2.1, in the same way as the first unit 13.1. In the case shown from one of the second units two cables extend to third units 13.3.1, 13.3.2 of a third hierarchical level. From them further branches can extend to fourth units 13.4.1, 13.4.2 in the next hierarchical level, etc. When comparing Figs. 1 and 2 to each other the significantly reduced total cable length appears required for the installation according to Fig. 2. The interconnection cables between the units can require a larger cross-sectional area, so that an interconnection cable between two units of two adjacent hierarchical levels requires a larger cross-sectional area in the case where the unit in the lower hierarchical level, i.e. the unit having a higher hierarchical level number according to the discussion above, is a ramification point to a ramification point of the next lower hierarchical level. The required increased cross-sectional area can in many cases be obtained by designing the interconnecting cable or cables from the central fuse box and between all inner and intermediate units as cables for a plurality of electrical phases, typically three-phase cables. If required, every individual conductor in the multiphase cables can have an increased cross-sectional area, compared to the cross-sectional area required in the conventional installation according to Fig 1. In Fig. 3 is shown how, in a typical electrical installation for a distribution network of today, various units including ceiling outlet points 1 or ceiling outlet boxes for ceiling lamps, wall outlet points 2 or wall outlet boxes for wall lamps, circuit breakers and switches 3 mounted to walls, wall outlet boxes 4, dimmers 5, outlet points or outlet boxes 6 for window lamps and a doorbell 7 are distributed between different fuse groups in a private home or an apartment. In the figure the connection of the groups to the central fuse box is not shown. Fig. 4 shows a hierarchical electrical installation for the same private home or apartment as in Fig. 3. The reduced required total length of the necessary electrical distribution cables appears clearly. In a hierarchical installation, as shown in Figs. 2 and 4, preferably all or some units in the electrical installation, such as wall outlet boxes, dimmers, switches, terminals for permanently installed electrically powered equipment etc., are replaced with or supplemented with or designed to also include elements that can be controlled by suitable electrical signals, particularly by digital signals, and in a preferred way also can provide electrical signals. The units preserve the same functionality as previously in regard of supplying power, contacting etc. Also ramification points which are no actual electrical components in the electrical distribution network and instead can be considered as conventional interconnection boxes, can be equipped with such controllable elements and can also be considered as units in the electrical installation. The schematic structure of such a controllable element 15, intended as an accessory to be mounted at the connection point for a unit or component is shown in Fig. 5a. In the case shown the unit is a wall outlet box 17, to which a phase conductor R, a zero conductor 0 and a ground conductor G in the electrical distribution network are connected. The controllable element includes connection boxes 16 for connection in the mains network at the unit. Moreover, the controllable element includes a communication module 19 to allow a connection to a local area network, LAN. The communication module is used for communicating logical signals or information signals between the controllable elements 15 and other units provided in the electrical distribution network and/or other new units or their controllable elements or corresponding device, this resulting in new functions integrated in the electrical distribution network. Furthermore, the controllable element 15 of a unit includes a processor

21 used to control and monitor the function of the unit, such as for handling and forwarding messages and possibly added monitoring and control functions in the electrical distribution network. The controllable element can also include for instance one or more electrical circuit breakers 23 and other electrical functional elements such as measuring units for measuring a condition of the electrical distribution network, for example for determining whether an electrical device, powered by the electrical distribution network, is connected to/is included in the unit, and in particular as shown a measuring unit 25 for measuring the intensity of current passing the controllable element and the unit, and hence the magnitude of the power that the unit draws from the electrical distribution network. In Fig. 5a a controllable element 15 is shown intended for only one passing electrical power supply cable. The circuit breaker 23 and the measuring unit 25 are connected both to the passing distribution cable for electrical power and to the processor 21, possibly through an interface 26. The various electronic circuits in the controllable element 15 obtain power from a power supply unit 20, which is connected to a cable in the electrical distribution network and converts the distributed voltage to voltages suitable for the circuits, for example direct-current voltages. The controllable elements can also be intended for a unit having a plurality of outlet points, such as for a combined wall outlet box having a plurality of individual outlet points or for a node. In these cases can, if desired, one electrical circuit breaker 23 and one measuring unit 25 can be arranged for each outlet point, as shown in Fig. 5b for two terminals in a common wall outlet box. Then, conventional double wall outlet boxes cannot be used but they must have separate connections to the electrical distribution network for each opening for a plug. Thus, a controllable element can in a basic version include connections for only one outlet box or only one unit, but it can, by adding modules, be expanded for more outlet boxes or units, by connecting expansion modules. Then, such expansion modules include only the components that are bounded by the dashed line 28. The controllable element 15 according to Fig. 5b can obviously also be used for a node having two outlet boxes. Every individual outlet point in the double wall outlet box 17 according to Fig. 5b can obviously also be connected individually to a simple controllable element of the type shown in Fig. 5a and thus, two controllable elements or in general one controllable element for each specific outlet point or connection point are/is required. New units including a controllable element or old units modified by adding controllable elements thus replace units that presently, in the conventional way, are used in an electrical distribution network. All the controllable elements 15 in the electrical distribution network are interconnected to form a local area network, a LAN, and are built, so that they, using their communication modules 19, can communicate through the local data network and so that their functions, primarily their switching- off-on functions, can be controlled by information, signals or messages communicated in the data network. This local data network can be wire based or wireless, or a combination of a wire based network and a wireless network. The data network is in the preferred case part of the electrical distribution network, so that the data communication takes place in the electrical cables in the electrical distribution network, the primary use of which is to supply power to various devices. It requires that the controllable elements 15 are adapted to or developed for this type of communication and that for each unit a controllable element included in the data network is provided. Such an element can, by being remotely controlled, also make some permanently installed devices, such as circuit breakers, timers and dimmers, superfluous. The remote control implies that such devices, intended to be manually operated at a place close to the respectively device, can be controlled from another part of the electrical distribution network, for example from or through a centrally arranged unit. The controllable element 15 for a manual switch 18 is shown in Figs. 5c and 5d. On the out- going side of the switch a resistor 14 having a suitably adapted resistance can be connected, so that the processor 21 can recognize, by evaluating the current measured by the measuring unit 25, whether the switch is in an open or closed position. For sensing the current through the resistor 14 thus the mains current itself can be used according to Fig. 5c or the current for a suitable low voltage obtained from the power supply 20 of the controllable element according to Fig. 5d can instead flow through the resistor. By using a low voltage such as in Fig. 5d a low cost switch can be used. The controllable element informs the data network and thereby another controllable element or other controllable elements 15 that belong belongs to, i.e. are directly connected at the respective outlet box/boxes, outlet point/points or ceiling connector/connectors, about the position of the switch, said latter controllable elements adjusting their controllable units in accordance therewith. In Fig. 6 the data network is schematically shown, in which signals can be communicated through electrical cables, either in separate lines or in the cables used for distribution of electrical power, or in which the communication of signals is done wirelessly. Also combinations of wireless and wired-based signal communication can be used. To the data network a centrally arranged unit, a central unit 27, can be connected, see Fig. 6, the purpose of which can be to control and monitor, using and cooperating with the controllable elements 15, the electrical distribution network. However, such tasks of the central unit can be distributed in the system so that all control operations are performed from and between the controllable elements. Using a cenfral unit for instance all functions in the electrical distribution network can be controlled, such as switching lamps on and off, time control of wall outlet boxes and lamps, providing dimmer functions, etc. Also other functions can be introduced in the electrical distribution network, and then they can also be controlled by the central unit. For instance, supervision of monitoring functions for the electrical distribution network in various aspects can be introduced, such as e.g. how hot the electrical conductors are or if too large current is flowing through some part of the cables. One of the functions in the electronic control can be that, when a controllable element 15 senses that the unit with which it is associated has been subjected to some manual action, e.g, by the fact that a wall switch has been switched on or that a plug in a wall outlet box has started to consume power from the electrical distribution network, in the controllable element a message is generated that is sent to the central unit 27, which decides what will happen, such as for example, switching a lamp/lamps on and possibly switching other lamps or units off. After receiving such a message the central unit sends, through the data network, a message about what is to happen to the controllable elements for the respective unit/units. The central unit 27 can of course also independently take decisions to send messages to controllable elements for different units, about actions that are to be performed in the electrical distribution network, such as to provide timer functions. The controllable elements 15 of one or several units can thus, for example via central unit 27, influence the function of one or more units, i.e. also other units than those with which they are associated. Consider for example the switching-on of an external, i.e. manually operated, switch 30.1 of the type wall switch for a lamp and the controllable element associated therewith. The controllable element senses the switching-on operation, either by detecting that current starts to flow through the switch or using a mechanical sensor built into the unit, and sends a digital message to the central unit 27 through the local data network that the switch has been switched on. The central unit can then through the local data network command that the original function of the unit will be preserved or carried out, i.e. that current will continue to be allowed to be supplied to the lamp or, in the case of a mechanical sensor, by the fact that the switch, also called circuit breaker, included in the controllable element will be switched on. Based on information in the central unit, the central unit can also command other functions. By feeding in some suitable way adequate information to the centrd unit it can also e.g. be accomplished, that when an ordinary manual switch is switched on arbitrarily selected lamps connected to the electrical distribution network are illuminated. Thus generally, e.g. the function of every manual switch can be reprogrammed, so that it also performs other functions than previously. In Fig. 6 is also seen, how the controllable elements 15 for a dimmer 30.2, a wall outlet box 30.3 and a ceiling outlet box 30.4 are connected in the data network. The data network is in the figure shown to have a ring configuration but it can also be the simple loop type. Furthermore, no wall outlet boxes or similar external connections/outlet boxes from the electrical cables in the electrical distribution network for releasable connection to electrical devices have to provide a voltage or be live in other cases than when a power consuming device is connected to the wall outlet box, provided that the controllable element for the respective outlet box/terminal/outlet point includes a switch and the outlet box/terminal/outlet point includes a mechanical or similar sensor for sensing that a device is connected, see the discussion below, or provided that every connected device has a special structure. In addition to the units that are provided in or connected to the original electrical distribution network, it can be possible to connect other units to the data network, such as telephone sets, alarm devices, remote controllers for various kinds of electronic home equipment. Equipment such as telephone sets, alarm sensors, modems for data transmission, etc. can be connected to the electrical distribution network using suitably designed connection boxes 30 and thereby to the data network, alternatively directly to the central unit 27. Depending on the type of equipment one or more devices can be connected that over the data network communicate with a separate central unit 27' having special functionality not included in the original central unit 27. The data network can also be connected to external communication, which can also influence or control the internal electronic control system, in the central units and in the controllable elements. In Fig. 6 is shown how a DVD- player 32.1, an IR-module 32.2, a telephone set 32.3, an alarm unit 32.4, a CD-player 32.5 and loudspeakers 32.6 are connected in the data network. Instead of using ordinary electrical fuses automatic securing of the power supply in the electrical distribution network can be accomplished, by the fact that the current intensity/the delivered electrical power in the cables is measured on different places using measuring units included in the controllable elements 15 and that information thereof is forwarded to the central unit 27 for controlling the distribution of electrical power, the central unit deciding whether the current in any cable will be interrupted due to too high current intensity or power, caused by e.g. instance shortcircuits, grounding errors etc. Alternatively, this central unit can adjust a limit value in an automatic securing function, which by itself administers current and power measurements and disconnects the current/power, if the limit value is exceeded. This automatic securing function can directly be obtained using the controllable elements of Figs. 5a and 5b, by the fact that the processor 21 includes a function for receiving such a limit value and another function for operating, in accordance with the result of the comparison, a switch included in the control device 23. Connection and control of an external unit for e.g. connection through a wall outlet box can be done by the fact that the data network is extended to include a controllable element, not shown, at the external unit and that the central unit controls this controllable element. This presupposes, that the external unit is prepared for such control by being already at delivery provided to include a suitably designed controllable element. This can be considered as expanding the electrical distribution network with a new unit or is extended to include a further unit. Such equipment, which is connected and which is built to be a part of the electrical distribution network, can then also be provided to include the possibility to send information to the central unit about e.g. its intended power consumption such as a maximum value thereof. In this way the central unit can sum the power needs for those power consumers, which are connected under the same automatic fuse that for example is a function of a controllable element of a node, and thereby the limit value for the maximum current, which is allowed to pass the fuse, can be set to an optimally low value, this giving as a result a high security in the electrical distribution network, such as against shortcircuits. In addition, an electrical distribution network built in this way can obtain increased functionality. If e.g. an iron, not shown, is connected to an electrical distribution network of the kind described herein and the iron is prepared to include suitable special electronic functions, such as a controllable element 15 of the type shown in Figs. 5a and 5b, for such an electrical distribution network, the iron identifies itself automatically when it by its plug is connected to a wall outlet box in the electrical distribution network and thereby the monitoring and control functions in the controllable element for the wall outlet box are started, which for example only accept that the iron is switched on for some maximum time period. After this time period the iron is switched off by interrupting the current in the wall outlet box to which the iron is connected. Thereupon, activating the iron again can be carried out, e.g. by pulling the plug out of the wall outlet box and thereafter reinserting it into the wall outlet box. To further describe the principle for example a CD-player and its loudspeaker can be considered. Information about sound level etc. and even the very digital signal itself, which represents the sound, can be transferred to the loudspeaker over the local data network. The loudspeaker is with a plug connected to the electrical distribution network and thereby to the data network. It receives the digital sound signal, converts is to an analog signal, amplifies it using the amplifier built into the loudspeaker, which is powered from the electrical distribution network. In the same way the CD-player itself is connected to a wall outlet box and thereby to the data network. The CD-player sends control information and the digital sound signal over the data network to the loudspeaker. Other similar devices can in this way be connected to the electrical distribution network and thereby also be interconnected to send and receive signals of various kinds. In a new installation of the electrical distribution network as described herein, according to the discussion above, no securing of the different groups in the fuse box is required since a similar securing function can be obtained in the electrical distribution network near the power consuming units using an automatic, centrally controlled securing function. This allows an alternative way to carry out the installation of the cables required for the electrical distribution network, which drastically simplifies the installation of the cables, as has been described above, among other things by the fact that significantly fewer and shorter lines/cables have to be installed. The installation of cables in the electrical distribution network can be designed as a tree structure according to the discussion above.

This implies that the data network required for handling the controllable elements in the preferred case can follow the cables installed in the electrical distribution network. If such a cable-based data network is used, the electrical distribution network described herein implies that the cables/electrical lines that are used for supplying mains power are also used for the data network, either so that the electrical signals in the data network pass in the same electrical conductors as the electrical current used for powering the various connected devices or pass in conductors parallel to the conductors through which the current for driving, i.e. for powering, various connected devices flows. If a wireless data network designed as an accessory to the electrical distribution network is used, the communication modules 19 in the controllable elements 15 included in the data network must be designed for wireless communication between the controllable elements and the central unit 27. The cenfral unit must then obviously also include a communication unit, not shown, for wireless signal communication. The principle of installing cables in the electrical distribution network is then as follows. In the general case three-phase voltages are feed via a main cable, that then includes three electrical phase conductors, to the electrical distribution network through corresponding main fuses, not shown, and in addition in, when applicable, a ground conductor and a zero conductor. This main cable, the inroming cable, can pass in a loop in the private home/apartment/house and ramifies into a tree structure at main nodes having branches including one, two or three electrical phase conductors to different components/subnodes. The ramifying in every node, which thus is a main node or a subnode, in the free structure of the phase conductors incoming to the node is designed depending on the power consumption in the different subtrees included in the free structure. The main cable can also be designed for another number of phases, for instance for only one phase such as in a small apartment. If three phases arrive on three corresponding phase conductors to a node in the free, each cable going out from the node can contain conductors for one, two or three phases, see Fig. 7a. If in the corresponding way two phases in two phase conductors come in in the cable incoming to a node, each cable going out from the node can contain only one conductor for a phase or the two conductors, see Fig. 7b. If the incoming cable contains only one conductor for thus a single phase, this cable can in the node be branched off to only one-phase conductors, see Fig. 7c. Several variants can consequently exist. On the electrical distribution network the data network is superposed in the preferred case. If the main cable contains conductors for only one phase, there is in every cable in the installation only three conductors, one conductor for one phase R, S or T, also called phase-conductor, one conductor for zero 0, also called zero-conductor, and one conductor for ground G, also called ground conductor. AU three conductors in a one-phase cable are used by the local data network. The phase-conductor and the zero- conductor are used to communicate signals in the data network whereas the ground conductor is used as a return conductor or ground for the data network. By this structure the data network only includes some one-phase conductors and the zero-conductors, so that a loop or a ring is obtained by the fact that the signal proceeds forwards in one-phase conductors and backwards in the portions of the zero conductors that are parallel to the one-phase conductors. If the data network is designed as a network of the Ethernet type having an open loop, the network must at its two ends be terminated by termination resistors. To prevent short-circuits in the electrical distribution network, in the case where the communication in the data network passes between two different conductors in the electrical distribution network, filters are used in required places for separating the high frequency data network from the low frequency mains electrical distribution network. These filters are included in units for separating the data signal and for adding, respectively, the data signal, see the discussion below. From Fig. 8 appears how a data loop, shown by the dashed line 29, can be obtained for an electrical distribution network having a simple tree structure. If the electrical distribution cable is the three-phase type, for the communication in the data network one of the phase-conductors is used, for instance always the phase-conductor for phase R, and the zero-conductor and the ground conductor. If the electrical distribution cable includes only two phases, one of the phase-conductors is used, for example always the conductor for phase R, when it its present, and in other cases the conductor for phase S together with the zero-conductor and the ground conductor for communication in the data network. It is always sufficient to then use only one phase- conductor to obtain a local data network having communication in both directions. To preserve the data network functions over nodes/ramification points in the tree structure, i.e. at the points where the electrical distribution cables ramify, special connectors are required. At the same time the data network extends over the entire tree of electrical distribution network. It means that the data network, which is superposed on the electrical distribution network, must be designed in such a way, that all the nodes of the tree structure are passed by the data network, compare Fig. 8. In principle a ramification point, i.e. a node, works so that the data network is separated from the electrical distribution network in the node, because otherwise a short-circuit is obtained for the data network. In Fig. 9a a ramification point for a one-phase conductor branching off into two one-phase- conductors is shown. Before the branching-off of the conductor for phase R into two mains conductors a unit 31 is connected in this conductor for separating or tapping, "dropping", the data signal, which has a high frequency, from the distribution voltage that has a relatively low frequency. The separated data signal is conducted to a unit 33 for addition or superposition, "adding", of the high frequency signal, that is connected in the phase-conductor in one of the conductors ramified from the incoming conductor. Between the dropping unit and the adding unit then a signal conductor 35 extends for transferring the separated high frequency signal carrying information. In the zero-conductor in the same ramified cable is in the same way a dropping unit 31 connected, that through a signal conductor 35 is connected to an adding unit 33 connected to the phase-conductor in the other ramified cable. Finally, there is also a dropping unit connected in the zero-conductor in the other ramified conductor, which has its output terminal for the dropped signal connected to an adding unit in the zero-conductor that enters the node. The circuit in a somewhat more complicated node including two ramified phase- conductors is shown in Fig. 9b. A ramification box for the ramifying case according to Fig. 9a is schematically shown in Fig. 9c. Based on the discussion above of the structure of the data network over one, two or three phase conductors, respectively, it is sufficient that the data network in a cable uses only one phase-conductor, even if more phase-conductors are provided, i.e. one or two other phase-conductors. More phase- conductors can be used if it would be advantageous. The nodes, which thus include all ramification points and all endpoints, i.e. outlet points, connection terminals to external devices, etc. in the tree that makes up the electrical distribution network, are suitable points for integration of different monitoring and confrol functions in the electrical distribution network, compare the description above of the controllable element 15. In dimensioning the electrical distribution network the functionality is determined, that is needed in each node and endpoint. Some nodes can then be designed to have controllable elements of the type shown in Fig. 5b. These controllable elements can contain, depending on what is required, a communication unit, a processor unit, one or more control units, e.g. switches, and one or more measuring units such as current or power meters. A ramification box having control functions for the ramification case according to Fig. 9a is schematically shown in Fig. 9d. The signal conductors for signals, that are dropped and added to the mains supply network, are in this case all connected to a modified communication module 19' that contains a switch to connect, in accordance with the setting of the circuit breakers included in the control units, suitable signal conductors, so that a loop without any interruption is obtained for the local data network. The functionality in each node can be of many different kinds depending on the function that the node is given in dimensioning the electrical distribution network, e.g. including one or some of the following functions:

- To collect information about following or inferior nodes, for example network status and needed power.

- To supervise the network status in the branch line.

- To switch off the power part in the case that assumed or set power consumption is exceeded by the actual measured power consumption/current intensity.

- To transmit network information to the central unit and/or possibly to other superior nodes. At the endpoints connections to external devices are carried out and/or manual influence on the network is made there. They include connectors for connection of energy consuming devices, for manually operated/automatically controlled control units, such as switches, dimmers, alarm sensors etc. In special designed connectors or fixed outlet boxes the same functionality as in the nodes can be provided, including that it is sensed whether a plug is connected, see Fig. 10a, in which a simple connector according to Fig. 5a housed together with a controllable element substantially according to the same figure is shown. The communication circuits must in this case also have a switching facility in order not to give an interrupt in the loop in the data network. The loop of the local data network can also be permanently closed in the connector, see Fig. 10b, this simplifying the communication module 19. In such a case the information about a connected device the maximum current/power demand can be read from the device through the data network and be used for setting an automatic security function in the control circuits of the connector. In "extending" the electrical installation, e.g. by connecting a device to a wall outlet box using a plug, provided that the device is prepared for the electrical distribution network described herein having a superposed data network, a connection to the data network is directly obtained through the plug when it is connected to the wall outlet box. This can for instance be accomplished by the fact that the plug is designed in a special way by being provided with a simplified controllable element 15'. Such a plug is then given the functions to close the loop for the local data network, see for example Fig. 10c, and to send information about a limit value of the current/power that the device requires. Obviously, the same functions as provided in the plug described with reference to Fig. 10c can instead be implemented within the device itself, which is to be connected to the electrical distribution network. This is true in particular for devices, which are intended to themselves receive special signals, for instance loudspeakers that can be connected to the electrical distribution network to only receive electrical signals representing sound, which is to be issued by the loudspeaker. In any case then the controllable element 15 at the point of connection to the electrical distribution network, i.e. usually at a wall outlet box, is suitably arranged to sense whether a device connected in the point is prepared for the network in the way described above and is programmed to then change its data network function, so that also this device becomes part of the data network. This means, that if the equipment connected to. the network is designed for connection to the combined network as described herein, this equipment will be capable of being included as part of the network according to the discussion above, as for example is applicable to e.g. irons and CD players loudspeakers and also other devices, such as alarm units, telephone sets, etc. It results in that if somebody buys e.g. a refrigerator, it can directly, when it is connected to the electrical distribution network, obtain access both to the power required for its operation and to data network functions, such as digital control/monitoring of the refrigerator. The same is valid for for example a TV set that by the connection of its plug also gets connection to an antenna and to possible cable TV functionality. No loudspeaker cables between a CD player and loudspeakers are required. A CD player is connected using its plug in the same way as the active loudspeakers. Summing up, this procedure of installing an electrical distribution network results in that connecting a device to the network, using a plug, gives access to power and at the same time or even solely to data network functions. This procedure gives many possibilities and advantages. Among other things obtained using the procedure, an infrastructure in the home is obtained, that can be called the "intelligent home" - communication is provided in every wall outlet box and the communication with connected devices is performed directly through the plug, together with the reduction of cables that the procedure implies, i.e. the reduction of the number of loose cables to various devices, alarm units, telephone sets, stereo sets, TV sets, etc. The nodes are designed as complete interconnection boxes, which contains arrangements according to the discussion above for separating the data traffic from the electrical distribution network and for allowing connection of the digital processing capability and the control/monitoring equipment that is required to give the nodes the functionality, which has been determined in dimensioning the electrical installation. Furthermore, the connection points can be designed as connectors that are already attached to the cable in the factory that can provide an assortment of cables in various lengths and having the different connectors that are needed. This would imply a highly simplified installation work, which then could be considered as an assembly work instead of being a handicraft. This procedure would in addition reduce the risk of fire in the electrical distribution system because of bad branch lines, manually carried out on the site. Furthermore, the conductors can be installed without using pipes, if they are made sufficiently resistible to for example mechanical interference. Furthermore, there is no need to add new conductors in old pipes in the same way as is often done today, because an expansion of the electrical distribution network is carried out from an adjacent connection point, i.e. a node. Fire protection in the electrical distribution network can be incorporated in the given structure by the fact that sensors for temperature of the conductors are installed in suitable nodes and signals representing the sensed temperature are forwarded to the central unit 27, which can command adequate action. By suitable manufacturing of the cables the major part of the electrical distribution network can be designed in such a way that the electrical fields are significantly reduced. While specific realizations of the invention here have been visualized and described, it is perceived, that a multiplicity of further advantages, modifications and changes easily are clear to professionals. Therefore is the invention in its wider aspects not limited to the specific details, representative devices and examples, which here are shown and described. In accordance with that can different modifications be done without that you alienate from the idea or the scope for the general invention concept, which is defined in the attached patent claims and its equivalents. Therefore it shall be understood, that the attached patent claims are intended to cover all such modifications and changes, which are contained in the real idea of the invention and its true frame.

Claims

CLAIMS 1. An installation for an electrical distribution network for distributing mains power including:

- a central connection terminal, at which the electrical distribution network is connected to a power source or an external distribution network and at which the electrical distribution network receives power,

- endpoints for connecting power consuming devices and manually operated actuator devices for the power consuming devices,

- cables between the central connection terminal and the endpoints,

- characterized in that the electrical distribution network is built to have a hierarchical structure or a tree structure, so that from the central connection terminal only one cable of a first level extends, which at a node of a first level is ramified into branching cables of a second level, and so that every branching cable of the second level extends to an endpoint for connection of at least one manually operated actuator device or at least one power consuming device or to a node of a second level, at which from every node of the second level branching cables of a third level extend, etc, and so that the supply path for electrical power from the central connection terminal to each of the endpoints only passes nodes and not through anyone of the endpoints.

2. An installation according to claim 1, characterized in that at at least one of nodes a controllable element is provided having an electronically controllable actuator unit and/or a measuring unit connected in the cable incoming to said at least one of the nodes or in a cable going out from said at least one of the nodes.

3. An installation according to claim 1, characterized in that at at least one endpoint a controllable element is provided having an electronically controllable actuator unit and/or a measuring unit connected in the cable incoming to said at least one of the endpoints.

4. An installation according to any of claims 2 - 3, characterized in - that at least one of the controllable elements is arranged to receive signals carrying values for maximum current or maximum power that is allowed to pass the cable, in which the respective controllable element is connected,

- that the controllable element includes an actuator unit and a measuring unit, which are connected in said cable, and - that the controllable element is arranged to compare received values to current or power, respectively, measured by the measuring unit and to control the actuator unit to interrupt the power supply through the cable, if a received value is lower than a measured value.

5. An installation according to any of claims 2 - 3, characterized in that the controllable elements are interconnected in a control network for communicating confrol signals.

6. An installation according to claim 5, characterized in that a central control unit is connected in the control network.

7. An installation according to claim 5, characterized in that the control network includes communication paths located parallel to the cables of the electrical distribution network.

8. An installation according to claim 5, characterized in that the control network includes communication paths extending in conductors of the cables in the electrical distribution network except at nodes and endpoints, so that in the electrical distribution network signals in the control network are superposed on the distributed mains power and/or heavy current.

9. An installation according to claim 8, characterized in that at all nodes bypasses at every ramification point for incoming conductors are provided, in particular so that a bypass includes dropping and adding units connected to each other through signal conductors to form pairs, which units are connected in individual conductors incoming to and going out from the node, so that a closed or uninterrupted loop is obtained in the data network.

10. An installation according to claim 8, characterized in that at at least one endpoint a confrol- lable element, which is connected in the cable incoming to the endpoint, includes an arrangement to keep the signal path in the confrol network closed, so that an uninterrupted loop in the data network is obtained, in particular an arrangement including a dropping unit and an adding unit connected to each other through a signal conductor or dropping units and adding units, which units are connected in individual conductors incoming to and going out from the endpoint, wherein in the case of a plurality of dropping units and adding units they are connected to a controllable switching unit.

11. An installation for an electrical distribution network for distribution of mains power including:

- endpoints for connection of power consuming devices and manually operated actuator devices for the power consuming devices,

- cables between the central connection terminal and the endpoints, characterized by a data network, in particular a digital network of the type local area network, for communicating signals and having communication channels extending parallel to or in the cables.

12. An installation according to claim 11, characterized in that the communication channels in the data network are interconnected to form a closed or uninterrupted loop.

13. An installation according to claim 11, characterized in that the electrical distribution network includes a node, at which at least three cables are interconnected, and that at this node interconnection devices interconnecting the communication channels are provided, so that for each of the at least three cables there is one communication channel incoming to the node and one communication channel going out from the node.

14. An installation according to claim 13, characterized in that a communication channel incoming to the node associated with one of the at least three cables is connected to only one communication channel going out from the node associated with another of the at least three cables.

15. An installation according to claim 11, characterized in that at at least one endpoint a controllable element is provided having an electronically controllable actuator unit and/or a measuring unit connected in the cable incoming to the endpoint.

16. An installation according to claim 13, characterized in that at at least one node a controllable element is provided having an electronically controllable actuator unit and/or a measuring unit connected in the cable incoming to the node or in a cable going out from the node.

17. An installation according to claim 11 , characterized in that at least one endpoint includes an interconnecting device for connecting a communication channel incoming to the endpoint to a communication channel going out from the endpoint.

18. A power consuming device for connection to an installation of an electrical distribution network, characterized by an element for transmitting a value of maximum current or maximum power to a controllable element connected in the electrical distribution network.

19. A power consuming device according to claim 18, characterized by an interconnecting device for connecting a signal communication channel incoming to the power consuming device to a signal communication channel going out from the power consuming device.

20. A plug for connection of a power consuming device to an electrical distribution network, characterized by an element for transmitting a value of maximum current or maximum power to a controllable element connected in the electrical distribution network.

21. A plug according to claim 20, characterized by an interconnecting device for connecting a signal communication channel incoming to the plug via one of its pins to a signal communication channel going out from plug via another of its pins.

22. An interconnection box for connecting at least three cables in an electrical distribution network including terminals for electrical conductors included in the at least three cables, characterized by interconnection devices for connecting the signal communication channels extending parallel to or in the electrical conductors, said interconnecting devices arranged to connect a communication channel incoming to the interconnection box associated with one of the at least three cables to only one communication channel going out from the inter connection box associated with another of the at least three cables.