GB2275835A

GB2275835A - Power distribution system; Lighting control system

Info

Publication number: GB2275835A
Application number: GB9403609A
Authority: GB
Inventors: David Tripp; Steven Doyle; Graham Bickford
Original assignee: MK Electric Ltd
Current assignee: Novar ED&S Ltd
Priority date: 1993-03-02
Filing date: 1994-02-25
Publication date: 1994-09-07
Anticipated expiration: 2014-02-25
Also published as: AU6112994A; GB2275835B; GB9304195D0; EP0687390A1; WO1994021008A1; GB9403609D0

Abstract

Power outlets S1, S2, S3 are interconnected by live L, neutral N, and earth E conductors and by two additional conductors SL, 2W provided for control purposes. Conductor SL incorporates normally-closed switches 7 located, for example, in or adjacent the power outlets. The switches 7 may be opened by insertion of a dummy connector or a flag 110, Fig. 7), or the system may have two types of connector (Figs. 8, 9) for coupling to the outlets, only a first of which types is able to open a switch 7 on coupling to a power outlet. A switch (22, Fig. 1) connected by a cable and a first type of connector to conductors L and SL at outlet S1 can thus control a lamp (39) connected by a cable and the second (non-switch-operating) type of connector to conductors SL and N at outlet S3, for example, Alternatively a lamp 38 connected to outlet S2 can be controlled from two positions D, E by means of a switch 72 at E connected to L and 2W by the first connector type at outlet S3, and by means of a connector of the first type at outlet S1 coupled to a relay F controlled by switch 72 and having contacts 52 - 54 connected with a switch 62 at D in a two-way switching circuit. The system can be implemented as a busbar-based system, or as a plug and socket based system, or a combination of both. A further type of connector may be provided which has a switch-operating member (152, Fig. 10) which can be selectively latched in a position disabling its switch-operating function. <IMAGE>

Description

An Electrical Control and Connection Svstem The present invention relates to an electrical control and connection system intended for use primarily for electric lighting but which may be used for power outlets.

The problem of providing a fully flexible solution to the installation and control of lighting fixtures in commercial office spaces is well known. The major elements of the problem are the need to provide a rapid and safe method of installing the lighting fixtures whilst permitting the arrangement of such lighting fixtures and of their control devices to be easily modified later as the use of the space changes. The problem is more fully described in EP 0 299 811 and in GB 2 255 865 A to which subsequent reference will be made. A number of solutions have been proposed, in the above and elsewhere, based on the use of busbars or other conductors enclosed in metallic trunkings and with tap-off points which are outlets spaced along the system.

EP 0 299 811, in the name of Telemechanique, proposes a trunking system having the normal electrical Line and Neutral conductors, together with safety earthing connection, supplemented by a further conductor which is used to provide control for the connected lighting fixtures. This further conductor is divided at some of the tap-off points thus providing a point at which an additional switch or other control device can be inserted in the system. A known disadvantage of this approach is that a plug must be inserted into every such tap-off point merely to maintain continuity of the further conductor.

British Patent Application 2 255 865 A in the name of KK Electric proposes an earlier MK system again with an array of four conductors one of which provides a control line. The control line is terminated at every tap-off point or outlet, the adjacent terminated ends of the conductor being electrically connected by a normally-closed switching mechanism. In the earlier MK Electric system two differing forms of plug are used to engage with the tap-off facilities in the array; one of these plugs is intended to operate the switching means incorporated in the tap-off facilities whilst the other form of the plug leaves the switching mechanism unaffected and thus the two adjacent ends of the busbar or conductor remain electrically connected. This overcomes both the above disadvantages of the Telemechanique approach in that all the tap-off areas are now identical and a switch, or other control means, can be inserted in any tap-off area.

Both systems provide a degree of flexibility to the lighting installation but have significant drawbacks when real installations are considered, in particular the control of a lighting fixture or group of fixtures from more than one point can only be achieved with some significant compromises in the design and layout of the lighting system or by resorting to the use of additional electronic signalling means. This is because there is normally only a single additional conductor provided in the system which has to be used for both supplying control signals or power to the lighting fixtures as well as providing some form of communication between the several switches or control means. In the case of the earlier MK Electric system two or more switches can be installed and twoway and multi-way control can be achieved. However both switches must be electrically positioned at one end of the group of lighting fixtures to be controlled, that end being determined by what is termed "the flow of control" in the earlier MK application.

It is one object of an embodiment of the present invention to provide for two-way and multi-way control of lighting installations without restriction as to the physical location of the connections for switches or control devices and particularly without preventing the connection of one or more lighting fixtures between the points of connection of the switches or control means.

A second object of an embodiment of the present invention is to provide the degree of flexibility required in a lightining installation without increasing the number of connectors on the plug or tap-off facility beyond the number of conductors in the system.

German Patent application DE 3 346 381 A, Brown, Boveri & Cie, uses a single design of connector and the flexibility of the system is correspondingly reduced. In this case the system is particularly concerned with the mechanical design of the components and, particularly, in the adoption of a modular design for the modules. No switching is included in the arrangement. A similar approach to the design of the modules is taken in an early German Patent DE 2 415 727, Brandi, although this system is not specifically intended for lighting applications. More particularly this system can be distinguished from the above and from the present application in as much as Brandi does not seek to produce a system capable of supporting branches in the controlled circuits nor to provide control of lighting fixtures from more than one place nor are there any switching in the control lines. Only the Line conductor is switched.

It is a further object of an embodiment of the present invention to provide the required degree of control whilst permitting both linear and branched circuit configurations.

US 4 445 737, Long assigned to AMP Inc., attempts to provide advantages by adding to each module a manual switching system, known to electrical engineers as a plug board matrix, which enables any two pairs of system conductors to be electrically connected. Whilst this achieves the desired end of increasing the flexibility it also increases, to an unacceptable extent, both the complexity of the installation and of the modification process.

It is an object of the present invention to provide a similar degree of flexibility for the user automatically and without apparent complexity.

An electrical lighting and connection system according to the present invention comprises an electrical lighting control and connection system comprising a longitudinal array of at least five electrical conductors including Line, Neutral and Earth conductors and at least two additional conductors provided for control purposes, characterised in that at least a first of said additional conductors is permanently provided with one or more switch means along its length and included in said array, said array having at least two lighting power outlets along its length, the conductors running between said outlets, a said switch means operable to make or break electrical continuity in said first additional conductor between adjacent said outlet, said outlets each providing access for a connector to connect to said conductors.

The provision of a permanent switch means at intervals in and along the array in a system where there are five or more conductors in the array enables a degree of control and flexibility which is the object of the invention It is a further objective of an embodiment of the present invention to provide a lighting control and connection system which may be implemented with equal facility either as a ducting based system, a cable system using terminal connectors to join adjacent lengths or using both techniques as the demands of the installation under consideration dictate, and in which the interface of the connector for the array is identical regardless of whether the particular variant of the system chosen uses cables or ducting.

There is increased concern for the safety of workers both in industrial locations as well as in offices and the importance of safe exit from the location in emergency situations is widely appreciated. In such circumstances the provision of light to aid escape may be critical even when the electric power supply to part or the whole of the installation has failed. In such cases the provision of emergency or maintained lighting is important and this requires that lighting fixtures are provided with a permanently live supply, failure of which is indicative of loss of power to the installation. It is another object of an embodiment of the present invention to provide such a permanent live supply at each means of connection thus enabling emergency or maintained lighting fixtures to be sited as the user requires.

Finally, there are known methods of providing electrical connection and physical support for lighting fixtures. Typical examples are the "Plug-in Lighting" products from MK Electric Ltd and a similar product produced by Ashley Accessories, of Ulverston, UK, under the tradename "Klix". These are the subject of two British Standards which place minimum performance limits upon these connectors, particularly in respect of their ability to mechanically support the weight of lighting fixtures and their electrical safety in use. It is an object of an embodiment of the present invention that the connector shall be suitable for mechanically supporting and electically connecting a lighting fixture without additional fixings.

The system of the present invention may comprise a first style of connector adapted to fit into a said outlet and to connect with at least two of said conductors, said first style of connector being so adapted and arranged to operate said switch means on insertion into said outlet and/or a second style of connector adapted to fit into a said outlet and to connect with at least two of said conductors, said second style of connector being unable to operate said switch means on insertion into said outlet. Alternatively a third style of connector may have a positionable means to operate or not operate said switch means as required. Where connectors are not required but sections of the array require to be isolated a "dummy connector" or rather operating means adapted to fit into the array to operate the switch means may be inserted into the array preferably but not necessarily at an outlet.

The array of the system may be encased in ducting or the array may be in the form of a multi cored cable or ducted sections of the array may be joined by a multi cored cable of the array which may have outlets along the length of the cable. The connectors may have electrical switches to control sections of the array. These switches may themselves be manually or remotely controlled.

An embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 shows diagrammatically a part of a longitudinal array of conductors with two different styles of connector according to the invention; Figure 2 shows the arrangement of Figure 1 with different connections; Figure 3 shows the arrangement of Figure 1 with different connectors; Figure 4 is a diagram of a flexible wired system according to the invention in which flexible conductors are connected to ducted conductors.

Figure 5 shows a connector at an outlet of the arrangments shown in Fig.s 1-4; Figure 6 shows a length of trunking for the arrangment shown diagrammatically in Fig.s 1 to 4 sectioned to show the control conductor fitted with a switch means, the other conductors are not shown; Figure 7 shows the same length of trunking shown in Fig.

6, but with the switch operated by the insertion of a switch operating means, Figure 8 shows a first style of connector including switch operating means combined together as one assembly inserted into a combined outlet and switch means for the system shown diagrammatically in Fig.s 1 to 4; Figure 9 shows a second style of connector according to an embodiment of the invention similar to that shown in Fig.

8 but without a switch operating means; and Figure 10 shows a third style of connector according to an embodiment of the invention which may be set to operate a switch or not as required for the system shown in Fig.s 1 to 4.

The description will, in the first place, describe the system in the context of a busbar or similar substantially continuous conductor system but it will be shown that all the arrangements and facilities possible with such a busbar-based system may equally be achieved using a connector and socket based derivative of the system and that, further, these two approaches may be combined as would be the case in real applications.

Figure 1 shows a length of a busbar conductor array system with three continuous conductors L, N and E for Line, Neutral and Earth respectively. Two additional conductors, designated SL and 2W are also shown which serve to carry supply and control signals to connected devices. Power outlets S1, S2 and S3 are shown at A, B and C respectively and several normally-closed switches 7, 7' and 7" are incorporated in the busbar designated SL at each outlet. Each switch 7 is shown as being next to each outlet but may be within or spaced from each outlet designed to be operated to the open position when one of at least two differing styles of connector is inserted in to the socket whilst the insertion of another style of connector leaves the switch in the closed position.

Switches 7 may also be opened by an operating means hereafter referred to as a "flag" as will be described with reference to Fig. 7. Flags provide no connections but merely operate switches 7 when inserted. They also indicate to the user where conductor SL is broken. The switch 7 reverts to the closed position whenever a corresponding connector or flag is removed.

The figure shows a connector A of the first type inserted into the leftmost socket sl on the figure, the connector A having contacts numbered 1 to 5 and terminals 23 to 27 inclusive, and has an operationg member (not shown) causing the associated switch 7 to open separating the contacts 6 and 18 in the busbar designated SL. A switch 22 forming part of the wiring installation, is connected to the connector A by means of a flexible cable. The switch may be operated to supply electric current from the Line busbar, designated L, via contact 3 and terminal 25, switch 22 and terminal 24, to contact 4 on the SL busbar thus energising the busbar to the right of contact 18. A lamp 38 is shown connected to the same connector A having switch 22 and which will be illuminated when the switch 22 is ON.

A further connector C, of the second style described above, is shown inserted into the rightmost socket 53, and which has terminals numbered 33 to 37 inclusive. No switch operating means is inserted hence the contact 6" and 18" of switch 7" are in the closed position. A lamp 39, is shown connected to terminals 34 and 36 of the connector C by means of a flexible cable and is thus, when the connector is inserted in to the socket, electrically connected to the SL and Neutral busbars.

The lamp will therefore illuminate whenever the SL busbar is energised by the operation of switch 22.

It will be appreciated that, since no switch operating means has been inserted to operate the contacts 6" and 18" of switch 7" in the SL busbar, that further lamps could similarly be connected to any extension of the busbar system towards the right-hand side of the figure. Similarly a lamp connected to connector B could be inserted in the socket S2 shown in the centre of the figure in which case it would also operate under the control of switch 22 without influencing the action of any other lamp.

It will be further appreciated that the user might wish to install additional lamps to the left of the switch connected at A, such lamps also being controlled by said switch. However this is not immediately possible since the contacts 6 and 18 have been seperated by the act of inserting the connector A in to the socket S1. Figure 2 therefore shows an alternative arrangement in which a switch 22 has been connected to a second type of connector C at socket S3. As a result of using the second type of connector the connection between 6" and 18" of switch 7" is unbroken. Control is therefore exerted by the switch in both directions along the busbar designated SL. It will be readily appreciated that the user might not, at the time of purchasing the connector, know whether he wishes to use it in accordance with Figure 1 or Figure 2. It is therefore desirable that the user may easily change the configuration of the connector from that of the first type of connector to that of the second type and vice versa. This may be achieved by using a third type of connector as is shown in Figure 10 and which will be described below.

Leaving the contacts 6" and 18" of switch 7" on the socket C electrically connected has permitted control, as indicated above, to flow towards the left of the figure along the busbar SL. However there will be circumstances in which the user will wish to limit the extent of such flow which may be done by inserting a connector of the first type in to a socket at which it is wished to terminate this flow. Such a connector is then being used merely to activate the switching element and not for connection It will be readily understood that the connector may therefore be replaced by a dummy connector having no electrical contacts. Such a dummy connector or flag will be desribed in relation to Figure 7.

Figure 3 shows a similar section of the busbar system to that shown in figure 1 and demonstrates how the system may be used to provide control from more than one point on the system.

The lamp 39 originally shown on the right of Figure 1 is now shown in the centre at socket 52 as discussed in preceding paragraphs. To the right-hand side of the figure at socket S3 a control switch E having contact arm 72 and contact 70 is connected by a flexible cable to the connector C, having contacts numbered 33 to 37 inclusive, and when operated serves to connect contacts 33 and 35. The switch thus energises the busbar designated 2W when the switch is in the closed position.

In Figure 3 at socket S1 an alternative device is shown connected to connector A. This has the operating coil of a contactor or relay connected to contacts 23 and 26 of the connector, that is, electrically connected between the 2W busbar and Neutral busbar. Thus the relay or contactor may be made to operate by switch E.

The contacts of a relay or contactor F are marked 52 and 54 and are of conventional change-over pattern. These contacts 52 and 54 are shown connected in conventional two-way switching mode with a further two-way switch, D, which may be connected by a flexible cable to terminals 53 and contact 54. The common terminal 60 of the switch D having contacts 61 and 62 is supplied from the Line busbar via contact 62, or alternatively via contact 54 and terminal 53. In a conventional manner, operation of either the relay contacts F or the switch D will either energise or de-energise the busbar designated SL thus turning the connected lamp 38, on or off.

Since relay or contactor F may be controlled by making contacts 70 and 72 of switch E, a full two-way switching circuit has been established.

The connector shown used to connect the switch E to socket S3 in Figure 3 is of the first style intended to operate the switch 7" to an open position. It will be appreciated that a second or third style of connector may also be used which would leave 6" and 18" electrically connected. In this case further lamps may be connected to any extension of the system from the right-hand side of Figure 3.

Figure 4 shows an isolated section of the busbar system and it will be appreciated that, since the number of conductors or busbars is the same as the number of contacts in the connector, the same connector as is used to connect devices to the busbar system may be used to interlink sections of the busbars system together. It will be further appreciated that this isolated section of the system could be represented by a length 180 of multi-core electric cable having a multi-pin plug G attached at one end whilst the other end of the cable is connected to a multi-pin sockets or plug H. Between G and H a socket 35 incorporating or associated with a switch 7" as described above. Further is will be appreciated that to increase the number of lighting fixtures or switching systems connectable to such an isolated portion of the system, the number of sockets may be further increased. This also enables a flexible approach to connecting parallel isolated lighting fixtures including other busbars.

The various connectors and switching arrangements of the system will now be described with reference to Figures 5 to 10.

Figure 5 shows the arrangement of a connector 80 which may be associated with or not associated with a switch operating means or as a plug G at one end of a ducted array. The connector 80 is inserted in an outlet 81 in ducting or in a flexible multi core cable. The connector has a flexible cable 82 which may be used to connect a control switch or light neither of which are shown. The connector 80 is shown with its cover removed for clarity, and consists of a body 83 fitted with four shorter pins 84 to 87 inclusive, for making contact with line conductor 88, neutral conductor 89, and the two control conductors 90 and 91, and a longer earth pin 92 for making contact with the earth conductor 93. The body 83 incorporates two prongs 94 which may be flexed by applying pressure at pads 95. The prongs 94 engage with the aperture of the outlet at 96 to retain the connector 80 in the outlet 81. Cable 97 securely attaches the outer sheath of the flexible cable to the connector body 83 by means of clamping screws 98. This ensures that any strain on the cable in the direction of arrow R is transmitted from the cable 82 to the connector body 83 and through the prongs 94 to the aperture 96 of the outlet 81. Where the outlet 81 is fitted to a rigid length of busbar trunking (not shown) the strain on the cable in the direction of arrow R is then resisted by the fixings of the trunking to the building structure. Where the connector is fitted to a length of flexible cable as shown by C in Figure 4 then provision is made for the connector to be fixed to a suitably strong structural member (not shown).

Figure 6 shows a sectioned length of trunking 101 which comprises a rigid duct body 99 which encases the array of five conductors 88 to 91, of which only the control conductor 90 fitted with a switch means 102 is shown. the switch means 102 comprises two fixed contacts 104 fixed to the twisted ends 105 of the conductor 90, and a moving contact plate 106 with contact points 107 at each end of the plate. The moving contact plate 106 is biased against the fixed contacts 104 by the compression spring 108, hence providing electrical continuity of the conductor 90. An aperture 109 is provided in the wall of the duct body 99 to permit operation of the switch means 102.

Figure 7 shows the same sectioned length of trunking 101 as shown in Figure 8, however in this case a switch operating means 110 acting as a flag has been inserted into the aperture 109 to operate the switch means 102. Switch operating means 110 comprises a body 111 formed of plastics which has a protrusion 112 and two flexible latching members 113 which are similar to the flexible latching members 984 shown in Figure 5. The flexible latching members 113 may be flexed inwards by finger pressure on surfaces 114 to allow insertion and removal of the switch operating means into and out of the aperture 109. Insertion of the switch operating means 110 into the aperture 109 causes the protrusion 112 to push the moving contact plate 106 against the force of the compression spring 108 causing the contacts 104 and 107 to open breaking the electrical continuity of the conductor 90.

Figure 8 shows a connector of the first style 120 which comprises a plug part 121 and switch operating means part 122 inserted into a combined outlet 81 and adjacent switch means 102. The plug part 121 and outlet 123 are similar to that shown in Figure 5 and the switch operating means part 122 and the switch means 102 are smiliar to that shown on Figures 6 and 7, apart from the two flexible latchings members 125 only one of which is visible each of which comprises a surface 126 and two patching portions 127 and 128 which retain the connector 120 in the apertures 129 and 130 respectively. For clarity only one conductor 90 has been shown. Insertion of the connector of the first style, since it incorporates switch operating means 122 which includes the protrusion 112, has operated the switch 102, broken the electrical continuity of the conductor 90. Hence when inserted as shown the plug portion 121 makes electrical contact with the portion 902 of the conductor 901, but not with the portion 903 of the conductor 901.

Figure 9 shows a connector of the second style 140 similar to the first connector style 120 shown in Figure 8 but without a switch operating means. Hence when the second style is inserted into a combined outlet 81 and adjacent switch means 102 the plug 141 makes electrical contact with the conductors as shown in Figure 5, but the switch 102 is not broken. Hence the plug is electrically connected to both portions of the conductor 902 and 903 of conductor 90.

Figure 10 shows a connector of the third style 150 which is similar to that shown in Figures 8 and 9, except that the switch operating means part 152 may be positioned to either one of the modes shown in Figures 8 and 9. The body 156 of the third connector style is sectioned to show the detail of the switch operating means part 152. The switch operating means part 152 comprises a moveable pin 153, a flat leaf spring 154 which is fixed by screw 155 to the body 156, and a locating pin 157 which is fixed to the leaf spring 154 and free to move in hole 158. The moveable pin 153 has two detents 159 and 160 which engage with locating pin 157.

Figure 10 shows the moveable pin 153 in a first position such that the protrusion 161 has operated switch 102 to break the electrical continuity of the conductor 90. To change the mode of the switch operating means part 152 so that insertion of the third connector 150 does not break the electrical continuity of the conductor 90, it is necessary to disengage locating pin 157 from indent 159 by deflecting leaf spring 154 in the direction of arrow Q. Moveable pin 153 is then free to move in the direction of arrow P to a second position where locating pin 157 will engage with indent 160. In this position the protrusion 161 is retracted such that it does not touch the moving contact plate 106 when the third part is inserted nto the outlet 81 and switch 102. Hence in this second position the switch is unbroken and the plug part 151 makes electrical contact with both portions 902 and 903 of conductor 90.

Claims

1. An electrical lighting control and connection system comprising a longitudinal array of at least five electrical conductors including Line, Neutral and Earth conductors and at least two additional conductors provided for control purposes, characterised in that at least a first of said additional conductors is permanently provided with one or more switch means along its length and included in said array, said array having at least two lighting power outlets along its length, the conductors running between said outlets, a said switch means operable to make or break electrical continuity in said first additional conductor between adjacent said outlet, said outlets each providing access for a connector to connect to said conductors.

2. A system as claimed in claim 1 further comprising a first style of connector adapted to fit into a said outlet and to connect with at least two of said conductors, said first style of connector being so adapted and arranged to operate said switch means on insertion into said outlet.

3. A system as claimed in claim 1 comprising a second style of connector adapted to fit into a said outlet and to connect with at least two of said conductors, said second style of connector being unable to operate said switch means on insertion into said outlet.

4. A system as claimed in claim 1 further comprising switch operating means adapted to fit into the array so as to operate said switch means on insertion into the array.

5. A system as claimed in claim 1 further comprising a third style of connector adapted to fit into a said outlet and to connect with at least two of said conductors, said third style of connector having a positionable means to operate said switch means or not operate said switch means as desired by an operator.

6. A system as claimed in claim 1 wherein the conductors are encased in and supported by ducting, and wherein said outlets and switch means are provided in said ducting.

7. A system as claimed in claim 1 wherein the conductors are in the form of a cable and wherein said outlets are provided in outlet means connected to said cable.

8. A system as claimed in claim 1 wherein said conductors terminate in a terminal connection.

9. A system as claimed in claim 1 wherein said switch means is included in an outlet means including said outlet.

10. A system as claimed in claim 1 including a said connector, wherein the connector includes a further electrical switch to control one or more lights connected to the array.