AU2008243065B2

AU2008243065B2 - Mounting box for electrical wiring accessories, assemblies and methods of installation thereof

Info

Publication number: AU2008243065B2
Application number: AU2008243065A
Authority: AU
Inventors: Andrew Purdie Baker; Keith Wray Ball; Terence Edward John Lovett; Michael David Sargent
Original assignee: Schneider Electric Industries SAS
Current assignee: Schneider Electric Industries SAS
Priority date: 2007-11-01
Filing date: 2008-10-31
Publication date: 2013-03-28
Anticipated expiration: 2028-10-31
Also published as: AU2008243065A1; GB0721484D0; NZ572472A; GB2454320A; GB0819430D0; GB2454320B

Abstract

MOUNTING BOX FOR ELECTRICAL WIRING ACCESSORIES, ASSEMBLIES AND METHODS OF INSTALLATION THEREOF A mounting box (10) for an electrical wiring accessory (42), the mounting box (10) having an open front with walls at the back, top, bottom, left and right sides, wherein the mounting box (10) is provided with first and second pluggable connectors (14, 16) each for receiving a compatible 10 supply wiring connector (60, 62), the first and second pluggable connectors (14, 16) each having a plurality of wiring terminals located within respective terminal ports (18) wherein corresponding terminals of the pluggable connectors (60, 62) are interconnected by rigid through conductors (12) to pass the electrical supply from one connector (14, 16) 15 to the other, the terminal ports (18) also providing space for conductors (12) to connect the supply within the box (10) to an accessory (42) mounted in said open front. 20 (Fig .1) 14 18 12 22 / /Fig. 2 18 12 22 24 14 Fig. 2

Description

Pool Secton 29 Regulation 3.2(2) AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: Mounting box for electrical wiring accessories, assemblies and methods of installation thereof The following statement is a full description of this invention, including the best method of performing it known to us: Pi11ABAU/1207 1 MOUNTING BOX FOR ELECTRICAL WIRING ACCESSORIES, ASSEMBLIES AND METHODS OF INSTALLATION THEREOF 5 The present invention relates to a mounting box for electrical wiring accessories. This includes mounting boxes for electrical wiring accessories of types adapted for use in electrical trunking, or types adapted for mounting in dry-lined walls. The invention further relates to assemblies and installations of such accessories and mounting boxes and 10 methods of installation thereof. Typically, a number of electrical accessories, such as power sockets, circuit breakers, light switches and the like, are installed at various locations along the walls of a building, either in surface-mounted trunking 15 or in apertures cut into wall boards. The electrical accessories are mounted to mounting boxes which are adapted to fit securely within channel portions of the trunking or within the wall board aperture. Electrical power is delivered to the electrical accessory by wiring the power cables to the electrical accessory. 20 An electrical accessory is conventionally installed by mounting the mounting box within the channel portion, wiring the power cables to the electrical accessory via apertures in the mounting box and then attaching the electrical accessory to the mounting box. The mounting box may be a 25 snap-fit within the channel or aperture, while the accessory is secured by two or more screws so that its face plate closes the box. Mounting electrical accessories in this manner is time consuming, since it requires the power cables to be wired to the accessory. It also requires 2 the person mounting the accessory to have a certain level of training in view of the inherent danger in dealing with electrical power. Pluggable wiring solutions to this are becoming widespread in building 5 installation generally, but known solutions rely on the availability of space beside and/or behind the mounting box, which limits their acceptance in trunking situations and situations of tight space in the wall cavity. Our patent applications GB0709793.4 (our ref GS 20/P49501.GB.03) and GB0718931.9 (GS 25/P102434.GB.02), not published at the present 10 priority date, and GB2432265A (GS 19/PF65380GB) describe various mounting boxes for trunking and wall board applications. In all of these, the aim is to allow "plug-and-play" installation of mounting boxes with accessories pre-assembled and pre-wired internally. In the 15 preferred embodiments, two pluggable connectors are provided on one or two side walls of each mounting box, with a through connection made between them, so that the supply cables and accessories can be daisy chained to supply the requisite number of sockets or other accessories in either a ring main or radial configuration. 20 Various manufacturers including, for example, Wieland of Germany, make pluggable connectors which can be adapted for the above purpose by provision of suitable apertures in the mounting box walls. Some of these connectors are provided with screwless terminals which automatically 25 contact, grip and retain cable conductors inserted into respective terminal ports in the connector body. Each port can receive two conductors side by side, so that the accessory and the through wiring can be accommodated. The provision of screwless termination greatly facilitates wiring, but the 30 number of flexible wiring connections to be cut, stripped and inserted still 3 limits the speed with which the accessories and boxes can be connected, assembled and tested. Moreover, larger installations have specified heavier duty cable, such as 4mm 2 conductor cross-section, in order to avoid excessive voltage drops over a very long circuit. The accessories 5 and pluggable connectors are generally designed to receive lighter duty cable, for example 2.5mm 2 , and fitting flexible cable of 4mm 2 gauge into the terminal ports can be difficult. Any discussion of documents, devices, acts or knowledge in this 10 specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art in Australia on or before the priority date of the claims herein. 15 Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 20 It would be desirable to provide an improved pluggable mounting system for electrical wiring accessories, bearing in mind the issues identified above. 25 According to a first aspect of the present invention, there is provided a mounting box for an electrical wiring accessory, the mounting box having an open front with walls at the back, top, bottom, left and right sides, wherein the mounting box is provided with first and second pluggable connectors each for receiving a compatible supply wiring connector, the 30 first and second pluggable connectors each having a plurality of wiring 3a terminals located within respective terminal ports wherein corresponding terminals of the pluggable connectors are interconnected by rigid conductors to pass the electrical supply from one connector to the other, the terminal ports also providing space for conductors to connect the 5 supply within the box to an accessory mounted in said open front. The provision of rigid through conductors facilitates production and assembly, in that the conductors can be pre-formed to the right length and shape, and fitted more readily into the box. The provision of rigid through 10 conductors also allows a conductor to be received within the terminal port of a connector which has an electrical cross-sectional area greater than that of a multi-stranded conductor which the terminal port is designed to 4 receive. Thus, for example, a 4mm 2 rigid conductor can be received into a terminal port designed to receive a 2.5mm 2 multi-stranded conductor, when a 4mm 2 multi-stranded conductor would not easily fit. 5 The rigid through conductors may comprise metal rods with a cross sectional area in excess of 3mm 2 . The mounting box may be provided with receptacles to receive and retain respective through conductors. The receptacles may be formed integrally 10 with the rear wall, for example by moulding. Alternatively, the receptacles can be provided in a separate insert. The receptacles may be formed to receive and temporarily retain the through conductors prior to provision of the pluggable connectors, the 15 pluggable connectors then serving to retain the through conductors more permanently by receiving ends of the through conductors in their respective terminal ports. The receptacles are preferably designed to protect against finger contact 20 with the through conductors, which may for cheapness be uninsulated. The receptacles may be formed so as to receive the through conductors from within the box, or from the outside. In either case, there may also be provided an insulating cover to prevent accidental contact of tools or 25 fingers with the conductors. The first and second pluggable connectors may be arranged in opposite sides of the mounting box. For example, the shorter two end faces can be provided with connectors so that cabling can extend lengthwise along a 30 trunking.

5 The through conductors in such a case may be generally straight in form and may have equal length. 5 Even when generally straight, the rigid conductors may be provided with a non-linear portion to engage with a corresponding restraining formation in the receptacle and prevent longitudinal displacement. The receptacles may also be provided with restraining formations near the 10 location of the pluggable connectors, to maintain space for entry of accessory wiring into the terminal ports alongside each through conductor. The first and second connectors may alternatively be fitted side-by-side in the same wall of the mounting box. This may be for example to be 15 compatible with the form of mounting disclosed in our earlier application ref GS 25, mentioned above. The through conductors may be formed with different lengths and or shapes to suit the location of their respective terminal ports in the first and 20 second pluggable connectors. The through conductors may for example be formed in '[' shapes, to be received by connectors fitted side-by-side. In a preferred embodiment, there are four terminals in each pluggable connector and four through conductors extending between the respective 25 terminals of the first and second connectors. A typical accessory will connect only to two or three of these terminals, but special applications can require a second live conductor.

6 The first and second pluggable connectors may be of opposite gender, allowing connection of successive identical boxes by successive identical plugged cables in a 'daisy chain' formation. 5 Whether the mounting box is adapted for mounting in a length of electrical trunking or through an aperture in a wall board, the accessory and mounting box according to the invention can be pre-assembled and tested at a factory location, and installed easily by plugged connections on site. 10 Preferably, the pluggable connectors are enclosed substantially within the mounting box. The lateral space occupied is thereby not increased, compared with conventional solutions. In a preferred embodiment, each pluggable connector is provided with 15 projections for snap-fitting into an aperture formed in the mounting box wall. Preferably, the mounting box has dimensions which conform to standards applicable in the territory. In the UK, for example, standard BS 4662:1970 20 and successor standards may be applied, the mounting box being of size UA1 (unit square), US2 (double outlet), or US3 (triple outlet). The dimension between top and bottom side walls in that case will be approximately 75mm and the length between end walls approximately 75mm, 135mm or 195mm respectively. 25 Preferably, the mounting box includes threaded bosses for attaching a conventional electrical accessory thereto. According to a second aspect of the present invention, there is provided 30 an assembly for mounting in electrical trunking, the assembly comprising 7 an electrical wiring accessory assembled together with a mounting box according to the first aspect, wherein a face plate of the accessory closes the open front of the mounting box and wherein electrical terminals of the accessory are pre-wired to corresponding terminals one or both of said 5 pluggable connectors to deliver electrical power from the supply wiring connector to the accessory without disassembly of the accessory from the mounting box. Preferably, each pluggable connector does not protrude from the side of 10 the mounting box further than the distance the face plate extends over front of the mounting box. According to a third aspect of the present invention there is provided an electrical installation comprising: 15 at least one section of electrical trunking mounted within a building; a plurality of accessories within mounting boxes according to the first aspect of the invention as set forth above, the boxes being mounted within the trunking; and a plurality of cable sections terminated with plugs mated with the 20 pluggable connectors of the assemblies, so as to supply electricity to said accessories and, through the through conductors of each mounting box, from each mounting box to the next. The cable sections and rigid through conductors may each be provided 25 with cross-sectional area of conductive material in excess of 3mm 2 , for example 4mm 2 . According to a fourth aspect of the present invention there is provided a method of installing a plurality of mounting boxes and electrical 30 accessories in a building, comprising the steps of: 8 - providing a plurality of mounting boxes having pluggable connectors and through conductors as set forth in the first aspect of the invention; - providing a plurality of lengths of supply wiring with compatible connectors; 5 - fixing the mounting box within a section of trunking or wall aperture; and - before or after said fixing step, plugging the supply wiring connectors into the pluggable connectors, electrical continuity between sections of supply wiring being provided through said pluggable 10 connectors of the mounting boxes and the rigid through conductors within. Preferably, the method further comprises the preliminary step of wiring an electrical accessory to terminals of at least one pluggable connector within a mounting box and attaching the electrical accessory to the mounting box 15 before the mounting box is attached within the trunking. The preliminary step can be performed at a factory location remote from the installation site. 20 The invention in a fifth aspect provides a method of assembling a mounting box with first and second pluggable connectors and through conductors to form a mounting box according to the first aspect of the invention as set forth above, the method comprising: - providing a mounting box carcass with apertures for first and 25 second pluggable connectors; - providing receptacles for receiving a plurality of rigid through conductors; and - assembling a plurality of rigid through connectors and said first and second pluggable connectors into the mounting box carcass, the ends of 9 the rigid through conductors entering terminal ports of the pluggable connectors to provide a series of through connections for electric supply. The through conductors may be assembled into the receptacles prior to 5 insertion of the pluggable connectors into their apertures. The receptacles may be formed integrally with the mounting box carcass, for example by moulding. 10 The method may further comprise wiring an electrical accessory to terminals of at least one pluggable connector within a mounting box and attaching the electrical accessory to the mounting box before the mounting box is attached within the trunking. 15 The step of wiring the electrical accessory may be performed through one of said apertures prior to inserting the connector into its the aperture. The above steps can all be performed at a factory location remote from the installation site. 20 10 BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which: 5 Figure 1 is a perspective view of a mounting box adapted according to a first embodiment of the invention; Figure 2 is a perspective view of a mounting box adapted according to a 10 second embodiment of the invention; Figure 3 shows the mounting box of Figure 1 with an electrical accessory being connected and assembled thereto; 15 Figure 4 shows the finished assembly being installed with cables in a pluggable wiring system; and Figure 5 shows the assembly in a third embodiment adapted for installation in walls rather than trunking.

11 DETAILED DESCRIPTION OF THE EMBODIMENTS A first embodiment of the invention concerns pre-wired wiring accessories installed in conduit trunking and is to complement the existing range of 5 wiring accessory assemblies used in 'plug & play' applications. Plug and play systems are systems that allow connection of electrical circuit(s) by means of plug and socket connectors, requiring less attention from a skilled electrician at the time of installation. Various components and systems for use in such systems are described in our earlier applications, 10 mentioned in the introduction above. The entire content of those earlier applications is hereby incorporated by reference. Plug and play systems can be found in schools, hospitals, and office applications where trunking conduit is used to house wiring accessories. 15 In some installations such as schools and hospitals cable runs may extend over many meters requiring cable sizes (cross-sectional area) to be increased to allow for voltage drop over the length of the cable run. 20 Until recently these installations have been cabled with 2.5mm 2 conductors per phase. Due to extended cables runs there is now a requirement for 4mm 2 conductors instead of 2.5mm 2 conductors. Conventional mounting boxes do not allow the required number of 4mm 2 25 conductors to be fitted easily. This can lead to increased difficulty of assembly due to the increase in physical size of the cables, and greater strain on cable terminations due to decreased bending radii of the cable. This invention concerns a mounting box for use specifically in Plug and 30 Play wiring installations but not exclusively. The mounting box is designed 12 to accommodate 4mm sq conductors within the rear section of the box (see Figure 1). Figure 1 shows the novel mounting box 10 assembled with rigid through 5 conductors 12 fixed to receptacles formed on the inside rear face of the box and Figure 2 shows a version 20 with them fixed within the outside face of the box. The conductors are secured to the mounting box primarily by being 10 terminated in connectors 14 and 16 mounted in opposite sides of the mounting box. Each connector has a plurality of terminal ports 18 leading to screwless terminals within a plastic body. These terminals provide electrical connection and mechanical retention of the conductors simply by pushing the conductor into them. A screwdriver can be used to release 15 the clamping mechanism if the connection needs to be disassembled in future. The receptacles for the through conductors 12 can be provided with projections to capture the conductors even before the connectors are 20 fitted. A central projection 22 from the receptacle wall engages with a kink 24 made in the conductor, to restrain the conductor against longitudinal sliding. Projections 26 near either end of the conductor keep its ends firmly to one side of the terminal port 18, so that flexible wiring from the accessory (not shown in Figures 1 and 2) can fit beside the rigid 25 conductor. Figure 3 shows the accessory 30 being connected and assembled with the through conductors 12 and pluggable connectors 14, 16. In this view it can be seen how the mounting box carcass 32 is adapted from a standard 30 mounting box to include rectangular apertures 34, 36 in its left and right 13 end walls. The pluggable connectors 14, 16 are mounted in the apertures. The rectangular apertures are dimensioned to receive push-fit pluggable connectors, such as Wieland Gesis con GST 18i3 series. (See http://www.wieland-electric.de/gesisCON.51.0.html ). The dimension in 5 that case is substantially 33mm by 15.6mm. Each pluggable connector when assembled is substantially enclosed within the mounting box, so that its connection port is substantially flush with the end face of the box. A flange 38, 40 projects a millimetre or two, but the whole assembly fits within the length of the accessory face plate. 10 The accessory 42 is a standard component. Width of the mounting box (outside top to bottom walls) is typically 75mm, according to UK standards (BS 4662:1970). Dimensions of length vary according to the accessory wanted. A single unit (socket or switch) will have width 75mm, double 15 135mm and triple 195mm. Depth may be 25mm, 35mm or 50mm, for example. Other sizes are of course possible, according to local conventions or special applications. The combined mounting box 10 and electrical accessory 30 constitute an 20 assembly for mounting in electrical trunking. Once the pluggable connectors are wired to the electrical accessory by short flexible insulated conductors 44 as shown, the electrical accessory 30 is then attached to the mounting box. This is effected by two screws 46, 48 which are screwed through the electrical accessory and into two threaded bosses 25 50, 52 in the mounting box. These bosses and screws may be shortened compared with conventional boxes, to avoid interfering with the connectors. It should be appreciated that other suitable means for attaching the accessory to the box may also be used. The face plate 42 of the electrical accessory closes the open front of the box 10. 30 14 Once the electrical accessory 30 has been attached to the mounting box, the assembly can be factory tested prior to shipping ready to be mounted in the trunking. The order of assembling these components can be selected according to convenience in several different ways. The rigid 5 through conductors 12 can be installed in the box prior to inserting the pluggable connectors into the apertures, as illustrated in Figure 3. The flexible connectors 44 to the accessory may be inserted into the terminal ports of one of the connectors prior to insertion of the connector 14, as shown in Figure 3, or they may be inserted only after the connectors, 10 through conductors and box carcass are assembled together. The receptacles for the rigid conductors are preferably moulded into the base of the box, but can be provided as a separate tray unit, if preferred. One advantage of the latter approach would be to use the same basic moulding of the box for applications with and without the through conductors. In that 15 case, the box carcass 32 can be manufactured with rectangular knock-out portions, so that the rectangular apertures are formed only as and when required. Figure 4 shows the finished assembly 54 of box and accessory being 20 installed between cable sections 56, 58 which are pre-assembled with compatible plugs 60, 62. The connectors on each cable may be male and female at opposite ends, where the two connectors on the mounting box are male and female. Alternatively it may be chosen to install only male or female connectors on the boxes, and only the opposite gender on the 25 cables. The form of box and layout shown in Figures 1 to 4 is intended for mounting in plastic or metal trunking running along the wall of the room where the accessory is to be installed. The trunking is omitted from the drawing but is of well known type. Projections 64 provide a snap fit engagement with shoulders provided along the length of the trunking 30 channel.

15 Figure 5 shows an alternative form of assembly 70, in which the two pluggable connectors (labelled again 14 and 16) are mounted in the same side of the box. Internally of the box, these are again connected together 5 with rigid conductors mounted within the mounting box in suitable receptacles. Naturally in this case the rigid through conductors will have a more complex form, being '[' shaped and probably of different lengths and shapes to reach from each terminal port in the first pluggable connector to the corresponding terminal port in the second pluggable connector. 10 The Figure 5 version is adapted for fitting into a wall aperture. By virtue of (i) the positioning of the connectors on the same side of the box, and (ii) the chamfered form of the opposite side of the box (labelled 74), the whole assembly can be plugged into the supply wiring behind the wall by pulling 15 the supply cable ends out through the wall aperture, and then tilted and inserted into the wall aperture to complete the installation without removing the accessory (30) from the box 72. The upper side of the box is provided with rigid projections 76 etc to engage behind the wall board at the upper edge of the aperture, and with spring-loaded projections 78 to 20 engage the rear of the wall board at the lower edge of the aperture, when the assembly is pushed home. More detail of this operation is described in our co-pending application ref GS25, mentioned above. In either embodiment, the compact connectors 14, 16 allow connection of 25 the 4mm 2 solid conductors 12 and the connection of 2.5mm 2 or other flexible conductors between the connector and the wiring accessory. The connectors allow the mounting box to be connected to other assemblies/ accessories. This is beneficial in that it allows heavier duty conductors to be used throughout the installation, but easily and within a small envelope 30 i.e. the interior envelope of the mounting box, the termination of the 16 conductors in the connectors is simplified and the number of flexible conductors in the mounting box is reduced. Guidance on terminal opening sizes for electrical accessory wiring can be found in the relevant standards, for example BS1363 Part 2 in the United Kingdom. 5 As the electrical accessory is pre-wired to the mounting box, there is no need for the assembly to be fitted to the trunking by highly qualified persons, as the assembly is snap-fitted into the trunking and plugged into the power supply. Also, the assembly can be pre-tested during 10 manufacture, which increases the speed of installation, as the installer does not need to do test any internal connections once installed. Given a stock of these mounting boxes, a contractor or supplier can readily pre-assemble pluggable accessory box assemblies which have 15 minimal height and length and which are compatible with standard trunking systems. This pre-assembly and testing can be performed at a factory location, rather than at the installation site. The mounting box can be based on a standard mounting box and modified 20 to include the pluggable connector. The supply wiring connector 14, 16 is a standard component. Modifications and improvements may be made to the above without departing from the scope of the present invention. For example, although 25 the electrical accessory has been described above as being an electrical power socket, it should be appreciated that the accessory could be any suitable type of electrical accessory such as circuit breakers, light switches, 3 or 4 pin plugs and the like.

17 Furthermore, although the mounting box has been illustrated and described above as having a rectangular open front and rectangular walls and sides, it should be appreciated that the mounting box could have an alternate shaped front, walls and sides, e.g. a circular open front etc. 5

Claims

1. A mounting box for an electrical wiring accessory, the mounting box having an open front with walls at the back, top, bottom, left and right 5 sides, wherein the mounting box is provided with first and second pluggable connectors each for receiving a compatible supply wiring connector, the first and second pluggable connectors each having a plurality of wiring terminals located within respective terminal ports wherein corresponding terminals of the pluggable connectors are interconnected 10 by rigid through conductors to pass the electrical supply from one connector to the other, the terminal ports also providing space for conductors to connect the supply within the box to an accessory mounted in said open front. 15

2. A mounting box for an electrical wiring accessory as claimed in claim 1, wherein the rigid through conductors may comprise metal rods with a cross-sectional area in excess of 3mm 2 .

3. A mounting box for an electrical wiring accessory as claimed in 20 claim 1 or claim 2, wherein the mounting box is provided with receptacles to receive and retain respective through conductors.

4. A mounting box for an electrical wiring accessory as claimed in claim 3, wherein the receptacles are formed integrally with the rear wall, 25 for example by moulding.

5. A mounting box for an electrical wiring accessory as claimed in claim 3, wherein the receptacles are provided in a separate insert. 19

6. A mounting box for an electrical wiring accessory as claimed in any of claims 3 to 5, wherein the receptacles are formed to receive and temporarily retain the rigid through conductors prior to provision of the pluggable connectors, the pluggable connectors then serving to retain the 5 rigid through conductors more permanently by receiving ends of the rigid through conductors in their respective terminal ports.

7. A mounting box for an electrical wiring accessory as claimed in any of claims 3 to 6, wherein the receptacles are designed to protect against 10 finger contact with the rigid through conductors, which may for cheapness be uninsulated.

8. A mounting box for an electrical wiring accessory as claimed in any of claims 3 to 7, wherein the receptacles are formed so as to receive the 15 rigid through conductors from within the box, or from the outside.

9. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the mounting box further comprises an insulating cover to prevent accidental contact of tools or fingers with the rigid through 20 conductors.

10. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the first and second pluggable connectors are arranged in opposite sides of the mounting box. 25

11. A mounting box for an electrical wiring accessory as claimed in any of claims 3 to 10, wherein the rigid conductors are provided with a non linear portion to engage with a corresponding restraining formation in the receptacle and prevent longitudinal displacement. 30 20

12. A mounting box for an electrical wiring accessory as claimed in any of claims 3 to 11, wherein the receptacles are provided with restraining formations near the location of the pluggable connectors, to maintain space for entry of accessory wiring into the terminal ports alongside each 5 rigid through conductor.

13. A mounting box for an electrical wiring accessory as claimed in any of claims 3 to 10, wherein the first and second connectors are fitted side by-side in the same wall of the mounting box. 10

14. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the through conductors are formed with different lengths and or shapes to suit the location of their respective terminal ports in the first and second pluggable connectors. 15

15. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein there are four terminals in each pluggable connector and four rigid through conductors extending between the respective terminals of the first and second connectors. 20

16. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the first and second pluggable connectors are of opposite gender, allowing connection of successive identical boxes by successive identical plugged cables in a 'daisy chain' formation. 25

17. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the pluggable connectors are enclosed substantially within the mounting box. 21

18. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein each pluggable connector is provided with projections for snap-fitting into an aperture formed in the mounting box wall. 5

19. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the dimension between top and bottom side walls is approximately 75mm and the length between end walls approximately 75mm, 135mm or 195mm respectively. 10

20. A mounting box for an electrical wiring accessory as claimed in any preceding claim, wherein the mounting box includes threaded bosses for attaching a conventional electrical accessory thereto. 15

21. An assembly for mounting in electrical trunking, the assembly comprising an electrical wiring accessory assembled together with a mounting box according to any of claims 1 to 20, wherein a face plate of the accessory closes the open front of the mounting box and wherein electrical terminals of the accessory are pre-wired to corresponding 20 terminals one or both of said pluggable connectors to deliver electrical power from the supply wiring connector to the accessory without disassembly of the accessory from the mounting box.

22. An assembly for mounting in electrical trunking as claimed in claim 25 21, wherein each pluggable connector does not protrude from the side of the mounting box further than the distance the face plate extends over front of the mounting box.

23. An electrical installation comprising: 30 at least one section of electrical trunking mounted within a building; 22 a plurality of accessories within mounting boxes according to any of claims 1 to 20, the boxes being mounted within the trunking; and a plurality of cable sections terminated with plugs mated with the pluggable connectors of the assemblies, so as to supply electricity to said 5 accessories and, through the rigid through conductors of each mounting box, from each mounting box to the next.

24. A method of installing a plurality of mounting boxes and electrical accessories in a building, comprising the steps of: 10 - providing a plurality of mounting boxes having pluggable connectors and rigid through conductors as claimed in any of claims 1 to 20; - providing a plurality of lengths of supply wiring with compatible connectors; - fixing the mounting box within a section of trunking or wall aperture; 15 and - before or after said fixing step, plugging the supply wiring connectors into the pluggable connectors, electrical continuity between sections of supply wiring being provided through said pluggable connectors of the mounting boxes and the rigid through conductors within. 20

25. A method of installing a plurality of mounting boxes and electrical accessories in a building as claimed in claim 24, wherein the method further comprises the preliminary step of wiring an electrical accessory to terminals of at least one pluggable connector within a mounting box and 25 attaching the electrical accessory to the mounting box before the mounting box is attached within the trunking.

26. A method of installing a plurality of mounting boxes and electrical accessories in a building as claimed in claim 25, wherein the preliminary 23 step can be performed at a factory location remote from the installation site.

27. A method of assembling a mounting box with first and second 5 pluggable connectors and through conductors to form a mounting box according to any of claims 1 to 20, the method comprising: - providing a mounting box carcass with apertures for first and second pluggable connectors; - providing receptacles for receiving a plurality of rigid through 10 conductors; and - assembling a plurality of rigid through connectors and said first and second pluggable connectors into the mounting box carcass, the ends of the rigid through conductors entering terminal ports of the pluggable connectors to provide a series of through connections for electric supply. 15

28. A method of assembling a mounting box as claimed in claim 27, wherein the receptacles are formed integrally with the mounting box carcass, for example by moulding. 20

29. A method of assembling a mounting box as claimed in claim 27 or claim 28, wherein the method further comprises the step of wiring an electrical accessory to terminals of at least one pluggable connector within a mounting box and attaching the electrical accessory to the mounting box before the mounting box is attached within the trunking. 25

30. A method of assembling a mounting box as claimed in claim 29, wherein the step of wiring the electrical accessory is performed through one of said apertures prior to inserting the connector into its the aperture. 24

31. A mounting box for an electrical wiring accessory as hereinbefore described with reference to figure 1 of the accompanying drawings.

32. A mounting box for an electrical wiring accessory as hereinbefore 5 described with reference to figure 2 of the accompanying drawings.

33. A mounting box for an electrical wiring accessory as hereinbefore described with reference to figure 5 of the accompanying drawings. 10

34. An assembly for mounting in electrical trunking as hereinbefore described with reference to figures 3 and 4 of the accompanying drawings.