Electrical distribution boards are generally used in buildings in which a three phase electrical power supply fed into the building is connected to the distribution board, and output leads from the board are supplied to individual power supply circuits at distributed locations around the building. The distribution board generally has three live inputs, one for each phase, a neutral input and an earth input, and corresponding output terminals for each power supply circuit to be supplied. Miniature circuit breakers are often connected to each of the output terminals and are actuated by the occurrence of faults on the lead connected to the particular terminal in question.

Existing distribution boards suffer from the disadvantage that the construction of the board is constrained by the necessity to dissipate heat generated by current flow in the electrical conductors. In addition, the connection of miniature circuit breakers to each terminal of the device hampers compact construction of the distribution board.

Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art.

According to the present invention, there is provided an electrical power supply distribution board, the board comprising: a plurality of electrical conductors, each said conductor comprising an elongate body portion, an input terminal provided adjacent one end of the body portion, and a plurality of output terminals provided at spaced apart locations along the body portion, wherein said body portions in use extend substantially parallel to each other with said input terminals arranged adjacent each other; electrical insulation means for electrically insulating said body portions from each other; and a thermally conductive support member adapted to be mounted to a base and comprising a receiving portion for receiving said elongate body portions and dissipating heat generated therein, and at least one support portion for supporting circuit breaker means connected in use to said output terminals.

By providing a support member which performs the dual purpose of acting as a heat sink and as a support for mounting circuit breaker means thereto, this gives the advantage of enabling a particularly compact construction of the distribution board.

In a preferred embodiment, the receiving portion comprises a receiving channel for receiving said elongate body portions and extending substantially along the length thereof, and at least one substantially hollow channel provided in use between the receiving channel and a base to which the support member is mounted.

This provides the advantage of enabling a particularly efficient construction of the support member. In particular, when the channels are arranged vertically, air flow through the channels in use permits particularly effective cooling.

In a preferred embodiment, the or each said support portion is substantially flat and is provided adjacent said receiving channel.

Preferably, the insulation means extends substantially along the length of said elongate body portions and comprises a respective slot for receiving each said body portion and is adapted to be received in said receiving channel.

In a preferred embodiment, the output terminals in use extend substantially laterally of both sides of the associated body portion.

By providing output terminals extending laterally on both sides of the associated body portions, a distribution board having a large number of output terminals can be constructed in a compact manner, for example by interspersing the output terminals of different conductors.

The output terminals may be substantially flat.

Preferably, selected ones of said conductors in use carry respective live phases.

In a preferred embodiment, a selected said conductor in use is a neutral connector.

The construction of the distribution board having four conductors gives the advantage of enabling particularly compact and efficient construction of the distribution board.

The distribution board may comprise circuit breaker means comprising a plurality of circuit breakers mounted to respective said output terminals.

The distribution board may further comprise electrical insulation means for covering exposed parts of said conductors.

This provides the advantage of minimising the risk that personnel may be inadvertently exposed to live components of the distribution board.

The electrical insulation means may comprise a plurality of retaining clips adapted to cover respective upper portions of the output terminals.

Alternatively, or in addition, the electrical insulation means may comprise an end cap for covering the ends of the electrical conductors remote from the input terminals.

Alternatively, or in addition, the electrical insulation means may comprise a housing for receiving the input terminals.

In a preferred embodiment, the distribution board further comprises a housing, wherein the housing comprises a plurality of elements removably surrounding a base to which the support member is mounted.

By providing a housing having a plurality of removable elements, this gives the advantage of facilitating installation of the distribution board by permitting easier access to cables during installation as a result of removal of the elements.

Alternatively, the housing may be constructed from a single element.

An aid to understanding the invention, a preferred embodiment thereof will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings in which: Figure 1 is an exploded schematic view of an electrical distribution board embodying the present invention and with the base and housing thereof removed for clarity of illustration; Figure la is a perspective view of an electrical conductor of the distribution board of Figure 1; Figure 2 is a perspective view of the distribution board of Figure 1 in the assembled condition and mounted to a base; and Figure 3 is an exploded view of a housing surrounding the distribution board of Figure 2.

Referring to Figure 1, an electrical distribution board 1 comprises three live electrical conductors 2, representing the red, yellow and blue live phases respectively, and of which the blue phase conductor is shown in detail in Figure la. A fourth conductor 3 for carrying the neutral phase is shown in dotted line in Figure 1. Two alternative embodiments are envisaged, one in which the neutral phase is carried by conductor 3, and one in which the three conductors 2 carrying respective live phases are not accompanied by a fourth conductor 3, the neutral phase being carried by alternative means as described below.

Referring to Figure la, each of the conductors 2 (and conductor 3 if present) comprises an elongate flat body member 4 having a generally flat input terminal 5 arranged at one end thereof and generally at right angles thereto. A series of output terminals 6 extend generally transversely to the body portion 4 from both sides thereof at spaced apart locations thereon, and the spacing between output connectors 6 is chosen such that when the conductors 2 (and conductor 3 if present) are arranged with their respective body members 4 parallel and adjacent to each other as shown in Figure 1, the output terminals 6 of each conductor are interspersed between those of other conductors to provide a series of output terminals of alternating red, yellow and blue phase (and neutral if the fourth conductor 3 is present).

An insulating liner 7 of extruded plastics material has a series of vertically extending channels 8 therein for tightly receiving the body portions 4 of the conductors. The liner 7 extends generally along the entire length of the body portion 4 to prevent arcing between body portions 4 of adjacent conductors.

An extruded aluminium main body 9 is mounted to a base plate 10 (see Figure 2) and comprises an upper receiving channel 11 for tightly receiving the liner 7 when the body portions 4 are received therein so as to be in good thermal contact with the liner 7. The main body 9 also comprises a pair of open ended channels 12 extending generally parallel to the upper receiving channel 11 and arranged between the receiving channel 11 and the base plate 10, and a support member 13 arranged on each side of the upper channel 11.

A plurality of miniature circuit breakers 14 (of which only one is shown in Figure 1) are adapted to be mounted to the support members 13 by means of clips (not shown) such that when the conductors 2 and liner 7 are received within the receiving channel 11, a miniature circuit breaker 14 can be mounted to the ends of each output terminal 6 of the conductors 2 in rows as shown in Figure 2. As will be appreciated by persons skilled in the art, the distal end of each output terminal 6 is received in a corresponding slot in a respective circuit breaker 14.

An interconnection box 15 is mounted to the end of the main body 9 and accommodates the input terminals 5 of the conductors 2 (and conductor 3 if present) such that live parts of the conductors are not exposed. This serves to minimise the risk of inadvertent contact by personnel of live parts of the apparatus. Interconnection links 16 (of which only one is shown in Figure 1) are connected to each input terminal 5 and each includes a connector portion 17 which extends through a corresponding slot 18 in the interconnection box 15 to enable connection to a cooperating miniature circuit breaker 19, of generally identical construction to the miniature circuit breakers 14.

In the arrangement shown in Figures 1 and 2 in which no neutral conductor 3 is present, three miniature circuit breakers 19 are shown, although persons skilled in the art will appreciate that four circuit breakers 19 will be present in the other embodiment. In the three conductor embodiment, a pair of shrouds 20 are provided to accommodate input and output connections for the neutral phase.

At the end of the receiving channel 11 remote from the interconnection box 15, a busbar end cap 21 covers the exposed ends of the connectors 2, and the upper portions of the output terminals 6 of the connectors 2 not accommodated within the slots of the miniature circuit breakers 14 are covered by a series of busbar retaining clips 22 in order to prevent inadvertent exposure to the live output terminals 6. An extruded label carrier 23 indicating the phases of the live output terminals (as shown in Figure 2) is mounted over the bus bar retaining clips 22.

The operation of the distribution board shown in Figures 1 and 2 will now be described.

In the assembled three conductor embodiment shown in Figure 2, the distribution board 1 is connected to a single three phase supply input (not shown), the three live phases being connected to the supply via miniature circuit breakers 19. The neutral connection of the supply input (not shown) is connected via a connection accommodated in one of the shrouds 20. The red, yellow and blue live phases are supplied to respective conductors 2 by means of the connection between interconnection links 16 and input terminals 5, and are then supplied to individual electrical supply circuits (not shown) via sets of output connectors 6 and miniature circuit breakers 14. In this manner, and in conjunction with individual neutral outputs from one of shrouds 20 and earth contacts 24, electrical power is supplied to individual power supply circuits located around the building in which the distribution board 1 is installed.

Referring now to Figure 3, it can be seen that the assembled distribution board can be located within a housing 25 having a closable cover plate 26 and an internal cover plate 27 for further reducing the risk of inadvertent exposure of personnel to live parts of the distribution board 1.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.