GB2112595A

GB2112595A - Electrical distribution board

Info

Publication number: GB2112595A
Application number: GB08233644A
Authority: GB
Inventors: Herbert Jackson
Original assignee: Dennis Vanguard International
Current assignee: Dennis Vanguard International
Priority date: 1981-11-26
Filing date: 1982-11-25
Publication date: 1983-07-20
Also published as: GB2112595B

Abstract

An electrical distribution board has rows of fuses (4) and bus bar (5) connectable to a mains supply. Shielding formations for the bus bar are built into the individual fuses so that when fuses are arranged in a row for use with a particular bus bar, the row of fuses provides shielding along the bus bar. The formations are channels formed by walls (12, 13) on each fuse, the open side of the channel being closed by a succession of L-shaped closure members (19) inserted in grooves of the channel to complete the shielding. End closures may be inserted into grooves to complete the shielding at the ends of the completed channel. <IMAGE>

Description

SPECIFICATION Electrical distribution board This invention relates to an electrica distribution board incorporating a plurality of fuses arranged in at least one row and each forming a respective connection with a live elongate bus bar of the board.

It is necessary, for safety reasons, to shield the live bus bar from inadvertent contact by a user when a fuse is removed from the board.

In sone conventional boards, the bus bar is housed within and shielded by an elongate channel, arranged adjacent to the row of fuses. In order to provide for different sizes of distribution board containing correspondingly differnt numbers of fuses, it is necessary either to provide a range of channels of different lengths to suit the varying requirements or to cut the channel to the desired length for use with a particular board.

An object of the invention is to provide an electrical distribution board in which the aforesaid inconvenience is avioded.

According to the invention, an electrical distribution board incorporates an elongate bus bar and at least one row of fuses connected thereto, each fuse including a shielding portion of a adjacent part of the bus bar whereby disposition of the fuses in said row provides a continuous shielding formation to prevent inadvertent access to the bus bar by a user.

Preferably, the shielding portion of each fuse is formed integrally with the fuse, as by moulding from plastics material. In one convenient practical arrangement, the fuse is of the kind having a fuse base and a fuse carrier adapted to form an assembly with the base, the shielding formation being preferably on the fuse base and conveniently in the form of a channel in the base.

Preferably, an open side and/or ends of the channel may be closed by removable closure members in order to complete the shielding formation. At least one of said members may perform the additional function of shielding a terminal of the fuse. One of the closure members may be lockable in its shielding position, conveniently by snap-engagement, and preferably acts to retain at least one other of the closure members in position.

The invention will also be understood to embrace a fuse having a shielding portion for a bus bar of a distribution board, the portion being arranged so that when a plurality of fuses is disposed adjacently in a row, said portions co-act to form a continuous shielding formation of a length dependent upon the number of fuses employed.

The invention will be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a view from one end, partly broken away, of one form of the distribution board of the invention; Figure 2 is a view, partly in cross-section, along the iine 2-2 of Fig. 1, of part of the board of Fig. 1, and Figure 3 is an exploded perspective fragmentary view of part of the board of Fig. 1.

Referring to Fig. 1 of the drawings, this shows an electrical distribution board having an open box-like casing 1, closed by a cover 2 which is shown broken away to facilitate illustration of the internal components of the board.

The casing 1 is provided at intervals with bearers 3 upon which are mounted respective rows of individual fuses 4, each row being associated with one phase of a multi-phase supply. For the usual three phase supply, three rows of fuses would be provided, but since the rows are identical, only two are illustrated, for convenience, the casing being shown as of variable length according to the number of rows of fuses employed. Each phase is supplied via a respective bus bar 5 connectable via a bar 6 and a main terminal 7 to the mains supply.

As will be seen more clearly from Figs. 2 and 3, the bar 6 is in the general form of a hook, with its end remote from the terminal 7 secured to the bus bar 5 by means of a screw 8 to form an electrical connection with the bus bar. In the embodiment shown, the screw 8 also performs the function of mechanically securing the bus bar to a terminal 9 of the fuse, electrical connection between the two being established via a bush 8A of brass or other suitable material. Other conventional means may be employed for this purpose, if desired. In this embodiment, the live terminal 7 and bar 6 are shielded by a housing 10 which spans two of the fuses (Fig. 1) and is provided with a cover 11 to complete the enclosure around these live components.

Other methods of shielding the live terminal may be employed, however, particularly for heavy duty boards. The other terminal of the fuse (not shown) carries the outgoing cable to the load, in conventional manner.

Figs. 2 and 3 illustrate the formation of the shielding for the bus bar along its length. The underside of each fuse is provided with a pair of integral opposed walls 12, 13, so as to form a channel which, in use, encloses the bus bar on three sides thereof. It will be seen that the juxtaposition in a row of the number of fuses required for a particular board, each row having eight fuses in the embodiment shown, will provide a channel of sufficient length to contain the bus bar 5. The open ends of the channel in the two end fuses of the row are blocked off by plates 1 4 inserted in pairs of opposed grooves 1 5 in the walls 12, 13, one of the plates 14 being shown in position in Fig. 3.In the event that the fuse were the be located at the opposite end of a row, the plate 1 4 would be inserted in the other pair of grooves 1 5 and is illustrated in broken lines in a position preparatory to insertion in the grooves.

The open side of the channel formed by the walls 12, 1 3 is closed by a succession of generally L-shaped closure members 16. One arm 1 7 of each member is relatively narrow and is inserted along a groove 1 8 of the fuse to cover a part of the terminal 9 which is normally unused but is adapted to provide an alternative form of connection to the terminal if required. The other arm 1 9 is dimensioned to rest snugly against rebated parts 20 of the walls 12, 13, to close off the channel as aforesaid. The arm 1 7 is provided with a pip 21 which performs a snap-engagement action against the fuse body to hold the closure member 1 6 in position and since the member 1 6 overlies the edges of the plates 14, it also retains the latter in position, avoiding the necessity for additional retaining means for those plates.

It will be seen that the invention provides a particularly simple and adaptable means of shielding a bus bar in a distribution board, avoiding the problems of sone conventional arrangements enumerated above. The channel formed in each fuse may be of any convenient shape and dimensions and the various closure plates may be retained in position by any convenient means, such as by snap-engagement, instead of or in addition to the means described above.

Claims

1. An electrical distribution board comprising an elongate bus bar and at least one row of fuses connected thereto, each fuse including a shielding portion for an adjacent part of the bus bar whereby disposition of the fuses in said row provides a continuous shielding formation to prevent inadvertent access to the bus bar by a user.

2. A distributuion board according to Claim 1 wherein the shielding portion of each fuse is formed integrally with the fuse.

A distribution board according to Claim 1 or Claim 2 wherein the fuse includes a fuse base and a fuse carrier adapted to form an assembly with the base, the shielding formation being on the fuse base.

4. A distribution board according to Claim 3 wherein the shielding formation is in the form of a channel in the base.

5. A distribution board according to Claim 4 wherein an open side and/or ends of the channel are closed by removable closure members to complete the shielding formation.

6. A distribution board according to Claim 5 wherein at least one of said members performs the additional function of shielding a terminal of the fuse.

7. A distribution board according to Claim 5 or Claim 6 wherein each of said closure members closing the open side of the channel is generally L-shaped and one arm thereof slides along a complementary retaining groove in a wall of the channel, thereby bringing the other arm to a position in which it closes said open side of the channel.

8. A distribution board according to Claim 5 wherein the closure members which close the open longitudinal ends of the channel are end plates engaged in grooves in the walls of the channel.

9. A distribution board according to Claim 8 when dependent on Claim 7 wherein each said end plate present is retained in position by said other arm of the adjacent generally Lshaped member.

10. A distribution board according to any one of Claims 7 to 9 wherein said one arm of each L-shaped closure member is provided with a formation for engagement with an adjacent part of the fuse base to retain said member in position.

11. A distribution board according to any one of the preceding claims wherein, for each row of fuses, a cover is provided to shield a live terminal lying externally of the shielding formation formed by the fuses, said cover embracing a portion of said formation.

1 2. A distribution board substantially as hereinbefore described with reference to the accompanying drawings.

1 3. A fuse for a distribution board according to any one of the preceding claims comprising a shielding portion for a bus bar of a distribution board, the portion being arranged so that when a plurality of fuses is disposed adjacently in a row, said portions co-act to form a continuous shielding formation of a length dependent upon the number of fuses employed.

14. A fuse according to Claim 1 3 comprising a fuse base and a fuse carrier adapted to form an assembly with the base, the shielding formation being on the base.

1 5. A fuse according to Claim 14 wherein the shielding formation is in the form of a channel in the base.

1 6. A fuse according to Claim 1 5 wherein an open side and/or ends of the channel are closed by removable closure members to complete the shielding formation.

1 7. A fuse according to Claim 16 wherein each of said closure members closing the open side of the channel is generally L-shaped and one arm thereof slides along a complementary retaining groove in a wall of the channel, thereby bringing the other arm to a position in which it closes said open side of the channel.

1 8. A fuse according to Claim 1 7 wherein the closure members which close the open longitudinal ends of the channel are end plates engages in grooves in the walls of the channel.

1 9. A fuse according to Claim 18 when dependent on Claim 9 wherein each said end plate present is retained in position by said other arm of the adjacent generally L-shaped member.

20. A fuse according to any one of Claims 1 7 to 1 9 wherein said one arm of each Lshaped closure member is provided with a formation for engagement with an adjacent part of the fuse base to retain said member in position.

21. A fuse substantially as hereinbefore described with reference to Figs. 2 and 3 of the accompanying drawings.