GB2130439A - Enclosure for electrical components - Google Patents

Abstract

An enclosure to contain electrical circuit elements such as circuit-breakers 4 has a base 1 having pillars 28 on its underside for attachment to a wall with a gap between the base and wall and a cover extending to the wall having aperture portions 11 allowing cables to pass from the outside of the enclosure into the gap. The circuit elements are mounted on the upper side of the base, and a hole (12, Figure 1) is provided in the base allowing cables to pass upwards from the gap. <IMAGE>

Description

SPECIFICATION Enclosure for electrical components This application relates to enclosures intended to contain electrical circuit components such as circuitbreakers.

Such enclosures for domestic or industrial use comprise a base on which the components are mounted and a cover to fit over the base. The base of the enclosure is commonly mounted on a wall and cables are led into the enclosure either through the wall or through apertures formed in the sides of the enclosure.

In a modern installation the enclosure may contain a large number of circuit-breakers or other electrical accessories forming parts of a large number of circuits each of which requires a cable entering the enclosure. The interior of the enclosure then becomes crowded with cables, restricting access to the circuit components to which they are connected. The presence of these cables effectively reduces the number of accessories which may be installed in an enclosure of given size. Moreover, when the cables enter the enclosure through apertures in the sides there is a risk of entry of water or other unwanted material which could cause electrical malfunctions on contact with exposed circuit elements in the enclosure.

According to one aspect of the present invention there is provided an enclosure for electric components comprising a base capable of supporting electric components on its upper side and having pillars on its lower side so that it may be mounted on a wall with the pillars in contact with the wall and with a gap between the base and the wall, and a cover fitting over the base and said components and extending to the wall, the cover having aperture portions allowing cables to pass from the outside of the enclosure into said gap and the base having a hole allowing the cables to pass from the gap to the upper side of the base.

The aperture portions may be cut-out portions and may be closed by slides fitting into grooves in the edge of the cover so that the cut-out portions which are not required may be closed. Cut-out portions may be provided on all the sides of the cover so that cables may be led into the enclosure from any direction.

In an alternative arrangement the aperture portions comprise weakened wall portions which may be knocked out to form the required apertures. When the enclosure is installed only the knock-out portions at the locations where passage of cables is required need be knocked out. With both arrangements the apertures may be provided with angled lips to direct any foreign object, such as a screwdriver, inserted into the aperture away from the base and hence away from electrically live components mounted on the upper side of the base.

Enclosures according to embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure lisa plan view of the base of an enclosure, Figure 2 is a cross-section along A-A of Figure 1 showing the base with a cover applied therein, Figure 3 shows the cover of Figure 2.

Figure 4 is a plan view similar to Figure 1 of another enclosure, Figure 5 is a cross-section along A-A of Figure 4 with a cover applied to the base, Figure 6 is a cross-section along B-B of Figure 4 with a cover applied to the base.

The enclosure shown in the drawings comprises a body of plastics material moulded as a single piece and forming a base 1. The upper side of the base has a pair of upstanding flanges 2 having outwardly turned edges 3 forming a mounting rail of the DIN or Top Hat type to support a line of miniature circuitbreakers 4 of a standard type; one of these circuitbreakers is shown in broken lines in Figure 2. A copper bus-bar 5 is connectable to the circuitbreakers by means of terminals 6. The bus-bar is provided with a clip-on protective cover 7 of plastics material. The bus-bar may be positioned in such a manner that each circuit-breaker may be removed without displacing the other circuit-breakers connected to the bus-bar.

A number of screw terminals 8 are mounted on bars 21 of electrically insulating material which are secured to pillars 22 on the upper surface of the base by screws 23.

When the circuit-breakers are mounted on the rail formed by flanges 2 one terminal of each circuitbreaker will be connected to a terminal 6 on the bus-bar in known manner and the other terminal of the circuit-breaker will be connected to a cable leading out of the enclosure connecting the circuitbreaker in the circuit which the circuit-breaker protects.

The terminals 8 may be numbered or otherwise coded to identify the circuits to which they relate.

The arrangement shown is one used for a singlephase system but a similar arrangement may be used for a poly-phase system, a number of parallel bus-bars then being provided corresponding to the number of phases.

The underside of base 1 is provided with pillars 28 integral with the base having holes 9 to receive screws 10, one of which is shown in Figure 2, for mounting the base on a wall or the like. The pillars are separated by open spaces 11 through which cables, not shown, may pass from the outside of the enclosure to the gap between the base and the wall.

As may be seen from Figure 1 three such pillars are provided and the greater part of the periphery of the base has open spaces 11 so that cables may pass into the gap between the plate and the wall from practically any direction.

The base has a hole 12 allowing cables to pass through the base for connection to the circuit elements mounted on the upper surface of the base.

The open spaces may be provided with angled lips to direct any objects inserted in the spaces after installation of the base away from the lower surface of the base.

The base may be provided with portions such as 30 (Figure 2) upstanding from its plane to provide increased space for the cables in the gap between the base and the wall.

The base is covered with the cover of plastics material shown separately in Figure 3. The cover fits over the base and is secured thereto by screws passing through holes 13 to engage internally threaded holes 14. The cover is provided with hinged lid 15 to allow access to the circuit breakers or other components mounted on rail 2. The edge of the cover abutting the wall on which the enclosure is mounted has cut-out portions 16 to allow wires and cables to pass through the cover. The cut-out portions are normally occupied by slides which fit into grooves formed in the thickness of the cover surrounding the cut-out portion and when the cover is applied to the base these slides may be removed or left in place to close the cut-out as required. When the cover is fitted the slides need be removed only from the cut-outs through which cables pass, the other cut-outs being closed.

When the enclosure is installed the cables connected to the circuit elements within the enclosure enter through a cut-out in the base, pass through the gap between the wall and the base and then pass through hole 12 for connection to an appropriate terminal. As there are no exposed electrically live elements in the gap between the base and the wall there is little risk of a foreign object passing through an open cut-out becoming electrically live.

The embodiment shown in Figures 4, 5 and 6 is similar to that of Figures 1-3 and like parts are denoted by like reference numerals. However in this embodiment the aperture portions are formed by a number of knock-outwall portions 41 which are arranged at intervals along the walls and are weakened at their edges 42, as shown in Figure 6, so that they are readily knocked out when the enclosure is installed to form the aperture allowing passage of a cable. Each knock-out portion is dimensioned to allow easy passage therethrough of a single cable.

In the embodiment of Figures 4 to 6 the means for supporting the circuit-breakers comprises a metal rail 43 which is secured to the base 1 by screws or other fastening means and is provided with flanges to form a mounting rail of the DIN type as in the embodiments of Figures 1-3. The circuit-breakers are mounted on the rail in the same way. The terminals 8 in the embodiment of Figures 4-6 are formed by holes 44 and clamping screws 46 in a bar 45 of electrically insulating material which is secured to the base either by screws 47 or by moulded catches.

In both embodiments the hole 12 is dimensioned and positioned to allow cables passing through the aperture portions into the space between the base and the wall to be connected easily to terminals and accessories mounted on the upper surface of the base, while allowing the base to prevent other objects inserted through the aperture portions into the space coming into contact with exposed metal members insidethe enclosure which may be electrically live. In both embodiments the base is of electrically insulating material, generally a plastics material, whereas the cover may be of plastics material or of metal; when the cover is of metal provision should be made for connecting it to earth.

In both embodiments described access to the interior of the enclosure is obtained by means of lid 15. However when access to the enclosure interior is not normally required after installation the lid will not be necessary and the front surface of the enclosure may then comprise a simple wall.

The enclosures described above are neat in appearance, flexible in use, and easy to manufacture and install.

The enclosures have been described in relation to circuit-breakers but it will be understood that like enclosures may be used for housing other types of circuit component.

Claims (9)

1. An enclosure for electric components comprising a base capable of supporting electric components on its upper side and having pillars on its lower side so that it may be mounted on a wall with the pillars in contact with the wall and with a gap between the base and the wall, and a cover fitting over the base and said components and extending to the wall, the cover having aperture portions allowing cables to pass from the outside of the enclosure into said gap and the base having a hole allowing the cables to pass from the gap to the upper side of the base.

2. An enclosure according to claim 1, in which said aperture portions comprise cut-out portions of the edge of the enclosure adjacent the wall and removal slides fitting in grooves in the cover to close the apertures.

3. An enclosure according to claim 1, in which said aperture portions comprise weakened portions of the cover which may be knocked out to form apertures.

4. An enclosure according to any preceding claim, in which the aperture portions are provided with angled lips to direct any objects inserted through the aperture portions into the space between the base and wall away from the base.

5. An enclosure according to any preceding claim, in which the upper side of the base is provided with a mounting rail for supporting a iine of similar electrical components side-by-side and a bus-bar to be connected to the components.

6. An enclosure according to claim 5, in which the base is of moulded plastics material and the mounting rail is integral with the base and formed on moulding thereof.

7. An enclosure according to any preceding claim, in which the cover is provided with an opening to allow access to the components from the outside of the enclosure and a lid to close the opening.

8. An enclosure according to any preceding claim, containing a plurality of ci rcuit-breakers supported on the upper side of the base.

9. An enclosure for electric components substantially as hereinbefore described with reference to Figures 1 to 3 or Figures 4 to 6 of the accompanying drawings.