GB2230901A

GB2230901A - Electrical distribution board equipped with disconnectors

Info

Publication number: GB2230901A
Application number: GB9008670A
Authority: GB
Inventors: Patrick Aubelis; Gary Manning
Original assignee: Merlin Gerin SA
Current assignee: Merlin Gerin SA
Priority date: 1989-04-26
Filing date: 1990-04-18
Publication date: 1990-10-31
Anticipated expiration: 2010-04-18
Also published as: FR2646568B1; AU622793B2; FR2646568A1; ZA903131B; AU5380290A; GB2230901B; GB9008670D0

Abstract

A mounting plate (10) for mounting electrical moulded case components such as circuit breakers (15) has an insulating block (22) containing a set of busbars (16, 18, 20) for supplying power to the components (15). In the insulating block (22) lateral connections (40) are connected to the busbars and extend into connection pads (46, 52) projecting laterally from the insulating block (22) so as to be connectible with the terminals (58) of the components (15) placed against the block (22). Each connection pad (46, 52) is associated with a switch (64, 66) which in the open position isolates the connection pad from the associated busbar (16) and in the closed position connects the input terminal (58) to the busbar (16). The switch (64, 66) bears an interlocking lug (92) which covers the edge (90) of the circuit breaker (15) and blocks the orifice giving access to the screw (60) of the terminal (58) to prevent any dismantling of the circuit breaker when the associated disconnector (64) has not been moved into the open position. <IMAGE>

Description

Description of Invention ELECTRICAL DISTRIBUTION BOARD EQUIPPED WITH DISCONNECTORS The invention relates to an electrical distribution board comprising - a plate for mounting electrical moulded case equipments, which are latched or secured onto a shaped support integral with the mounting plate, - a set of busbars extending parallel to said shaped support to supply power to said equipments, spaced out along the busbars having input terminals adjacent to this set of busbars, - lateral connections linking said input terminals to said set of busbars.

A typical electrical distribution board by definition is a factory - built assembly of switchgear and control gear for voltages up to and including 1000V ac and 1200V dc, with additional particular requirements for multi-pole and/or single pole miniature circuit.breakers (MCB's) boards and consumer units.

The basic constituent components for a typical distribution board are: - A formed metal or insulated enclosure to prevent persons from accidental contact w-ith live or moving parts contained therein and to protect internal equipment against external effects.

- A removable cover which is designed for closing an opening in the external enclosure and which can be removed for carrying out certain installation operations and maintenance work.

- A hinged door which gives access to the switchgear and control gear for normal operation of devices only but not for carrying out certain installation operations and maintenance work referred to above.

- A base or pan assembly comprising a plate that supports the busbar assembly and all outgoing devices relative to the incoming supply, this plate being attached to the enclosure.

- A single or multi-pole set of busbars insulated from the pan assembly and each other. There are broadly two -types of distribution board type 'A' and type 'B'. The type 'A' board, consists of a single phase set of copper busbars and the 'B' type board a three phase set, the 'A' type board being designed to incorporate single pole MCB's only and the 'B' type board being designed to incorporate both multi-pole and single pole MCB's respectively.

- An incoming arrangement to the busbar assembly via direct connections or some other device affording isolation locally at the incoming terminals.

- An outgoing arrangement from the busbar assembly via a fixed or removable copper link to each outgoing device.

- A neutral bar mounted on insulated standoff with a connection point for every single pole circuit. Some manufacturers supply an isolatable link for the incoming terminal of the 'B' type distribution board.

- An earth bar mounted directly to the enclosure with a connection point for each single pole circuit. A more recent innovation is to isolate this bar from the enclosure thus creating a clean earth.

It is an objective of the present invention to provide an electrical distribution board with the maximum shrouding of live parts.

The electrical distribution board according to the invention is characterised in that said set of busbars and said lateral connections are integrated into an insulating block, from which the extremities of said lateral connections project laterally to constitute connection pads to said input terminals and in that a disconnector, incorporated in said insulating block, is inserted into each one of said lateral connections to isolate, in the open position, the pad corresponding to the busbar and to connect, in the closed position, the inlet terminal to the associated busbar, and that said disconnector comprises a control handle accessible from the exterior of said insulating block.

The mounting plate is preferably designed to receive two columns of electrical equipments located on either side of a busbar unit, extending vertically in a manner well known to specialists. The circuit breakers or the circuit breaker poles, arranged opposite one another, are connected to one same lateral connection, and hence to the same busbar. In the case of a three-pole board described in detail below, the three busbars extend in a plane parallel to the mounting plate and they are integrated into a base of insulating material, secured or latched onto the mounting plate. The lateral connections extend in a plane parallel to the mounting plate at the level of the upper surface of the base, in a direction perpendicular to the longitudinal direction of the busbars.The connection lugs formed by the ends of the lateral connections each present a break in continuity, or are separated from their lateral connections by an insulating gap, which can be bridged by the disconnector in the closed position. The disconnector is preferably arranged as a sliding part which moves in the direction of the lateral connections to occupy two positions selectively, one being a closed position corresponding to the bridging of the break in continuity and the connection of the pad to the lateral connection, and the other corresponding to an open position in which the connection pad is isolated from the associated lateral connection. The disconnector has a control switch accessible on the front of the insulating block.

The disconnector preferably includes two flexible blades arranged as a jumper overlapping two fixed contact pads, one integral with the connection pad, and the other integral with the lateral connection. The two contact pads are separated by an insulating distance constituting the break in continuity between the connection pad and the lateral connection, and the sliding part electrically links the two fixed contact pads when it is moved into the closed position. The fixed contact pads and the moving sliding part are located on the insulating base and the assembly is covered by an insulating cap or cover, preventing any access to live parts. The disconnector handle is accessible from the front face of the cover which can be latched onto the base in a manner well known to specialists.

In accordance with an important development of the invention, the disconnector has an interlocking lug which is moved into a position of interlocking the associated circuit breaker when the sliding part of the disconnector is in the closed position. The inlerlocking lug integral with the sliding part projects out of the insulating block when the disconnector is in the closed position, and it then interacts with the circuit breaker unit to interlock the latter and prevent any dismantling. The overlapping lug is designed to cover the orifice giving access to the screw of the circuit breaker terminal when in the interlocked position. This overlapping position prevents access to a live part on the one hand, the screw of the terminal in this case, and on the other hand any unscrewing and thus any electrical disconnection of the circuit breaker from the connection pad, whilst the disconnector is in the closed position. The withdrawal of a circuit breaker previously requires the sliding of the disconnector into the open position on the one hand in order to give access to the screw of the terminal, and on the other hand to permit the raising of the moulded case for its electrical and mechanical disconnection. The spacing of the connection pads naturally corresponds to the module of the modular system of electrical equipments, the terminals being connected successively to busbars 1, 2 and 3 to permit the connection of a multiple-pole equipment of individual poles protecting the three phases of a three-phase network.The withdrawal of a three-phase circuit breaker naturally requires the movement into the open position of the three associated disconnectors.

The invention is applicable to an insulating block which has only two bars or a greater number of bars, depending on whether the distribution is of the single-phase or polyphase type.

Other advantages and characteristics will be revealed more clearly by the following description of an embodiment of the invention, given as a non-restrictive example, and illustrated on the enclosed drawings, in which: - figure 1 is a plan view of a distribution board according to the invention, the lower part of the figure showing an insulating block with the cover or cap removed, no circuit breaker being shown, - figure 2 is a cross section along the line II-II of figure 1, showing on the left part a circuit breaker connected to the set of busbars, - figure 3 is a schematic perspective view showing the electrical connections and the disconnectors of the insulating block according to figure 1.

On the figures, an electrical distribution board has a mounting plate 10, for example in metal, the two edges of which 12, 14 are shaped to permit the latching-on of moulded cases, for example of modular electrical apparatus such as miniature circuit breakers 1 5. In the central part of the mounting plate 10 a set of busbars 16, 18 and 20 is secured, incorporated in an insulating block 22 which extends parallel to the shaped edges 12 and 14. The insulating block comprises an insulating base 24 secured by latching hooks 26 Into orifices 28 of the mounting plate 1 0. The base 24 is covered by a cover or cap 30, which itself is latched by hooks 31 onto the base 24. The three flat bars 16, 18 and 20 of the set of three-phase busbars are arranged in corresponding recesses 32, 34 and 36 of the base 24, and extend in a plane parallel to the mounting plate 10.On the front surface 38 of the base 24 are located transverse connections 40, 42 and 44, three only of which are visible on the figure 1, the other three being obscured by the cover 30. These transverse connections 40, 42 and 44 are spaced regularly along the set of busbars 16, 18 and 20, and naturally they can be greater in number if the length of the busbars, 16, 18 and 20 and hence the length of the distribution board are longer. The transverse connections 40, 42 and 44 are regularly spaced with a gap corresponding to the pitch of the modular system, this being 18 mm in the case of the system commercially known as "multi 9".The lateral or transverse connections 40, 42 and 44 are extended on either side by connection lugs or pads 46, 48, 50, 52, 54 and 56 which project laterally from the insulating unit 22 and are separated from the lateral connection by a break in continuity or an insulating gap of a length '1x". The connection lugs 46, 48, 50, 52, 54 and 56 are located at the level of the terminals 58 of the poles or circuit breakers 15, likely to be mounted on the mounting plate 10. When the circuit breaker 15 is put into position, the terminal 58 slides onto the corresponding connection lug 46, 48, 50, 52, 54, 56, and the tightening up of the screw 60 of the terminal 58 permits securing and electrical connection of the circuit breaker 15 to the set of busbars 16, 18 and 20.In the position shown on the left part of figure 2, we see that the circuit breaker 15 has, in the usual manner, a securing latch 61 latching onto the shaped edge 12 to prevent any inadvertent removal. The small surface of the moulded case of the circuit breaker 15 carrying the terminal 58 is placed against the lateral surface of the insulating block 22 and held in this side-by-side position by the terminal 58 gripping the connection lug 46. Each connection lug 46, 48, 50, 52, 54 and 56 is connected to a pole of a circuit breaker 1 5 whose moulded case extends transversally to the set of busbars 16, 18 and 20, the successive cases being placed side-byside in a manner well known to specialists.Each lateral connection 40, 42, 44 is connected by a connection tag 62 to one of the bars 16, 18, 20, the electrical link being made either by screws or rivets or any other suitable method.

It is easy to see that a busbar supplies power through the opposing connection pads 46, 52; 48, 54; and 50, 56 to two circuit breakers 15 arranged facing one another. The first lateral connection 40 is for example connected to the first busbar 16, the following lateral connections 42 and 44 being connected to the busbars 18 and 20 respectively.

In accordance with this invention, each lateral connection 40, 42 and 44 has two disconnectors 64 and 66, each associated with one of the connection pads 46, 52 to bridge the insulating gap "x". By referring more especially to figure 3, we see that the connection pad 46, 52 which is flat in shape has on its upper surface a pad with fixed contacts 68, 70 arranged in line with an opposing pad of fixed contacts 72, 74 integral with the upper surface of the transverse connection 40. The fixed contact pads 68 to 74 are arranged in a same plane, perpendicular to the busbars 16, 1 8 and 20 and they are spaced two by two, separated by an interval corresponding to the interval of the break in continuity "x".A sliding part 76, 78 in the form of a yoke carrying two contact blades 80 combines with each of the pairs of fixed contacts 68, 72; 70, 74 to connect electrically the connection pads 46, 52 in the closed position with the transverse connection 40, or conversely to isolate these connection pads 46, 52 in the open position of the disconnector 64, 66. The yokeshaped part 76 and the flexible contact blades 80, arranged as a contact bridge, can comprise a single part folded and shaped to produce contact fingers in the form of a bridge clasping the fixed contact pads 68, 72; 70, 74. The yoke-shaped part 76, 78 is embedded in an insulating part 82, 84 which has on the front or upper part a knob or control handle 86 projecting from the insulating block 22 through an elongated aperture 88.

It is easy to see that the disconnectors 64, 66 can be controlled by the handles 86 to displace, in the direction of the transverse connection 40, the moving equipment in particular the gripper contacts 80 to bring the latter into the closed position of the disconnector shown on the left part of figure 2, in which the gripper contacts 80 overlap the gap "x" separating the fixed contact pads 68, 72. By sliding in the opposite direction, the contact bridges 80 can be brought into the open position of the disconnector, shown on the right part of figure 2.

The moving part is guided by the fixed contact pads and by a groove 88 made in the cover 30 of the insulating block 22.

Naturally, it is possible to provide additional guiding parts, integral in the cover 30. The disconnectors 64, 66 can be controlled independently of one another. The disconnectors of the other lateral connections 42, 44 are identical to those described above, associated with the lateral connection 40, and each of these disconnectors can be controlled individually. In the case of connecting a multiple-pole circuit breaker 15, it is possible to couple the handles 86 of the associated disconnectors to obtain isolation of the connection pads of the different poles in one single operation.

Referring to figure 2, we see that the height of the insulating block 22 is slightly greater than that of the edge 90 of the moulded case of the circuit breaker 15, and that the insulating piece 82 of the disconnector sliding piece bears an interlocking lug 92 extending in the direction of the connection pad 46. In the closed position of the disconnector 64, shown on the left part of figure 2, the lug 92 projects laterally from the insulating block 22 through a matching aperture and covers the edge 90 in such a way as to interlock the moulded case in its position mounted on the mounting plate 10. In this closed position of the disconnector 64, the interlocking lug overlaps and covers the orifice 94 giving access to the screw 60 of terminal 58. It may be seen that in the closed position of the disconnector 64, no live part in particular the screw 60, is accessible.Similarly, it is impossible to yain access to and to unscrew the screw 60 whilst the disconnector 64 is closed. Any incorrect operation is thus excluded and before any attempt to dismantle and withdraw the circuit breaker 15, the disconnector 64 must obligatorily be brought into the open position corresponding to withdrawal of the interlocking lug 92 which releases the orifice giving access 94 to the screw 60. The position of the disconnectors 64, 68 can be identified by any suitable means, in particular by the appearance of the customary symbols 0, 1 in the orifice 88 make in the cover 30.

Withdrawal of an equipment 1 5 requires the prior movement of the associated disconnector into the open position, which prevents any incorrect operation. The disconnectors are incorporated into the insulating block containing the set of busbars, the dimensions of which are practically not increased, the structure of the assembly being particularly simple. It is evident that the bridge of the disconnector contacts can be made differently and in particular can be of the type with movement perpendicular to the fixed contacts, or the disconnector can be of the pivoting contact type. The disconnector can also be incorporated into the link between the lateral connection and the associated busbar.

Naturally, the invention is in no way restricted to the embodiment described in detail.

Claims

1. Electrical distribution board comprising: - a mounting plate (10) for electrical moulded case equipments (15), which are latched or secured onto a shaped support (1 2, 1 4) integral with the mounting plate, - a set of busbars (16, 18, 20) extending parallel to said shaped support (12, 14) to supply power to said equipments (1 5), spaced along the set of busbars and having input terminals (58) adjacent to this set of busbars, - lateral connections (40, 42, 44) linking said input terminals (58) with said set of busbars (16, 18, 20), characterised in that said set of busbars (1 6, 18, 20) and said lateral connection (40, 42, 44) are integrated into an insulating block (22), from which the extremities of said lateral connections project laterally to constitute connection pads (46 - 56) to said input terminals (58) and in that a disconnector (64, 66) incorporated into said insulating block (22), is inserted into each of said lateral connections to isolate, in the open position, the corresponding pad from the busbar and to connect, in the closed position, the input terminal (58) to the associated busbar (16, 18, 20), and in that said disconnector (64, 66) has a control handle (86) accessible from the exterior of said insulating block (22).

2. Distribution board in accordance with claim 1, characterised in that said lateral connections (40, 42, 44) with their connection pads (46 - 56) are spaced regularly with a gap corresponding to that of the poles of said equipments (15), these poles extending in alignment with the associated lateral connections.

3. Distribution board according to claim 1 or 2, characterised in that equipments (15) are arranged on either side of said insulating block (22) which has connection pads (46 - 56) on both sides, each associated with a disconnector (64, 66).

4. Distribution board according to claim 1, 2 or 3, characterised in that said disconnector (64, 66) has a sliding part (76 - 82) moving transversally in the direction of the associated lateral connection (40, 42, 44), which comprises break in continuity (x) capable of being bridged by said sliding part (76 - 82) in the closed position of the disconnector.

5. Distribution board according to claim 4, characterised in that said sliding part (76 - 82) comprises an interlocking lug (92) which in the closed position of the disconnector (64, 66) projects laterally from the insulating block (22) to interlock the latter onto the mounting plate (10).

6. Distribution board according to claim 5, characterised in that said interlocking lug (92) combines with the upper edge (90) of said moulded casing in such a way as to close off, when the disconnector (64, 66) is in the closed position, the orifice (94) for access to the screw (60) of the terminal (58).

7. Distribution board according to any one of the preceding claims, characterised in that said insulating block (22) has a base (24) latched onto the mounting plate (10), said base (24) having three parallel longitudinal locations (32, 34, 36) each receiving a flat bar (16, 18, 20) of said set of busbars arranged in one plane, parallel to the mounting plate (10), in that said lateral connections (40, 42, 44) with their disconnectors (64, 66) are arranged on the upper surface (38) of the base (24) perpendicularly to said busbars (16, 18, 20) each lateral connection being electrically linked by a tag (62) with one of the busbars and in that an insulating cover (30) is clipped onto the base (24) to cover the lateral connections (40, 42, 44) and the disconnectors (64, 66) allowing the connection pad (46 - 56) and the handle (86) for controlling the disconnector to project in the open position of the latter.

8. Distribution board in accordance with any one of the preceding claims, characterised in that the handle (86) of the disconnector (64, 66) has a mark (0,1) indicating the position of the disconnector visible on the front surface of the insulating block (22) opposite the mounting plate (10).

9. Distribution board according to any one of the preceding claims, characterised in that the flat lateral connections (46, 56) extend in a plane parallel to the mounting plate (10) and in that each disconnector (64,66) has two fixed contacts (68, 72; 70, 74) arranged on either side of a break in continuity (x) of the lateral connection (46 - 56), in that the two fixed contacts consist of two pads extending in a plane perpendicular to the mounting plate (10) which contains the longitudinal axis of the lateral connection (40, 42, 44) and in that the sliding part of the disconnector (64, 66) contains two flexible contact blades (80) laterally gripping the said two fixed contacts in the closed position.

10. Distribution board according to any one of the preceding claims, characterised in that the insulating block (22), of parallelepiped form, has two lateral surfaces against which the small side faces equipped with input terminals (58) of the moulded cases of the equipments (15) are placed, and a front surface flush with the edges (90) of said moulded cases.

11. An electrical distribution board substantially as hereinbefore described with reference to the accompanying drawings.

12. Any novel feature or combination of features described herein.