EP1791231B1 - Electrical overvoltage protection device, and electrical switchboard comprising this device - Google Patents

Description

TECHNICAL FIELD TO WHICH THE INVENTION REFERS

The present invention relates to an electrical apparatus for protection against transient overvoltages, in particular of atmospheric origin, commonly known as surge arrester, which comprises a housing, one side of which is provided with a pair of holes giving access to input terminals known as d 'food.

It also relates to a switchboard or an electrical cabinet incorporating such an electrical device.

BACKGROUND

Generally, in an electrical panel, the surge arrester is conventionally positioned apart from the other electrical appliances of the switchboard. It is for example mounted at the end of a mounting rail of said board outside the row of electrical devices placed on this rail.

As input, the surge arrester is connected by a pair of large section power supply cables to a fuse cartridge connected to the distribution terminal block of the electrical panel by another pair of high-section power supply cables.

At the output, the surge arrester is connected by an earth cable to the ground connection terminal of the electrical panel.

The other electrical devices in the switchgear are electrically powered independently of the surge arrester by means of cables with a large section, which are separate from those supplying the surge arrester, connected to the distribution terminal block of the switchgear.

The installer must then separately connect the surge arrester and other electrical devices which is tedious and not always easy to achieve given the size and rigidity of cables with large section.

The function of the surge arrester is to clip a lightning wave arriving at the electrical panel. However, there is always a residual voltage between the input and output terminals of the surge arrester and each wire of the arrester wiring has a clean impedance which induces a residual voltage, these residual voltages reducing the filtering capacity of the lightning wave .

Document is known EP 0 867 896 , an electrical apparatus for transient overvoltage protection which comprises a housing of which two opposite faces are each provided with an access opening to a connection terminal.

Document is also known EP 1 357 638 , a transplanting device to be connected to the housing of a modular unit of a unit to establish a transverse electrical connection with a modular unit of another parallel row.

OBJECT OF THE INVENTION

In order to overcome the aforementioned drawbacks of the state of the art, the present invention proposes a new surge arrester which can be easily interposed between the terminal block of an electrical panel and the first apparatus. electrical protection or sectioning of a row of the array so as to facilitate the wiring operation and allow positioning of the surge arrester closest to the ground terminal block to reduce the length of the surge arrester wiring.

More particularly, there is provided according to the invention a modular electrical apparatus for protection against transient overvoltages, in particular of atmospheric origin, according to claim 1.

Other non-limiting and advantageous features of the electrical apparatus according to the invention are set forth in claims 2 to 8.

The invention also proposes an electrical distribution board or cabinet comprising a plurality of electrical appliances arranged in parallel rows located at different levels, a surge arrester as mentioned above placed at the head of the lowest row located closest to a terminal block connected to the earth and connected by means of two feeding combs to the adjacent electrical apparatus on said row, and a longitudinal energy distribution bar provided with electrical connectors distributed over its length including connection pins inserted into electrical appliances placed at the head of said rows, said power bar having two connection points of two electrical cables from the power network placed in the immediate vicinity of said surge arrester.

Thus, advantageously in the table according to the invention, by placing the surge arrester on the row closest to the ground connection terminal block, by integrating in the surge arrester housing the means for disconnecting the varistors from its two branches and by associating this surge arrester to a longitudinal power supply bar electrically powered closer to the lightning arrester, the length of the arrester wiring is minimized. Indeed, it minimizes the wiring distance between the arrester and the ground terminal and eliminates the wiring between the input terminal connected to the power supply network and the disconnectors and between the disconnectors and the surge arrester. This limits the total residual voltage clipped during a lightning strike and then increases the filtering capacity of the lightning wave.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT

• la figure 1 est une vue schématique en plan d'une partie d'un tableau de distribution électrique selon l'invention;
• la figure 2 est une vue schématique en perspective des deux appareils électriques situés en tête de la deuxième rangée du tableau de la figure 1; et
• la figure 3 est une vue schématique en perspective des bornes d'entrée de l'appareil électrique selon l'invention de la figure 2.

The following description with reference to the accompanying drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be achieved. In the accompanying drawings:

• the figure 1 is a schematic plan view of a portion of an electrical distribution board according to the invention;
• the figure 2 is a schematic perspective view of the two electrical devices located at the head of the second row of the table of the figure 1 ; and
• the figure 3 is a schematic perspective view of the input terminals of the electrical apparatus according to the invention of the figure 2 .

On the figure 1 there is shown an electrical panel T which comprises electrical devices 10, 30, 40 modular placed on rows formed by rails 50 arranged in parallel at different levels of Table T.

Here Table T comprises 2 rows of electrical devices 30, 40 modular among which there are head circuit breakers 30 which are starting points of the electrical power supply of other electrical devices here division circuit breakers 40.

The rails 50 on which the electrical devices 10, 30, 40 are mounted are, in a conventional manner, generally U-section sections with lateral wings whose returns are directed one opposite the other.

These profiles are for example made of metal material.

The head circuit breakers 30 and the division circuit breakers 40 are in the form of a generally parallelepipedal housing with two parallel main lateral faces, a rear face, an upper face, a lower face and a front face all perpendicular to the main lateral faces.

Each housing has a width measured from one to the other of its two main faces, equal to one or more times a base width, called "basic module", which is of the order of 18 mm.

In particular, the housings of the division circuit breakers 40 have a width equal to the base module M and the boxes of the head circuit breakers 30 have a width E equal to twice the base module M.

Each of the electrical devices 30, 40 conventionally comprise, in its rear face (not visible in the figures) a notch for mounting on a rail 50 while its upper face has access holes to electrical connection terminals.

As shown in figure 2 , each head circuit breaker 30 has here in its upper face, a pair of holes 31N, 31P giving access to input terminals for its power supply and a pair of holes 32N, 32P giving access to output terminals intended to be electrically connected to the input terminals of the divisional circuit breakers in the same row. The two pairs of holes 31 N, 31 P, 32 N, 32 P are separated by a partition wall 33 which rises perpendicular to the upper face of the corresponding head circuit breaker 30.

Each division circuit breaker 40 here comprises on its upper face two holes giving access to input terminals connected to the output terminals of the head circuit breaker 30 of the row, and on its lower face two holes giving access to output terminals respectively. connected to the phase and neutral poles of an individual circuit, for example a circuit of sockets or a lighting circuit.

As shown more particularly in figure 1 in a conventional manner, the electrical appliances 30, 40 of the same row are electrically connected to each other by means of two parallel parallel standard power feed combs 1 (a comb 1 for the phase terminals and a comb 1 for the terminals of neutral) whose 2 straight teeth are spaced from the distance of a base module M.

For this, the holes 32N, 32P giving access to the output terminals of each head circuit breaker 30 are positioned at two different levels and are separated from each other by a distance equal to half of a basic module M so that, on the one hand, the hole 32N giving access to the neutral output terminal is located at the same level as the hole giving access to the neutral input terminal of the adjacent divisional circuit breaker 40 being separated from it by a base module M, and, on the other hand, the hole 32P giving access to the terminal The phase output terminal is located at the same level as the hole giving access to the phase input terminal of said divisional circuit breaker 40 while being separated from it by a base module M.

The holes 31 N, 31 P giving access to the input terminals of each head circuit breaker 30 are also positioned at two different levels and are spaced from each other by a distance equal to half of a module. base M.

In addition, the holes 31 N, 32N giving access to the input and output neutral terminals of each head circuit breaker 30 are located at the same level and spaced apart from each other by a base module M.

The holes 31 P, 32P giving access to the input and output phase terminals of each head circuit breaker 30 are located at the same level and spaced apart from each other by a base module M.

However, the partition wall 33 of each head circuit breaker 30 has a height greater than or equal to the height of the teeth 2 so that it avoids the short-circuiting of the head circuit breaker 30 by the electrical connection of its terminals. input and output by means of a comb 1 introduced into the holes 31 N, 31 P, 32N, 32P.

As shown in figure 1 , Table T comprises at the head of its low row, located near the grounding terminal LV terminal, an electrical apparatus 10 for protection against transient overvoltages, in particular of atmospheric origin, commonly called surge arrester.

This arrester 10 advantageously comprises a housing 11, one face 23 is provided with a pair of holes 11N, 11P giving access to input terminals 14N, 14P said supply and another pair of holes 12N, 12P giving also access to input terminals 15N, 15P said subconnect electrically connected to said power input terminals 14N, 14P (see Figures 2 and 3 ).

According to the example shown in the figures, the holes 11N, 12N give access to neutral terminals 14N, 15N and the holes 11P, 12P give access to phase terminals 14P, 15P.

As shown more particularly in figure 3 , the supply input terminals 14N, 14P and subconnection 15N, 15P are conventionally screw terminals which are electrically connected to an active element 18 (comprising a varistor per branch) of the arrester 10, this active element 18 being connected electrically to an output terminal (not visible in the figures) connected to earth via the LV terminal block.

The arrester 10 is a modular electrical apparatus with a housing 11 having, in parallelepipedal form, two parallel main lateral faces 20, a rear face 22, an upper face 23, a lower face 23 and a front face 21 which are all perpendicular to the main lateral faces 20.

The housing 11 conventionally comprises a base and a cover attached to the base, forming said faces of the housing.

For attachment of the arrester 10 on the rail 50 the rear face 22 of the housing 11 has a notch (not visible in the figures) in its central zone.

The upper and lower faces 23 of the casing 11 are perpendicular to the rear face 22 and, here, it is on the upper face 23 that the pairs of holes 11N, 11P, 12N, 12P open jointly, giving access to the input terminals. supply 14N, 14P and 15N, 15P.

The front face 21 has, in its median part, a projecting portion 24 on either side of which there are two lateral facets 25, which, established at the same level, are both substantially parallel to the rear face 22 of the casing 11 of the surge arrester 10.

That of the lateral facets 25 which is adjacent to the upper face 23 and which is in line with the supply input terminals 14N, 14P and 15N, 15P, has, in correspondence with them, holes 26N, 26P, 27N, 27P giving access to the head of their clamping screw 14'N, 14'P, 15'N, 15'P.

The other side facet 25 adjacent to the lower face 23 of the housing 11 has a hole 13T for access to the output terminal.

For example, and as shown, the holes 11N, 11P, 12N, 12P have a generally rectangular outline, while the holes 26N, 26P, 27N, 27P and the hole 13T have a generally circular outline.

As shown by figures 1 and 2 , the casing 11 of the surge arrester 10 having a width E, measured from one to the other of its two lateral main faces 20, equal to twice the basic module M (just like the head circuit breaker 30 positioned next to it on the rail 50), preferentially, the holes 11N, 11P giving access to the supply input terminals 14N, 14P are positioned at two different levels while being spaced from each other by a distance equal to half of a base module M, and the holes 12N, 12P giving access to the subchanging input terminals 15N, 15P are also positioned at two different levels while being spaced from each other by a distance equal to half of a base module M so that the holes 11N, 12N giving access to the neutral terminals 14N, 15N are established at the same first level, while being separated from each other by a distance P equal to the same basic module M, and the holes 11P, 12P giving access to the phase terminals 14P, 15P have established at the same second level distinct from the first level, being spaced from each other by the same distance P equals to said basic module M.

Advantageously, this distance P is equal to the distance P1 separating two successive teeth 2 from a standard feed comb 1.

As shown more particularly in figure 2 , the holes 12N, 12P giving access to the 15N, 15P dubbing input terminals of the arrester 10 are respectively positioned at the same levels as the holes 31 N, 31 P giving access to the input terminals of the adjacent electrical apparatus.

In addition, the holes 12N, 31N giving access to the neutral terminals respectively of the arrester 10 and of the adjacent electrical apparatus 30 are spaced from the distance P equal to the base module M and the holes 12P, 31P giving access to the The phase terminals respectively of the surge arrester 10 and the adjacent electrical apparatus 30 are also spaced apart from a base module M.

Thus the arrester 10 and the electrical apparatus 30 can be electrically connected to each other by means of two parallel parallel standard power feed combs 1 (a comb 1 for the phase terminals and a comb 1 for the neutral terminals) whose teeth 2 lines spaced from the distance P1 equal to the basic module M are introduced into the holes 12N, 31N and 12P, 31 P.

As shown more particularly in figure 3 , preferably the arrester 10 comprises at a first level, a first conductive element 16 forming a double stirrup 16A, 16B which, on the one hand, electrically connects them the neutral terminals 14N, 15N of said input and supply input terminals arranged at this first level, and, on the other hand, connects these neutral terminals 14N, 15N to a varistor of the active element 18 of the surge arrester 10. The arrester 10 comprises at a second level distinct from the first level, a second conductive element 17 forming a double stirrup 17A, 17B which, on the one hand, electrically interconnects the phase terminals 14P, 15P of said input terminals feeding and transplanting arranged at this second level, and, secondly, electrically connect these phase terminals 14P, 15P to the other varistor of the active element 18.

In order to maintain safety at the end of life of each varistor which, because of current leakage, then increases in temperature by Joule effect, the arrester 10 integrates into its housing 11 a thermal fuse (not shown in the figures) disposed in series with each varistor. This thermal fuse opens when the varistor reaches a predetermined temperature threshold.

The casing 11 of the arrester 10 also advantageously incorporates a fuse cartridge placed in series with each varistor and its associated thermal fuse.

This fuse cartridge is adapted to be tripped in the event of a short-circuit of said varistor and has a tripping intensity-time operating curve in which, for each intensity value, the value of the tripping time is less than the value of tripping time given for the same intensity value by the operating curve of the main circuit breaker S of the electrical installation to which the surge arrester is connected, whereby a short circuit of a surge arrester varistor does not trip said circuit breaker principal S.

Moreover, as shown in figure 1 Advantageously, the switchboard T comprises a device 100 for distributing energy to the electrical devices 10, 30 arranged at the top of the two parallel rows.

This device comprises a longitudinal bar 100 as described in the application for FR 2 847 732 owned by the plaintiffs. As this longitudinal bar is not strictly part of the present invention, it will not be described here in detail.

Essentially this longitudinal bar 100 extends in a direction transverse to the rails 50 forming said rows so as to cross. She is provided with electrical connectors 110 distributed over its length, here two electrical connectors for the two rows.

The longitudinal bar 100 provided with its electrical connectors 110 is arranged on one side of the board T so that each electrical connector 110 that it carries is positioned above the first electrical apparatus 30, 10 of each row of the board.

The longitudinal bar 100 is flat, it comprises an insulating envelope in which two rigid flat strips, made of current-conducting material (metallic material), carrying electrical connectors, each comprising a connection pin to be plugged into a terminal, extend in parallel. input of an electrical apparatus 10, 30.

Each electrical connector of a strip is juxtaposed with an electrical connector of the other strip to form in pairs an electrical connector 110 of the longitudinal bar 100, with a phase pin 111 and a neutral pin 112 to be plugged into the terminals of input of said electrical apparatus 10, 30.

In particular, the phase 111 and neutral pins 112 of an electrical connector 110 of the longitudinal bar 100 are to be introduced into the holes 11N, 11P of the surge arrester 10 to be plugged into the supply input terminals 14N, 14P .

Advantageously, as shown in figure 1 , the longitudinal bar 100 is energized as close to the arrester 10 by electrical cables 103, 104 from the power supply network.

The bars are connected near the electrical connector 110 supplying the arrester 10 to two connectors 102, 101 connected to the electrical cables 103, 104. One of the bars of the longitudinal bar 100 is connected to the phase pole while the other bar is connected to the neutral pole.

Thus, thanks to its double pairs of input terminals (a pair of power input terminals 14N, 14P and a pair of subconnection input terminals 15N, 15P) connected to each other and accessible by holes 11N, 11P, 12N, 12P opening on the same face 23 of its housing 11 and spaced from each other by a base half-module M, the surge arrester 10 can be easily interposed between the incoming terminal block BA of the table and the first electrical appliance 30 for protecting or disconnecting a row of the panel T, the 15N, 15P of the surge arrester input terminals 10, powered electrically via the power input terminals 14N, 14P, connectable by means of of standardized feed combs 1 to the input terminals of said electrical head apparatus 30 of the corresponding row.

In addition, by placing the surge arrester 10 on the row of the panel T closest to the terminal block LV of the earth connection, by integrating into the casing 11 of the surge arrester 10 the means of disconnection (thermal fuse and fuse cartridge) of the varistors of its two branches and associating this arrester 10 with a longitudinal bar 100 of power supply electrically powered closer to the arrester 10, minimizes the length of wiring arrester 10. In effect, it minimizes the wiring distance between the surge arrester 10 and the ground terminal block BT and the wiring is eliminated between the input terminal block BA connected to the power supply network and the disconnectors and between the disconnectors and the arrester 10. This limits the total residual voltage clipped during a lightning strike and the filtering capacity of the lightning wave is increased.

Claims (9)

1. Modular electrical equipment (10) for protecting against transient voltage surges, in particular that originate from the atmosphere, which electrical equipment comprises a casing (11) that presents, in the shape of a rectangular parallelepiped, two parallel main side faces (20) for fitting to the corresponding parallel side faces of other pieces of modular electrical equipment, a rear face (22), a top face (23), a bottom face (23), and a front face (21) that are all perpendicular to the main side faces (20), one of which said top and bottom faces (23) is provided with a pair of holes (11N, 11P) that give access to "feed-in" inlet terminals (14N, 14P), and with another pair of holes (12N, 12P) also that give access to "feed-out" inlet terminals (15N, 15P) that are electrically connected to said feed-in inlet terminals (14N, 14P), said electrical equipment being characterized in that the holes (11N, 12N) that give access to the neutral terminals (14N, 15N) of said feed-in and feed-out inlet terminals are established at a first level that extends along a direction that is orthogonal to said main side faces (20), and the holes (11P, 12P) that give access to the line terminals (14P, 15P) of said feed-in and feed-out inlet terminals are established at a second level, distinct from the first level, that extends along the direction that is orthogonal to said main side faces (20), the holes (11N, 11P) that give access to the feed-in inlet terminals (14N, 14P) being spaced apart from each other, in said direction that is orthogonal to said main side faces (20), by a distance that is equal to half a basic module M, and the holes (12N, 12P) that give access to the feed-out inlet terminals (15N, 15P) being spaced apart from each other, along said direction that is orthogonal to said main side faces (20), by a distance that is equal to half a basic module M, such that the holes (11N, 11P) that give access to the feed-in inlet terminals (14N, 14P) are adapted to receive an electrical connector of a longitudinal power-distribution busbar, and the holes (12N, 12P) that give access to the feed-out inlet terminals (15N, 15P) are adapted to receive the teeth of two comb busbars.
2. Electrical equipment (10) according to claim 1, characterized in that said pairs of holes (11N, 11P; 12N, 12P) open out onto the top face (23) of the casing (11).
3. Electrical equipment (10) according to claim 1 or claim 2, characterized in that the casing (11) presents a width E, measured from one of its two main side faces (20) to the other, that is equal to twice a basic width, known as a basic module M, the holes (11N, 12N) that give access to the neutral terminals (14N, 15N) of said feed-in and feed-out inlet terminals are spaced apart from each other by a distance P that is equal to said basic module M along said direction that is orthogonal to the main side faces (20) of the casing (11), and the holes (11P, 12P) that give access to the line terminals (14P, 15P) of said feed-in and feed-out inlet terminals are spaced apart from each other by a distance P that is equal to said basic module M along said direction that is orthogonal to the main side faces (20) of the casing (11).
4. Electrical equipment (10) according to claim 3, characterized in that said distance P is equal to the distance P1 between two successive teeth (2) of a standard comb busbar (1).
5. Electrical equipment (10) according to claim 3 or claim 4, characterized in that two successive holes (11N, 11P, 12N, 12P) are spaced apart, along said direction that is orthogonal to the main side faces (20) of the casing (11), by a distance that is equal to half the basic module M.
6. Electrical equipment (10) according to any preceding claim, characterized in that it includes firstly, at a first level, a first conductor element (16) that forms a double bracket (16A, 16B) that electrically connects the neutral terminals (14N, 15N) of said feed-in and feed-out inlet terminals that are arranged at the first level, and secondly, at a second level distinct from the first level, a second conductor element (17) that forms a double bracket (17A, 17B) that electrically connects the line terminals (14P, 15P) of said feed-in and feed-out inlet terminals that are arranged at the second level, said first and second conductor elements (16, 17) being electrically connected to the active element (18) of said equipment.
7. Electrical equipment (10) according to any preceding claim, characterized in that, in its casing (11), it incorporates a fuse cartridge that is arranged in series with a varistor.
8. Electrical equipment (10) according to the preceding claim, characterized in that the fuse cartridge is adapted to operate in the event of said varistor short circuiting, and has a time/current characteristics curve in which, for each current value, the value of the disconnection time is shorter than the value of the disconnection time given for the same current value by the characteristics curve of a main circuit breaker of an electrical installation to which said electrical equipment is intended to be connected, as a result of which said main circuit breaker does not disconnect when a varistor of the lightning arrester short circuits.
9. An electrical distribution board or panel (T) comprising: a plurality of pieces of electrical equipment (30, 40) that are arranged on parallel rows that are situated at various levels; a lightning arrester (10) according to any preceding claim that is positioned at the beginning of the lowest row, situated as close as possible to a grounding terminal (BT), and that is connected by means of two comb busbars (1) to the adjacent piece of electrical equipment (30) on said row; and a longitudinal power-distribution busbar (100) that is provided with electrical connectors (110) that are distributed along its length and that include connection terminals (111, 112) that are plugged into the pieces of electrical equipment (10, 30) that are positioned at the beginnings of said rows, said power-distribution busbar (100) presenting two connection points for connecting two electrical cables coming from the electricity network, which connection points are positioned in the immediate proximity of said lightning arrester.

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