EP1747564A1

EP1747564A1 - Overvoltage protection device comprising an improved display system

Info

Publication number: EP1747564A1
Application number: EP05757170A
Authority: EP
Inventors: Michel Georges Jean Donati
Original assignee: Soule Protection Surtensions SA
Current assignee: ABB France SAS
Priority date: 2004-04-19
Filing date: 2005-04-18
Publication date: 2007-01-31
Anticipated expiration: 2025-04-18
Also published as: EP1747564B1; ES2430195T3; FR2869155A1; WO2005109452A1; FR2869155B1

Abstract

The invention relates to a device which is used to protect an electrical installation against overvoltages. The inventive device consists of: a protection component (10); means (20) for disconnecting the protection component (10); and means (30) for displaying the state of the protection component (10), comprising a control part (40) which can move and a display member (50) which indicates if the protection component (10) is in service or disconnected according to the position of the control part (40). The invention is characterised in that the control part (40) and the disconnection means (20) are disposed such that, when opening, the disconnection means (20) move away sufficiently from the control part (40) in order to release and, in this way, authorise the free movement of the control part (40). The invention also relates to electrical overvoltage protection devices.

Description

SURGE PROTECTION DEVICE WITH IMPROVED VISUALIZATION SYSTEM

TECHNICAL AREA

The present invention relates to the general technical field of devices for protecting electrical installations or equipment against transient electrical overvoltages.

The present invention relates more particularly to a device for protecting an electrical installation against overvoltage comprising: - at least one protective component, - means for disconnecting the protective component from the electrical installation, suitable for disconnecting the protective component , and likely to occupy a closed position, in which the protective component is connected, and an open position, in which the protective component is disconnected, - means for displaying the state of the protective means, functionally connected to the disconnection means and comprising: - a control part, capable of moving under the dependence of the disconnection means, - a display member, associated with the control piece so that the display member indicates, depending on the position of the control part, if the protective component is in service or disconnected. PRIOR ART

The protective devices for electrical installations are commonly used to protect in particular electrical and electronic devices against overvoltages which may, for example, be generated by discharges due to lightning. These devices generally comprise an active part formed by one or more protection components of the varistor or spark gap type for example.

Varistors are components commonly used to protect electrical installations or equipment against transient overvoltages.

When an overvoltage occurs within the installation, the varistor undergoes a current shock which has the effect of degrading it.

The degradation of the varistor is difficult, if not impossible, to predict since it depends not only on the number of current shocks undergone by the varistor during its life, but also on their amplitude.

It is therefore difficult to predict a priori the life and the degree of aging of a varistor, and the user is often led to observe after the fact that it has been destroyed, so that the installation runs the risk to operate for a certain latency period without protection.

In order to allow rapid identification of a defective varistor, and to reduce the latency time mentioned above, it is known to equip each varistor with display means, capable of indicating to a third party that the varistor is out of service . The varistors generally encountered are thus associated with disconnection means, adapted to disconnect the vaπstance when it is in a degraded state, to which are functionally connected means for visualizing the state of the varistor, generally actuated by the means of disconnection, and which allow to indicate to a third party whether the varistor is in service or disconnected.

The display means can thus be in the form of a cursor, associated with a display piece, and able to move in translation under the action of the disconnection means, so as to indicate, depending on its position, the state of the varistor, and this by placing the display piece opposite, for example a colored screen, with a display window formed in the housing of the protection device.

In known protection devices, the cursor and the display part are either secured to the disconnection means, in particular a disconnection blade, or independent while being controlled and actuated by the latter.

In all cases, the movement of the disconnection means towards their open position generates the movement of the cursor, movement controlled or even guided by the disconnection means or independent guide means.

However, it may happen that the cursor or the display part is hampered in its movement, in particular in the case where the cursor and / or the display part are badly dimensioned, or even if the guide means are defective, thus leading to poor cursor guidance.

In this situation, the cursor and / or the display part can then hinder or even prevent the disconnection of the varistor. The latter then remains connected and the display means do not indicate any anomaly, while the varistor is greatly degraded and is no longer able to protect the installation.

In addition, the assemblies in which the cursor and / or the display part are actuated and their movements controlled by the disconnection means generally require perfecting of the dimensioning of the parts, so as on the one hand to avoid the formation of games between these last, and secondly to avoid any risk of blockage of the disconnection and / or display system. Such a constraint then contributes to significantly increasing the cost of manufacturing the devices.

We therefore see the advantage of producing a protection device against overvoltages which, while falling within a simple and economical design is likely to disconnect, in the most reliable and efficient way possible, the protection component, in particular the varistor, of the installation to be protected, and to indicate at the same time to a third party that the same protection component is out of service.

STATEMENT OF THE INVENTION

The objects assigned to the invention therefore aim to propose a new device for protecting electrical installations against overvoltages which ensures a particularly reliable and rapid disconnection of the protection component when the latter is in a degraded state.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages which guarantees easy, reliable and instantaneous visualization of the state of the protection component. Another object of the invention is to propose a new device for protecting electrical installations against overvoltages, the design of which is particularly simple and economical.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages requiring only a limited number of parts to obtain the connection / disconnection function on the one hand, and display on the other hand go.

Another object of the invention is to propose a new device for protecting electrical installations against overvoltages allowing the simultaneous and differentiated display of the state of several protection components connected in parallel.

The objects assigned to the invention are achieved by means of a device for protecting an electrical installation against overvoltage comprising: - at least one protection component, - means for disconnecting the protection component, suitable for disconnecting the protective component of the electrical installation, and capable of occupying a closed position, in which the protective component is connected, and an open position, in which the protective component is disconnected, - display means the state of the protection means, functionally connected to the disconnection means and comprising: - a control part, capable of moving under the dependence of the disconnection means, - a display member, associated with the control part in such a way that the display member indicates, depending on the position of the control piece, whether the protective component is in service or disconnected, characterized in that the control piece is mounted resiliently movable between a first position, corresponding to a connected state of the protection component, in which the control part is elastically stressed and held in position by the disconnection means, and a second position, corresponding to a state disconnected from the protection component, in which the control part is no longer held by the disconnection means, the control part and the disconnection means being arranged in such a way that the disconnection means, when they open, deviate sufficiently from the control part to thereby release and authorize free movement of the control part.

SUMMARY OF DRAWINGS

Other features and advantages of the invention will become apparent and will emerge in more detail on reading the description given below, with reference to the appended drawings, given purely by way of non-limiting illustration, in which:

- Figure 1 illustrates, in a perspective view, a device for protection against overvoltages with a varistor.

- Figures 2a and 2b illustrate, in a schematic view, a display system of the state of a varistor, when the varistor is in service (Figure 2a) or disconnected (Figure 2b).

- Figures 3a and 3b illustrate, in a schematic view, a second embodiment of a system for displaying the state of a varistor when the varistor is in service (FIG. 3a) or disconnected (FIG. 3b).

- Figure 4 illustrates, in a perspective view, a device for protection against overvoltages according to the invention with two varistors mounted in parallel.

- Figures 5a, 5b, 5c illustrate, in a schematic view, a display system of the state of two varistors mounted in parallel when the two varistors are in service (Figure 5a), when only one of the varistors is in service (Figure 5b) or when the two varistors are disconnected (Figure 5c).

- Figure 6 illustrates, in a schematic view, an improved variant of the display system according to the invention.

- Figures 7a, 7b, 7c illustrate, in a schematic view, a variant of the display system of the state of two varistors mounted in parallel when the two varistors are in service (Figure 7a), when only one of the varistors is in service (Figure 7b) or when the two varistors are disconnected (Figure 7c).

- Figures 8a, 8b, 8c illustrate, in a schematic view, another variant of the display system of the state of two varistors mounted in parallel when the two varistors are in service (Figure 8a), when only one of the varistors is in service (Figure 8b) or when the two varistors are disconnected (Figure 8c).

FIGS. 9, 9a, 9b, 9c illustrate, in a schematic view, another variant of a system for displaying the state of two varistors mounted in parallel when the two varistors are in service (FIG. 9a), when only one of the varistors is in service (Figure 9b) or when the two varistors are disconnected (Figure 9c).

- Figures 10, 10a, 10b, 10c illustrate, in a schematic view, another variant of a system for displaying the state of two varistors mounted in parallel when the two varistors are in service (Figure 10a), when only one of the varistors is in service (Figure 10b) or when the two varistors are disconnected (Figure 10c).

- Figures 10'a, 10'b, 10'c illustrate the visual appearance of the viewing window of the viewing system shown in Figures 10, 10a, 10b, 10c.

BEST WAY TO IMPLEMENT THE INVENTION

The overvoltage protection device according to the invention is intended to be connected bypass to the electrical equipment or installation to be protected.

The expression “electrical installation” refers to all types of devices or networks liable to undergo voltage disturbances, in particular transient overvoltages due to lightning.

This device will be described based on Figures 1 to 10'c.

The device for protecting electrical installations against overvoltage, which comprises at least one protective component 10, is advantageously intended to be disposed between a phase of the installation to be protected, and the earth.

In the following description, it is considered that each protection component of the device is formed by a varistor 10. Obviously, the protective components could be of a completely different nature without departing from the scope of the invention, the use of a varistor being indicated only by way of example and in no way constituting a limitation of the invention.

It is also conceivable, without departing from the scope of the invention, that the device, instead of being connected in diversion between a phase and the earth, be connected between the neutral and the earth, between the phase and the neutral or between two phases (in the case of differential protection).

The protection device according to the invention comprises at least one varistor 10, disconnection means 20 for each varistor, sensitive to the state of the varistor, and adapted to individually disconnect each varistor from the electrical installation when the varistor is is in a degraded state, and means 30 for viewing the state of each varistor, functionally connected to the disconnection means 20.

Advantageously, the protection device is formed by a protection cell 1 which may include one or more modules 2 each containing a varistor 10 (Figures 1 and 4).

As shown in FIG. 1, each module 2 advantageously comprises a base 3 made of electrically insulating material, a varistor 10, two connection blades 4A, 4B electrically conductive and constituting the poles of the varistor, and disconnection means 20 .

The disconnection means 20 are preferably formed by a thermal disconnector, such as for example a disconnection blade 21 in thermal contact with the associated varistor 10, so that heating of the varistor, linked to the end of life of the latter, causes the disconnection blade 21 to open, thereby isolating the varistor from the lines to be protected.

The disconnection means 20 are thus capable of occupying a so-called closed position, in which the varistor 10 is connected to the network or to the electrical installation, and an open position, in which the varistor is disconnected from the installation. electric. These two positions are illustrated in FIG. 4.

Advantageously, the disconnection blade 21 extends between two ends 21 A, 21 B, one of said ends 21 A preferably being fixed using a hot-melt weld on the extension 5 of one of the blades connection 4A, 4B. The end 21A of the disconnection blade 21 is thus preferably welded under stress, so that when the varistor 10 reaches the end of its life, it heats up and causes the solder to melt, which, once broken, allows release of the disconnection blade 21.

Thanks to its intrinsic elasticity, the disconnection blade 21 then moves away from the connection blade 4B, as shown in FIG. 4 (module 2 located on the left of the protection cell 1).

We will now describe the structure of the display means 30 shown in FIGS. 2a, 2b, 3a, 3b, 5a, 5b, 5c and 6.

The display means 30 are adapted to inform a third party of the state of the varistor (s) contained in the protection cell 1. These display means 30 are functionally connected to the disconnection means 20.

According to the invention, the display means 30 comprise, for each protection cell 1, a control part 40 able to move under the dependence of the disconnection means 20.

The display means 30 also include a display member 50 associated with the control piece 40, so that the display member 50 indicates, as a function of the position of the control piece 40, whether the varistor 10 is in service or disconnected.

The control part 40 and the display member 50 are preferably made of insulating plastic.

According to the invention, the control piece 40 is mounted resiliently movable between a first position, illustrated in FIGS. 2a, 3a, 5a corresponding to a connected state of the varistor (s) 10, in which the control piece 40 is elastically stressed and held in position by the disconnection means 20, and a second position, illustrated in FIGS. 2b, 3b, 5c, corresponding to a state disconnected from the varistor (s) 10, in which the control part 40 is no longer maintained by the disconnection means 20.

According to the invention, the control piece 40 and the disconnection means 20 are arranged so that the disconnection means 20, when they open, move away enough from the control piece 40 to release and thus allow movement free from control panel 40.

Once released, the control part 40 is thus free to move, that is to say that it is neither actuated nor guided in movement by other means than its own structure.

Particularly advantageously, the control piece 40 comprises at least one so-called active part 40A which, when the disconnection means 20 are in their closed position, bears against the latter (FIGS. 2a, 3a, 5a).

Thus, during the opening of the disconnection means 20, these deviate sufficiently from the control part 40 to break the contact between the active part 40A of the control part 40 and the disconnection means 20, thus releasing the control part 40.

Each disconnection blade 21 is thus advantageously dimensioned so that when it is no longer under stress, that is to say when the solder with one of the poles of the varistor 10 is broken, it moves away at a sufficient distance from the control part 40 to allow the release of the latter. The disconnection blade 21 thus assumes a triple function: - in normal operation, it serves for the electrical connection of the varistor 10, - at the end of the life of the varistor 10, it serves to disconnect the latter, - finally, it also serves to release and therefore trigger the display means 30 of the state of the varistor 10.

Advantageously, the mounting of the control piece 40 relative to the disconnection means 20 is such that the active part 40A, when it is released from the disconnection means 20, is able to move in a direction D2 substantially perpendicular to the main direction D1 for moving the disconnection means 20 (FIGS. 2b, 3b, 5c).

The design of the protection device according to the invention, and in particular the mounting of the display means 30 of the state of the varistor allows thus, thanks to the small number of parts cooperating together and the limited number of points of contact between these parts, ensuring rapid and reliable disconnection of the degraded varistor (s). This reliability is further accentuated by the material independence of the display means 30 and the disconnection means 20.

In addition, thanks to the simultaneous or almost simultaneous movement of the display means 30 and the disconnection means 20, a third party can very quickly perceive that a varistor is disconnected.

In a particularly advantageous manner, the display means 30 are formed by mechanical means mounted in a housing 60, which preferably also contains a protection cell 1 comprising one or more varistors 10.

Several embodiments of the invention will now be described with reference to FIGS. 1 to 6.

According to a first embodiment of the invention, shown in FIGS. 2A and 2B, the control part 40 is formed by a branch 41 preferably substantially rigid, elastically mounted in translation within the housing 60 by means of a elastic means 70 of the spring type. The branch 41 may advantageously be formed by a fairly fine rod or even by a plate, and extends longitudinally in a direction substantially parallel to the main direction D1.

The elastic means 70 is advantageously adapted to occupy a compressed position when the branch 41 is constrained laterally, that is to say in a direction substantially perpendicular to its direction of extension, by the disconnection means 20 (FIG. 2a), and a rest position when the branch 41 is released from the disconnection means 20 (Figure 2b).

According to this embodiment, the branch 41 will preferably be rigid enough so that its active part 40A can come to bear firmly against the disconnection means 20 and more particularly against the end 21 A of the disconnection blade 21.

The assembly corresponding to this first embodiment is shown in FIGS. 2a and 2b in the case where the protection device, specifically the protection cell 1, comprises only one module 2, that is to say a single varistor 10. The housing 60 is thus preferably dimensioned so as to contain a protection cell 1 comprising a single varistor 10.

Obviously, the assembly described in this first embodiment of the invention can also be transposed in the case where the protection cell 1 comprises several varistors 10 mounted in parallel.

Such a case will be described in more detail below.

According to this first embodiment of the invention, the disconnection means 20 are formed by a single disconnection blade 21, the end of which 21A is capable of moving in the main direction D1, once the weld has broken.

The elastic means 70 can advantageously be interposed between on the one hand one of the walls 60A of the housing 60, and on the other hand the control part 40.

Thus, when the end 21A of the disconnection blade 21 no longer constitutes an obstacle or a stop against the movement of the control part 40, the elastic means 70, initially compressed, tends to become relax (Figure 2b) thus causing the branch 41 to move in the direction D2.

According to this embodiment of the invention, the display member 50 is advantageously formed by a panel 51, for example rectangular, preferably mounted on and secured to the control part 40, precisely the branch 41. The member display 50, specifically the panel 51, is more advantageously arranged so as to move opposite a window 61 formed in one of the faces 60B of the housing 60, located opposite the base 3, to obtain a different visual appearance through the window 61, depending on the position of the control part 40.

Thus, when the disconnection means 20 are in the closed position, as shown in FIG. 2a, the elastic means 70 is compressed and the panel 51 is positioned in the extension of the window 61. It is then likely to be viewed from the outside.

On the contrary, when the disconnection means 20 are in the open position, as shown in FIG. 2b, the panel 51 is in a position offset in the direction of movement D2 relative to the window 61 and therefore cannot , in this configuration, be viewed from the outside.

In order to further facilitate the visualization of the state of the varistor, the panel 51 may present, from the outside, a colored appearance, for example green, indicating to a third party that the varistor is in service.

According to a second embodiment of the invention, shown in FIGS. 3a and 3b, the control piece 40 advantageously comprises a branch 41 which is substantially flexible and mounted under stress within the housing 60 by means of the disconnection means 20. The branch 41 can as well have a first end 41A fixed and for example secured to one of the walls 60A of the housing 60. In a particularly advantageous manner, the branch 41 also has a second end 41 B, forming the active part 40A of the control part 40, and free to move elastically along an angular travel between the first position shown in Figure 3a and the second position shown in Figure 3b.

Thus, in the same way as in the first embodiment described above, when the weld melts, the end 21A of the disconnection blade 21 moves substantially in the main direction D1 until it does not constitute plus an obstacle to the free movement of the control part 40. Thanks to its intrinsic elasticity and its flexibility, the branch 41 can then make a partial or total return to its rest position, as shown in FIG. 3b.

In the latter FIG. 3B, it can be seen that in the open position of the disconnection means 20, the active part 40A of the control part 40 advantageously abuts against one of the walls 60C of the housing 60.

In the same way as in the first embodiment described above, the display member 50 is preferably formed by a panel 51 capable of coming opposite a window 61 formed in one of the walls 60B of the housing 60, to thus indicate to a third party that the varistor associated with these display means 30 is in service.

Between the connected state of the varistor 10 represented in FIG. 3A and the disconnected state represented in FIG. 3b, the display member 50, precisely the panel 51, moves along an angular stroke between a position in which it is located substantially opposite of window 61 and a position where it is in angular offset relative to window 61.

According to a second embodiment of the invention shown in Figures 4 to 6, the device comprises a protection cell 1 comprising a first and a second varistor 10 mounted in parallel and associated respectively with a first and a second disconnection means 20 (Figure 4).

According to this embodiment, the control part 40 is advantageously formed by a first and a second branch 410, 420. In this configuration, the display means 30 advantageously have symmetry with respect to the plane S delimiting the separation between the two varistors 10 (Figures 5a, 5b, 5c).

Each of the branches 410, 420 can advantageously be mounted according to the first or the second embodiment described above. The branches 410 and 420 are then independent of each other and can provide a differentiated visual indication depending on whether the two varistors are in service, one of the varistors is disconnected, or else the two varistors are disconnected.

It is thus conceivable to produce the control part 40 using two flexible branches 410, 420, each having a fixed end secured to one of the opposite side walls 60A, 60C of the housing 60. The assembly described in the first mode of embodiment of the invention, which uses elastic means 70, can also be adapted to the case where two varistors 10 are mounted in parallel, and this with some obvious adaptations.

According to a preferred variant, the branches 410, 420 of the piece of control 40 are assembled so as to form a pin 400 which preferably extends longitudinally in the main direction D1 and which, in its constrained position (FIG. 5a), is interposed between the first and the second disconnection means 20, of such that the latter, in the closed position, exert an external lateral stress on the branches 410, 420 tending to close the pin.

In the same way as in the embodiments described above, the branches 410, 420 of the pin 400 can be formed by rods or plates.

Thus, the pin 400 advantageously comprises a fixed end 400A and two so-called free ends 410B, 420B which come to bear, by lateral approach, against the disconnection means 20 when the latter are in their closed position (FIG. 5a).

The ends 410B, 420B advantageously form the active parts 40A of the control part 40.

In this embodiment, the display member 50 is preferably formed by two panels 510, 520 which, when the two varistors 10 are in service (FIG. 5a), are both substantially opposite a window 61 formed in the wall 60B of the housing 60.

In a particularly advantageous manner, the pin 400 is adapted to provide a differentiated visual indication depending on whether one or the other of the varistors 10 is disconnected. Thus, as shown in FIG. 5b, the pin 400 is capable of occupying an intermediate position in which the first branch 410 is constrained laterally by the first disconnection means 20 and the second branch 420 is released from the second means disconnection 20 thus indicating that only one varistor 10 is disconnected. In this configuration, one of the panels 510 associated with the varistor in service remains opposite window 61, occupying in particular half of the surface of window 61, and the other panel 520, associated with the disconnected varistor, is is found to be substantially angularly offset with respect to the window 61, thus indicating to a third party that the associated varistor is disconnected.

The pin 400 is also advantageously capable of occupying a final position in which the two branches 410, 420 are released from the disconnection means 20. Each panel 510, 520 is then angularly offset relative to the window 61, thus indicating that the two varistors 10 are disconnected.

Obviously, the display member 50 can be simply formed by the portions of branches 410, 420 located opposite the window 61 when the varistors are in service.

In the same way as in the previously described embodiments, each disconnection means 20 is capable of being erased by deviating sufficiently from the control part 40 so as to release one of the branches 410, 420, and this when heating of the varistor leads to the fusion of the solder maintaining the disconnection means 20, precisely the disconnection blade 21, in the stress position.

In a particularly advantageous manner, the pin 400 has an intrinsic elasticity such that it naturally tends to deploy, that is to say to open when it is no longer under stress. The deployed configuration of the pin 400 thus constitutes its rest position.

According to a variant of the invention, capable of being applied to all the embodiments previously described, the active part 40A of the part control 40 comprises release means 80 arranged to facilitate the release of the active part 40A during the opening of the disconnection means 20 (Figure 6).

In a particularly advantageous manner, the release means 80 are constituted by one or more folds 81 formed in the active part 40A, so that the latter has an oblique front 82 facilitating the release of the control part 40. Thus, when the disconnection means 20, precisely the disconnection blade 21 moves away from the control piece 40, the existence of the oblique front 82 allows the active part 40A of the control piece 40 to be released more easily by sliding against the end 21A the disconnection means 20.

Obviously, other embodiments of the invention can be envisaged, without departing from the scope of the invention.

Thus, by way of illustration, some possible embodiments of the invention will now be described with reference to Figures 7a to 10'c.

According to a first variant shown in FIGS. 7a, 7b, 7c, the control part 40 can be formed by two independent branches 410, 420 and connected together by means of an elastic means 70 such as a spring. The elastic means 70 advantageously tends to bring the active parts 40A closer to the control part 40. According to this variant, the control part 40 does not have a fixed end. The active parts 40A are advantageously kept apart from one another by the disconnection means 20, and this against the elastic means 70 tending to bring them together. The ends 410A, 420A of the branches 410, 420 opposite the active parts 40A advantageously form the display member 50 and for this purpose come into the field of the display window 61 when the means of disconnection 20 are in their closed position and exert an internal lateral stress on the branches 410, 420 (FIG. 7a).

In the intermediate position shown in FIG. 7b, one of the varistors is disconnected, so that the associated branch 420 is released from the corresponding disconnection means 20 and its end 420A is no longer opposite window 61. L The visual appearance of window 61 therefore indicates to the user that 50% of the varistors are out of service.

When the second varistor is itself out of service, the branch 410 is pushed back by the elastic means 70 thus discovering the other half of the window 61 which now indicates that all the varistors are out of service.

According to a second alternative embodiment shown in FIGS. 8a, 8b, 8c, the control part 40 is formed by a pin 400 comprising a fixed part 400A from which two branches 410, 420 leave. The two branches 410, 420 are further connected, preferably in their middle part, by means of an elastic means 70 such as a spring which tends to separate them from one another. The pin 400 is thus held in its closed position shown in FIG. 8a by means of the disconnection means 20 which come to bear, when the two varistors are in service, on the active parts 40A of the two branches 410, 420 located near the fixed end 400A.

According to this variant, the display member 50 is also formed by the free ends 410A, 420A of the branches 410, 420 which come to nest one inside the other opposite the window 61.

When one of the disconnection means 20 departs from the associated branch 420, following the disconnection of one of the varistors, this has the effect to allow the elastic means 70 which repels said branch 420 to relax towards one of the walls 60C of the housing 60. Simultaneously, the free end 420A of the branch 420 moves away from the window 61, so that the latter indicates that one of the two varistors is out of service. In this configuration, only half of the window 61 is occupied by the display member 50.

When the second varistor is itself out of service, the branch 410 is pushed back by the elastic means 70 thus discovering the other half of the window 61, the visual appearance of which indicates that all the varistors are disconnected and that it is necessary to proceed to their change.

Another alternative embodiment of the invention is shown in Figures 9, 9a, 9b, 9c.

According to this variant, the pin 400 is formed by two branches 410, 420 whose shapes give the pin 400 its intrinsic elasticity, and the display member 50 is formed by the free ends 410A, 420A of said branches 410, 420 Said free ends 410A, 420A are advantageously shaped so as to each cover around 50% of the window 61 when the two varistors 10 are connected.

In this variant, the disconnection means 20 exert an external lateral stress on the active parts 40A of the branches 410, 420 tending to close the pin 400. The display system corresponding to this variant is thus capable of providing the user with one of the following three visual indications: - 100% of the varistors are in service (figure 9a), - 50% of the varistors are disconnected (figure 9b), - or 100% of the varistors are disconnected (figure 9c). Another alternative embodiment of the invention is shown in Figures 10, 10a, 10b, 10c. According to this variant, the pin 400 is formed by the assembly of two branches 410, 420, so that one of the branches 420 is located in the foreground when looking through the window 61, the other branch 410 being located behind branch 420. As in the previous variant, it is the specific shape of branches 410, 420 which give the pin 400 its structural elasticity.

According to this variant, on the other hand, the display member 50 is designed so as to overestimate the deterioration in the state of the varistors in order to encourage the user to replace them as soon as one of the varistors is disconnected. . Thus, the display member 50 is designed so as to minimize the risk of error in interpretation of the visual appearance of the window 61. In fact, in the variants described above, the display member 50 is designed to so that when one of the varistors is disconnected, only 50% of the window 61 is uncovered, so that the user may think that the protection device is about half of its life. Under these conditions, the user can then consider that he still has a certain latency time to effect the change of the device. However, during the entire period when the first varistor is disconnected, the installation benefits from protection reduced to a single varistor, until the replacement of the faulty varistor. Consequently, if a current shock of very large amplitude occurs, the installation risks being completely unprotected, and this in a sudden and unpredictable manner.

According to the variant shown in FIGS. 10, 10a, 10b, 10c which, moreover, constitutes an independent invention in its own right, the display member 50 is designed so that at the first disconnection, the window 61 is more exposed 50%. As illustrated in FIG. 10, the display member 50 is thus distributed between the two branches 410, 420 and is preferably situated at the free ends 41 OA, 420A of said branches 410, 420.

Particularly advantageously and as shown in Figure 10, the branch 420, located in the foreground relative to the window 61, has an extension a of its free end 420A. This extension can for example be of trapezoidal shape and colored in red. As shown in FIG. 10, a light b is provided in the free end 420A, said light b being intended to come substantially opposite the window 61 when the pin 400 is in the closed position and the two varistors are in service (Figure 10a).

In a particularly advantageous manner, the end 420A of the branch 420 also comprises a part c, preferably colored in white, and arranged in the extension of the light b so as to also come substantially opposite the window 61 when the pin 400 is in its closed position illustrated in FIG. 10a.

As shown in Figure 10, the branch 410 and precisely the end 410A of the latter has a portion d, for example colored white and rectangular, dimensioned so that it comes substantially opposite the window 61 in the closed position of the pin 400, and precisely behind the part c and the light b of the branch 420.

As shown in Figure 10'a, the user sees, in the configuration illustrated in Figure 10a, a homogeneous window 61, for example 100% white. Specifically, the window 61 allows on the one hand to view the part c, for example white, and on the other hand the portion d also preferably white. Following the first disconnection, illustrated in FIG. 10b, one of the disconnection means 20 departs from the active part 40A of the branch 420, thus releasing the latter. The end 420A then moves, by elastic effect, relative to the window 61.

As illustrated in FIG. 10'b, the extension a then comes to the foreground opposite the window 61, thus concealing most of the portion d of the branch 410. As illustrated in FIG. 10 ' b, the window 61 is occupied for the most part (for example at 80%) by the extension a preferably red, the remaining 20% being occupied by the portion d preferably white. This visual aspect is thus likely to encourage the user to change the protection components as quickly as possible.

At the second disconnection shown in FIG. 10c, the active part 40A of the branch 410 is in turn freed from the corresponding disconnection means 20 so that the end 410A of said branch 410 also departs from the window 61. In this configuration, the extension a, preferably red, is always in the foreground when looking through the window 61 (Figure 10'c). This extension a preferably occupies about 80% of the window 61. The window 61 also lets glimpse, in this configuration, the bottom e of the housing 60, preferably red so that the window 61 appears completely red to the user, indicating to him that it is imperative to change the protection components as soon as possible because the installation is no longer protected.

Other variants can also be envisaged, and in particular if the protection cell 1 comprises more than two varistors 10 in parallel, it is possible to envisage producing a control part 40 comprising more than two branches. According to this variant, not shown in the figures, several windows may be provided in the housing, a given window corresponding for example to a given varistor.

It is also possible, in the case of a protection device comprising several varistors in parallel, to juxtapose several protection cells 1, each comprising two modules 2, each cell being associated with a single pin.

Advantageously, the protection device according to the invention can also be equipped with remote signaling means, allowing a third party to view the state of the varistors remotely. Such remote signaling means are well known to those skilled in the art and will not be the subject of a more detailed description.

The protection device according to the invention therefore makes it possible, thanks to a particularly simple mounting of the display means 30, to ensure not only a particularly reliable and effective disconnection of the varistors when the latter are in a degraded state, but also to simultaneously allow a third party to view the state of these varistors and this by limiting the risk of seizure of the mechanism or even possible parts guiding problems.

Indeed, due to the small contact surface between the functional parts, the risk of blocking of one part by another is significantly reduced.

POSSIBILITY OF INDUSTRIAL APPLICATION

The invention finds its industrial application in the design and manufacture of surge protection devices.

Claims

- Device for protecting an electrical installation against overvoltage comprising: - at least one protective component (10), - means for disconnecting (20) the protective component (10), suitable for disconnecting the protective component (10 ) of the electrical installation, and capable of occupying a closed position, in which the protective component (10) is connected, and an open position, in which the protective component (10) is disconnected, - display means (30) of the state of the protection component (10), functionally connected to the disconnection means (20) and comprising: - a control part (40), capable of moving under the dependence of the disconnection means (20), - a display member (50), associated with the control piece (40) in such a way that the display member (50) indicates, as a function of the position of the control piece (40), if the protective component (10) is in use ice or disconnected, characterized in that the control piece (40) is mounted resiliently movable between a first position, corresponding to a connected state of the protective component (10), in which the control piece (40) is elastically stressed and held in position by the disconnection means (20), and a second position, corresponding to a state disconnected from the protective component (10), in which the control part (40) is no longer held by the disconnection means (20), the control part (40) and the disconnection means (20) being arranged so that the disconnection means (20), when they open, deviate sufficiently from the control part (40) to release and thus authorize the free movement of the control part (40).

- Device according to claim 1 characterized in that the control part (40) comprises at least one so-called active part (40A), which bears against the disconnection means (20) in their closed position, the mounting being such that said active part (40A) is able to move in a direction (D2) substantially perpendicular to the main direction (D1) of movement of the disconnection means (20).

- Device according to claim 1 or 2 characterized in that the control part (40) comprises a branch (41) substantially flexible, one of the ends (41 A) is fixed, and the other end (41 B) is free to move elastically along an angular travel between the first position and the second position.

- Device according to claim 1 or 2 characterized in that the control part (40) is formed by a branch (41) substantially rigid, elastically mounted in translation by means of an elastic means (70), said elastic means (70) being adapted to occupy a compressed position when the branch (41) is constrained laterally by the disconnection means (20), and a rest position when the branch is released from the disconnection means (20).

- Device according to claim 1 or 2 characterized in that it comprises a protection cell (41) comprising first and second protection components (10) mounted in parallel and associated respectively to a first and a second disconnection means (20), the control part (40) being formed by first and second branches (410, 420) mounted in opposition so that the control part (40) has symmetry with respect to the plane (S) defining the separation between the two protective components (10).

- Device according to claim 5 characterized in that the branches (410, 420) of the control part (40) are assembled so as to form a pin (400) which, in its constrained position, is interposed between the first and the second disconnection means (20) so that the latter, in the closed position, exert an external lateral stress on the branches (410, 420), tending to close the pin (400).

- Device according to claim 6 characterized in that the pin (400) is capable of occupying an intermediate position in which the first branch (410) is constrained laterally by the first disconnection means (20) and the second branch is released of the second disconnection means (20), thus indicating that a single protective component (10) is disconnected, and a final position, in which the two branches (410, 420) are released from the disconnection means (20), indicating as well as the two protection components (10) are disconnected.

- Device according to one of claims 3 to 7 characterized in that each disconnection means (20) is formed by a disconnection blade (21), welded to one of the poles of the corresponding protection component (10), and able to move from the closed position to the open position after fusion of the weld, thereby releasing the branch (41) from the associated control part (40). - Device according to one of claims 1 to 8 characterized in that the display means (30) are mounted in a housing (60). - Device according to claim 9 characterized in that the display member (50) is formed by at least one panel (51), mounted on the control part (40) and arranged so as to move opposite a window (61) provided in the housing (60) to obtain a different visual appearance through the window (61), depending on the position of the control part (40). - Device 'according to claim 2 characterized in that the active part (40A) of the control part (40) comprises release means (80) arranged to facilitate its release when opening the disconnection means (20) . - Device according to claim 11 characterized in that the release means (80) consist of one or more folds (81) formed (s) in the active part (40A) so that the latter has an oblique front (82 ) facilitating the release of the control part (40). - Device according to one of the preceding claims, characterized in that the protective component (10) is formed by a varistor.