Low and medium voltage electrical enclosures

Abstract

To perform a function to maintain a constant temperature state against temperature variations inside an electrical enclosure, with a simple structure without using an electrical system.SOLUTION: A low and medium voltage electrical enclosure 1 includes a supporting structure which defines an internal space delimited by walls 13 forming one or more compartments housing one or more electrical apparatuses. At least one of the walls is provided with one or more venting openings that put into communication of an internal space with an outside of the electrical enclosure 1 and / or one of the compartments with a second compartment. The venting openings are provided with a cover 21 closing a corresponding venting opening in a first-closed-operating condition at first predetermined temperatures. The enclosure is provided with an actuating device adapted to open the cover in a second-open-operating condition at second predetermined temperatures. The actuating device includes an actuating mechanism having a Shape Memory Alloy-based (SMA-based) actuating element that has a first dimension at the first predetermined temperatures and is reversibly changeable into a second dimension at the second predetermined temperatures.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to low and medium voltage electrical enclosures, and more particularly to low and medium voltage electrical enclosures having improved cooling capabilities and characteristics. [Background technology]

[0002] In general, an enclosure for low and medium voltage electrical distribution is a known device formed by a supporting structure bounded by side, rear, top and bottom walls and closed by a door, which houses in one or more internal compartments electrical appliances and devices, e.g. circuit breakers and / or similar devices, busbar systems, electrical equipment and similar devices. Summary of the Invention [Problem to be solved by the invention]

[0003] In the current state of the art, existing low and medium voltage electrical enclosures have some drawbacks that would be desirable to overcome. For example, one of the known problems with low and medium voltage electrical enclosures is that changing temperature conditions due to working conditions and / or the number and type of equipment within the enclosure can reduce the performance of the equipment and possibly even result in interruption of service conditions and even failure (temporary or permanent) of the equipment / installation within the enclosure.

[0004] Cooling systems are provided to avoid, or at least mitigate, problems caused by temperature changes inside the enclosure, however known cooling systems, such as forced air inside the enclosure, have several drawbacks and can cause additional problems. For example, a cabling system may be required to provide power and control functions to the cooling system, which in turn is subject to regular maintenance interventions, dedicated certification may be required and the presence of further electrical equipment inside the enclosure (typically) may give rise to electromagnetic compatibility issues with the need to carry out dedicated EMC tests. [Means for solving the problem]

[0005] The present disclosure therefore aims to provide a low- and medium-voltage electrical enclosure making it possible to overcome at least some of the above-mentioned drawbacks. In particular, the present invention aims to provide a low to medium voltage electrical enclosure in which temperature changes can be easily controlled. More particularly, the present invention aims to provide a low to medium voltage electrical enclosure that includes a device for controlling temperature changes therein and that does not require dedicated wiring or power supplies.

[0006] Furthermore, the present invention aims to provide a low- and medium-voltage electrical enclosure which is provided with a device for controlling temperature changes inside it and which does not require costly maintenance interventions. It is also an object of the present invention to provide a low and medium voltage electrical enclosure having a device for controlling temperature variations therein and which does not require additional testing or certification. It is also an object of the present invention to provide a low to medium voltage electrical enclosure which is provided with a device for controlling temperature changes therein, is highly reliable, and can be manufactured relatively easily and at competitive costs.

[0007] Accordingly, the present invention relates to a low to medium voltage electrical enclosure comprising a support structure defining an interior space bounded by walls forming one or more compartments for housing one or more electrical devices. 1. A low- and medium-voltage electrical enclosure according to the invention, characterized in that at least one of the walls is provided with one or more vents leading between an exterior of the low- and medium-voltage electrical enclosure and the internal space and / or between one of the compartments and a second compartment, the one or more vents being provided with a cover adapted to close the corresponding vent in a first closed operational state at a first pre-determined temperature and an actuation device adapted to open the cover in a second open operational state at a second pre-determined temperature, the actuation device further comprising an actuation mechanism having a shape memory alloy based (SMA based) actuation element having a first dimension at the first pre-determined temperature and reversibly changeable to a second dimension at the second pre-determined temperature, the reversible dimensional change of the SMA based actuation element from the first dimension to the second dimension determining a reversible movement of the cover from the first closed operational state to the second open operational state and vice versa.

[0008] As a result of the particular construction of the low and medium voltage electrical enclosure of the present invention, as better explained in the following description, the above mentioned problems are avoided or at least significantly reduced. Indeed, under very specific predetermined temperature conditions, a cover blocking one or more vents (openings) in the outer and / or inner walls of the enclosure may be open, thereby allowing convection air circulation within the enclosure to maintain the temperature at a desired value. In other words, under certain temperature conditions, the IP rating of the enclosure may temporarily change depending on whether said one or more vents are open or closed.

[0009] As better explained below, movement of the cover from a closed to an open state is determined and controlled by a temperature sensitive actuator, i.e., an actuator that operates in response to temperature changes without the need for an additional power supply or a dedicated control system. In this regard, the actuators used in the housing according to the present disclosure are formed by shape memory alloy-based (SMA-based) actuation elements.

[0010] Shape memory alloys are well-known materials that have the ability to reversibly change dimensions in response to temperature conditions. The response speed of shape memory alloys to temperature changes is very fast, and during the dimensional change they can exert enough force to actuate relatively simple mechanisms. Moreover, the temperature coefficient of shape memory alloys (i.e., the temperature value or range at which they undergo a certain dimensional change) can be adjusted and fine-tuned according to needs by selecting the appropriate material based on known criteria.

[0011] In other words, the SMA-based actuating element used in the housing of the present invention changes its dimension in response to temperature conditions within the housing. In particular, at a first predetermined temperature condition, the SMA-based actuating element has a first dimension, and at a second predetermined temperature condition, the SMA-based actuating element has a second dimension. The SMA-based actuating element can be operatively connected to a cover to move said cover from a closed position to an open position in response to temperature conditions within the housing.

[0012] Thus, for example, if the temperature inside the enclosure rises excessively (or in any event rises above a predetermined level), the cover will move from the closed position to the open position, thereby allowing temporary, controlled convection air circulation inside the enclosure (as well as allowing the enclosure's IP rating to be temporarily changed), and then, when the temperature falls back below the predetermined level, the cover will move from the open position back to the closed position (and thus restoring the original IP rating).

[0013] It is clear that the function can be reversed depending on the needs, i.e. when the temperature falls below a certain value or range, and such a fall results in a deterioration of the working conditions. The SMA-based actuating element may be based on a shape memory alloy having a negative temperature coefficient, i.e., a shape memory alloy that contracts when the temperature exceeds the predetermined value or range, in which case the SMA-based actuating element reduces its operating dimension (i.e., shrinks) when the temperature exceeds the predetermined value or range. Alternatively, the SMA-based actuating element may be based on a shape memory alloy with a positive temperature coefficient, i.e., a shape memory alloy that expands when the temperature exceeds said predetermined value or range, in which case the SMA-based actuating element increases its operating dimension (i.e., lengthens) when the temperature exceeds said predetermined value or range.

[0014] Furthermore, it is noteworthy that the operating principle of the SMA-based operating element (e.g., linear movement in response to temperature) is extremely simple, and therefore the operating mechanism connecting the SMA-based operating element and the cover is extremely simple and therefore extremely easy to manufacture and maintain. In a preferred embodiment of the low to medium voltage electrical enclosure according to the present invention, one or more covers are hinged to a rim portion of a corresponding vent, the covers being pivotally movable from said first closed operational state to said second open operational state and vice versa under the action of an SMA based actuation element.

[0015] In most preferred embodiments of the low and medium voltage electrical enclosure of the present invention, the SMA based actuating element advantageously comprises a rod or wire having a first predetermined length at said first predetermined temperature and a second predetermined length at said second predetermined temperature. In fact, according to this embodiment, the SMA based actuating element shortens or lengthens in a linear actuating direction along its longitudinal extension depending on the temperature conditions, thereby making it very easy to couple with the actuating mechanism of the cover.

[0016] For example, in this case the actuation mechanism may conveniently comprise a lever having a first end operably connected to the cover and a second end operably connected to the first end of the bar or wire, such that linear movement of the SMA based actuation element is immediately transmitted to the cover in a very simple manner. In a particular embodiment of the low to medium voltage electrical enclosure of the present invention, the bar or wire then preferably has a second end fixed to a fixed point on the enclosure. Indeed, according to this embodiment, the movement of the SMA-based actuating element is only in one direction, as will be better explained below.

[0017] Alternatively, in a particular embodiment of the low-medium voltage electrical enclosure of the present invention, the enclosure comprises one or more sets of first and second vents provided with corresponding first and second covers. In this embodiment, the SMA-based actuation element advantageously comprises a bar or wire having a first predetermined length at said first predetermined temperature and a second predetermined length at said second predetermined temperature. Furthermore, said actuation mechanism comprises first and second levers each having a first end connected to said first and second covers, respectively. And, said bar or wire advantageously has a first end operably connected to said first lever and a second end operably connected to said second lever.

[0018] Indeed, according to this embodiment, an SMA-based actuation element is positioned between the two vents and the corresponding covers, the movement of which is performed in two directions acting simultaneously on said first and second levers, as will be better explained below. In a particular embodiment of the low to medium voltage electrical enclosure according to the invention, the actuation mechanism may preferably comprise a resilient element cooperating with said SMA-based actuation element during the dimensional change from said first dimension to said second dimension, in this way the resilient element can assist and regulate the opening and closing movement of the cover depending on the precise temperature conditions.

[0019] In particular, in such a case, the elastic element may advantageously be a spring which cooperates with the SMA-based actuating element during movement of the corresponding cover from the second open operating state to the first closed operating state and vice versa. In a preferred embodiment of the low to medium voltage electrical enclosure of the present invention, the SMA based actuating element has a negative temperature coefficient, i.e., the first predetermined temperature is lower than the second predetermined temperature and the first dimension of the SMA based actuating element is greater than the second dimension of the SMA based actuating element.

[0020] The number and location of the vents on the wall of the low and medium voltage electrical enclosure can be varied as required. For example, the one or more vents may be advantageously positioned on a sidewall of the enclosure, either grouped together or in scattered areas corresponding to particular locations on the sidewall, depending on the cooling needs of various compartments within the enclosure.

[0021] Alternatively or in combination with the previously described embodiment, the one or more vents are arranged in a top wall of the housing. Furthermore, in further particular embodiments of the low to medium voltage electrical enclosure of the invention, which may be alternatively or combined with the above-mentioned embodiments, the one or more vents may be advantageously arranged on an internal wall separating a first compartment and a second compartment within the internal space of the enclosure. Further features and advantages of the present invention will become more apparent from the description of preferred, but non-exclusive, embodiments of a low- and medium-voltage electrical enclosure according to the invention, illustrated by way of example in the accompanying drawings, in which: [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view of a first embodiment of a low- and medium-voltage electrical enclosure according to the present invention. [Figure 2a] FIG. 2a is a first perspective view of a first embodiment of a cover and a corresponding actuator according to the invention in a first, closed, operative state as viewed from outside the housing. [Figure 2b] FIG. 2b is a second perspective view of the first embodiment of a cover and corresponding actuator according to the present invention in a second, open, operational state, as viewed from outside the housing. [Diagram 3] FIG. 3 is a third perspective view of the first embodiment of the cover and corresponding actuator according to the present invention in a second open-air operating state as viewed from inside the housing. [Figure 4a] FIG. 4a is a first side view of a first embodiment of a cover and corresponding actuation device according to the present invention in a first closing operational state. [Figure 4b] FIG. 4b is a second side view of the first embodiment of a cover and corresponding actuation device according to the present invention in a second opening operational state. [Figure 5a] FIG. 5a is a first side view of a second embodiment of a cover and corresponding actuation device according to the present invention in a first closing operational state. [Figure 5b] FIG. 5b is a second side view of a second embodiment of a cover and corresponding actuator according to the present invention in a second opening operational state. [Figure 6a] FIG. 6a is a first side view of a third embodiment of a cover and corresponding actuation device according to the present invention in a first closing operational state. [Figure 6b] FIG. 6b is a second side view of the third embodiment of a cover and corresponding actuation device according to the present invention in a second opening operational state. [Figure 7] FIG. 7 is a perspective view of a second embodiment of a low-medium voltage electrical enclosure according to the present invention. [Figure 8] FIG. 8 is a perspective view of a third embodiment of a low-medium voltage electrical enclosure according to the present invention. [Figure 9] FIG. 9 is a perspective view of a second embodiment of a cover and corresponding actuator according to the present invention in a second open operational state.

[0023] With reference to the accompanying drawings, a low to medium voltage electrical enclosure shown in various embodiments having the reference numerals 1, 10, 100, in its more general definition comprises a support structure 11 defining an interior space 12 bounded by a top wall (external wall, wall) 13, a side wall (external wall, wall) 14 and one or more interior walls 15, and having one or more compartments for accommodating one or more electrical devices. One of the features of the low- and medium-voltage electrical enclosure 1, 10, 100 of the present invention is given by the fact that at least one of the outer walls 13, 14 is provided with one or more ventilation openings 20, 30 leading between the exterior of the low- and medium-voltage electrical enclosure 1, 10, 100 and the interior space 12.

[0024] Alternatively or additionally, at least one of the interior walls 15 of the housing 1, 10, 100 is also provided with one or more vents 20, 30 leading between one of said compartments and a second compartment within the interior space 12. The vents 20, 30 are conveniently provided with corresponding covers 21, 31 for closing the vents 20, 30 in a first closed operational state at a first predetermined temperature, and the electrical enclosure 1, 10, 100 is conveniently provided with an actuator 40 adapted to move the covers 21, 31 from the first closed operational state to a second open operational state at a second predetermined temperature.

[0025] A further feature of the low to medium voltage electrical enclosure 1, 10, 100 of the present invention is given by the fact that the actuation device 40 advantageously comprises an actuation mechanism 41 having a shape memory alloy based (SMA based) actuation element 42, 421 reversibly changeable to a first dimension at a first predetermined temperature and to a second dimension at a second predetermined temperature. Thus, the reversible dimensional change of the SMA-based actuation elements 42, 421 from a first dimension to a second dimension determines the reversible movement of the covers 21, 31 from a first closed operating state to a second open operating state, and vice versa.

[0026] Thus, in the open state, controlled convection ventilation of the low to medium voltage electrical enclosure 1, 10, 100 is possible until such time that the temperature returns to below the first predetermined temperature, at which point the SMA-based actuating element 42, 421 changes its dimension from the second dimension to the first dimension, thereby moving the cover 21, 31 from the second open operational state to the first closed operational state, restoring the original closed state and original IP rating of the enclosure 1, 10, 100. As shown in the accompanying figures, in preferred embodiments of the presently disclosed low and medium voltage electrical enclosures 1, 10, 100, the covers 21, 31 are hingeable to the rim portions 211, 311 of the corresponding vents 20, 30 and the covers 21, 31 are pivotable between a first, closed and a second, open operational condition in accordance with the mechanisms previously described.

[0027] In most preferred embodiments of the low to medium voltage electrical enclosures 1, 10, 100 of the present invention, the SMA based actuating element 42, 421 preferably comprises a rod or wire having a first predetermined length at said first predetermined temperature and a second predetermined length at said second predetermined temperature. As shown in the attached figures, the actuation mechanism can be very simple when the SMA-based actuation element 42, 421 is formed of a bar or wire. With particular reference to figures 2 to 6, in this case, advantageously, said actuation mechanism 41 comprises a lever 51 having a first end 511 operably connected to the corresponding cover 21, 31 and a second end 512 operably connected to the first end 43, 431 of the bar or wire 42, 421.

[0028] In the embodiment of the low to medium voltage electrical enclosure 1, 10, 100 shown in Figures 2-5, said bar or wire 42 has a second end 44 fixed to a fixed point 45 of said enclosure 1, 10, 100. The movement of the SMA based actuating element 42 is therefore only in one direction, with the first end 43 of the bar or wire 42 acting on the second end 512 of the lever, which determines its movement and the resulting movement of the cover 21 from the closed position to the open position and vice versa.

[0029] In an alternative embodiment of a low to medium voltage electrical enclosure 1, 10, 100 shown in FIG. 6, the electrical enclosure 1, 10, 100 comprises one or more pairs of first and second ventilation openings 20 provided with corresponding first and second covers 21. In this case, the SMA based actuation element 421 advantageously comprises a rod or wire having a first predetermined length at said first predetermined temperature and a second predetermined length at said second predetermined temperature. In response, the actuation mechanism 41 advantageously comprises first and second levers 51, 52 having first ends 511 connected to said first and second covers 21, respectively. Furthermore, said rod or wire 421 has a first end 431 operably connected to said first lever 51 and a second end 441 operably connected to said second lever 52.

[0030] Indeed, according to this embodiment, the SMA-based actuating element 421 is arranged between the two vents 20 and the corresponding covers 21, mirroring each other. The movement of the bar or wire 421 is performed in two opposite directions acting simultaneously on said first and second levers 51, 52, such that a first end 431 of the bar or wire 421 acts on a first lever 51 and a second end 441 of the bar or wire 421 acts on a second lever 52, thereby determining their opposite movements and, consequently, the movement of the cover 21 from the closed position to the open position and vice versa.

[0031] Referring to FIG. 5, in certain embodiments of the low to medium voltage electrical enclosures 1, 10, 100 of the present disclosure, the actuation mechanism 41 advantageously comprises a resilient element 60 which cooperates with said SMA based actuation element 42, 421 during the dimensional change from said first dimension to said second dimension. Said elastic element 60 may for example be formed by a spring having one end fixed to a fixed point on the housing 1, 10, 100 and a second end fixed to a suitable point on the lever 51. The spring 60 thus cooperates with the SMA-based actuating element 42, 421 during the movement of the cover 21, 31 from the second open operating state to the first closed operating state. In fact, according to this embodiment, the spring 60 is mechanically arranged in parallel with the SMA-based actuating element 42, 421 and can assist and regulate the opening and closing of the cover depending on the precise temperature conditions.

[0032] In the embodiments of the low to medium voltage electrical enclosure 1, 10, 100 shown in the accompanying figures, the first predetermined temperature is lower than the second predetermined temperature and the first dimension of the SMA based actuating element 42, 421 is greater than the second dimension of the SMA based actuating element 42, 421. In other words, in the embodiment shown, the SMA-based actuating element 42, 421 is based on a shape memory alloy with a negative temperature coefficient, i.e. a shape memory alloy that contracts when the temperature exceeds a predetermined value or range, and therefore the SMA-based actuating element 42, 412 contracts when the temperature exceeds said predetermined value or range.

[0033] Alternatively, according to an embodiment based on the reverse operating condition, not shown, the SMA-based actuating element 42, 421 can be based on a shape memory alloy with a positive temperature coefficient, i.e., a shape memory alloy that expands when the temperature exceeds a predetermined value or range, in which case the SMA-based actuating element 42, 421 increases its actuating dimension (i.e., lengthens) when the temperature exceeds said predetermined value or range.

[0034] 7, in one embodiment of the low to medium voltage electrical enclosure 10 of the present invention, vents 20 are located on the side walls 14 of said enclosure 10, and are specifically concentrated in a first location at the bottom of said side walls 14 and in a second location at the top of said side walls 14. However, as previously mentioned, the location of the vents 20 may vary depending on the cooling needs of various compartments within the enclosure 10.

[0035] Alternatively, with reference to FIG. 1, the one or more vents 20 , 30 may be conveniently located in the top wall 13 of the housing 1 . In a particular embodiment of the low to medium voltage electrical enclosure 100 of the present invention, the one or more vents 20, 30 may be conveniently located in an interior wall 15 of the enclosure 100 that separates a first compartment from a second compartment in the interior space 12 of the enclosure 100. An embodiment is shown in Figure 8 where, for clarity, details of the interior space 12 of the enclosure 100 are depicted without side walls.

[0036] It is apparent that any combination of the above-described embodiments is possible with regard to the number and positions of the ventilation openings 20, 30 in the low-medium voltage electrical enclosure 100 of the present invention. The shape and dimensions of the vent can be selected as required. For example, with reference to Figures 1-8, the shape of the vent 20 and the corresponding cover 21 may be circular. However, as shown with reference to Figure 9, the shape of the vent 30 and the corresponding cover 31 may be square or rectangular.

[0037] If the vents 20, 30 are of relatively wide dimensions and / or it is preferred to have some protection thereover, a net or mesh 30 may be conveniently placed corresponding to said vents. It will be apparent from the above description that the low to medium voltage electrical enclosure of the present invention fully achieves its intended objectives and overcomes the above-mentioned problems of existing enclosures. In particular, in the low- and medium-voltage electrical enclosure of the present invention, the opening and closing temperatures of the vent cover are determined in advance, and as a result, by appropriately selecting the material of the SMA-based actuating element, the internal temperature fluctuations can be easily controlled.

[0038] In this manner, the device for controlling temperature fluctuations inside a low- and medium-voltage electrical enclosure of the present invention does not require dedicated wiring or power supply, and can be installed very easily and quickly. Furthermore, as a result of the very simple construction of the device for controlling the temperature changes in the enclosure, maintenance interventions are usually not necessary or can be carried out very easily and quickly.

[0039] Furthermore, as there are no electrical or additional components, there are no compatibility issues and, as a result, no need to carry out dedicated EMC testing or obtain additional certifications. The low and medium voltage electrical enclosure thus conceived is capable of several variations, all of which are covered by the appended claims. In fact, the materials used, the incidental dimensions and shapes can be any, depending on the requirements and the current state of the art. [Explanation of symbols]

[0040] 1, 10, 100: Low and medium voltage electrical enclosures (enclosures) 11:Support structure 12: Interior space 13: Upper wall (outer wall) 14: Side wall (outer wall) 15:Inner wall 20, 30: Ventilation holes (openings, net or mesh) 21: Cover (first cover) 31: Cover (Second cover) 40: Actuator 41: Operating mechanism 42, 421: Actuating element (bar or wire) 43, 431: first end 44: Second end 45: Fixed point 51: Lever (first lever) 52: Second Lever 60: Spring 211, 311: Rim part 441: Second end 511: First end 512: Second end

Claims

1. A low and medium voltage electrical enclosure (1, 10, 100) comprising a support structure (11) defining an interior space (12) bounded by walls (13, 14, 15) forming one or more compartments for housing one or more electrical devices, at least one of said walls (13, 14, 15) has one or more ventilation openings (20, 30) between the exterior of said low and medium voltage electrical enclosure (1, 10, 100) and said interior space (12) and / or between one of said compartments and a second compartment, the one or more vents (20, 30) comprising covers (21, 31) adapted to close the corresponding vents (20, 30) in a first closed operational state at a first predetermined temperature, and an actuator (40) adapted to open the covers (21, 31) in a second open operational state at a second predetermined temperature; The actuation device (40) comprises an actuation mechanism (41) having a shape memory alloy-based (SMA-based) actuation element (42, 421) having a first dimension at a first predetermined temperature and reversibly changeable to a second dimension at a second predetermined temperature; a reversible dimensional change of the SMA-based actuation element (42, 421) from the first dimension to the second dimension determines a reversible movement of the cover (21, 31) from the first closed operational state to the second open operational state, and vice versa; the electrical enclosure (1, 10, 100) comprises one or more pairs of first and second vents (20, 30) provided with corresponding first and second covers (21, 31); the SMA-based actuating element (42, 421) comprises a bar or wire (42, 421) having a first predetermined length at the first predetermined temperature and a second predetermined length at the second predetermined temperature; the actuation mechanism (41) comprises first and second levers (51, 52) having first and second ends (511, 512) connected to the first and second covers (21, 31), respectively; The low and medium voltage electrical enclosure (1, 10, 100), characterized in that the bar or wire (42, 421) has a first end (431) operably connected to the first lever (51) and a second end (441) connected to the second lever (52).

2. A low- or medium-voltage electrical enclosure (1, 10, 100) comprising a support structure (11) defining an interior space (12) bounded by walls (13, 14, 15) forming one or more compartments for housing one or more electrical devices, at least one of said walls (13, 14, 15) has one or more ventilation openings (20, 30) between the exterior of said low and medium voltage electrical enclosure (1, 10, 100) and said interior space (12) and / or between one of said compartments and a second compartment, the one or more vents (20, 30) comprising covers (21, 31) adapted to close the corresponding vents (20, 30) in a first closed operational state at a first predetermined temperature, and an actuator (40) adapted to open the covers (21, 31) in a second open operational state at a second temperature; The actuation device (40) comprises an actuation mechanism (41) having a shape memory alloy-based (SMA-based) actuation element (42, 421) having a first dimension at a first predetermined temperature and reversibly changeable to a second dimension at a second predetermined temperature; a reversible dimensional change of the SMA-based actuation element (42, 421) from the first dimension to the second dimension determines a reversible movement of the cover (21, 31) from the first closed operational state to the second open operational state, and vice versa; the actuation mechanism (41) comprising an elastic element (60) cooperating with the SMA-based actuation element (42, 421) during a dimensional change from the first dimension to the second dimension; A low and medium voltage electrical enclosure (1, 10, 100), characterized in that both the SMA-based actuating element (42, 421) and the elastic element (60) are disposed within the interior space (12).

3. 3. The low-medium voltage electrical enclosure (1, 10, 100) according to claim 1 or 2, characterized in that the cover (21, 31) is hinged to a rim (211, 311) of the corresponding vent (20, 30) and is pivotable between the first closed operational state and the second open operational state.

4. The low-medium voltage electrical enclosure (1, 10, 100) according to claim 2 or claim 3 relying on claim 2, characterized in that the SMA-based actuating element (42, 421) comprises a bar or wire (42, 421) having a first predetermined length at the first predetermined temperature and a second predetermined length at the second predetermined temperature.

5. 5. The low and medium voltage electrical enclosure (1, 10, 100) according to claim 4, characterized in that the actuating mechanism (41) comprises a lever (51) having a first end (511) operably connected to the cover (21, 31) and a second end (512) operably connected to the first end (43, 431) of the bar or wire (42, 421).

6. 6. The low-medium voltage electrical enclosure (1, 10, 100) according to claim 5, characterized in that the bar or wire (42, 421) has a second end (44) fixed to a fixing point (45) of the electrical enclosure (1, 10, 100).

7. An electrical enclosure (1, 10, 100) comprising one or more pairs of first and second vents (20, 30) provided with corresponding first and second covers (21, 31); the SMA-based actuating element (42, 421) comprises a bar or wire (42, 421) having a first predetermined length at the first predetermined temperature and a second predetermined length at the second predetermined temperature; the actuation mechanism (41) comprises first and second levers (51, 52) each having a first end (511) connected to the first and second covers (21, 31); The low-medium voltage electrical enclosure (1, 10, 100) according to any one of claims 2, 3 and 4, characterized in that the bar or wire (42, 421) has a first end (431) operably connected to the first lever (51) and a second end (441) connected to the second lever (52).

8. The low and medium voltage electrical enclosure (1, 10, 100) according to claim 2, claim 3 relying on claim 2, or any one of claims 4 to 7, characterized in that the elastic element (60) is a spring which cooperates with the SMA-based actuating element (42, 421) during the movement of the cover (21, 31) from the second open operational state to the first closed operational state.

9. the first predetermined temperature is lower than the second predetermined temperature; The low and medium voltage electrical enclosure (1, 10, 100) according to any one of claims 1 to 8, characterized in that the first dimension of the SMA based actuating element (42, 421) is greater than the second dimension of the SMA based actuating element (42, 421).

10. The low and medium voltage electrical enclosure (1, 10, 100) according to any one of claims 1 to 9, characterized in that the one or more vents (20, 30) are arranged in a side wall (14) of the electrical enclosure (1, 10, 100).

11. The low- and medium-voltage electrical enclosure (1, 10, 100) according to any one of claims 1 to 10, characterized in that the one or more vents (20, 30) are arranged in a top wall (13) of the electrical enclosure (1, 10, 100).

12. The low- and medium-voltage electrical enclosure (1, 10, 100) according to any one of claims 1 to 11, characterized in that the one or more vents (20, 30) are arranged in an inner wall (15) separating a first compartment and a second compartment of the electrical enclosure (1, 10, 100).

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