Electrical protection device configured to automatically determine a cause of an opening of an electrical circuit and associated method

Abstract

The present invention relates to an electrical protection device comprising a movable contact (11) connected to the electrical circuit, a switching handle (50), and an electronic control unit. The device (1) further comprises an electrical linkage element (60) connecting the movable contact (11) and the electronic control unit (90), a switch (70), and a mechanical linkage element (80) connected to the switching handle (50). The electronic control unit is configured to measure the first and second voltages, compare them to determine the cause of the electrical circuit opening (either manual opening or fault-induced opening), send a first signal if the cause is manual opening, and send a second and / or third signal if the cause is fault-induced opening.

Description

[0001] The present invention relates to an electrical protection device configured to automatically determine the cause of an opening in an electrical circuit and an associated method.

[0002] The invention is particularly applicable to the field of miniature circuit breakers (MCBs), used to protect low-voltage electrical installations.

[0003] Many electrical protection devices, in addition to opening when an electrical fault is detected (which causes the electrical circuit to open), can also be opened manually by a user, for example, by operating a lever. It can be advantageous to distinguish between opening by a user and opening caused by an electrical fault. For this purpose, it is known to add an accessory, such as an additional module, to existing protection devices, enabling this differentiation of the cause of opening.

[0004] However, this increases the size of the electrical protection device and complicates the installation of the device, since the module must be installed and connected to the rest of the electrical protection device.

[0005] The aim of the invention is therefore to resolve these drawbacks and to propose an electrical protection device that can distinguish the cause of an opening, which is compact and easy to install.

[0006] To this end, the invention relates to an electrical protection device adapted to be connected between an input conductor and an output conductor of an electrical circuit, and to open the electrical circuit, either manually or following the detection of an electrical fault, the device being further configured to automatically determine the cause of an opening of the electrical circuit, the device comprising: a moving contact, connected to the electrical circuit, and movable between: ∘ a conduction position, in which the moving contact closes the electrical circuit, and ∘ an isolation position, in which the moving contact opens the electrical circuit; a switching handle, movable between an opening position and a closing position, the movement of the switching handle to the opening position by manual control resulting in the moving contact being placed in the isolation position; a switching mechanism configured to switch between an armed configuration in which the moving contact is in the conduction position and the switching handle in the closing position, and a tripped configuration in which the moving contact is in the isolation position and the switching handle in the opening position;a trigger configured to activate the switching mechanism in case of detection of an electrical fault to control the triggered configuration; an electronic control unit.

[0007] According to the invention, the device further comprises: an electrical linking element, connecting the moving contact and the electronic control unit, configured so that a first current flows through the electrical linking element to the electronic control unit, a first voltage being representative of the position of the moving contact in the conduction position or in the isolation position; a switch, connected to the electronic control unit and movable between a pressed position and a free position, configured so that a second current flows through the switch to the electronic control unit, a second voltage being representative of the position of the switch between the pressed position and the free position;a mechanical linkage element, connected to the switching handle and movable between: ∘ a press position, the mechanical linkage element then pressing on the switch and holding it in the pressed position, and ∘ a release position, the mechanical linkage element then releasing the switch which tilts into the free position, ; and the electronic control unit is configured to measure the first voltage and the second voltage, compare the first voltage and the second voltage to determine the cause of the electrical circuit opening between a manual opening and an opening due to a fault, send a first signal if the cause of opening is a manual opening and send a second and / or third signal if the cause of opening is an opening due to a fault.

[0008] Thanks to the invention, the electrical protection device incorporates the ability to determine the cause of a circuit opening and to distinguish between a manual opening and an opening caused by an electrical fault, without adding an extra module, as this function is directly integrated into the device's housing. The invention therefore reduces the size of devices incorporating this cause-of-opening capability. Furthermore, thanks to the invention, it is not necessary to mount an additional module or connect it to the electrical protection device, thus simplifying installation.

[0009] According to other advantageous aspects of the invention, the electrical protection device comprises one or more of the following features, taken individually or in any technically possible combination: The moving contact is a phase-activated moving contact. The mechanical linkage is in the press position when the switch handle is in the closed position and in the release position when the switch handle is in the open position. The electrical linkage is a spring, in contact with the moving contact when the moving contact is in the conductive position and separated from the moving contact when the moving contact is in the isolated position, with one end of the electrical linkage connected to the electronic control unit. The mechanical linkage is a connecting rod, attached to the switch handle, with one end configured to press or release the switch.The device further includes a thermal trip and / or a magnetic trip configured to switch the moving contact from the conduction position to the isolation position when the thermal trip and / or magnetic trip is energized by an electrical fault such as a short circuit or overload. The device is integrated into a housing, the housing having a width, measured along a width direction, of less than 20 mm, preferably equal to or less than 18 mm.

[0010] The invention also relates to a method for automatically determining the cause of an opening in an electrical circuit, the method being implemented by the device described above, the method comprising: a measurement of the first voltage and the second voltage; a comparison of the first voltage to a first voltage threshold; when the first voltage becomes lower than the first voltage threshold, a measurement of a duration between a moment when the first voltage becomes lower than the first voltage threshold, and a moment when the second voltage becomes lower than a second voltage threshold; a comparison of the duration with a duration threshold; sending the first signal when the duration is less than the duration threshold, the first signal corresponding to a manual opening; sending of the second signal and / or the third signal when the duration is greater than or equal to the duration threshold, the second signal and / or the third signal corresponding to an opening on fault.

[0011] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations: The method includes sending a second signal when the duration is greater than or equal to the duration threshold and when a current intensity value is less than a current threshold. The method further includes sending a third signal when the duration is greater than or equal to the duration threshold and the current intensity value is greater than or equal to the current threshold. The duration threshold is less than 10 ms, preferably 6 ms. The current threshold is equal to the nominal current flowing in the electrical circuit multiplied by a predetermined value, for example, three. The method further includes sending a fourth signal when the duration is greater than or equal to a network fault duration threshold, the network fault duration threshold being greater than the duration threshold.

[0012] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which: [ Fig. 1 ] there figure 1 is a view of an electrical protection device according to the invention, from a first angle, shown in a closed configuration; [ Fig. 2 ] there figure 2 is a view of the electrical protection device of the figure 1 from a second perspective; Fig. 3 ] there figure 3 is a view of detail III of the figure 1 ; Fig. 4 ] there figure 4 is a view similar to the figure 3 , the electrical protection device being in an open configuration; [ Fig. 5 ] there figure 5 is a flowchart of a process according to the invention in one embodiment; and [ Fig. 6 ] There figure 6 presents, on two inserts a) and b), a graph representing a variation of a first voltage and a second voltage in the protection device of the figure 1 , in the case of a manual opening and in the case of an opening due to a fault.

[0013] The electrical protection device is described below with reference to figures 1 à 4 .

[0014] There figure 1 shows a first-angle view of an electrical protection device 1, also called device 1 according to the invention. On the figure 1 This electrical protection device 1 is a circuit breaker, in this case a miniature circuit breaker (MCB), but the invention can also be applied to other types of circuit breakers or other electrical devices intended for the protection of electrical installations and / or people. Here, device 1 protects electrical installations against abnormal conditions, in particular short circuits and current overloads. Device 1 is specifically designed for use in protecting low-voltage electrical installations, for example, electrical voltages less than or equal to 1000 V AC. For this purpose, when device 1 is in operation, it is connected to an electrical circuit, more precisely between an input conductor and an output conductor of the electrical circuit, which are not shown in the figures.The input conductor is, for example, a busbar and the output conductor is, for example, an electrical cable.

[0015] We define a width direction X, a depth direction Y, and a height direction Z, which are perpendicular to each other and fixed relative to device 1. The width direction X is horizontal and normal to the plane of the figures 1 à 4 .

[0016] Device 1 comprises a housing 2, essentially enclosed and containing most of the other components of device 1. Housing 2 is made of an electrically insulating material. The X, Y, and Z directions are fixed relative to housing 2.

[0017] On the figure 1 Only part of case 2 is visible, namely one half of the casing. Case 2 includes another half of the casing 3 visible at the figure 2 and globally symmetrical to the one that is represented, with respect to a plane P2 which delimits the half-hull 2 ​​on its side.

[0018] Device 1 comprises a movable contact 11 and a fixed contact 12. The movable contact 11 is generally called the phase movable contact 11, and the fixed contact 12 is generally called the phase fixed contact 12. The fixed contact 12 is fixed relative to the housing 2 and is connected to the input conductor of the electrical circuit. The movable contact 11 is connected to the output conductor of the electrical circuit and is located opposite the fixed contact 12 in the height direction Z. The movable contact 11 preferably comprises a conductive end 13, which provides the electrical contact function. The movable contact 11 preferably comprises a contact holder 15, which carries the conductive end 13. The movable contact 11 pivots, relative to the housing 2, via the contact holder 15, about a movable contact axis X11, parallel to the width direction X. This pivoting is performed between a conduction position, shown in the diagram. figure 1 and a position of isolation, shown figure 4 In the conduction position of the moving contact 11, the conductive end 13 is in electrical contact with, and pressing against, the fixed contact 12, allowing current to flow between the input and output conductors of the electrical circuit. In other words, in the conduction position, the moving phase contact 11 closes the electrical circuit. In the isolation position, the conductive end 13 of the moving contact 11 is separated from the fixed contact 12, so as to be electrically isolated from it. In other words, in the isolation position, the moving phase contact 11 opens the electrical circuit.

[0019] The electrical protection device 1 advantageously comprises a second movable contact 21 and a second fixed contact 22, visible at the figure 2 The second moving contact 21 is generally called the neutral moving contact 21, and the second fixed contact 22 is generally called the neutral fixed contact 22. The neutral fixed contact 22 is connected to the input conductor of the electrical circuit. The neutral moving contact 21 is connected to the output conductor of the electrical circuit. The neutral moving contact 21 preferably comprises a conductive end 23 and a contact holder 25, similarly to what has been described for the phase moving contact 11. The neutral moving contact 21 pivots, relative to the housing 2, about the axis X11, that is, about the same axis as the moving contact 11. Alternatively, the pivoting of the phase moving contact 11 and the neutral moving contact 21 could be provided for around two separate axes, preferably parallel to each other.The pivoting of the neutral contact 21 is performed between a conduction position and an isolation position. Similar to the phase contact 11, in the conduction position of the neutral contact 21, the conductive end 23 of the neutral contact 21 is in electrical contact with, and pressing against, the fixed neutral contact 22. In other words, in the conduction position, the neutral contact 21 closes the electrical circuit. In the isolation position, the conductive end 23 of the neutral contact 21 is separated from the fixed neutral contact 22, so as to be electrically isolated from it. In other words, in the isolation position, the neutral contact 21 opens the electrical circuit.

[0020] The movable phase contacts 11 and neutral contacts 21 are advantageously pivotable independently of the housing 2. When moving from their respective insulation positions to their respective conduction positions, the movable phase contacts 11 and neutral contacts 21 advantageously rotate in the same direction. In particular, the conductive ends 13 and 23 are then displaced essentially in a direction opposite to the Z direction. When the movable phase contacts 11 and neutral contacts 21 are in the conduction position, the electrical circuit is closed, and electric current flows through the fixed phase contact 12 to the movable phase contact 11, and through the fixed neutral contact 22 to the movable neutral contact 21.

[0021] The electrical protection device 1 further comprises at least one trip unit. In the illustrated example, two trip units are shown, each configured to be energized by a predetermined electrical fault of a distinct type. Each trip unit is designed to individually trigger the isolation of the moving contacts of phase 11 and neutral 21 when one of the trip units is energized. Here, one of the trip units is a thermal trip unit 30 and is designed to be energized by a predetermined electrical fault, such as a current overload. The other trip unit is a magnetic trip unit 35 and is designed to be energized by a short circuit. Such trip units 30 and 35 are known in themselves and are not described in further detail.

[0022] Optionally, and not shown, device 1 includes an additional trip unit, configured to be triggered by another electrical fault of a predetermined type, namely a residual current fault. Device 1 is then a so-called RCBO circuit breaker, from the English "Residual Current Breaker with Overcurrent Protection".

[0023] The electrical protection device 1 also includes a switching mechanism 40.

[0024] The switching mechanism 40 is housed in the casing 2. The switching mechanism 40 is configured to switch between an armed configuration, shown on the figure 1 , in which the switching mechanism 40 places the moving phase contacts 11 and neutral contacts 21 in the conducting position, and a tripped configuration, partially shown on the figure 4 , in which the switching mechanism 40 puts the phase 11 and neutral 21 moving contacts into the isolation position.

[0025] A first contact spring 45 bears against the first moving contact 11, specifically against the contact holder 15, and against the switching mechanism 40. A second contact spring 46 bears against the second moving contact 21, specifically against the contact holder 25 and against the switching mechanism 40. The contact springs 45 and 46 are helical torsion springs. The first and second contact springs 45 and 46 are expected to apply, respectively to the moving phase contacts 11 and neutral contacts 21, a torque around the axis X11 that tends to bring the moving phase contacts 11 and neutral contacts 21 into contact with the fixed phase and neutral contacts 12 and 22.

[0026] The electrical protection device 1 also includes a switching handle 50. The switching handle 50 is designed to be operated by a user between an open position and a closed position, and vice versa. The switching handle 50 is pivotable relative to the housing 2, about a handle axis X50, parallel to the X direction, between a closed position, shown in the figures 1 à 3 , and an opening position, shown on the figure 4 .

[0027] The switch handle 50 includes a base 51, through which the switch handle 50 is pivotally mounted on the housing 2. The switch handle 50 includes a crank 52, carried by the base 51, through which the user can rotate the switch handle 50 by applying torque around the handle axis X50. To be accessible to the user, the crank 52 is located at least partially outside the housing 2.

[0028] The switching mechanism 40 advantageously includes a spring, called the "control spring," not shown. The control spring applies a torque around the control lever axis X50 to the switch handle 50, bearing against the housing 2. This torque tends to return the switch handle 50 from its closed position to its open position. For example, the control spring is a helical torsion spring housed inside the base 51 around the control lever axis X50, with one arm bearing against the switch handle 50 and the other arm bearing against the inside of the housing 2.

[0029] The position of the switching handle 50, visible from outside the housing 2, visually indicates to the user the current configuration ordered for the electrical protection device 1, namely an isolation position of the moving contacts of phase 11 and neutral 21 when the switching handle 50 is in the open position, and a conduction position of the moving contacts of phase 11 and neutral 21, when the switching handle 50 is in the closed position.

[0030] The switching mechanism 40 advantageously includes a connecting rod 42, visible on the figure 2 The connecting rod 42 links the switching handle 50 to the rest of the switching mechanism 40. Thus, when the switching mechanism 40 is in the triggered position, the switching handle 50 is in the open position, and when the switching mechanism 40 is in the armed position, the switching handle 50 is in the closed position.

[0031] Following the detection of an electrical fault such as an overload or short circuit by one of the trip units 30 or 35, the trip unit 30 or 35 activates the switching mechanism 40 in the tripped configuration. The phase and neutral moving contacts 11 and 21 are placed in the isolation position, and the switching handle 50 is moved to the opening position. Device 1 thus opens the electrical circuit. A duration T, or delay T, between the moment the phase and neutral moving contacts 11 and 21 are moved to the isolation position and the moment the switching handle 50 is moved to the opening position, is greater than a threshold duration Ts. This threshold duration Ts is advantageously on the order of a few milliseconds, for example, between 4 and 8 ms, for example, 6 ms.This delay T is due in particular to the time required to move the moving contacts 11 and 21, the switching mechanism 40 and the switching handle 50 following the detection of the fault by the trigger 30 or 35, and to the torque of the springs, in particular the control spring.

[0032] A user, by operating the lever 52, can then switch the switching handle 50 from the open position to the closed position, thus bringing the phase 11 and neutral 21 moving contacts into the conduction position from the isolation position, in order to reset the device 1 and close the electrical circuit.

[0033] Conversely, a user, by actuating the lever 52, can switch the control lever 50 from the closed position to the open position, thereby switching the phase 11 and neutral 21 moving contacts from the conductive position to the isolation position, for example, to perform operations on the electrical circuit or to check the proper functioning of device 1. In this case, the movement of the control lever 50 from the closed position to the open position occurs almost simultaneously with the movement of the phase 11 and neutral 21 moving contacts to the isolation position. Almost simultaneous means that the time T between the movement of the control lever 50 from the closed position to the open position and the movement of the phase 11 and neutral 21 moving contacts to the isolation position is less than the time threshold Ts.

[0034] The device 1 further includes an electrical linking element 60, a switch 70, a mechanical linking element 80, a current sensor 85 and an electronic control unit 90, which cooperate advantageously, as described in more detail below, to determine the position of the movable contacts 11 and 21 and of the switching handle 50, and to determine the cause of an opening of the electrical circuit by the device 1.

[0035] The electrical connection element 60, visible on the figures 1 à 4 is, for example, a spring and comprises an end 61 and an end 63 opposite end 61. End 61 of the electrical connecting element 60, visible at the figure 2 is connected to the electronic control unit 90. When the phase moving contact 11 is in the conduction position, the end 63 is in contact with the phase moving contact 11, as shown in the figure 3 and when the phase moving contact 11 is in the isolation position, the end 63 is separated from the phase moving contact 11, as shown in the figure 4 .

[0036] A first voltage V1 can be measured at the electrical connecting element 60. If this first voltage V1 is non-zero, it indicates that the phase moving contact 11 is in a closed state. Conversely, the first voltage V1 is zero when the phase moving contact 11 is in an open state. In other words, when the phase moving contact 11 is in the conductive position, the first voltage V1 is non-zero and a current flows from the phase moving contact 11 into the electrical connecting element 60. When the phase moving contact 11 is in the isolated position, the first voltage V1 is zero, and no current flows into the electrical connecting element 60. Thus, the first voltage V1 is representative of the position of the phase moving contact 11 in the conductive or isolated position.

[0037] According to an unrepresented variant, the end of the electrical connecting element 60 is in contact with the neutral moving contact 21 when the neutral moving contact 21 is in the conduction position and not the phase moving contact.

[0038] The switch 70 is connected to the electronic control unit 90, for example by a wired connection. A second voltage V2 can be measured at the switch 70. The switch 70 is movable between a pressed position, visible to the figure 3 , and a free position, visible to the figure 4 The second voltage V2 varies depending on whether the switch 70 is in the free or pressed position.

[0039] For example, in the pressed position, the second voltage V2 is non-zero, that is to say, of a value greater than a single predetermined value, the threshold being equal for example to a few millivolts, and in the free position, the second voltage V2 is zero, that is to say, of a value less than said predetermined threshold.

[0040] Alternatively, the second voltage V2 is zero when switch 70 is in the pressed position, and non-zero when it is in the free position. Advantageously, this alternative embodiment reduces energy consumption. Thus, the second voltage V2 represents the position of switch 70, between the pressed and free positions. Preferably, switch 70 is in the free position by default, so that when no force is exerted on switch 70, it remains in the free position.

[0041] The mechanical linking element 80 is visible on the figures 1 , 3And 4 The mechanical linkage element 80 is connected to the switching handle 50, more precisely to the base 51, so as to be mobile at the same time as the switching handle 50.

[0042] In one embodiment, shown in the figures, the mechanical linkage element 80 is a connecting rod. Alternatively, the mechanical linkage element 80 could be made in another form, for example, a rotating plate, a sliding slide, or a belt. One end 81 of the mechanical linkage element 80 is aligned with the switch 70 along the Y-axis and is movable between a pressed position and a released position. In the pressed position, visible in the figure 3 The end 81 presses on the switch 70 in a direction opposite to the Y direction and holds it in the pressed position. In the released position, visible on the figure 4 , the end 81 no longer presses on the switch 70, which is then in the free position.

[0043] The mechanical linkage 80 is therefore in the pressed position when the switch lever 50 is closed and in the released position when the switch lever 50 is open. Alternatively (not shown), the mechanical linkage is in the pressed position when the switch lever is open and in the released position when the switch lever is closed. Thus, the second voltage V2 represents the position of the switch lever 50, between the closed and open positions.

[0044] The current sensor 85 is housed inside the casing 2. The current sensor 85 is configured to measure an intensity I of the current flowing through the device 1.

[0045] The electronic control unit 90 is housed inside the casing 2, part of the electronic control unit being visible on the figure 1 and the other part being visible on the figure 2 In the embodiment illustrated in the figures, the electronic control unit 90 is an electronic circuit board. Alternatively, the electronic control unit 90 can be implemented in a form other than an electronic circuit board, for example, as a dry contact connected to a wired data concentrator. The electronic control unit 90 is configured to determine the cause of the electrical circuit opening, either a manual opening, i.e., caused by a user toggling the switch handle 50 from the closed position to the open position, or a fault opening, caused by one of the triggers 30 or 35. Advantageously, the electronic control unit 90 includes a memory, configured to continuously record a current value I, and in particular to record the current value I before a possible opening of the electrical circuit.Put another way, the electronic control unit 90 allows a value of the current I to be memorized just before a possible opening of the device.

[0046] When device 1 is operating, the electronic control unit 90 measures the first voltage V1 and the second voltage V2, and compares the first voltage V1 to a first voltage threshold Vs1 and the second voltage V2 to a second voltage threshold Vs2, in order to determine, when the electrical circuit opens, whether this opening is caused by a manual opening or a fault opening. The electronic control unit 90 is also configured to send a first signal if the cause of the opening is a manual opening, and a second and / or third signal if the cause of the opening is a fault opening.

[0047] In a particularly advantageous manner, the electronic control unit 90 is configured to send the second signal when the trigger 30 is the cause of the opening of the electrical circuit, and to send the third signal when the trigger 35 is the cause of the opening of the electrical circuit.

[0048] The signals are, for example, signals sent wirelessly to a human-machine interface (HMI), not shown, which displays to the user the cause of the electrical circuit opening by device 1. Advantageously, additional information about the cause of the opening is also displayed. For example, if the first signal is sent, the HMI simply displays a manual opening, but if the second or third signal is sent, the HMI displays, for example, the type of electrical fault and / or steps to follow to verify that the electrical fault does not persist in the circuit.

[0049] A method for automatically determining the cause of an open electrical circuit is described in more detail below with reference to the figure 5 The process includes a step 201 of measuring the first and second voltages V1 and V2. The measurement is carried out by the electronic board 90. The measurement step 201 is carried out for example with a frequency equal to or greater than the frequency of the input current of the device 1 (for example 50Hz in France).

[0050] The process also includes a comparison 202 of the first voltage V1 to the first voltage threshold Vs1. If the first voltage V1 is greater than or equal to the first voltage threshold Vs1, the process returns to step 201. This corresponds to a situation where the electrical circuit is closed.

[0051] If the first voltage V1 is less than the first voltage threshold Vs1, this means that the phase moving contact 11 is in the isolation position, and therefore that device 1 has opened the electrical circuit. A step 203 is then carried out, which consists of measuring the time T between the moment when the first voltage V1 falls below the first voltage threshold Vs1, corresponding to the moment when the phase moving contact 11 switches to the isolation position, and the moment when the second voltage V2 falls below the second voltage threshold Vs2, corresponding to the moment when the switching lever 50 switches to the opening position.

[0052] The process further includes a comparison 204 of the duration T measured in step 203 with the duration threshold T s . If the duration T is less than the duration threshold T s , then the switching lever 50 and the phase contact 11 have been moved almost simultaneously, which corresponds to a manual opening.

[0053] In this case, step 205 is performed, in which the electronic control unit 90 sends the first signal. This first signal is advantageously received by the human-machine interface in order to generate a display indicating to the user that the cause of the opening is a manual opening.

[0054] If the duration T is greater than or equal to the duration threshold T s, then the switching lever 50 has been moved after the phase moving contact 11 has passed into the isolation position, which corresponds to a fault opening.

[0055] In this case, advantageously, a step 206 is carried out, in which the current intensity I measured by the current sensor 85 before the opening of the device 1 and recorded by the memory of the electronic board 90 is compared with a current threshold Is. The current threshold Is is advantageously calculated based on a nominal current of the electrical circuit and is equal to the nominal current flowing in the electrical circuit multiplied by a predetermined value, this value being, for example, three. If the nominal current of the electrical circuit is 32 A, then the current threshold Is is, for example, 96 A.

[0056] If the current intensity I before opening of device 1 is less than the current threshold Is, then a step 207 is carried out, step 207 consisting of sending the second signal by the electronic control unit 90. This second signal is advantageously received by the human machine interface in order to generate a display indicating to the user that the cause of opening is a fault opening following a current overload in the electrical circuit.

[0057] If the value of the current intensity I is greater than or equal to the current threshold Is, then a step 208 is carried out, consisting of the sending of the third signal by the electronic control unit 90. This third signal is advantageously received by the human machine interface in order to generate a display indicating to the user that the cause of opening is a fault opening following a short circuit in the electrical circuit.

[0058] Recording the current intensity I by the memory of the electronic card 90 thus makes it possible, in the event of the opening of the device 1 on fault, to determine the cause of the fault between a current overload or a short circuit.

[0059] In an alternative not shown, if the duration T is greater than or equal to the duration threshold Ts, steps 206 and 207 are not performed, and a step corresponding to the sending of the second signal is performed instead. In this case, the second signal corresponds to a fault opening, without specifying the nature of the fault.

[0060] There figure 6 represents a variation of the first and second voltages V1 and V2 in the case of manual opening and in the case of fault opening. On insert a) of the figure 6 Representing a manual opening, the voltages V1 and V2 decrease simultaneously. Thus, the time T between the moment when the first voltage V1 falls below the first voltage threshold Vs1 and the moment when the second voltage V2 falls below the second voltage threshold Vs2 is less than the time threshold Ts. On insert b) of the figure 6 , corresponding to a fault opening, the duration T between the moment when the first voltage V 1 became less than the first voltage threshold V s1 and the moment when the second voltage V 2 became less than the second voltage threshold V s2 is greater than the duration threshold T s .

[0061] On the figure 5 The first voltage V1 is represented as being greater than the second voltage V2. According to other variants not shown, the first voltage V1 is less than the second voltage V2, or equal to the second voltage V2.

[0062] Alternatively, rather than measuring a first voltage V1 and a second voltage V2, and comparing them respectively to the first voltage threshold Vs1 and the second voltage threshold Vs2, the electronic control unit 90 measures a first and a second current and compares them to a first current threshold and a second current threshold.

[0063] According to an unrepresented variant, a fourth signal, corresponding to a current loss upstream of device 1, is emitted when the first voltage is below the first voltage threshold and the second voltage remains above the second voltage threshold for a duration exceeding a network fault duration threshold, which is itself greater than the duration threshold Ts. Indeed, during a current loss upstream of the device, the first voltage drops to zero, but this is not caused by the phase contact moving to the isolation position. Consequently, the lever does not switch to the open position. This allows differentiation between a current loss due to a break upstream of the device and an electrical fault in the circuit.

[0064] In a particularly advantageous way, the second and / or third signals are only sent once the network fault duration threshold has been reached, to avoid sending the second and / or third signal once the duration threshold has been reached, and sending the fourth signal once the network fault duration threshold has been reached, which could lead to confusion about the nature of the fault detected by the device.

[0065] The electrical connecting element 60, the switch 70, the mechanical connecting element 80, the current sensor 85, and the electronic control unit 90 together perform a function known as OFSD, or "Open Closed Fault Signal," allowing the user to identify the cause of the electrical circuit opening as either a manual cause or a fault-related cause, and advantageously, in the event of an electrical fault, to also determine the type of electrical fault that caused the circuit opening. This facilitates remote control of the device 1, particularly for determining whether intervention is necessary following an electrical fault.

[0066] Advantageously, the elements used to automatically determine the cause of opening and their arrangement allow the compactness of the protection device 1 to be maintained, particularly along the width direction X. In particular, the housing 2 can have a width measured along the width direction X of less than 20 mm, preferably equal to 18 mm.

[0067] Any feature described for an embodiment or variant in the foregoing may be implemented for the other embodiments and variants described above, provided that it is technically feasible.

Claims

1. Electrical protection device (1), adapted to be connected between an input conductor and an output conductor of an electrical circuit, and to open the electrical circuit, on manual control or following detection of an electrical fault, the device (1) being further configured to automatically determine a cause of an opening of the electrical circuit, the device (1) comprising: - a movable contact (11), connected to the electrical circuit, and movable between: ∘ a conduction position, in which the movable contact (11) closes the electrical circuit, and ∘ an isolation position, in which the movable contact (11) opens the electrical circuit; - a switching handle (50), movable between an open position and a closed position, the movement of the switching handle (50) into the open position by manual control causing the movable contact (11) to be placed in the isolation position;- a switching mechanism (40) configured to switch between an armed configuration in which the movable contact (11) is in the conduction position and the switching handle (50) in the closing position, and a triggered configuration in which the movable contact is in the isolation position and the switching handle (50) in the opening position; - a trigger (30, 35) configured to actuate the switching mechanism (40) in the event of detection of an electrical fault to control the triggered configuration; - an electronic control unit (90); ; characterized in thatthe device (1) further comprises: - an electrical connection element (60), connecting the movable contact (11) and the electronic control unit (90), configured so that a first current flows in the electrical connection element (60) to the electronic control unit (90), a first voltage (V1) being representative of the position of the movable contact (11) in the conduction position or in the isolation position; - a switch (70), connected to the electronic control unit (90) and movable between a pressed position and a free position, configured so that a second current flows through the switch (70) to the electronic control unit (90), a second voltage (V2) being representative of the position of the switch (70) between the pressed position and the free position;- a mechanical connecting element (80), connected to the switching lever (50) and movable between: ∘ a support position, the mechanical connecting element (80) then pressing on the switch (70) and holding it in the pressed position, and ∘ a release position, the mechanical connecting element (80) then releasing the switch (70) which switches to the free position, and; in that the electronic control unit (90) is configured to measure the first voltage (V1) and the second voltage (V2), compare the first voltage (V1) and the second voltage (V2) to determine the cause of opening of the electrical circuit among a manual opening and an opening on fault, send a first signal if the cause of opening is a manual opening and send a second and / or a third signal if the cause of opening is an opening on fault.

2. Device (1) according to claim 1, wherein the movable contact (11) is a phase movable contact (11).

3. Device (1) according to any one of the preceding claims, in which the mechanical connecting element (80) is in the support position when the switching lever (50) is in the closed position and in the release position when the switching lever (50) is in the open position.

4. Device (1) according to any one of the preceding claims, in which the electrical connection element (60) is a spring, in contact with the movable contact (11) when the movable contact (11) is in the conduction position and separated from the movable contact (11) when the movable contact (11) is in the isolation position, one of the ends (61) of the electrical connection element (60) being connected to the electronic control unit (90).

5. Device (1) according to any one of the preceding claims, in which the mechanical connecting element (80) is a connecting rod, connected to the switching lever (50), and one end (81) of which is configured to press or release the switch (70).

6. Device (1) according to any one of the preceding claims, further comprising a thermal trigger (30) and / or a magnetic trigger (35) configured to switch the movable contact (11) from the conduction position to the isolation position when the thermal trigger (30) and / or the magnetic trigger (35) is excited by an electrical fault of the short circuit or overload type.

7. Device (1) according to any one of the preceding claims, the device (1) being integrated in a housing (2), the housing (2) having a width, measured in a width direction (X), less than 20 mm, preferably equal to or less than 18 mm.

8. Method for automatically determining a cause of an opening of an electrical circuit, the method being implemented by a device (1) according to any one of the preceding claims, the method comprising: - a measurement (201) of the first voltage (V1) and the second voltage (V2); - a comparison (202) of the first voltage (V1) with a first voltage threshold (Vs1); - when the first voltage (V1) becomes lower than the first voltage threshold (V s1 ), a measurement of a duration (T) between a moment when the first voltage (V1) becomes lower than the first voltage threshold (V s1 ), and a time when the second voltage (V2) becomes lower than a second voltage threshold (V s2 ); - a comparison of the duration (T) with a duration threshold (T s ); - sending the first signal when the duration (T) is less than the duration threshold (T s), the first signal corresponding to a manual opening; - sending of the second signal and / or the third signal when the duration (T) is greater than or equal to the duration threshold (T s ), the second signal and / or the third signal corresponding to an opening on fault.

9. Method according to claim 8, comprising sending the second signal when the duration (T) is greater than or equal to the duration threshold (T s ) and when a current intensity value (I) is lower than a current threshold (I s ), the method further comprising sending the third signal when the duration (T) is greater than or equal to the duration threshold (T s ) and the current intensity value (I) is greater than or equal to the current threshold (I s ).

10. Method according to any one of claims 8 or 9 in which the duration threshold (T s ) is less than 10 ms, preferably equal to 6 ms.

11. Method according to any one of claims 8 to 10 in which the current threshold (I s ) is equal to a nominal current flowing in the electrical circuit multiplied by a predetermined value, for example three.

12. Method according to any one of claims 8 to 11, further comprising sending a fourth signal when the duration (T) is greater than or equal to a network fault duration threshold, the network fault duration threshold being greater than the duration threshold (T s ).

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