Electrical protection device configured to automatically determine the cause of an open electrical circuit and associated method

Abstract

Electrical protection device configured to automatically determine the cause of an open electrical circuit and associated method. 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. (See Figure 3 for a simplified explanation.)

Description

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

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

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

[0003] Many electrical protection devices can, in addition to being opened when an electrical fault is detected, which causes the opening of an electrical circuit in which they are connected, be opened manually by a user, for example by operating a lever. It may be advantageous to distinguish opening by a user from opening caused by an electrical fault. For this purpose, it is known to add an additional accessory, for example an additional module, to already existing protection devices, allowing this distinction of 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 then to resolve these drawbacks and to propose an electrical protection device making it possible to 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, on manual control or following detection of an electrical fault, the device being further configured to automatically determine a cause of opening the electrical circuit, the device comprising: - a movable 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 lever, movable between an open position and a closed position, moving the switching handle to the open position by manual control causing the moving contact to be placed in the isolation position; - a switching mechanism configured to switch between an armed configuration in which the movable contact is in the conduction position and the switching handle in the closing position, and a triggered configuration in which the movable contact is in the isolation position and the switching handle in the opening position; - a trigger configured to actuate the switching mechanism upon 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 connection element, connecting the movable contact and the electronic control unit, configured so that a first current flows in the electrical connection element to the electronic control unit, a first voltage being representative of the position of the movable contact in the conduction position or in the isolation position; - a switch, connected to the electronic control unit and movable between a depressed 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 depressed position and the free position; - a mechanical connecting element, connected to the switching lever and movable between: • a support position, the mechanical connecting element then pressing on the switch and holding it in the pressed position, and • a release position, the mechanical connecting element then releasing the switch which switches to the free position,

[0008] 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 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.

[0009] Thanks to the invention, the electrical protection device integrates the capacity to determine the cause of the opening of a circuit, and to distinguish a manual opening from an opening caused by an electrical fault, without adding an additional module. mentary, this function being directly integrated into the device housing. The invention therefore makes it possible to reduce the size of devices integrating this capacity to distinguish the cause of opening. Thanks to the invention, it is also not necessary to mount an additional module, nor to connect it to the electrical protection device, which facilitates installation.

[0010] According to other advantageous aspects of the invention, the electrical protection device comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0011] - The moving contact is a phase moving contact.

[0012] -The mechanical connecting element is in the support position when the switching handle is in the closed position and in the release position when the switching handle is in the open position.

[0013] - The electrical connecting element is a spring, in contact with the movable contact when the moving contact is in the conduction position and separated from the moving contact when the moving contact is in the isolation position, one of the ends of the electrical connection element being connected to the electronic control unit.

[0014] - The mechanical connecting element is a connecting rod, connected to the control lever mutation, and one end of which is configured to press or release the switch.

[0015] - The device further comprises a thermal trigger and / or a trigger magnetic device configured to switch the movable contact from the conduction position to the isolation position when the thermal trip device and / or the magnetic trip device is excited by an electrical fault such as a short circuit or overload.

[0016] - The device is integrated into a housing, the housing having a width, measured along a width direction, less than 20 mm, preferably equal to or less than 18 mm.

[0017] The invention also relates to a method for automatically determining a cause of opening of 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 time when the first voltage becomes lower than the first voltage threshold, and a time 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;

[0018] sending 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.

[0019] According to other advantageous aspects of the invention, the method comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0020] - The method comprises sending the second signal when the duration is greater than or equal to the duration threshold and when an intensity value of a current is less than a current threshold, the method further comprising sending the third signal when the duration is greater than or equal to the duration threshold and the intensity value of the current is greater than or equal to the current threshold.

[0021] - The duration threshold is less than 10 ms, preferably equal to 6 ms.

[0022] - The current threshold is equal to a nominal intensity circulating in the circuit electrical multiplied by a predetermined value, for example three.

[0023] - The method further comprises 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.

[0024] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the drawings in which: - [Fig.l] [Fig.l] is a view of an electrical protection device according to the invention, from a first angle, shown in a closed configuration; - [Fig.2] [Fig.2] is a view of the electrical protection device of the [Fig.l] from a second angle; - [Fig.3] [Fig.3] is a view of detail III of [Fig.l]; - [Fig.4] [Fig.4] is a view similar to [Fig.3], the protection device electric being in an open configuration; - [Fig.5] [Fig.5] is a flowchart of a method according to the invention according to one embodiment; and - [Fig.6] [Fig.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 [Fig.l], in the case of manual opening and in the case of opening on fault.

[0025] The electrical protection device is described below with reference to Figures 1 to 4.

[0026] [Fig.l] shows a view from a first angle of an electrical protection device 1, also called device 1 according to the invention. In [Fig.l], this electrical protection device 1 is a circuit breaker, here a miniature circuit breaker called MCB, from the English "Miniature Circuit Breaker", but the invention can also be applied to other types of circuit breakers, or to other electrical devices intended for the protection of electrical installations and / or people. Here, the device 1 protects the electrical installations against abnormal conditions, in particular short circuits and current overloads. The device 1 is more particularly intended to be used to protect low voltage electrical installations, for example electrical voltages less than or equal to 1000 V AC. For this, when the 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, not shown in the figures.The input conductor is for example a busbar and the output conductor is for example an electric cable.

[0027] A width direction X, a depth direction Y and a height direction Z are defined, which are perpendicular to each other and which are fixed relative to the device 1. The width direction X is horizontal and normal to the plane of figures 1 to 4.

[0028] The device 1 comprises a housing 2, essentially closed and containing the majority of the other elements of the device 1. The housing 2 is formed from an electrically insulating material. The directions X, Y and Z are fixed relative to the housing 2.

[0029] In [Fig. 1], only a part of the housing 2 is visible, namely a half-shell. The housing 2 comprises another half-shell 3 visible in [Fig. 2] and generally symmetrical to that which is shown, with respect to a plane P2 which delimits the half-shell 2 on its side.

[0030] The 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, ensuring the electrical contact function. The movable contact 11 preferably comprises a contact carrier 15, which carries the conductive end 13. The movable contact 11 is pivotable, relative to the housing 2, by means of the contact carrier 15, around a movable contact axis XI1, parallel to the width direction X. This pivoting is carried out between a conduction position, shown in [Fig.l], and an insulating position, shown [Fig.4]. In the conduction position of the movable contact 11, the conductive end 13 is in electrical contact with, and resting against, the fixed contact 12, allowing the passage of current between the input conductor and the output conductor of the electrical circuit. In other words, in the conduction position, the phase moving contact 11 closes the electrical circuit. In the isolation position, the conductive end 13 of the phase moving contact 11 is moved away from the fixed contact 12, so as to be electrically isolated therefrom. In other words, in the isolation position, the phase moving contact 11 opens the electrical circuit.

[0031] The electrical protection device 1 advantageously comprises a second movable contact 21 and a second fixed contact 22, visible in [Fig. 2]. The second movable contact 21 is generally called the movable neutral contact 21 and the second fixed contact 22 is generally called the fixed neutral contact 22. The fixed neutral contact 22 is connected to the input conductor of the electrical circuit. The movable neutral contact 21 is connected to the output conductor of the electrical circuit. The movable neutral contact 21 preferably comprises a conductive end 23 and a contact holder 25, in a manner similar to that described for the movable phase contact 11. The movable neutral contact 21 is pivotable, relative to the housing 2, around the axis XI1, that is to say around the same axis as that of the movable contact 11.It could nevertheless be provided, as a variant, that the pivoting of the phase 11 and neutral 21 moving contacts is carried out around two distinct axes, preferably parallel to each other. The pivoting of the neutral moving contact 21 is carried out between a conduction position and an isolation position. In a similar manner to the phase 11 moving contact, in the conduction position of the neutral moving contact 21, the conductive end 23 is in electrical contact with, and resting against, the neutral fixed contact 22. In other words, in the conduction position, the neutral moving contact 21 closes the electrical circuit. In the isolation position, the conductive end 23 of the neutral moving contact 21 is spaced from the neutral fixed contact 22, so as to be electrically isolated therefrom. In other words, in the isolation position, the neutral moving contact 21 opens the electrical circuit.

[0032] The moving phase 11 and neutral 21 contacts are advantageously pivotable relative to the housing 2 independently. When they move from their respective isolation positions to their respective conduction positions, the moving phase 11 and neutral 21 contacts advantageously rotate in the same direction. In particular, the conductive ends 13 and 23 are then moved essentially in a direction opposite to the direction Z. When the moving phase 11 and neutral 21 contacts are in the conduction position, the electrical circuit is closed, and electric current flows in the fixed phase contact 12 to the moving phase contact 11, and in the fixed neutral contact 22 to the moving neutral contact 21.

[0033] The electrical protection device 1 further comprises at least one trigger. In the illustrated example, two triggers are shown, each configured to be excited by an electrical fault of a respective distinct predetermined type. Each trip unit is designed to individually trigger the phase 11 and neutral 21 moving contacts to the isolation position 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 per se and are not described in further detail.

[0034] Optionally, not shown, the device 1 comprises an additional trigger, configured to be excited by another electrical fault of a predetermined type, namely a differential type electrical fault. The device 1 is then a circuit breaker called RCBO, from the English “Residual Current Breaker with Overcurrent Protection”.

[0035] The electrical protection device 1 also comprises a switching mechanism 40.

[0036] The switching mechanism 40 is housed in the housing 2. The switching mechanism 40 is configured to switch between an armed configuration, shown in [Fig.l], in which the switching mechanism 40 places the moving phase 11 and neutral 21 contacts in the conduction position, and a triggered configuration, partially shown in [Fig.4], in which the switching mechanism 40 places the moving phase 11 and neutral 21 contacts in the isolation position.

[0037] A first contact spring 45 bears against the first movable contact 11, in particular against the contact carrier 15, and against the switching mechanism 40. A second contact spring 46 bears against the second movable contact 21, in particular against the contact carrier 25 and against the switching mechanism 40. The contact springs 45 and 46 are helical torsion springs. It is provided that the first and second contact springs 45 and 46 apply, respectively to the movable phase 11 and neutral 21 contacts, a torque around the axis XI1 which tends to put the movable phase 11 and neutral 21 contacts in abutment against the fixed phase and neutral contacts 12 and 22.

[0038] The electrical protection device 1 also comprises a switching handle 50. The switching handle 50 is designed to be actuated 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, around a handle axis X50, parallel to the direction X, between a closed position, shown in Figures 1 to 3, and an open position, shown in [Fig.4].

[0039] The switching lever 50 here comprises a base 51, by means of which the switching lever 50 is pivotally mounted on the housing 2. The switching lever 50 comprises a crank pin 52, carried by the base 51, and by by means of which the user can actuate the switching lever 50 in rotation, by exerting a torque around the lever axis X50. To be accessible by the user, the crank pin 52 is arranged at least partly outside the housing 2.

[0040] The switching mechanism 40 advantageously comprises a spring, called a "control spring", not shown. The control spring applies, to the switching lever 50 and by bearing on the housing 2, a torque around the lever axis X50 which tends to return the switching lever 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 lever axis X50, and one branch of which bears on the switching lever 50 and another branch of which bears on the inside of the housing 2.

[0041] The position of the switching handle 50, visible from outside the housing 2, visually indicates to the user the current configuration commanded for the electrical protection device 1, namely a positioning of the phase 11 and neutral 21 moving contacts in the isolation position when the switching handle 50 is in the open position, and a positioning of the phase 11 and neutral 21 moving contacts in the conduction position, when the switching handle 50 is in the closed position.

[0042] The switching mechanism 40 advantageously comprises a connecting rod 42, visible in [Fig. 2]. The connecting rod 42 connects 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.

[0043] Following the detection of an electrical fault of the overload or short-circuit type by one of the triggers 30 or 35, one of the triggers 30 or 35 controls the switching mechanism 40 in the triggered configuration, the moving phase and neutral contacts 11 and 21 are put in the isolation position and the switching handle 50 switches to the opening position. The device 1 thus opens the electrical circuit. A duration T, or delay T, between a moment when the moving phase and neutral contacts 11 and 21 switch to the isolation position and a moment when the switching handle 50 switches to the opening position, is greater than a duration threshold Ts. This duration threshold Ts is advantageously of the order of a few milliseconds, for example between 4 and 8 ms, for example equal to 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 detection of the fault by the trigger 30 or 35, and to the torque of the springs, in particular the control spring.

[0044] A user, by actuating the crank 52, can then switch the switching handle 50 from the open position to the closed position, thus causing the moving phase 11 and neutral 21 contacts to be put into the conduction position from the isolation position, in order to reset the device 1 and close the electrical circuit.

[0045] Conversely, a user, by actuating the toggle 52, can switch the switching handle 50 from the closed position to the open position, thus causing the moving phase 11 and neutral 21 contacts to be placed in the isolation position from the conduction position, for example to carry out operations on the electrical circuit, or to check the correct operation of the device 1. In this case, the switching handle 50 moves from the closed position to the open position almost simultaneously with the moving phase 11 and neutral 21 contacts moving into the isolation position. By almost simultaneous, it is meant that the duration T between the switching handle 50 moving from the closed position to the open position and the moving phase 11 and neutral 21 contacts moving into the isolation position is less than the duration threshold Ts.

[0046] The device 1 further comprises an electrical connection element 60, a switch 70, a mechanical connection 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.

[0047] The electrical connection element 60, visible in Figures 1 to 4, is for example a spring and comprises an end 61 and an end 63 opposite the end 61. The end 61 of the electrical connection element 60, visible in [Fig. 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 [Fig. 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 [Fig. 4].

[0048] A first voltage Vi can be measured at the electrical connection element 60. If this first voltage Vi is non-zero, this indicates that the phase moving contact 11 is in a closed state. On the contrary, the first voltage Vi 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 conduction position, the first voltage Vi is non-zero and a current flows from the phase moving contact 11 in the electrical connection element 60. When the phase moving contact 11 is in the isolation position, the first voltage Vi is zero, no current flows in the electrical connection element 60. Thus, the first voltage Vi is representative of the position of the moving phase contact 11 in conduction or isolation position.

[0049] According to a variant not shown, the end of the electrical connection element 60 is in contact with the moving neutral contact 21 when the moving neutral contact 21 is in the conduction position and not the moving phase contact.

[0050] 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 in [Fig. 3], and a free position, visible in [Fig. 4]. The second voltage V2 varies depending on the free or pressed position of the switch 70.

[0051] For example, in the pressed position, the second voltage V2 is non-zero, i.e. 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, i.e. of a value lower than said predetermined threshold.

[0052] Alternatively, the second voltage V2 is zero when the switch 70 is in the pressed position, and non-zero when it is in the free position. Advantageously, this alternative embodiment makes it possible to reduce energy consumption. Thus, the second voltage V2 is representative of the position of the switch 70, between the pressed position and the free position. Preferably, the switch 70 is by default in the free position, so that when no stress is exerted on the switch 70, it remains in the free position.

[0053] The mechanical connecting element 80 is visible in Figures 1, 3 and 4. The mechanical connecting element 80 is connected to the switching handle 50, more precisely to the base 51, so as to be movable at the same time as the switching handle 50.

[0054] In one embodiment, shown in the figures, the mechanical connecting element 80 is a connecting rod. Alternatively, the mechanical connecting element 80 could be made in another form, for example a rotating plate, a translating drawer, or even a belt. One end 81 of the mechanical connecting element 80 is opposite the switch 70 along the Y axis, and is movable between a pressing position and a releasing position. In the pressing position, visible in [Fig. 3], the end 81 presses on the switch 70 in a direction opposite to the Y direction and keeps it in the pressed position. In the releasing position, visible in [Fig. 4], the end 81 no longer presses on the switch 70, which is then in the free position.

[0055] The mechanical connecting element 80 is therefore in the support position when the switching lever 50 is closed and in the release position when the switching lever 50 is open. Alternatively, not shown, the mechanical connecting element is in the support position when the switching lever is open and in the release position when the switching lever is closed. Thus, the second voltage V2 is representative of the position of the switching lever 50, between the closed position and the open position.

[0056] The current sensor 85 is housed inside the housing 2. The current sensor 85 is configured to measure an intensity I of the current passing through the device 1.

[0057] The electronic control unit 90 is housed inside the housing 2, a part of the electronic control unit being visible in [Fig.l] and the other part being visible in [Fig.2]. In the embodiment illustrated in the figures, the electronic control unit 90 is an electronic card. Alternatively, the electronic control unit 90 may be produced in a form other than an electronic card, for example in the form of a dry contact connected to a data concentrator by wire. The electronic control unit 90 is configured to determine a cause of opening of the electrical circuit, between a manual opening, that is to say caused by a user who switches the switching handle 50 from the closed position to the open position, and an opening on fault, caused by one of the triggers 30 or 35.Advantageously, the electronic control unit 90 comprises a memory, configured to continuously record a value of the intensity I of the current, and in particular to record the value of the intensity I of the current before a possible opening of the electrical circuit. In other words, the electronic control unit 90 makes it possible to store a value of the current I just before a possible opening of the device.

[0058] When the device 1 is in operation, the electronic control unit 90 measures the first voltage Vi and the second voltage V2, and compares the first voltage Vi to a first voltage threshold Vsi and the second voltage V2 to a second voltage threshold Vs2, in order to determine, when the electrical circuit is opened, whether this opening is caused by a manual opening or an opening due to a fault. The electronic control unit 90 is also configured to send a first signal, if the cause of opening is a manual opening, and a second and / or a third signal if the cause of opening is an opening due to a fault.

[0059] 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.

[0060] The signals are for example signals sent wirelessly to a human-machine interface, not shown, which displays to the user the cause of the opening of the electrical circuit by the device 1. Advantageously, additional information on the cause of the opening is also displayed. For example, if the first signal is sent, the human-machine interface simply displays a manual opening, but if the second or third signal is sent, the human-machine interface displays for example the type of electrical fault and / or steps to follow to check that the electrical fault does not persist in the electrical circuit.

[0061] A method for automatically determining the cause of an opening of the electrical circuit is described in more detail below with reference to [Fig.5]. The method comprises a step 201 of measuring the first and second voltages VietV2. The measurement is carried out by the electronic card 90. The measurement step 201 is for example carried out with a frequency equal to or greater than the frequency of the input current of the device 1 (for example 50Hz in France).

[0062] The method also comprises a comparison 202 of the first voltage Vi with the first voltage threshold Vsl. If the first voltage Vi has a value greater than or equal to the first voltage threshold Vsl, the method returns to step 201. This corresponds to a situation where the electrical circuit is closed.

[0063] If the first voltage Vi is lower than the first voltage threshold Vsb, this means that the phase moving contact 11 is in the isolation position, and therefore that the device 1 has opened the electrical circuit. A step 203 is then carried out, and consists of a measurement of the duration T between a moment when the first voltage Vi becomes lower than the first voltage threshold Vsb corresponding to the moment when the phase moving contact 11 switches to the isolation position, and a moment when the second voltage V2 becomes lower than the second voltage threshold Vs2, corresponding to the moment when the switching lever 50 switches to the opening position.

[0064] The method further comprises a comparison 204 of the duration T measured in step 203 with the duration threshold Ts. If the duration T is less than the duration threshold Ts, then the switching lever 50 and the phase contact 11 have been moved almost simultaneously, which corresponds to a manual opening.

[0065] In this case, a 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 opening is a manual opening.

[0066] If the duration T is greater than or equal to the duration threshold Ts, then the switching lever 50 has been moved after the phase moving contact 11 has moved to the isolation position, which corresponds to an opening on fault.

[0067] In this case, advantageously, a step 206 is carried out, in which the intensity I of the current measured by the current sensor 85 before the opening of the device 1 and recorded by the memory of the electronic card 90, is compared with a current threshold Is. The current threshold Is is advantageously calculated as a function of a nominal intensity of the electrical circuit, and is equal to the intensity nominal current circulating in the electrical circuit multiplied by a predetermined value, this value being for example equal to three. If the nominal intensity of the electrical circuit is 32A, then the current threshold Is is for example 96A.

[0068] If the intensity I of the current before opening of the device 1 is lower than the current threshold Is, then a step 207 is carried out, step 207 consisting of the sending of 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 an opening on fault following a current overload in the electrical circuit.

[0069] If the value of the intensity I of the current 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 an opening on fault following a short circuit in the electrical circuit.

[0070] Recording the intensity I of the current by the memory of the electronic card 90 thus makes it possible, in the event of the device 1 opening due to a fault, to determine the cause of the fault between a current overload or a short circuit.

[0071] In a variant not shown, if the duration T is greater than or equal to the duration threshold Ts, steps 206 and 207 are not carried out, and a step corresponding to the sending of the second signal is carried out as a replacement. The second signal corresponds in this case to an opening on fault, without specifying the nature of the fault.

[0072] [Fig.6] represents a variation of the first and second voltages Vi and V2 in the case of a manual opening and in the case of an opening on fault. On insert a) of [Fig.6], representing a manual opening, the voltages Vi and V2 decrease at the same time. Thus, the duration T between the moment when the first voltage Vi became lower than the first voltage threshold Vsl and the moment when the second voltage V2 becomes lower than the second voltage threshold Vs2 is lower than the duration threshold Ts. On insert b) of [Fig.6], corresponding to an opening on fault, the duration T between the moment when the first voltage Vi became lower than the first voltage threshold Vsi and the moment when the second voltage V2 becomes lower than the second voltage threshold Vs2 is higher than the duration threshold Ts.

[0073] In [Fig.5], the first voltage Vi is represented as being greater than the second voltage V2. According to other variants not shown, the first voltage Vi is less than the second voltage V2, or equal to the second voltage V2.

[0074] Alternatively, rather than measuring a first voltage Vi and a second voltage V2, and comparing them respectively to the first voltage threshold Vsi 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.

[0075] According to a variant not shown, a fourth signal, corresponding to an absence of current upstream of the device 1 is emitted when the first voltage is lower than the first voltage threshold and the second voltage remains higher than the second voltage threshold, for a duration greater than a network fault duration threshold, greater than the duration threshold Ts. Indeed, during an absence of current upstream of the device, the first voltage becomes zero, but this is not caused by the moving phase contact being placed in the isolation position. As a result, the handle does not switch to the open position. This makes it possible to distinguish an absence of current due to a cut-off upstream of the device from an electrical fault in the electrical circuit.

[0076] In a particularly advantageous manner, 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.

[0077] The electrical connection element 60, the switch 70, the mechanical connection element 80, the current sensor 85 and the electronic control unit 90 together perform a functionality called OFSD, or “Open Closed Signal Fault”, allowing the user to identify the cause of the opening of the electrical circuit between a manual cause and a cause on fault, and advantageously, in the event of an electrical fault, to also know what type of electrical fault generated the opening of the circuit. This facilitates remote control of the device 1, in particular to determine whether it is necessary to intervene following an electrical fault, or not.

[0078] Advantageously, the elements used to automatically determine the cause of opening and their arrangement make it possible to maintain the compactness of the protection device 1, in particular in the width direction X. In particular, the housing 2 may have a width measured in the width direction X of less than 20 mm, preferably equal to 18 mm.

[0079] Any feature described for one embodiment or variation in the foregoing may be implemented for the other embodiments and variations described above, as long as technically feasible.

Claims

Claims

1. Electrical protection device (1), adapted to be connected between an input conductor and an output conductor of an electrical circuit, and to effect an opening of 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 that the device (1) further comprises: - an electrical connecting element (60), connecting the movable contact (11) and the electronic control unit (90), configured so that a first current flows in the connecting element electrical (60) to the electronic control unit (90), a first voltage (Vi) 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 handle (50) and movable between: • a pressing position, the mechanical connecting element (80) then pressing on the switch (70) and holding it in the pressed position, and • a releasing 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 (Vj) and the second voltage (V2), compare the first voltage (Vj) 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, wherein the mechanical connecting element (80) is in the support position when the switching lever (50) is in the closing position and in the release position when the switching lever (50) is in the opening position.

4. Device (1) according to any one of the preceding claims, in which the electrical connecting element (60) is a spring, in contact with the movable contact (11) when the movable contact (11) is in 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 (Vi) and the second voltage (V2); - a comparison (202) of the first voltage (Vi) with a first voltage threshold (Vsl); - when the first voltage (Vi) becomes lower than the first voltage threshold (Vsi), a measurement of a duration (T) between a moment when the first voltage (Vi) becomes lower than the first voltage threshold (Vsi), and a moment when the second voltage (V2) becomes lower than a second voltage threshold (Vs2); - a comparison of the duration (T) with a duration threshold (Ts); - a sending of the first signal when the duration (T) is lower than the duration threshold (Ts), the first signal corresponding to a manual opening;- sending the second signal and / or the third signal when; the duration (T) is greater than or equal to the duration threshold (Ts), the second signal and / or the third signal corresponding to an opening on fault.

9. The method of claim 8, comprising sending the second signal when the duration (T) is greater than or equal to the duration threshold (Ts) and when an intensity value of a current (I) is less than a current threshold (Is), the method further comprising sending the third signal when the duration (T) is greater than or equal to the duration threshold (Ts) and the intensity value of the current (I) is greater than or equal to the current threshold (Is).

10. Method according to any one of claims 8 or 9 in which the duration threshold (Ts) 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 (Is) is equal to a nominal intensity circulating 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 (Ts).

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