Apparatus comprising an electrical contact provided with a brightness sensor and method for estimating wear

Abstract

One aspect of the invention relates to an electrical apparatus comprising a contact chamber (23) housing an electrical contact (3) comprising an open state and a closed state, a detection chamber (21) and a window (20) between the two said chambers, and a wear estimation device (4) of the electrical apparatus comprising a light sensor (41) in the detection chamber (21) for detecting light when an electric arc appears in the breaking chamber (23).The electrical device optionally includes a computing unit (42) configured to receive an opening information corresponding to the passage of the electrical contact (3) from the closed state to the open state, perform a light detection by the light sensor (41), calculate an electric arc detection time by comparing the time of receipt of the opening information and the duration of light detection, and estimate wear of the device when the duration of electric arc detection is greater than a predetermined value.

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of electrical switching components equipped with a device for detecting wear linked to electric arcs.

[0002] The present invention relates to an electrical device provided with a device for detecting wear linked to electric arcs and in particular a contactor. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various carbon emission restrictions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies to both new aircraft types and those currently in operation, requiring the implementation of technological solutions to bring them into compliance with current regulations. Civil aviation has been mobilizing for several years now to contribute to the fight against climate change.

[0004] Technological research efforts have already led to significant improvements in the environmental performance of aircraft. The Applicant takes into consideration the factors impacting all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental impacts with the aim of improving the energy efficiency of aircraft. Consequently, the Applicant is working to reduce its climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible to reduce the environmental footprint of its activity.

[0005] This ongoing research and development work focuses on new generations of aircraft engines, the weight reduction of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies, and finally aeronautical biofuels.

[0006] In the context of the use of electrical technologies, there are electrical devices comprising one or more normally open or normally closed electrical contacts in a contact chamber. For example, a contactor, in particular a power contactor, comprises at least one electrical contact changing from a closed state to an open state in the contact chamber.

[0007] An electrical contact comprises at least one fixed terminal and a movable conductor, each generally comprising a contact pad, each having a contact surface in contact with each other in the closed state and spaced apart from each other in the open state. For electrical contacts with high electrical power, when changing from one state to the other, and especially when changing from a closed state to an open state, an electric arc forms between the contact surface of the fixed terminal and the contact surface of the movable conductor and normally extinguishes when the movable conductor is sufficiently far from the fixed terminal.

[0008] This electric arc damages the fixed terminal and the moving conductor during this passage, particularly at the level of their contact pads. This degradation is even more significant for high voltage direct current electrical contacts. Some electrical contacts include two fixed terminals and the moving conductor is a moving bridge allowing electrical conductivity to be achieved between the two fixed terminals in the closed state. This thus allows two electric arcs to be formed during the transition from the closed state to the open state.

[0009] When the pellets are worn due to erosion, for example by the electric arc or the environment in the arc chute or due to a higher current in the line or a drop in the dielectric strength of the insulators, the electric arc lasts longer than in the case without wear. This longer duration of the electric arc reduces the reactivity of the device to cut the electric line, and can cause damage in the arc chute or on the device supplied by the electric line that the electrical contact must cut.Furthermore, in the event of a short-circuit type cut, typically greater than 1,000A under 800Vdc, the intensity of the electric arc which appears at the separation of the contact surfaces during their mechanical separation is such that parts of the electrical contact or insulating walls of the contact chamber may suffer irreversible damage: partially melted metal parts which may degrade the insulating walls or elements of the actuator moving the moving conductor (spring, rods, etc.), particles of matter in the contact chamber which may cause deterioration of the actuator, insulating parts degraded by electric arcs, etc.

[0010] In these cases, the reuse of the electrical contact must be prevented because it may no longer cut the electrical line in which the electrical contact is located in the open state. Indeed, in certain cases, when the electrical contact is controlled in the open state, the electric arc may not extinguish and thus cause electrical conductivity between the fixed terminal and the moving conductor which could cause a fire. This is the case, for example, if a particle prevents the moving conductor from finishing its travel to an opening position corresponding to the open state or if a metal particle forms a bridge forming two electric arcs between the moving conductor and the fixed terminal.

[0011] There is therefore a need to improve the safety of an electrical appliance. SUMMARY OF THE INVENTION

[0012] The invention offers a solution to the problems mentioned above, by making it possible to estimate wear of the electrical device, for example of an electrical contact, by measuring at least the propagation time of an electric arc during opening, using a brightness sensor.

[0013] One aspect of the invention relates to an electrical apparatus comprising: A housing comprising a contact chamber, a detection chamber, a base separating the contact chamber and the detection chamber, and a window comprising an opening passing through the base (22) opposite an area detectable by the brightness sensor (41), located between the contact chamber and the detection chamber, making it possible to illuminate the detection chamber from light in the contact chamber, An electrical contact housed in the contact chamber, said contact having a closed state and an open state, A brightness sensor mounted in the detection chamber, configured to detect light in the detection chamber coming from the arc cutting chamber and passing through the window when at least one electric arc appears in the arc cutting chamber, and wherein the wear estimation device further comprises a test light load housed in the detection chamber and electrically controlled by the computing unit to perform an operational test of the brightness sensor, the computing unit being configured to transmit a sensor failure signal in the event of non-detection of light when the test light load is powered.

[0014] Thanks to the invention, it is possible to detect a luminous flux coming from an electric arc. This detection makes it possible to transmit a luminous detection signal comprising information on the electric arc, by its duration and / or its luminous intensity. This information can thus make it possible to estimate wear of the device linked to electric arcs. This estimation can be carried out by a calculation unit internal to the device or by an external (remote) processing unit, and be sent to a control / command system of an aircraft using the device or to light up a warning light.

[0015] In addition, the opening that is directly formed between the arcing chamber and the detection chamber avoids problems with transparent walls damaged or having reduced transparency due to a layer deposit following electric arcs. The test light load makes it possible to check whether the sensor is still functioning due to the risk of damage by the electric arc passing through the opening.

[0016] Thus, the wear estimate makes it possible to transmit a message to an operator or user indicating that the device has suffered too much damage, potentially affecting its future performance. Indeed, the erosion suffered by the contact pads at each switching or the reduction in the dielectric strength of the insulators or even a failure of the device such as an actuator or a spring in the device increases the duration of the electric arc during opening, and therefore the time of interruption of the power line. The device must then be inspected and possibly replaced. In addition, placing the brightness sensor in a detection chamber separate from the contact chamber prevents damage to the brightness sensor by the electric arc.

[0017] In addition to the characteristics which have just been mentioned in the preceding paragraph, the apparatus according to one aspect of the invention may have one or more additional characteristics among those described in the following paragraphs, considered individually or according to all technically possible combinations:

[0018] According to one embodiment, the apparatus comprises a device for estimating wear of the electrical apparatus, said device comprising the brightness sensor, and a calculation unit configured to: receiving a light detection signal from the light sensor, measuring an electric arc detection duration from the received light detection signal, estimating wear of the device when the electric arc detection duration is greater than a first predetermined value.

[0019] According to an example of this embodiment, the apparatus comprises a test light load housed in the detection chamber and electrically controlled by the computing unit to perform an operational test of the brightness sensor, the computing unit being configured to transmit a sensor failure signal in the event of no light detection when powering the test light load. According to an example, the test light load is a diode.

[0020] According to an example of this embodiment, the brightness sensor measures the luminous flux and the computing unit is configured to further determine wear of the apparatus when the measurement of the luminous flux is greater than a first threshold value. In this embodiment, the electric arc detection duration is terminated when the measured value of the luminous flux is less than a second threshold value.

[0021] According to an example of this embodiment, the computing unit is further configured to: Record in a memory of the calculation unit, each maximum value or the value of the integral of the measurement of the luminous flux from the duration of electric arc detection and Add each maximum value or value of the integral of the measurement of the luminous flux, Inform of preventive maintenance of the electrical contact when the value of the addition is greater than a third threshold value.

[0022] According to an example of this embodiment, the calculation unit transmits information about a faulty electrical contact or insulation if wear is estimated.

[0023] According to an example of this embodiment, the computing unit emits a maintenance information signal if the duration of the electric arc detection is greater than a second predetermined value. This second predetermined value is less than the first predetermined value.

[0024] According to one embodiment, the brightness sensor is of the phototransistor or photodiode or photoresistor or fiber optic sensor type.

[0025] According to one embodiment, the electrical contact comprises a first fixed terminal and a second fixed terminal, and a movable conductor forming a bridge in contact with the first and second fixed terminal in the closed state, said conductor being distant from the first and second fixed terminal in the open state.

[0026] According to an example of this embodiment, the electrical apparatus is a contactor further comprising a return spring for moving the movable conductor to one state and an electromagnetic actuator for moving the movable conductor to the other state.

[0027] According to another embodiment, the electrical apparatus is a circuit breaker further comprising an overload, differential current and / or short circuit detection device for triggering the electrical contact from a closed state to an open state.

[0028] A second aspect of the invention relates to an assembly comprising: an electrical appliance according to the first aspect of the invention, a cut-off device comprising an additional electrical contact in series with the electrical contact of the electrical appliance and a control unit configured to control the additional contact of the cut-off device and the contact of the appliance, a calculation unit configured to measure an electric arc detection duration Da from the light detection signal received by the brightness sensor, and to transmit wear information of the electrical appliance to the control unit, the control unit being configured to control an opening of the electrical contact of the cut-off device if wear is estimated. According to a variant, the calculation unit is remote from the electrical appliance and is connected to the brightness sensor to receive the light detection signal.In this variant, the computing unit can be configured in the same way as in the previous example.

[0029] A third aspect of the invention relates to a method for estimating the wear of an electrical device as defined above, said method comprising the steps of: Receiving opening information corresponding to a transition from a closed state to an open state of electrical contact, Transforming light detected by a brightness sensor into a light detection signal, Measuring an electric arc detection duration according to the light detection signal, Estimating wear of the device when the electric arc detection duration is greater than a predetermined value.

[0030] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0031] The figures are presented for information purposes only and in no way limit the invention. [ Fig. 1 ] represents a block diagram of an apparatus according to one embodiment of the invention. [ Fig. 2 ] represents a timing diagram representing a control signal, an electrical contact state, an optical detection and a fault estimation. DETAILED DESCRIPTION

[0032] The figures are presented for information purposes only and in no way limit the invention.

[0033] [ Fig. 1 ] shows a schematic representation of an apparatus according to one embodiment of the invention.

[0034] In this embodiment the device is a contactor comprising an actuator 1. Alternatively, the device could be a circuit breaker.

[0035] The apparatus comprises a housing 2 comprising a contact chamber 23 and a detection chamber 21 preferably separated from each other by an insulating wall, hereinafter called base 22. The housing 2 further comprises a window 20 between the contact chamber 23 and the detection chamber 21. In this example, the window 20 comprises an opening in the base 22. Alternatively, the base 22 comprises a translucent or transparent area.

[0036] In this example, the actuator 1 is mounted in the detection chamber 21 but it could be housed in another chamber separate from the contact chamber 23 and the detection chamber 21. The actuator 1 comprises in this example an electromagnet comprising a coil 11 fixed to the housing 2, a fixed magnetic core 12 fixed to the housing 2, a mobile magnetic core 13 surrounded by the coil 21. The mobile core 13 is located opposite the fixed core 12, and is, when the coil 11 is powered, magnetically attracted towards the fixed core 12 from a rest position as shown in the figure 1 to a magnetized position. The actuator 1 further comprises a control rod 10 fixed to the movable core 13 and a return spring 14 for returning the movable core 13 to its rest position. In this example the return spring 14 is mounted compressed between the fixed core 12 and the movable core 13.

[0037] In this example, the control rod 10 passes through the window 20. However, as specified above, in the case of the actuator 1 located in another chamber, the control rod 10 passes through an opening in another wall of the housing 2.

[0038] The apparatus further comprises an electrical contact 3 housed in the contact chamber 23. The electrical contact 3 comprises at least one fixed terminal 32 and a movable conductor 31 movable in this embodiment by the control rod 10 relative to the conductor 31 between a spaced position and a contact position.

[0039] In this embodiment, the electrical contact 3 is configured to open or close a high voltage DC power line, for example 800 volts.

[0040] The electrical contact 3 is in a closed state when the movable conductor 31 is in the contact position, that is to say in contact with the at least one fixed contact 32, here in this case when the movable conductor 31 is in physical and electrical contact with the first fixed terminal 32 and the second fixed terminal 32' forming an electrical bridge between the two fixed terminals 32, 32'.

[0041] The electrical contact 3 is in an open state when the movable conductor 31 is in the spaced position, that is to say that the movable conductor 31 is distant from at least one fixed contact, here in this case when the movable conductor 31 is distant from the first and second fixed terminal 32, 32'.

[0042] In this example, the first and second fixed terminals 32, 32' respectively comprise a first and second electrically conductive body and respectively a first and second conductive pad 320, 320' located on the conductive body, for example mounted by crimping. The movable conductor 31 comprises an electrically conductive body 311 and a first and second pad 310, 310' mounted facing respectively the first and second pad 320, 320' of the fixed terminal 32, 32', in contact with the latter in the contact position.

[0043] In this embodiment, the movable conductor 31 of the contactor is a movable bridge and the electrical contact 3 comprises a second fixed terminal 32'.

[0044] In this example, the electrical contact 3 further comprises a compression spring 34 mounted between a wall of the control rod 10 and the movable conductor 31. The movable conductor 31 is crossed by the control rod 10, and is mounted between the return spring 34 and a stop of the control rod 10. In this example, the electrical contact 3 is a normally open contact, but it could be, according to another example, a normally closed contact.

[0045] The electrical contact 3 changes from the open state to the closed state when the actuator 1 (here the coil 11) is energized, and the movable core 13 moves to the magnetized position, moving the control rod 10, the compression spring 34 and the movable conductor 31 towards the two fixed terminals 32, 32'. The stroke of the movable conductor 31 is shorter than that of the movable core 13. Thus the movable conductor is in contact with the fixed terminals 32, 32' before the movable core 13, causing the compression spring 34 to compress until the movable core 13 is in the magnetized position.

[0046] The electrical contact 3 changes from the closed state to the open state when the coil 11 of the actuator 1 is no longer electrically powered, and the movable core 13 moves to the rest position, moving the control rod 10, the compression spring 34 and the movable conductor 31 to a remote position away from the two fixed terminals 32, 32'.

[0047] The apparatus comprises a device 4 for estimating wear of the electrical apparatus. The wear estimation device 4 comprises a brightness sensor 41, in this case a phototransistor, mounted in the detection chamber 21. According to a variant, the brightness sensor 41 is a fiber optic sensor. The brightness sensor 41 makes it possible to detect light in the detection chamber 21 coming from the contact chamber 23 passing through the window 20. In other words, the brightness sensor 41 is positioned in the detection chamber 21 to detect light in an area facing the window 20. In the example shown, as indicated previously, the window 20 is an opening crossed by the control rod 10. Alternatively, the base comprises a translucent or transparent wall and the brightness sensor 41 is facing this transparent wall.Thus, in the event of an electric arc 6, 6' between the mobile conductor 31 and the at least one first fixed terminal 32, the luminous flux coming from the electric arc 6, 6' illuminates at least the area where the brightness sensor 41 is located by passing through the window 20. The brightness sensor 41 can therefore detect a luminous flux coming from the electric arc 6.

[0048] In this embodiment, the brightness sensor 41 can further detect the luminous flux coming from a second electric arc 6' in the breaking chamber 23 between the second fixed terminal 32' and the movable conductor 31. The two electric arcs 6, 6' form and extinguish at the same time, each generating a luminous flux, a part of which is detectable by the brightness sensor 41. As explained previously, these electric arcs 6, 6' are in particular formed when the electrical contact 3 changes from the closed state to the open state. The compression spring 34 makes it possible, for its part, to apply compression of the movable conductor 31 to the first and second fixed terminals 32.

[0049] The wear estimation device 4 further comprises a calculation unit 42 configured to receive opening information corresponding to the passage of the electrical contact 3 from the closed state to the open state and a light detection signal by the brightness sensor 41. The calculation unit 4 comprises electronic components for processing analog and / or digital signals and furthermore a microcontroller and / or processor etc. In this example, the calculation unit 42 receives information on the state of the electrical contact 3. Alternatively, it could receive only the opening information corresponding to the passage of the electrical contact 3 from the closed state to the open state.

[0050] In this embodiment, the wear estimation device 4 further comprises a test light load 43 housed in the detection chamber 21 and electrically controlled by the calculation unit 42. The calculation unit 42 is configured (either upon receipt of a test request or randomly or according to a predetermined time) to perform an operating test of the brightness sensor 41. Thus, the calculation unit 42 is configured to transmit a sensor failure signal in the event of receipt of a light detection signal by the brightness sensor 41 when powering the test light load 43. The calculation unit 42 can, for example, pulse control the light load 43 so that it flashes, and verify the concordance of this flashing with each light detection signal received by the brightness sensor 41.

[0051] In this example, the calculation unit 4 which comprises in this example an electronic card crossed by the control rod 10, which makes it possible to give information on the state of the electrical contact 3. For example, the control rod 10 comprises an electrically conductive zone, for example tubular, corresponding to the difference in travel between the movable core and the movable conductor, making it possible to make electrical contact with an electrical conductor of the electronic card during the movement of the control rod 10 when the movable conductor is in the closed position (during the compression and decompression of the compression spring 34).According to another example, the movable rod 10 comprises a stop and the calculation unit 42 comprises a mechanical switch mounted for example on the electronic card opposite the stop comprising a compression spring operating according to the same stroke as that of the compression spring, that is to say according to the difference in stroke between the movable core and the movable conductor. According to yet another example, the measurement estimation device 4 comprises a low-voltage electrical contact operating according to the same stroke as that of the high-voltage electrical contact 3. For example, the low-voltage electrical contact comprises a movable conductor mounted on the rod, a compression spring and respectively one or two fixed terminals, for example mounted on the electronic card.

[0052] In this example, the state information corresponds to that of the light load (in this case open state for off state, and closed state for on state, but this could be reversed). Thus in this example the opening information transmitted to the calculation unit 42 corresponds to a falling edge of a signal of the state of the light load 3, i.e. the transition of the light load 3 from an on state to an off state. The calculation unit 4 has for example an input connected to the light load 3.

[0053] According to another example, the opening information corresponds to opening control information, for example sent after a predetermined delay.

[0054] The computing unit 4 is configured to measure an electric arc detection duration 6, 6' from the light detection signal transmitted by the brightness sensor 41.

[0055] There figure 2represents a timing diagram representing on the first line a command of the electrical contact, on the second line a state of the electrical contact 3, on the third line a detection of brightness by the brightness sensor 41, and on the fourth line an estimate of wear of the device.

[0056] When a command of the electrical contact 3 to the closed state or to the open state is produced, the electrical contact 3 changes state according to this command as visible on the first two lines with a delay, linked to the movement time of the movable contact 31.

[0057] In the case of an electric arc, represented on the second line by a hatched square, the current continues to flow in the electrical contact corresponding to a closed state of the electrical contact despite the open position of the contact. It can be seen on this second line that three electric arcs have therefore been formed at three events numbered 1, 2, 3. On the second line of the timing diagram, the event of one or two electric arcs 6, 6' at the electrical contact 3 is therefore indicated at each hatched part. During these events, the state of the electrical contact 3 is therefore closed, because a current flows in the electrical line. In this embodiment, the current flows via the two electric arcs 6, 6' but the movable contact 31 moves from the closed position to the open position and the electric arc can continue to exist in this open position for a more or less long time as shown in event 3.The latter is longer than event 2, which is itself longer than event 1.

[0058] The brightness sensor 41 transforms a detection of light in the arc chute into a light detection signal corresponding to the brightness of this electric arc in the detection chamber, as shown on the third line of the timing diagram.

[0059] The calculation unit 42 is configured to measure an electric arc detection duration Da from the light detection signal transmitted by the brightness sensor 41. In this embodiment, the light detection is proven when the measured value of the luminous flux by the brightness sensor is greater than a second threshold value. Thus, in this embodiment, the electric arc detection duration is terminated when the measured value of the luminous flux is less than the second threshold value. Indeed, this makes it possible to measure in the light detection signal by the brightness sensor 41, only the time exceeding this second threshold value in order to avoid measuring a duration of light originating neither from an electric arc nor from the test light load.Other solutions are possible, for example measuring a duration from a derivative value of the light detection signal corresponding to a sudden increase in light due either to an electric arc or to the light emitted by the test light load 43.

[0060] According to another embodiment not shown, the electrical device does not include the calculation unit. In this embodiment, the brightness sensor includes an output intended to be connected to a calculation unit remote from the electrical device. For example, the calculation unit is part of an electronic control unit. Thus in this example, the device detects an electric arc by means of the brightness sensor 41 configured to transmit a signal for detecting light in the detection chamber by the brightness sensor 41. This signal is received by the calculation unit which processes it to extract information on the luminous flux in the arc cutting chamber, such as an electric arc duration or a power of an electric arc.

[0061] The brightness sensor 41 can thus continue to detect light in the detection chamber 42 coming from the luminous flux produced by the electric arcs 6, 6'.

[0062] The calculation unit 42 is further configured to estimate wear of the device when the electric arc detection duration Da is greater than a first predetermined value Dt. This is for example the case at event 3 on the second line of the timing diagram, in which the duration Da of the electric arcs 6, 6' is greater than the first predetermined value Dt corresponding to an anomaly duration of the device. In this case, for example the calculation unit 42 is configured to produce a wear signal of the device to inform a user or an operator. The wear signal of the device can thus correspond to wear of the electrical contact or wear of an electrical insulator or even wear of the actuator, increasing the time of the electric arc as explained previously.

[0063] Furthermore, in this example, the calculation unit 42 is configured to determine a behavior symptomatic of wear of the device if the duration Da of the electric arcs 6, 6' is each time greater than a second predetermined value Dc less than the first predetermined value Dt. The calculation unit 42 can thus transmit a maintenance information signal to alert a maintenance operator to carry out preventive maintenance.

[0064] According to one example, when the wear is determined, the calculation unit 42 is configured to transmit to a control unit controlling (directly or indirectly) an electrical contact in series with this electrical contact 3 to open the line securely and / or transmit information to a user / operator by controlling (directly or indirectly by a control system for example of an aircraft) an indicator light on a dashboard or information on a screen.

[0065] According to one embodiment, the brightness sensor 41 measures the intensity of the luminous flux (in lumens) and the calculation unit 42 is configured to further estimate wear of the device when the measurement of the luminous flux is greater than a first flux threshold value. This makes it possible to estimate wear even in the event of an electric arc having a duration less than the predetermined value Dt but sufficiently powerful to have damaged the device. An operator will thus be able to check whether the device has been damaged.

[0066] In particular, according to an example of this embodiment, the calculation unit 42 comprises a memory and is configured to record in said memory each maximum value or value of the integral of the measurement of the luminous flux measured by the brightness detector from the start of the electric arc detection duration and add each of these values ​​(maximum value or value of the integral) of the measurement of the luminous flux, and finally inform of preventive maintenance of the electrical contact when the value of the addition is greater than a third threshold value.

[0067] One aspect of the invention also relates to a method for estimating wear of an electrical device, preferably of a device according to the preceding description, comprising the steps of: Transformation of a light detection by a brightness sensor 41 into a light detection signal, Measurement of an electric arc detection duration Da according to the light detection signal, Estimation of wear of the device when the electric arc detection duration Da is greater than a predetermined value Dt.

[0068] Furthermore, the method may comprise steps corresponding to the various functionalities described above carried out by the calculation unit 42. For example, the method comprises a step of transmitting information to inform a control unit of wear, and a step of commanding the control unit to open a contact in series with the contact of the device. The method may also comprise a step of sending information about a need for preventive maintenance when the electric arc detection duration Da is greater than that of a predetermined value Dc.

[0069] Unless otherwise specified, the same element appearing in different figures has a single reference.

Claims

1. Electrical apparatus comprising: - A housing (2) comprising a contact chamber (23), a detection chamber (21), a base (22) separating the contact chamber (23) and the detection chamber (21), and a window (20) comprising an opening passing through the base (22) opposite an area detectable by the brightness sensor (41), located between the contact chamber (23) and the detection chamber (21) allowing the detection chamber (21) to be illuminated from a light in the contact chamber (23), - An electrical contact (3) housed in the contact chamber (23), said contact having a closed state and an open state, characterized in thatit comprises a brightness sensor (41) mounted in the detection chamber (21), configured to detect light in the detection chamber (21) coming from the cutting chamber (23) and passing through the window (20) when at least one electric arc appears in the cutting chamber (23), and - wherein the wear estimation device (4) further comprises a test light load (43) housed in the detection chamber (21) and is adapted to be electrically controlled to perform an operational test of the brightness sensor (41).

2. Electrical appliance according to the preceding claim, comprising a wear estimation device (4) of the electrical appliance, said device (4) comprising the brightness sensor (41) and a calculation unit (42) configured to: - Receive a light detection signal by the brightness sensor (41), - Measure an electric arc detection duration (Da) from the received light detection signal, - Estimate wear of the appliance when the electric arc detection duration (Da) is greater than a first predetermined value (Dt).

3. Electrical apparatus according to claim 2, wherein the brightness sensor (41) is configured to measure the intensity of the luminous flux in an area of ​​the detection chamber (21) and the calculation unit (42) is configured to further determine the wear of the apparatus when the measured intensity of the luminous flux is greater than a first flux threshold value.

4. Electrical apparatus according to claim 3, in which the calculation unit (42) is configured to: - Record in a memory of the calculation unit (42) each maximum value or value of the integral of the measurement of the luminous flux from the calculated electric arc detection duration (Da), - Add each maximum value or value of the integral of the measurement of the luminous flux, - Inform of preventive maintenance of the electrical contact (3) when the value of the addition is greater than a second threshold value.

5. Electrical apparatus according to any one of claims 2 to 4, wherein the test light load (43) is electrically controlled by the computing unit (42) to perform an operational test of the brightness sensor, the computing unit (42) being configured to transmit a sensor failure signal in the event of no light detection when the test light load (43) is powered.

6. Electrical apparatus according to one of the preceding claims, wherein the electrical contact (3) comprises a fixed contact and a movable contact, the electrical apparatus being a contactor further comprising: - an electromagnetic actuator (1) comprising ∘ a coil (11) fixed to the housing (2), ∘ a magnetic fixed core (12) fixed to the housing (2), ∘ a magnetic movable core (13) surrounded by the coil (21), the movable core (13) is located opposite the fixed core (12), ∘ a control rod (10) fixed to the movable core (13) and the control rod (10) passing through the opening of the window (20), - a return spring (14) for returning the movable core (13) to its rest position, for moving the movable conductor (31) towards the other among the open or closed state.

7. An electrical apparatus according to one of the preceding claims, the apparatus being a contactor and further comprising a return spring (14) for moving a movable conductor (31) to one of the open or closed state, and an electromagnetic actuator (1) for moving the movable conductor (31) to the other of the open or closed state.

8. Electrical apparatus according to one of claims 1 to 5, the apparatus being a circuit breaker and further comprising an overload and / or differential current and / or short-circuit detection device, for triggering the electrical contact (3) from a closed state to an open state.

9. Assembly comprising: - an electrical appliance according to one of the preceding claims, - a cut-off device comprising an additional electrical contact, in series with the electrical contact (3) of the electrical appliance, - a control unit configured to control the additional contact of the cut-off device and the contact of the appliance, - a calculation unit (42) configured to measure an electric arc detection duration (Da) from the light detection signal received by the brightness sensor (41) and to transmit wear information of the electrical appliance to the control unit, - and in which the control unit is configured to control an opening of the additional electrical contact of the cut-off device if wear is estimated.

10. Method for estimating wear of an electrical device according to any one of claims 1 to 7, the method comprising the steps of: - Receiving opening information corresponding to a transition from a closed state to an open state of the electrical contact (3), - Transforming a light detection by the brightness sensor (41) into a light detection signal, - Measuring an electric arc detection duration (Da) according to the light detection signal, - Estimating wear of the device when the electric arc detection duration (Da) is greater than a first predetermined value (Dt).

Images