Patent Application
20090190289
The invention relates to tripping of switchgear apparatuses by means of electronic processing. The invention relates more particularly to an electronic trip device able to be integrated in existing switchgear apparatuses and which acts on the contacts of the latter by means of an integrated electromagnetic actuator. An electronic module of the trip device can further comprise known functionalities, in particular threshold parameter setting, current measurements, test connector, display and communication functions.
The invention also relates to a case for an electronic trip device having a design that has been optimized for maximum compactness. The invention also relates to the trip device and the assembly method thereof which is simplified in spite of the density of integrated functionalities.
As illustrated in the document FR 2 696 275 and represented schematically in
Different trip units are known, with in particular the development of electronic trip devices 2 which, compared with magnetic or thermal-magnetic trip devices, enable for example the current thresholds causing breaking to be adjusted by suitable means 5 and checks to be made by means of a test connector 6. Typically, an electronic trip device 2 comprises a case 7 made from insulating material in which a processing unit of the printed circuit board type is housed, receiving signals indicative of the distribution circuit. When the value of the current signals exceeds preset thresholds for preset time periods, the processing unit sends a signal to an actuating device 3, such as a solenoid, which separates the pairs of contacts of circuit breaker 1.
The trip devices 2 are generally removable and are fitted in the case of circuit breaker 1 only when installation of the latter is performed. It is moreover usual for trip devices 2 to be interchangeable to satisfy the variety of demand, ranging from basic protection to the most advanced protection, comprising multiple setting points and/or different measuring functions such as voltage, power and/or energy measurement. Furthermore, it may be desirable to replace a trip device 2 on an existing switchgear unit 1, in case of malfunctioning or in order to add new functions. Although the functionalities of a trip device 2 and the parameters to be set 5 may be consequent in number, dimensioning of the trip units 2 is therefore subjected to strict criteria relating to their housing 4.
The use of microprocessors should indeed enable all the protection functions to be accommodated in cases 7 of small dimensions. However, the space requirements inherent to these functionalities cannot be minimized at will, in particular on account of the constraints generated by the connections between the different component elements performing processing, measuring, parameter setting and actuation. The usual wires, solders or contact blades impose a compromise among the functions integrated in trip unit 2, the others then being able to be performed by external auxiliary units connected by means of hard-wired connections. In particular, the contact actuation system does not form part of electronic trip device 2.
In spite of the various designs, such as for example that described in the document EP 0 991 095, electronic trip devices are therefore not optimised and require connection of auxiliaries, thereby making the circuit breaker assembly procedure more cumbersome.
Among other advantages, the object of the invention is to palliate the shortcomings of existing electronic trip units and to propose a trip device having a design that enables the different component elements necessary for performing the required functionalities to be included. In particular, the trip device according to the invention complies with the space occupation constraints and can replace a trip unit, in particular a magnetic or thermal trip unit, in an existing circuit breaker. Furthermore, the trip device according to the invention integrates both the electromagnetic actuation device of the circuit breaker contacts and measurement and processing of the different values representative of the current flowing in the distribution circuit, and also the means enabling the user to set the tripping threshold parameter values. Assembly thereof is thereby facilitated. In addition, as the architecture is common to the different circuit breakers whatever the number of poles or the breaking intensity of the latter, assembly and storage of the different components are rationalised.
According to one feature, the invention relates to an electronic trip device that can be connected to a switchgear unit by connecting strips. The invention also relates to the electronic module of such a device and to its case.
The case of the module thus comprises a bottom part and a cover which fits onto and around the bottom part to form a cavity, preferably by clipping, in which cavity a printed circuit board is housed. The cover presents holes for operating auxiliaries such as extension parts of thumb-wheels of the printed circuit board and a test connector. Its external surface can also comprise a recess for fitting a display read-out.
In the bottom part of the case according to the invention, a sheath is provided for housing an actuator in tight manner with respect to the cavity surrounding same, the actuator being able to take an inactive position and an active position in which it is protruding from the case orthogonally to the side panel facing the connecting strips of the trip device in order to actuate the circuit breaker contacts. The sheath opens out onto the side panels of the case via a passage for connection of the actuator and via a hole enabling the actuator to take its active position. Preferably, a mobile striker is securedly affixed to the cover and driven by the actuator when moving from the inactive position to the active position. In the module and the trip device according to the invention, the actuator placed in the sheath is preferably an electromagnetic actuating device comprising a push-rod sliding out of the sheath and a connector passing via the connection passage.
The electronic module also preferably comprises a printed circuit board in the cavity of the case, a board whereto the connector of the actuator is connected, preferably via the edge thereof, and advantageously by means of a localised connection between the side panels of the cover and the bottom part. The connections with a transformer unit to form an electronic trip device are preferably also made via the edge and between the walls of the bottom part and the cover of the case according to the invention. This solution increases the compactness of the device and prevents any action which might result in incorrect positioning and/or damage to the connecting wires. Said transformer unit and the electronic module are preferably secured to one another by clipping so as to eliminate any screw or other non-captive securing means.
According to a preferred embodiment of the invention, the electronic module comprises other functionalities than protection by tripping following analysis of the currents, and the interfaces for activating these functionalities are advantageously developed on an additional printed circuit board fitted in the cavity of its case. Each of the additional printed circuit boards is preferably at least partially superposed on the main board, and data transfer takes place by means of non-wired orthogonal connectors. The connectors between the boards are advantageously in the form of spring contacts or gold-plated pistons which enable any defects caused by coplanar stacking to be compensated. The module can in particular comprise a board presenting an interface towards the outside, the case then being provided with a suitable arrangement, for example being L-shaped.
Advantageously, the electronic module according to the invention comprises a direct processing unit of the voltage values, and possibly that of the neutral, which data it transfers to the main printed circuit board. The board dedicated to this processing is preferably fitted in the cavity of the case with a dielectric shield that is either moulded or moulded from a casting, insulating this board from the rest of the electronic components. The case is then moreover arranged such as to tap the voltage directly. In particular, the bottom part of the case can be made in two parts, with a bottom and a double bottom joined to one another, preferably by welding, to form an insulated space in which means can be positioned enabling the value of the voltages and of the neutral to be tapped. In particular, arrangements of chicane type can define paths in which conductors are placed comprising a first strip connecting e.g. with the connecting strips of the transformer unit, and a second strip internal to the cavity. A hole in the bottom at the level of these second strips enables a contact, preferably a gold-plated piston, to transmit data to the insulated processing printed circuit located opposite the hole.
The case and the electronic module according to the invention can comprise other functionalities. For example, a sliding device can be fitted between the bottom and the double bottom of the case to communicate an outside push. Contact-free connecting means can also be provided, with an optic passage arranged in the case, preferably at the level of means for securing with another unit also provided with optic communication means. When said unit is secured, for example by clipping onto a rail, the communication means can transmit their data via said optic passage.
The case and the electronic module according to the invention are suitable for trip devices of any rating, and for any number of poles, in particular three or four. The trip device can be fitted in the case of a switchgear unit, also an object of the invention, in order to trigger separation of the contacts thereof. For this purpose, the trip device according to a preferred embodiment of the invention is associated with an alignment of breakable screws of the comb connector type so that fitting in a circuit breaker arrangement is achieved by connecting each of the comb connector screws on the connecting strips, tightening, and sectioning of the screws, the residual part whereof remains connected to an assembly of consequent size. This makes for ease of assembly guaranteeing uniformity of the tightening torques.
According to another feature, the invention refers to the method for assembling an electronic trip device whose geometry is optimised to incorporate all the functions, in particular actuation. A bottom part of the electronic module case comprises a cavity in which a sheath is located opening out onto a hole on two opposite side panels. In a preferred embodiment, the bottom part is achieved by welding a bottom onto a double bottom, and by locating conductors between the latter enabling a voltage and/or neutral tap to be made, or even other elements of pusher type. A preferably electromagnetic actuator is fitted in the sheath of the bottom part, with its connector passing through one of the holes and the sliding part of the actuator able to be protruding via the other hole.
The method according to the invention is continued by securing the bottom part onto the transformer unit of the trip device, preferably by clipping. In particular, to reduce heating, the primary conductor of the transformer unit is composed of two parts only, welded or otherwise securedly affixed via one end at the level of a loop passing twice in the magnetic circuit. To enable each part of the conductor to pass in the centre of the magnetic circuit, at least one of the parts is not completely folded at the level of its ends. In particular, the last angle between two sides of the loop is obtuse, and it is closed to 90° once fitted around the case of the transformation element so as to operate in conjunction with an end of the other part to be welded.
The printed circuit boards are then fitted in the cavity, with partial stacking and direct connection due to the orthogonal contacts which advantageously act as springs. The connectors of the actuator and of the transformer unit are secured to the main printed circuit board by brazing, preferably on the edge. The cavity is closed by a cover that is fitted parallel to the main printed circuit board, preferably by clipping. Actuating means of the board are coupled to the cover, preferably by clipping after the cover has closed off the cavity. Other elements such as a display read-out can also be assembled. The trip device thus assembled can be fitted in a switchgear unit.
Other advantages and features will become more clearly apparent from the following description of particular embodiments of the invention, given for illustrative and in no way non-restrictive purposes only, represented in the accompanying drawings.
The invention will be described hereinafter according to a preferred embodiment comprising options of the trip device 200 which can be omitted if required. Alternatives will be clearly apparent to the person skilled in the art, and the different components enumerated should not be construed as being indispensable to the object for which protection is sought for. To lighten the figures, some of these elements, optional for the object of the invention, will not be included in all the graphic representations.
Moreover, the trip device according to the invention can be fitted on the different existing “moulded case” switchgear units, operating in particular between 16 and 630 A, whatever the number of poles concerned, even if the embodiment presented concerns an electronic trip device for a three-pole circuit breaker 1 as illustrated in
Finally, for the sake of simplification of presentation of a preferred embodiment of the invention, trip device 200 will be described in relation to the assembly/fitting position in which circuit breaker 1 is placed flat, with recess 4 of the case facing upwards, i.e. the surface of trip device 200 accessible to the user and equipped with the setting adjustment means is at the top, substantially horizontal. The use of relative position terms such as “side”, “top”, “bottom” etc., should not be interpreted as being a limiting factor.
As usual, a trip device 200 defines an external enclosure inserted in a recess 4 of the case of circuit breaker 1, the (outer) top surface whereof is provided with setting and display elements accessible to the user. According to the invention, the enclosure of trip device 200 is delineated by assembly of an electronic processing module with a current transformer unit 10, which can be of conventional design. In particular, as illustrated in
In particular, transformer unit 10 comprises a plurality of transformation elements 10i each with a primary conductor 17 designed to be connected to the power supply line via one end 18 and to connect with a switchgear device 3 via the other end 16, the two strips preferably being parallel to one another. The magnetic circuit of preferred transformation elements 10i is rectangular in shape for ease of assembly with switchgear device 3 and electronic module 200. The magnetic circuit and the secondary winding are fitted in an insulating case 12 of suitable shape, substantially that of a rectangular parallelogram, provided with a passage through which primary conductor 17 passes. To obtain a signal representative of the current after transformation, primary conductor 17 preferably passes through the magnetic circuit twice, forming a substantially rectangular loop with two portions that are coplanar in the passage and separated by a sufficient space to ensure insulation or for an additional insulating shield to be fitted. Furthermore, conductor 17 is rigid over the whole length thereof so as to maintain the position of the loop around the magnetic circuit, which means that conductor 17 has to be formed in several parts which it is recommended to weld.
Advantageously, to reduce heating due to the high resistance of a weld, each conductor 17 of unit 10 is manufactured in two parts 171, 172 each comprising one of the end strips 16, 18. Reducing the number of welding points is moreover advantageous as far as time and manufacturing cost are concerned, while at the same time increasing reliability. Although it is rigid, at least one of the parts 171 of conductor does not have its final shape before it is inserted in the passage. However, to enable a rigid conductor to be “deformed” around a moulded plastic case 12, each of the parts 17i is made of metal folded substantially into the final shape. In particular, as illustrated in
In some configurations, in particular to position the junction point 19 at the most suitable place for the fitter and/or if the output terminal strip 16 cannot pass through the passage of case 12, it is possible for both of the two parts 17i not to be made in their final configurations and for two deformations to be performed closing the terminal angle between two portions around the magnetic circuit case 12.
The three conductors of the three-pole transformer unit 10 open out onto a side panel of case 12 via three connecting strips 161, 162, 163 substantially forming a plane and provided with connecting holes, which will be connected to the three current input terminal strips of switchgear device 3 of circuit breaker 1. On the lateral face opposite case 12, each conductor opens out via a terminal strip 18 enabling connection to the external circuit. The presence of the measuring and power supply transformers of transformer unit 10 impose a notable size constraint on the unit. This element therefore occupies a large part of recess 4 of the case of circuit breaker 1, which part is incompressible.
The electronic processing module of trip device 200 according to the invention therefore has to be integrated in the residual space of recess 4 of the circuit breaker. In particular, for a three-pole circuit breaker 1 of 100 A, respectively 630 A, the size of trip device 200 (length×width×depth in the assembled position of circuit breaker 1) is about 100×25×48 mm3, respectively 130×45×65 mm3. For a four-pole circuit breaker, often only one dimension is increased, for a respective length of 135 and 175 mm. The transformer unit 10 conventionally occupies 60% of the depth, only leaving less than 20 or 30 mm for the electronic processing module case 20.
The electronic module of a trip device 200 comprises a case 20 according to the invention housing the different elements necessary for processing tripping information. Its shape matches recess 4 to be filled, and its bottom surface can be juxtaposed on the substantially rectangular top surface of case 12 of transformer unit 10. Case 20 of the electronic module is formed by a first bottom part 22 on which the different elements making up the module are positioned and which fits on transformer unit 10, and a second part forming a cover 24 which protects the different components of the module (
According to a preferred embodiment of the invention and as illustrated in
In the preferred embodiment of the invention, as a supplement to the current value communicated by connectors 14 of transformer unit 10, electronic trip device 200 makes use of the value of the voltage flowing in each phase of the electric circuit. This type of phase voltage measurement implies insulation constraints of the means 30 used which, according to the invention, are thus integrated in the electronic module, or more exactly in the bottom part 22 of its case 20. The bottom part 22 is for this purpose composed of a double bottom 32 and a bottom 34 that are secured to one another and between which the conductors 30 associated with the voltage measuring function are positioned (
Voltage tap conductors 301, 302, 303 present a first end 361, 362, 363 designed to operate in conjunction with the connecting strips of switchgear unit 3 and/or with connecting strips 161, 162, 163 of transformer unit 10, being in contact or directly above the latter in the assembled position, and a second end strip 381, 382, 383 for connection of the voltage measuring means.
As illustrated in
Arrangements 32i of double bottom 32 preferably form actual insulating ducts accepting rough-cut conductors 30i which enables costs to be reduced. Conductors 30 can be made of stainless steel, with a voltage tap at the level of second end 38 achieved by means of gold-plated contacts acting as springs (
Voltage tap conductors 30 are thereby housed in an integration space of bottom part 22 formed by assembly of the two walls 32, 34. This space can also be used to integrate other functional elements in case 20 of the electronic module, for example a control means 40 for an auxiliary module. If mechanical transmissions from trip device 200 to other units than switchgear device 3 of circuit breaker 1 are envisaged, the means necessary for this type of operation can in effect be provided right from the moment assembly of trip device 200 is performed. In particular, an arrangement of double bottom 32 can be made for a part 40 transmitting a push on a safety module located outside electronic trip device, in particular a differential protection unit as described in the document FR 2 701 335. Push actuator 40 is advantageously made from charged thermoplastic material and its shape ensures a rigidity procuring an optimised force transmission. Preferably, the shape of the housing provided for push actuator 40 guides the latter in sliding without any risk of jamming and guarantees precise bearing points of good quality. Fitting of actuating means 40 is quick, without any risks of errors and does not require any specific tooling. It may be preferred to fit this option for all trip devices 200, including when it is not certain that the available mechanical actuating means 40 will be used.
In an electronic module, the quality of the connections between conducting metal parts and printed circuit boards depends partly on the level of tightness. According to a preferred embodiment of the invention, double bottom 32 is secured to bottom 34 of first part 22 of case 20 by ultrasonic welding. This solution further guarantees the mechanical strength of voltage tap conductors 30. Additional actuating means 40 are provided with the same advantages of protection against polluting environments and post-breaking projections.
To enable precise voltage measurement and reliable determination of the power and the energy balance of switchgear device 1, it is recommended to introduce a real value of the neutral voltage in the electronics. In the case of three-pole circuit breaker 1, it is thus advantageous to integrate an additional conductor 42 in bottom part 22, which conductor comprises a connector 46 at one end in order to be connected to wiring coming from the neutral of installation 1. Neutral conductor 42 can be a wire in a heat-shrink sheath crimped at the other end onto a connecting strip 48, such as a stainless steel blade. Advantageously, as illustrated in
As illustrated in
Bottom part 22 of case 20 of the electronic module is thus L-shaped with a cavity 28 comprising a substantially rectangular main portion 28A and a substantially orthogonal extension 28B. An actuating means 40 (not illustrated here—see
It should however be noted that these assembly steps of bottom part 22 illustrated in
According to the invention, actuator 50 of the contacts of switchgear device 3 is integrated in trip device 200, and more particularly in the electronic module, in order to increase the reactivity of the latter. Advantageously and even if other alternatives such as a piezoelectric trip device are possible, a small electromagnetic trip device 50 is used, for example as described in the document FR 2 893 445.This type of actuating device 50 illustrated in
Contact actuator 50 has to be electrically insulated from the electronic components of the module. It is therefore fitted in first bottom part 22 inside a sheath 58 that is hermetically tight with respect to cavity 28 designed to further accommodate the electronic processing unit. Alternatively, sheath 58 as such can comprise open holes on cavity 28, holes that operate in conjunction with actuating device 50 (for example via a set of pins, not illustrated, on yoke 52 and the walls of sheath 58) in such a way that the fitted assembly formed by actuator 50/sheath 58 is tight with respect to said cavity 28. Furthermore, and in particular for an electromagnetic actuator 50, positioning and movement along the axis of moving part 54, which are important for reliability, are ensured by a suitable shape and size of sheath 58, which is securedly attached to walls 26. Advantageously, on account of the compactness of the electronic module according to the invention and the small amount of space available in cavity 28, sheath 58 is integrally moulded in bottom part 22, one of its walls being formed by the bottom surface of case 20. Precision of axial positioning is thereby ensured when bottom part 22 is manufactured, sheath 58 being centred on a predefined reference system. The absence of intermediate parts moreover results in a short and optimised chain of dimensions.
Sheath 58 is in the general shape of a parallelogram, its top face, opposite and parallel to the bottom of cavity 28A, preferably lets side panels 26 extend there-beyond in order to be able to position and guide a printed circuit board on this surface. Sheath 58 comprises a hole 60 at a side panel 26 of bottom part 22 for fitting of device 50, and which advantageously acts as passage for actuating means 54. Actuator 50 preferably acts between two connecting strips 36i, 36i+1. Sheath 58 further comprises means for passage of connector 56 of said actuator 50, preferably a second hole 62 on the opposite wall from assembly and actuation hole 60. Actuating device 50 thus takes a rest position and can protrude from sheath 58 when its connector 56 transmits the information necessary for tripping. Due to the location of board 64 above actuator 50, the connection of connector 56 can be flexible and short, and connector 56 is preferably coupled to board 64 via the edge, as described in particular in document FR 2 907 265.
The size of sheath 58 is adjusted so as to provide mechanical strength and support and to perform guidance of its movable means 54. Error prevention means can also be fitted, for example a raised obstacle placed asymmetrically in sheath 58 and operating in conjunction with actuator 50, to prevent assembly errors and damage of the parts involved. Preferably, to improve the functional clamping of device 50 and the resistance thereof to shocks and vibrations generated by transformer unit 10 and resulting from tripping, the inside panels of sheath 58 comprise clips, thereby not requiring the use of added elements. This advantage can in particular be useful when the module is being assembled and before the latter is fitted in the case of circuit breaker 1, to prevent any accidental “loss” of electromagnetic device 50. This solution results in simple assembly and disassembly of actuator 50, without any specific tools being required, in spite of the small clearance constraints on the housing.
Bottom part 22 equipped with actuator 50 (which can itself be fitted in bottom 34 before being assembled on double bottom 32) can be assembled on transformer unit 10, as illustrated in
According to an option, to limit pollution that may reach trip unit 200, a membrane can be fitted between switchgear unit 10 and trip device 200. Indeed, in particular for three- and four-phase breaking devices, some breaking operations at high voltage can generate particles which escape from the cartridges of breaking device 3 and could be deposited at the level of voltage taps 30, under double bottom 32. Fitting a part (not shown) snugly following the shape of switchgear unit 10 prevents pollution from getting up into the connection zone of trip device 200, while at the same time participating in its strength during shocks and vibrations. For example, a moulded silicon shield, the flexible material whereof further enables adjustment securing of transformer units 10, is particularly suitable as it can also increase the dielectric strength between active parts.
It should be noted that, due to integration of the components already fitted in bottom part 22 (voltage and neutral tap conductors 30, 42, actuating means 40, 50, and so forth), and to the smallness of connecting means 14, 56 extending there-beyond, no risk of pinching the wires is to be feared. It is moreover possible for all the elements described in the assembly on completion of the step illustrated in
Assembly of a trip device according to the invention is continued by fitting the electronic processing unit comprising one or more printed circuit boards performing the different functions required (
According to the invention, although it is very compact and integrates actuating device 50, the electronic module can perform a large number of functions. To meet this density requirement, the electronic boards relative to the different functionalities are stacked in case 20 of the module, and communications are made directly by means of non-wired contacts 66, of spacer stud type, preferably having a spring function so as to compensate the static indeterminancy of stacking of coplanar boards for data transfers to be reliable in all cases. According to a preferred embodiment of the invention, the flexible non-wired communication means 66 are of piston type with suitable travel so as to absorb shocks and vibrations without generating any stress on the boards. Optimisation of the travels and integration of springs with this type of connection 66 further enables the dimensional variations of different levels to be absorbed, ensuring permanent contact. To transmit the very weak current signals (about 5 mA) associated with voltages close to 0 V such as those present in an electronic trip device, contacts 66 are coated on the surface thereof with a suitable material, in particular gold.
For data transmission to be direct, it is preferable for each additional board to be placed at least partially facing main processing board 64 which performs the tripping functionality.
Central board 64 is preferably of a size corresponding to main part 28A of cavity 28, i.e. it is substantially of the same size as case 12 of transformer unit 10. For the sake of simplification of manufacture and rationalisation of procurements and storage, it is preferable for the latter not to form the complete L. Main board 64 preferably comprises the printed circuit performing the tripping functions including all the options of a trip device 200 according to the invention, with in particular the parameter setting means, such as thumb-wheels, and connecting strips, preferably on the sides, for connectors 14, 56 of transformer unit 10 and of bottom part of case 20. Contacts 66 for transfers within the processing unit are formed on the other boards arranged back-to-back with the latter.
Assembly of the processing unit boards can be performed prior to fitting of the secured assembly in cavity 28, for example by clipping by suitable means. Another option, illustrated in
In particular, as specified above, the preferred embodiment comprises a customer interface located at the level of base 28B of the L, for example to enable the user to make a communication with external means and/or to connect wires. An interface board 70 is fitted in this part 28B of case 20, partially overlapping on central part 28A, contacts 66 to main board 64 and the user interface means 72 being arranged on the top face thereof.
In the preferred embodiment of the invention and as specified above, the voltage of the circuit is measured by conductors 30 and the value thereof is processed. In order to guarantee user safety, regulatory insulation has to be performed, with in particular lowering of the measured voltage before the latter is transferred to main circuit board 64. A specific board 74, called voltage board, is fitted for this purpose, preferably in the residual space next to sheath 58 of actuating device 50 and facing terminal strips 38 (and 48) of voltage 30 (and neutral 42) tap conductors. Voltage dropping resistors of the circuit enable the initial voltage to be reduced by a factor of about a thousand before the data is communicated to processing unit 64, which guarantees the regulatory resistance of the module front panel and ensures user safety. As mentioned in the above and illustrated in
Voltage board 74 is fitted with an insulating thermoplastic shield 78 that can be integrated in cavity 28 of case 20 without any specific tools, the strength and precise positioning of which shield being ensured by details of shape and by clips. Indeed, in the same way as insulation of voltage tap conductors 30, strict electrical separation of voltage board 74, with the exception of connectors 66 with main board 64, guarantees correct operation of trip device 200. As illustrated in
Assembly of the electronic module is continued by fitting processing board 64 in the main part of cavity 28, above the others 70, 74 and sheath 58 of electromagnetic actuator 50.
Main processing board 64:
Once boards 64, 70, 74 have been fitted in cavity 28 of bottom part 22 of case 20, the connections from transformer unit 10 and to actuating device 50 are made, in particular by brazing connectors 14, 56 onto board 64, preferably on the edge of the latter.
Due to the choice of flexible direct contacts 66, the restricted space is not an impediment for the number of data transfer means. Connectors 14, 56 can moreover be housed in the available space. It is advantageous to reduce the wired length 15 of connectors 14, 56, and in particular to limit same so that the flexible parts are pressing along side panel 26 of the bottom part 22 of case 20 when connected.
Before completing assembly of case 20 by closing bottom part 22 by means of cover 24, a striker 84 is positioned facing outlet hole 60 of mobile push-rod 54 of actuator 50 to form the interface between actuator 50 and switchgear device 3. In addition to the different mechanical qualities between these two elements 54, 84 justifying the presence of a striker 84, it is in fact frequent for integration of an electromagnetic actuating device 50 in electronic module 200 to imply the presence of an intermediate element 84 able to offset the axis of the tripping force. Conceptually, the axes of the transmitting part 54 and receiving part can be not aligned to one another. Striker 84 is thus designed with a form enabling the thrust axis to be transferred. Furthermore, the design of striker 84 is optimised for quick assembly with error prevention by asymmetric shapes. In particular, it is fitted on guides 86 of side panel 26 of bottom part 22 of case 20, the sets of clearances of which are optimised to guarantee precise bearing points. To prevent any risk of losing striker 84 during the assembly steps, it is advantageous for the axial positioning of this striker to be completed only when bottom part 22 is closed by cover 24. For example, whereas striker 84 is engaged in a “vertical” position on its guides 86 and then folded down before being closed off by cover 24, a flexible tab 88 of cover 24 then biases it to an operating position.
The assembly can be closed by second part 24 of electronic module case 20 forming a cover, which operates in conjunction with bottom part 22 and comprises a passage facing hole 60 of sheath 58 enabling movement of actuator 50 and striker 84 towards the outside.
As specified above, for reasons of tightness, cover 24 is preferably provided with side panels 26′ forming a cavity 28′ in which the whole of bottom part 22 and of previously assembled components are fitted, with the exception of striker 84 which is however held in place by cover 24, and of connecting strips 16, 36. Connectors 14, 56 with main printed circuit board 64 are thus protected from the environment, being located between side panels 26, 26′ of the two parts of case 20 (
It is moreover possible to leave an optic passage 90, advantageously arranged to maintain the tightness of cavity 28 by matching the shapes. In addition to mechanical actuating part 40 mentioned above, the electronic module according to the invention also in fact preferably comprises additional means for communicating with a remote auxiliary, such as an earth fault detection device. On account of the restricted space and the optional aspect of this type of additional function, the communication means integrated in the trip device according to the invention do not comprise wired connectors but are based on an optic connection 90 implemented on processing unit 64 of the electronic module according to the invention. This type of connection is reliable and insensitive to pollution, with an absence of physical contact between connection points which excludes the risk of wear due to friction resulting from vibrations.
Case 20 is thereby designed with additional assembly means for an auxiliary module, in particular a fitting rail 92 on a side panel 26′ of cover 24, for example of dovetail type, so that assembly and disassembly operations of an auxiliary module (not shown) connected thereto are easy while keeping the mechanical strength to resist shocks and vibrations when the clearances are optimised. Securing of the auxiliary module on the trip device can be performed by an element of clip type. Auxiliary module fitting rail 92 is moreover designed to enable an optic connection 90 between main printed circuit board 64 and the module fitted on rail 92, for example a hole in rail 92 on panels 26, 26′ of case 20 operates in conjunction with a diode fitted under board 64, preferably ensuring the tightness of cavity 28A even if no auxiliary module is fitted. Auxiliary module is also provided with a diode facing that of trip device 200 in its fitted position. The two means can exchange their data by means of optic path 90, 90′ arranged in walls 26, 26′ and that of the auxiliary module case. The optic connecting means preferably comprise red transmission/receipt light-emitting diodes, the wavelength representing the best trade-off between functionality and cost.
Advantageously, when this optic connection 90 option is not used, a protection element 94 (
Preferably, the tightness of cavity 28 containing the electronic unit of the module is completed by clipping cover 24 on bottom 22, an operation that is simple and quick while remaining reversible (
Once case 20 has been closed, buttons 100 for setting the tripping thresholds parameters, a preferred embodiment of which is described in FR 2 913 143, can be fitted in suitable holes 96 to operate in conjunction with thumb-wheels of processing board 64. Other alternatives are possible, in particular fitting control devices 100 on board 64 before cover 24 is fitted in place. An information tag 102 and a protective plate 104, preferably a transparent visor, are positioned at the level of parameter setting means 100 and of test connector 96′ to protect the latter against external aggressions. Device 94 protecting the optic connection is also advantageously fitted, for example by pinching on rail 92.
The data from the electronic circuits can moreover be displayed on the top surface of case 20 by elements of indicator light type. Remanent display devices can in particular be used, in particular using the bistable cholesteric technology. The data is thus indicated even in case of a power supply outage by a change of colour of one (or more) pixel(s) of an indicator light of a few mm2 taking two colours typical of the state, for example red and green.
According to a preferred embodiment, a part of the top surface of case 20 is dedicated to fitting a flat display module 106 communicating directly with strips 108 of underlying processing board 64 via vertical contacts passing in a recess 96″ provided in the part forming cover 24. Advantageously, to compensate the static indeterminancy, here again piston contacts 108 are used. Preferably, display 106, for example of pull-down menu type, is fitted simply and reversibly by two connecting points, for example a fixed latch/hole 110, 110′ cooperation on one side and a screw 112 cooperating with insert 98 of cover 24 and fitted captive on display 106 on the opposite side. The mechanical strength does however meet standard requirements, in particular if insert 98 is made of metal, for example of brass fitted ultrasonically. To guarantee a functional tightness of IP4 type and to protect electronic module 106 against dielectric breakdowns, a recess 114 is made in the top face of cover 24 for display 106 to form a flat surface with the rest of cover 24/plate 104 while being insulated from the electronic circuit. Printed circuit board 64 is in fact inaccessible with the exception of contacts 108, so that the electronics of the trip device according to the invention are protected, including when actions are performed on display 106, which actions can be performed keeping the electronic module powered-on if required.
Locking of the top part of cover 24 can be associated with these last assembly steps, for example a switch 116 preventing the programming from being modified to guarantee that the electronic module is tamperproof. In particular, after programming has been completed, the keypad is protected by folding down a visor which solicits switch 116 via arrangement 98′, then the assembly is sealed. If access is desired, switch 116 will have to be deliberately actuated.
Three-pole trip device 200 according to the invention, also illustrated in
When assembly is performed, the holes of connecting strips 16, 16q of trip device 200, 200q and of switchgear unit 3 are placed facing one another and secured to one another by means of a rod-type element 130. To simplify and speed-up assembly of these two components, trip device 200q according to the invention is advantageously provided with a connecting comb 132. As illustrated in
The invention therefore proposes an optimised architecture for an electronic trip device 200 which can replace existing trip devices while at the same time providing a wide range of functionalities, and also proposes a simplified assembly method of such a trip device. Due to the solutions chosen according to the invention, a compact electronic control and communication trip device 200 can be integrated in a predefined small volume 4, while at the same time being able to comply with the following specifications:
Trip device 200 according to the invention can furthermore be 100% tested for all its functions, including as far as the quality of the welds is concerned (checking establishment of connections), even once assembled. A voltage and current input on each phase 18 of the electronic module, for example by means of gripper contacts, can be detected by means of test connector 96′ on the front panel. In spite of the compactness of the assembly, this tap connector 96′ can comprise up to fourteen test points, compared with the usual seven points accessible to the customer. The different tests and calibrations can be performed at the end of the assembly line, preserving the internal tightness of the assembly, all the connections to be made with the test means being external to case 20 of trip device 200. Furthermore, optic connection 90 can also be checked.
Although the invention has been described with reference to an electronic tripping system of an electrical switchgear unit, it is not limited thereto. Other elements can be concerned by the invention. In particular, the electrical connections between several layers and at different voltage and current levels according to the invention can be found in any type of apparatus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 08 00130 | Jan 2008 | FR | national |
| 08 00131 | Jan 2008 | FR | national |
