MXPA00010763A - Low voltage multipole circuit breaker with high electrodynamic resistance, whereof the pole shaft is arranged in the compartment housing the poles - Google Patents

Abstract

The invention concerns a low voltage multipole circuit breaker (10) with high electrodynamic resistance comprising a box made of insulating material, subdivided into a front compartment (12) housing a control mechanism (24) for opening and closing the circuit breaker and a rear compartment (14) separated from the front compartment by an intermediate wall (20). The rear compartment (14) is itself subdivided into elementary compartments (36) by separating partitions (38), each elementary compartment (36) housing one of the circuit breaker poles (56). The control mechanism (24) is linked to a pole shaft (78) common to the whole set of poles (56). The pole shaft (78) is located in the rear compartment (14) and is supported by bearings passing through the partition walls.

Description

CIRCUIT BREAKER OF MULTIPLE LOW VOLTAGE POLES WITH ELEVATED ELECTRODYNAMIC RESISTANCE, WHOSE POLO ARROW IS PLACED IN THE POLO ACCOMMODATION COMPARTMENT BACKGROUND OF THE INVENTION The invention relates to a low voltage, high current multi-pole circuit breaker with high electrodynamic resistance. In the past, high-current circuit breakers (for indication purposes between 630 A and 6300 A) that act as base switch gears for entrants and feeders in high-energy installations were formed by assembled composite elements in a metal frame, where they are called "open" energy circuit breakers. But progressively the team of this scale inherited part of the technology of circuit breakers of lower energy, called circuit breakers "molded box" because they are characterized by protective insulating envelope, molded generally reinforced polyester, which houses the poles with its extinguishing chambers, and a mechanism of operation and firing devices. The protective envelope, helping to ensure the confinement of the switch and the limitation of its external effects, the integral division between the poles and better insulation between the power circuit and the auxiliary, in turn, allow the overall dimensions of these devices to be reduced. EP-A-0,332, 321 discloses a circuit breaker of this type, whose box is formed by assembling an intermediate box, the cover forming the front panel of the circuit breaker, and a rear panel. The front face of the intermediate shaft divides the box into a front compartment bounded by this face and the cover, and a rear compartment designed to house the poles and electrically isolate them from the front compartment. The front compartment houses an operating mechanism that acts on a cross switching arrow common to all poles, called the pole arrow. This arrow is supported by bearings adjusted on the front face of the intermediate box. The rear compartment is in turn subdivided by insulating separation divisions into individual compartments for the poles. The front wall of the intermediate box further comprises, for each pole, an opening for access to the corresponding individual compartment. Each pole comprises a pair of separable contacts with a stationary contact and a movable contact, and an arc extinguishing chamber. Each movable contact is linked mechanically to the transverse arrow by means of a connecting rod passing through the front wall of the intermediate box through the corresponding access opening. Each rod connecting one of the movable contacts to the transverse arrow is arranged in such a way that in the closed position of the contacts, and in a plane of cross-section straight perpendicular to the pivot axis of the pole arrow, the distance between a straight line that passes through the axes of rotation of the connecting rod and the axis of pivoting of the arrow is small. In other words, the leverage of the resultant of the forces exerted by the contacts on the pole arrow is small, which guarantees that the connecting rod, when transmitting large electrodynamic forces, only generates a low torque at the level of the arrow . In static equilibrium in the closed position of the contacts, the operating mechanism exerts on the arrow a torque that opposes the electrodynamic forces transmitted by the connecting rods, • This torque only generates low forces at the level of the mechanism of operation. Additionally, the result of the reaction forces at the level of the guide bearings of the arrow is large and opposes the forces transmitted by the connecting rod and by the mechanism of operation This architecture is characteristic of circuit breakers with high electrodynamic resistance These circuit breakers, in fact by definition in order to selectively achieve time in the electrical installation, they must be able to withstand the flow of established fault currents that generate large electrodynamic forces that tend to separate the contacts. The relative arrangement of the pole arrow, the connecting rods with the movable contacts of the connecting rod to the operating mechanism must be such that these forces do not result in the separation of the contacts or the opening of the operating mechanism. In this case, the selected arrangement allows these forces to be transmitted to the box by means of the arrow bearings so that the operating mechanism is not subjected to too large torques or torques However guiding the pole arrow and transmitting the forces to the circuit breaker box they are not completely satisfactory The transversal arrow in fact, must be dimensioned, arranged and sustained in such a way that the deformation of the same is limited and does not impede its operation In addition, the pole bearings of the pole need to be well secured in the box as the large forces transpose, so that we can not detach them from the front riffle or the slit in1.Rrme.dia . are set T.1 do P, 1 rigid meter impose the nsn of fixing parts and large and bulky and co-intes and p spnsí ri O? PS common 1 p in l a lm a te r "R 1 breaker assembly It requires a large number of parts, resulting in a fast installation and an annoying adjustment This architecture also limits the turbine speed of the circuit breaker, as well as the numerous connection aids for the connection rods. between the pole arrow and each of the poles are perj nd i ci a 1 is to the tightness of the cameras dp ex inión nevertheless the electric arc v 1 as vapnri 7.ari nnes endnter i cas (-eneradas nor Pstp at the ripple level the mns of the divisions of the sea dp ext inción gives rise to an exoesi va pressure and a ppe dp aas pne ienp to be channeled to the output orifices provided with appropriate filters In order dp nn i mppd go the entrance of the arch to the c ara dp extinction is judicious to place these orific Exit valves at the bottom of the extinguishing chambers. The prespure of the openings for the passage of the connecting rods located above the contacts at the entrance of the terminal. cameras, therefore, considerably damages the flow of gases to the exit orifices. It allows an uncontrolled gas flow through the front compartment and openings in the front face, directly to the outside, without any protective filter.

SUMMARY OF THE INVENTION The object of the invention, therefore, is to overcome the disadvantages of the prior art and, in particular, to increase the rigidity of the mechanism of a circuit breaker with high electrodynamic resistance, at low cost. According to the invention, this problem is solved by means of a low voltage circuit breaker of high electrodynamic resistance with a box made of insulating material, comprising an operating mechanism linked to a pole arrow supported by bearings fixed in a manner secure to the box, a plurality of poles, each pole comprising at least a pair of separable contact parts, at least one of the contact parts of each pair, called the movable contact part, being mechanically linked to the pole arrow , the pole arrow, the operating mechanism and the movable contact part being able to move between a position open corresponding to the separation of the contact parts of each pair, and a closed position corresponding to the contact between the contact parts of each pair, the circuit breaker box comprising a front compartment that houses the operating mechanism and a rear compartment separated from the front compartment by an intermediate wall and subdivided into individual compartments by separation divisions, each individual compartment accommodating one of the poles of the circuit breaker, a circuit breaker whose axis of rotation of the pole arrow is located in the rear compartment In the state of the art devices whose pole arrow is located in the front compartment, a minimum distance had to be provided between the pole arrow and the movable contact parts in the open position The link between the movable contact parts and the arrow, in fact, was made through the intermediate wall between the front compartment and the rear compartment The configuration according to the invention allows this distance to be considerably reduced or even eliminated, since there is no longer any part placed between the arrow and the contact parts The overall dimensions of the device can be reduced in this way This arrangement also allows the electrodynamic forces exerted on the contacts to be taken by the boxIn fact, it is possible to place the support bearings in the rear compartment If these bearings are programmed to be secured at least partially to the intermediate wall, then it is easy to make the parts of They work in compression instead of working in tearing, in response to the electrodynamic forces exerted on the moving contact parts. Additionally, this arrangement allows the holes for the passage of the connecting rods between the pole arrow and each movable part. Eliminate Contamination in the frontal compartment is reduced in this way and the flow of the interruption gases to the exit orifices of the base of the extinguishing chamber is improved. Assembly is made easier by the fact that it is no longer necessary adjust the link between the pole arrow and each connecting rod through holes in the intermediate division Each of the separation divisions of preference supports one of the bearings and the arrow of pole passes through each division to the level of one of the bearings. This arrangement allows the bearings to multiply and distribute regularly along the pole arrow, without increasing the overall dimensions of the assembly. Alternatively, it is also possible to provide that the bearings are disposed between the separation divisions of the chambers, on autonomous supports. Advantageously, each of the separation divisions comprises a dividing element molded with the intermediate wall, on an edge of which a semi-cylindrical sector forming a part of the corresponding bearing is formed. In this way you get a multifunctional part that makes assembly easier and reduces costs. Advantageously, the intermediate wall comprises a window for the passage of a mechanical link part between the pole arrow and the operating mechanism. Preferably, the external surface of the pole arrow is made of electrically insulating material, in particular thermosetting polystyrene plastic. This arrangement allows electrical isolation to be obtained both between the poles and with the operating mechanism. The thermosetting material provides the advantage of a good Dielectric strength after breakage. In practice, the arrow can be made of voluminous thermosetting material, Alternatively, the arrow can have a metallic body covered with an insulating material, The circuit breaker advantageously comprises at least one connecting rod between the pole arrow and each part of the body. movable contact, linked to the pole arrow by means of a pivot in such a way that in a certain relative position of the arrow and the rod, called the assembly position, the rod can move freely in a direction parallel to the axis of the pivot, and that once the rod has been adjusted and moved from its adjustment position, a positive link is achieved which impedes the translation movement of the rod in a direction parallel to the axis of the pivot, the assembly position being such that in the state of operation, the pole arrow and the rod never adopt this position.

BRIEF DESCRIPTION OF THE DRAWINGS Other advantages and particularities of the invention will become more clearly apparent from the following description of an embodiment of the invention, provided as a non-restrictive example. only and represented in the accompanying drawings, in which: Figure 1 represents a perspective view of a circuit breaker according to the invention, cut at the level of a pole. Figure 2 represents a detailed view of a pole arrow and a part of a circuit breaker box according to the invention. Figure 3 shows a cross section of the circuit breaker of Figure 1, in the closed position. Figure 4 represents a cross section of the circuit breaker of Figure 1. in the open position, Figure 5 shows a perspective view of the pole arrow and of a connecting rod to one of the poles in a preceding position. to your assembly.

Figure 6 represents a perspective view of the pole arrow and of a connecting rod for connection to one of the poles in a respective position called the assembly position. Figure 7 represents a perspective view of the pole arrow on which the connecting rod is adjusted, in its positioning with respect to one another when the circuit breaker is open.

Figure 8 represents a perspective view of the pole arrow on which the connecting rod is adjusted, in its placement with respect to each other when the circuit breaker is closed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to Figures 1 to 3, a low voltage non-limiting circuit breaker 10 with high electrodynamic resistance is arranged in a molded case comprising a front compartment 12 and a rear compartment 14. The front compartment 12 is limited by a front panel 16, the side panels 18 molded with the front face, and an intermediate wall 20 separating it from the rear compartment. It comprises openings in the front panel for passage of a pivoting handle 22 to perform the readjustment of a circuit breaker operation mechanism 24, an opening pressure button and a closing pressure button. The operation mechanism 24 is housed in the front compartment 12. The rear compartment 14 is bounded by the intermediate wall 20, by a back plate 26 constituting a rear panel, and by side panels 28 a part of which is molded with the back plate and another part of which is molded with the intermediate wall. The rear plate 26 supports the connection strips 30 for connection of the circuit breaker 10 to an external electrical circuit. The rear plate 26 and the intermediate wall 20 are fixed to each other by means of fixing screws 32 dimensioned so as to be able to withstand high shear stresses. A window 34, visible in particular in FIG. 2, is arranged in the intermediate wall 20 and allows communication to occur between the front compartment 12 and the rear compartment 14. The rear compartment 14 is subdivided into individual compartments 36 by separation divisions 38. Each division 38 comprises two lateral parts arranged on each side of a central part. Each side part comprises a partition element 40 molded with the back plate and a partition element 42 molded with the intermediate wall, the partition elements 40, 42 being connected in the assembled unit. The central part comprises a partition element 44 molded with the rear plate of a greater height than the adjacent side elements 40. This dividing element 44 comprises ribs 46 which cooperate when assembling with complementary slots 48 of the lateral dividing elements 42 securely joined to the intermediate wall 20. The division element 44 The middle of the back plate comprises a smooth semi-cylindrical surface 50. The intermediate wall 50 comprises a complementary central dividing element 52 of smaller height which also comprises a uniform semi-cylindrical surface 54 oriented to that of the element securely attached to the back plate. of the circuit breaker is housed in each individual compartment 36. Each pole 56 comprises an arc extinguishing chamber 58 and a separable contact device. The latter comprises a stationary contact portion 60 electrically connected to a circuit breaker connection strip 30 which passes through the back plate 26 of the insulator box, and a movable contact portion 61 The latter is provided with a plurality of parallel contact fingers 62 mounted pivoted on a first transverse axis 64 supported by a support tunnel 66 The heel of each finger is connected by a flexible conductor 68 formed by a a braided metal strip to a second circuit breaker connection strip 30 Each finger 62 comprises a contact pad 70 which cooperates with a pad 72 of the stationary contact portion 60 in the closed position of Figure 3 The tunnel 66 is of U-shape (of figure 5) its end located near the second connecting strip it is equipped with a shaft 74 housed in a bearing securely attached to the insulating box, so as to allow the pivoting of the tunnel 66 between a closed position of the pole 56, shown in FIG. 3, and an open position, shown in FIG. Figure 4. A pressure spring device 76 is disposed in a notch of the tunnel 66 and urges the contact fingers 62 to pivot in a clockwise direction about the first axis 64. The arc extinguishing chamber 58 comprises a stack of plates of deionization of the electric arc attracted when the pole separation occurs, and also holes for the exit of the extinguishing gases. Further details on the structure of the poles 56 can be found in document FR-A-1, 650, 34, the description of which at this point is incorporated herein by reference. A pole arrow 78 is placed between sectors 50. 54 semi-cylindrical which. once assembled, they form airtight bearings that support the arrow 78 in rotation around its axis 79. The arrow 78 is molded of thermosetting polyester. Each of the tunnels 66 is coupled to the pole arrow 78 by a pair of parallel transmission rods 80 which pivot about an axis which is the Same as the ee 64 Each rod 80 is linked to the pole arrow 78 by a pivot 81 The operation mechanism 24 comprises an energy storage closing device and an opening device This mechanism is known as such and for additional details refer to document FR-A-2, 589, 626 which, at this point, is incorporated herein by reference. It will be simply remembered that the opening device comprises an articulation device comprising two rods 82, 84 hinged to one another by a pivot axis 86, the lower transmission rod 82 being mechanically coupled to the pole arrow 78 by a pivoting shaft 88 which operates in conjunction with a bearing made in the crank 90 securely attached to the arrow 78. An opening spring 92 is secured between the shaft 88 and a safety key Fig. 3 shows that in the closed position the window 34 made in the intermediate wall 20 serves the purpose of allowing the lower transmission rod 82 and the opening spring 92 to pass In the closed position, the leverage of the rods 80 in the pole arrow 78 is notoriously lower than that of the transmission rod 82. In other words, the distance between the axis 79 of the arrow 78 of pole and the plane it contains the axes 64, 81 of the pivots of the rods 80 is less than the distance between the axis 79 of the pole arrow 78 and the plane containing the axes 86, 88 of the pivots of the lower transmission rod 82. In practice, the ratio of the two distances is less than 0.3. In the closed position shown in Figure 3, it can be seen that for each pole 56 the contact pads 70 of the contact fingers 62 are pressing on the pad 72 of the contact part 60 stationary. The contact pressure is provided by the spring device 76 which allows any possible play of the mechanism and wear of the pads 70, 72 to be compensated. The electrodynamic forces exerted on the contact fingers 62 are brought to the level of the tunnel 66 by the bearing surfaces of the springs 76 and by the shaft 64. and generate a moment around the pivot axis 74 of the tunnel 66 which has to do that the tunnel 66 pivots in the direction of separation of the contacts. This moment is compensated by an opposite moment exerted by the rods 80 in the tunnel 66 at the level of their axis 64 of relative pivoting. In the dynamic equilibrium, the rods 80, therefore, are subjected to the level of their link pivot 64 by connoting them to the tunnel 66 at a force directed towards its link pin 81 that connects them to the pole arrow 78. This force, transmitted to the pivot 81, generates a moment around the axis 79 of the pole arrow 78. The same phenomenon occurs for each of the poles. A moment generated by the lower transmission rod 82 of the opening device articulation is opposed to the sum of the moments of the forces exerted by all the rods 80 and by the opening spring 92 on the arrow 78. Due to the position relative of the rods 80, the transmission rod 82 and the pole arrow 78, that is, the weakening of the levering of the rods 80 compared to that of the transmission rod 82 the result at the level of the transmission rod 82 remains moderate. The characteristics of a circuit breaker of high electrodynamic resistance, therefore, must be found here, since the electrodynamic forces on the contact parts only generate limited stresses on the opening mechanism, so that the latter can oppose them. . In equilibrium, the pole arrow 78 exerts pressure forces at the level of the support bearings, the result of which forces is a reaction force opposing the sum of the forces exerted by the rods 80 and the rod 82. from transmission. These relatively high pressure forces are exerted mainly on the cylindrical sector 54 formed in the intermediate wall 20. When the opening of the circuit breaker occurs, the rod 82 stops the counter-clockwise rotation of the pole arrow This rotation, generated jointly by the opening spring 92 and the result of the electrodynamic forces at the level of the link pins 81 of the rods 80 and of the arrow 78, drives all the tunnels 66 to the open position shown in figure 4. In this position, the crank 90 of the pole arrow 78 leaves slightly from the window 34. Figures 5 to 8 describe the mode of assembly of the pivot link between the pole arrow 78 and the connecting rods 80 with each tunnel 66. The pole arrow 78 comprises, for each pole, an arm 94 carrying two coaxial pins 81 eccentric with respect to the pivoting shaft 79 of the pole arrow 78. These pivots 81 are each located in a notch 98 of the side face 100 of the arm. A tab 102 hanging from the notch 98 materializes a slot 104. Each rod 80 comprises, on the side designed to operate in conjunction with the arrow 78, a cylindrical bore 108 designed to form a bearing for one of the pivots 81, and a flat part 110. When assembling occurs, the rod 80 is presented in such a way that the flat part 110 is parallel with the lower edge of the tongue 100, in the relative assembly position shown in FIG. 6. It is then possible to insert the pins 81 into the perforations 108. Once assembled, the assembly formed by the rods 80 and the pole arrow 78 is placed in the box, where it oscillates between two extreme positions; a position corresponding to the opening of the contacts and shown in Figure 7 and a position corresponding to the closure of the contacts and shown in Figure 8. In both of these positions, as well as in all the intermediate positions, the rods 80 operate in conjunction with the corresponding grooves 104 of the pole arrow 78, which form a guide preventing any movement of the rods 80 in a direction parallel to the pivot axis 81. A simple positive link is achieved in this way, which does not require the use of any additional intermediate part. Naturally, the invention is not limited to the example described above. It is evident, for example, that the pivot axis of the rods 80 in the tunnels 66 is not necessarily the same as the pivot axis of the fingers 62. There can also be only one rod 80 __ * t_: by pole. In addition, arrangements can be made to increase the tightness at the level of the bearings passing through the divisions. A bearing in this manner can be provided having a zigzag profile with a central annular groove operating in conjunction with a complementary roughness of the arrow. Additional bearings can also be provided at the level of the external side walls of the box. The circuit breaker described in the example comprises an energy storage mechanism. However, within the scope of the invention, the operating mechanism of the pole arrow can be of any kind. The described mechanism, therefore, can be replaced by any other known mechanism, be it a mechanism with manual reset or motor driven.

Claims (6)

1. - A low voltage circuit breaker of high electrodynamic resistance with a box made of insulating material, comprising an operating mechanism linked to a pole arrow supported by bearings fixed securely to the box, a plurality of poles, each pole comprising at least one pair of separable contact parts, at least one of the contact parts of each pair, called the movable contact part, being mechanically linked to the pole arrow, the pole arrow, the operating mechanism and the movable contact part being able to move between an open position corresponding to the separation of the contact parts of each pair, and a closed position corresponding to the contact between the contact parts of each pair, the circuit breaker box comprising a compartment front that houses the operating mechanism and a rear compartment separated from the front compartment by an intermediate wall and subdivided into compartments, individual by means of separation divisions, each individual compartment housing one of the poles of the circuit breaker, characterized in that the axis of rotation of the pole arrow is placed in the compartment later.

2. The circuit breaker according to claim 1, characterized in that each of the separation divisions supports one of the bearings and in that the pole arrow passes through each division at the level of one of the bearings .

3. The circuit breaker according to claim 2, characterized in that each of the separation divisions comprises a dividing element molded with the intermediate wall, on an edge of whose wall a semi-cylindrical sector forming a part is formed. of the corresponding bearing.

4. The circuit breaker according to any of the preceding claims, characterized in that the intermediate wall comprises a window for the passage of a mechanical link part between the pole arrow and the operating mechanism, 5.- The breaker circuit according to any of the preceding claims, characterized in that the external surface of the pole arrow is made of electrically insulating material, in particular of thermosetting polyester plastic. 6. The circuit breaker according to any of the preceding claims. characterized in that it comprises at least one connecting rod between the pole arrow and each movable contact part, this rod being linked to the pole arrow by means of a pivot in such a way that in a certain relative position of the arrow and of the rod , called the assembly position, the connecting rod can move freely in a direction parallel to the axis of the pivot, and in that the connecting rod has been adjusted and moved from its adjustment position, a positive link is achieved which prevents the translation movement of the rod in a direction parallel to the axis of the pivot, the assembly position being such that in the operating state, the pole arrow and the rod never adopt this position.