CN1465084A - Modular four-pole residual current circuit breaker - Google Patents

Abstract

A single-pole miniature circuit breaker, comprises: a casing on which there are two terminals for connection, in input and in output from the circuit breaker, to a phase of a low-voltage electric circuit, said casing having a front wall from which an actuation lever protrudes, a rear wall for coupling to a supporting element, two side walls that are substantially mutually parallel and whose distance is equal to a base module M, an upper wall and a lower wall, inside the casing there being provided: fixed and moving contact means that can be mutually separated in order to interrupt the flow of current in said phase;-- a kinematic mechanism that is operatively connected to said actuation lever and is suitable to move said moving contact means;--electric are quenching means; a device for protection against short-circuits, which comprises a coil and a moving striker suitable to interact operatively with said kinematic mechanism; a device for protection against overloads, which comprises a heat-sensitive element that is suitable to interact operatively with the kinematic mechanism; characterized in that said fixed and moving contact means comprise a first pair of contacts, having a first fixed contact and a first moving contact, and a second pair of contacts, having a second fixed contact and a second moving contact, a first arc quenching chamber and a second arc quenching chamber being respectively associated with said first and second pairs of contacts, said first and second pairs of contacts being electrically series-connected to each other and being crossed by currents that have the same direction.

Description

miniature circuit breaker rod

The present invention relates to a miniature circuit breaker pole for low voltage applications, ie operating voltages up to 1000 volts.

It is known that low voltage electrical systems use suitable protective devices, generally referred to in the art as modular circuit breakers or miniature circuit breakers.

These circuit breakers are dimensionally characterized in that, depending on the number of poles used, the width of these circuit breakers is equal to the width of a standard module or is a multiple of the width of a standard module, as stated in the relevant international standards, and these circuit breakers pass through It is normally used mounted on a suitable support element, such as a DIN rail, which in turn is usually placed in a suitably arranged electrical enclosure.

One of the main requirements for a modular circuit breaker of the residual current or magnetothermal type is the ability to ensure a sufficient level of protection against any failure or misoperation in the system with a fast tripping time , while taking up as little space as possible. In particular, due to the type of application for which the circuit breakers are planned, it should especially be understood that these circuit breakers occupy as little space as possible, so that the number of devices used can be increased for the same space available, or the same number can be reduced. space required for the installation.

This need is particularly important in the case of miniature or thermal-magnetic module circuit breakers of the type to which the present invention relates, since these devices are considered to provide a sufficient level of protection against possible overload conditions and against the majority of all currents; in the event of a short circuit the currents involved are in fact usually of very high values, and the interruption of this current requires suitable electrical and mechanical strength properties, to obtain which it is necessary to use such The components, which are properly sized and arranged according to a specific structure, ultimately affect the overall dimensions of the circuit breaker, especially its width.

At present, in known types of miniature circuit breakers, on the one hand such solution in which the breaking capacity is increased by increasing the size of the components used and by adopting a specially constructed structure, thus increasing the width of the circuit breaker relative to the width of the standard basic module, and on the other hand , keep that standard width, but buy a breaker with a reduced breaking capacity.

The object of the present invention is to provide a low-voltage miniature circuit breaker bar which makes it possible to avoid the disadvantages of the prior art and which, in particular, can Significantly improve its performance, more specifically its ability to break in short-circuit conditions, so that no corresponding increase in size, especially width, is required.

This and other objects which will become apparent hereinafter are achieved by a single pole miniature circuit breaker comprising:

A housing on which two terminals are provided for connection to phases of a low voltage circuit in the form of an input and an output of a circuit breaker; the housing has a front wall from which an actuating handle protrudes; for A rear wall coupled to the support element; two side walls, which are substantially parallel to each other and at a distance equal to the basic module M; an upper wall and a lower wall; inside the housing are provided:

fixed and mobile contact devices, which can be separated from each other to interrupt the current in the phase;

a kinematic mechanism operatively connected to the actuating handle and adapted to move the moving contact device;

Arc quenching device;

means for protection against short circuits comprising a coil and a mobile striker adapted to operatively interact with the movement mechanism;

Device for protection against overloading comprising a heat sensitive element adapted to operatively interact with a movement mechanism; characterized in that the fixed and mobile contact means comprise a first pair of contact parts and a second pair of contact parts , the first pair of contacts has a first fixed contact and a first moving contact, the second pair of contacts has a second fixed contact and a second moving contact, a first arc quenching chamber and a second arc Quenching chambers are respectively associated with the first and second pair of contacts, the first and second pair of contacts being electrically connected to each other in series and passing a current having the same direction.

In this way, the circuit breaker according to the invention is able to provide significantly improved functional characteristics with respect to the prior art, while offering optimized space requirements.

Representing the invention by way of non-limiting example only in the accompanying drawings, a preferred but not exclusive embodiment of a circuit breaker according to the invention is described, from which further characteristics and advantages of the invention will become apparent, in which:

Figure 1 is a perspective view of a circuit breaker according to the present invention;

Figure 2 is another perspective view detailing the components of the circuit breaker of Figure 1;

Figure 3 is a perspective view of components of a circuit breaker according to the invention, taken from the opposite side with respect to Figure 2;

4 is a schematic diagram of the arrangement of magnetic field flux lines outside the arc in an overcurrent state when the contacts are separated; and

Fig. 5 is a circuit diagram of a circuit breaker according to the present invention.

With reference to the cited figures, the miniature circuit breaker bar according to the invention comprises a housing 1 having a front wall 2 from which an actuating handle 3 protrudes, which handle is coupled to the housing so that it can be rotated around Pivot with suitably arranged; Rear wall 4, this rear wall is shaped conveniently so that connect unillustrated supporting guide, for example DIN track; Two side walls 5 and 6, these side walls are substantially parallel to each other, and Their distance is equal to the basic module M, which defines the width of the circuit breaker; upper wall 7 and lower wall 8 . Moreover, there are two corresponding terminals 9 on the housing, one of which is only partially visible in Figure 1, and corresponding clamping terminals for connection to the pole to be protected in the form of input and output of the circuit breaker. The phase; terminals 9 of the low voltage circuit may be arranged at the upper and lower walls, as shown in FIG. 1 , or may be arranged differently therefrom.

Specifically, taking into account normal manufacturing tolerances, this basic modulus is equal to 17.5( ⁺ ₀ ^0.5 )mm, as stated in the DIN 43880 standard.

The functional parts of the circuit breaker are arranged inside the housing 1 in a manner that will become apparent from the description below, and include: fixed and mobile contact means, which can be separated from each other so as to make the phases of the circuit current interruption; kinematic mechanism known per se, indicated generally by reference numeral 10, operatively connected to the actuating handle 3 and adapted to move the moving contact means; arc quenching means; for protection against means for any short-circuit fault; and means for protection against overloading.

In particular, according to an embodiment known in the art and therefore not described in detail, the means for protection against short-circuit faults are of the electromagnetic type and comprise a coil 11 wound around a support element 12, and an impact The striker 13 is operatively associated with the coil 11 and is only partially shown in FIGS. 2 and 3; The direction of the wall 8 is shifted so that, in the short-circuit condition, this striker operatively interacts with the kinematic mechanism 10, actuating it and finally separating the contacts and interrupting the current in the phase to be protected.

The means for protection against overloads further comprises a thermosensitive element 14, such as a bimetal sheet, which is electrically connected to the connection terminal 9; A predetermined limit disengages the kinematics and thus also separates the contacts and interrupts the current flow in the phases.

Advantageously, in an embodiment of the circuit breaker according to the invention, the fixed and mobile contact means comprise a first pair of contacts provided with a first fixed contact 15 and a first mobile contact 16, the first mobile The contact 16 is electrically connected to the element 14 by a suitable conductor, such as a flexible cord 19; and a second pair of contacts, which provides a second fixed contact 17 and a second moving contact 18, the two pairs of contacts 15-16 and 17 -18 are electrically connected in series with each other in a manner described in detail below.

Specifically, as shown in FIGS. 2 and 3, the first fixed contact portion 15 and the second fixed contact portion 17 are arranged side by side at an appropriate distance along the line connecting the side walls 5 and 6, that is, along the broken circuit and the contacts 15 and 17 are arranged such that their surfaces electrically coupled with the corresponding mobile contacts face the wall 8, so that these surfaces are transverse to the front and rear walls of the housing and side wall placement.

In turn, the first moving contact part 16 and the second moving contact part 18 are advantageously provided by two shaped conductors which are structurally separated from each other and which are mounted in such a way as to be on the contact holder 29 of the kinematic mechanism 10 with Spaced apart by a distance corresponding to the distance between the fixed contacts 15 and 17; the mobile contact holder 29 is arranged inside the housing and rotates about an axis 20 which is moved along the connecting side wall 5 and 6 and therefore substantially parallel to the axis of rotation 21 of the actuating handle 3 .

In combination, in an embodiment of the circuit breaker according to the invention, the arc quenching device comprises two arc quenching chambers 22 and 23, each chamber being operatively associated with a pair of contacts, the contacts Parts are indicated by reference numerals 15-16 and 17-18, respectively; the arc quenching chambers 22 and 23 are arranged side by side with each other in the vicinity of the rear wall 4, so that each chamber is close to the corresponding side walls 5 and 6, And these arc quenching chambers are separated by a partition 24 of plastic material interposed therebetween. In order to optimize the steering and quenching of any arc, two corresponding arc-guiding conductors, denoted by reference numerals 25-26 and 27-28 respectively, are additionally associated with each chamber 22 and 23 . Specifically, the first arc guiding conductor 25 is electrically connected to the connection terminal 9 and is shaped such that it has a free end arranged at the base of the chamber 22, while the second arc guiding conductor 26 has the first fixed contact 15 fixed thereon. , the second arc-guiding conductor is electrically connected at one end to the coil 11 and has the other end which is free and arranged in the upper part of the chamber 22 . In turn, the two arc-guiding conductors associated with the chamber 23 consist of a third conductor 27 and a fourth conductor 28 electrically connected to the second moving contact 18 by means of a second flexible cord 19 and constructed so that Having a free end arranged at the base of the chamber 23, on this fourth conductor is fixed a second fixed contact 17 electrically connected to the second terminal 9 and having a part.

Advantageously, the circuit breaker according to the invention uses an auxiliary conductor 30 having a first end connected to the coil 11 and a second end connected to the arc-guiding conductor 27 associated with the chamber 23; in particular, In the embodiment shown in Figures 2 and 3, the auxiliary conductor has a first part 31 and a second part in which one end is free and connected to the coil and placed at right angles to the axis of the coil, Adjacent to and perpendicular to the first part 31 , this second part is placed along the line connecting the walls 7 and 8 and is arranged such that a part of it is laterally adjacent to the coil 11 and its free end is connected to the conductor 27 . Thus, the first fixed contact 15 and the second moving contact 18 are electrically connected in series with the coil 11 , the auxiliary conductor 30 , the arc guide conductor 27 and the second flexible cord 19 interposed, providing the circuit of FIG. 5 .

Thus in this way, through the arrangement of the various components and the structure of the electrical connection between the elements, the two pairs of contacts 15-16 and 17-18 are electrically connected in series and arranged close to each other so that under normal operating conditions They flow current in the same direction.

Thus, when the contacts are separated due to a short-circuited condition, two electric arcs are generated between each pair of contacts 15-16 and 17-18, these arcs being schematically indicated by reference numeral 40 in FIG. 4 and electrically connected in series with each other; Each pair of arc-guiding conductors is thus influenced by a corresponding magnetic field on which the root of the arc 40 moves, the flux lines 41 of which have the same direction and at least partially overlap. In this way, the magnetic fields work in concert to create a force that acts on and quenches the arc more quickly and efficiently. In particular, thanks to the presence of two pairs of contacts and the overlapping of the magnetic fields, the circuit breaker according to the invention is able to interrupt the current flow in phases in two zones, which are arranged electrically in series, the breaking capacity of which is practically due to The aforementioned synergistic effect is surprisingly high, in some cases even higher than twice the breaking capacity value of the single pair of contacts which is part of the rod according to the invention. In practice it has been found that the circuit breaker according to the invention achieves the intended purpose thanks to the arrangement of the various components and their electrical connection to each other so that the functional characteristics obtained are compared to existing ones of the same size, especially of the same width Circuit breakers have been significantly improved. Moreover, in addition to the above-mentioned advantages, the present invention has two moving contacts, although this may be somewhat limited, but even when one of the moving contacts has itself been welded to the corresponding fixed contact, there are two moving contacts. The possibility of structurally separate moving contacts also makes it possible to have a protective release function.

This circuit breaker is therefore considered susceptible to many variants and modifications, all of which fall within the scope of the inventive concept; all the details can also be replaced by other technically equivalent elements. In fact, the materials and dimensions can be arbitrary according to the requirements and the state of the art.

Claims (8)

1. single pole miniature circuit breaker, it comprises:

Housing has two terminals on this housing, be used for form with the input and output of circuit breaker be connected to low-voltage circuit mutually; Described housing has antetheca, and actuating handle is outstanding from this antetheca; Be used to be connected to the rear wall on the supporting member; Two sidewalls, these sidewalls are parallel to each other basically and its distance equals base module M; Upper wall and lower wall; In this housing, be provided with:

Fixing and move contact device, these contact devices can be separated from each other so that make described current interruptions in mutually;

Motion, this motion are operably connected to described actuating handle and are applicable to and move described mobile contact device;

The arc-quenching device;

Be used to protect preventing the device of short circuit, it comprises coil and is suitable for operationally and the interactional mobile striker of described motion;

Be used to protect the device to prevent to transship, it comprises and being suitable for operationally and the interactional temperature-sensitive element of motion; It is characterized in that, described contact device fixing and that move comprises first pair of contact site and second pair of contact site, this first pair of contact site has first fixed contact and first and moves contact site, this second pair of contact site has second fixed contact and second and moves contact site, the first arc-quenching chamber and the second arc-quenching chamber are associated with described first and second pairs of contact sites respectively, and described first and second pairs of contact sites are electrically connected with being one another in series and the electric current that passed through has identical direction.

2. circuit breaker according to claim 1 is characterized in that, described base module M equals about 17.5mm.

3. circuit breaker according to claim 1 and 2 is characterized in that, the conductor by two moulding being separated from each other on the structure provides described first to move contact site and described second and move contact site.

4. circuit breaker according to claim 3, it is characterized in that, described first and second move contact site installs like this, so that on the contact retainer of motion, be spaced from each other, described contact retainer is arranged in the housing, make this contact retainer around a rotational, this axis is placed along the line that connects described sidewall.

5. according to one or multinomial described circuit breaker in the aforementioned claim, it is characterized in that, the electric arc guiding conductor of two correspondences is associated with the described first and second arc-quenching chambers, first free end that is electrically connected on first splicing ear and has an end that is arranged in first chamber in the described electric arc guiding conductor, second second end that has first end that is electrically connected on described coil and be arranged in the second end place of first chamber in the described electric arc guiding conductor, be fixed with described first fixed contact on second in the described electric arc guiding conductor, the 3rd electric arc guiding conductor dbus is crossed bonding conductor and is electrically connected on second and moves contact site and have the free end of an end that is arranged in second chamber, the 4th guiding conductor is electrically connected on second splicing ear and has the part at the second end place that is arranged in second chamber, is fixed with second fixed contact on the 4th guiding conductor.

6. circuit breaker according to claim 5, it is characterized in that, described first and second pairs of contact sites are arranged to closer to each other, make each contact portion from the time, form the electric arc of two correspondences, these electric arcs electricity each other arrange that in series described electric arc induces corresponding magnetic field on described electric arc guiding conductor, and the line of flux in this magnetic field has identical direction and overlapping at least in part.

7. according to one or multinomial described circuit breaker in the aforementioned claim, it is characterized in that, it comprises auxiliary conductor, this auxiliary conductor has first and second portion, this first places and lateral approach coil partly along the line that connects described upper wall and lower wall, the one end is connected in the 3rd electric arc guiding conductor, and this second portion is adjacent to first and vertical with first, and second portion has an end that is connected in described coil.

8. circuit breaker according to claim 7, it is characterized in that, first fixed contact and second moves contact site and in series is electrically connected, described coil, described auxiliary conductor, described the 3rd electric arc guiding conductor and be used for described the 3rd electric arc guiding conductor and the described second described conductor that moves the connection between the contact site is placed in described first fixed contact and described second and moves between the contact site.

Images