RU2477541C2 - Automatic circuit breaker for application in lv circuits - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: automatic LV circuit breaker contains a housing including: a pair of poles, each containing the first contact and the second contact, designed so that to enable mutual connection/disconnection; a kinematic closing/opening mechanism linked to the first and the second poles to perform the contacts connection/disconnection; the first, second and third protective devices intended for activation of the kinematic mechanism disengagement and contacts opening as a result of the corresponding first, second or third situation of malfunction of the electric installation linked to the circuit breaker; a connective means connecting the kinematic closing/opening mechanism to the first, second and third protective devices. According to the invention, the first (20) and the second poles (30) of the circuit breaker (1) are positioned symmetrically to the left and to the right of the circuit breaker longitudinal axis (100) while the kinematic closing/opening mechanism (40) is positioned in the centre relative to the first and the second poles (20, 30).

EFFECT: simplification of the circuit breaker assembly inside a single space-efficient housing.

12 cl, 13 dwg

Description

Technical field

The present invention relates to a circuit breaker, in particular to a circuit breaker having many functions and at the same time having an extremely compact design.

State of the art

Circuit breakers are ordinary, well-known electrical devices. They are typically used in electrical installations (such as residential, industrial, or commercial installations) to provide electrical installation protection and safety for users by automatically opening the circuit breaker itself and then cutting off the power supply in the event of a malfunction.

These fault situations are usually short circuits, overloads, and earth leakages. In order to provide protection against these malfunctions, one or more protective devices are connected to the circuit breaker itself, which can distinguish a normal working situation from malfunctioning situations. These devices usually contain a power drive, which, tracking a specific malfunction situation, acts on the kinematic mechanism of the switch to turn on the automatic trip and open the contacts.

The most common well-known protective devices are magnetothermal devices that provide protection against short circuits and overloads, and differential devices that provide protection against earth leakage currents.

One of the common shortcomings is caused by the fact that in some applications, the protective devices include additional modules associated with the circuit breaker to provide it with special protective functions. Specifically, the circuit breaker and protective devices are located inside individual enclosures having a width of a predetermined modular type (for 1 DIN module it is 17.5 mm). The enclosures are then connected and connected to obtain the desired type of protection.

This entails an increase in cost, since for the placement of various devices it is necessary to have many cases, in addition, the need for appropriate means of connection and coordination for proper connection with the switch, plus the corresponding indirect labor costs for installation work.

In addition, even where the protective devices and the operating part of the circuit breaker are enclosed in one case, this usually turns out to be rather cumbersome in size (for example, the width is greater than two standard modules), especially when both poles are protected. It should also be noted that in these cases the usual well-known protective devices require a special mechanism for connecting to the trip kinematic mechanism with subsequent complications at the stage of designing the protection and manufacturing of the circuit breaker and related devices.

As can be seen from the above description, conventional well-known circuit breakers show a number of disadvantages for which appropriate solutions were proposed, but which are still not completely satisfactory.

Summary of the invention

The main objective of the present invention is to provide an automatic low-voltage switch capable of overcoming the disadvantages described above.

In the context of the foregoing, one of the objectives of the present invention is to provide an automatic low-voltage circuit breaker that allows many protective functions to be realized, but with a reduced number of components.

Another object of the present invention is to provide an automatic low-voltage circuit breaker in which various components of the circuit breaker as well as protective devices are enclosed in one housing.

Another objective of the present invention is to provide an automatic low-voltage switch, in particular a bipolar switch, in which both poles are protected and in which various components of the switch, as well as protective devices, are enclosed in one housing.

An additional objective of the present invention is the provision of an automatic low-voltage switch, in which the connection between the protective devices and the trip kinematic mechanism of the switch is simplified.

Another objective of the present invention is the provision of an automatic low-voltage switch, which is as narrow as possible in size, namely in width.

An additional objective of the present invention is the provision of an automatic low voltage switch containing a reduced number of parts, which is easy to assemble and install.

And another objective of the present invention is the creation of an automatic low-voltage switch, which is extremely reliable, relatively easy to manufacture and has a competitive cost.

This task, as well as these and other tasks, which will be explained in more detail below, are achieved in an automatic low-voltage circuit breaker, which contains a housing made of insulating material, which includes:

a first pole comprising a first contact and a second contact configured to mutually connect / disconnect with each other;

a second pole comprising a third contact and a fourth contact, configured to mutually connect / disconnect with each other;

a kinematic closing / opening mechanism connected to the first and second pole for performing a connection / disconnection action between the first and second contacts, and the third and fourth contacts;

first, second and third protective devices designed to activate the release of the kinematic mechanism of closing / opening and opening of contacts as a consequence of the corresponding first, second or third situation of a malfunction in an electrical installation associated with a switch;

connection means that connects the kinematic closing / opening mechanism to the first, second and third protective devices.

Due to its design and functionality, the circuit breaker in accordance with the present invention can greatly simplify the production of mechanisms and connections between the various components of the circuit breaker. In other words, unlike other conventional known switches, by means of one mechanism, the connecting means is able to connect protective devices to the trip kinematic mechanism of the switch, reducing the number of mechanical components and optimizing the space filled inside the case.

Brief Description of the Drawings

The invention is further explained in the description of the preferred embodiments with reference to the accompanying drawings, in which:

Figure 1 is a General view of a first embodiment of a circuit breaker in accordance with the present invention;

Figure 2 is a side view of the switch of figure 1;

Figure 3 - functional diagram of the location of the switch of figure 1;

Figure 4 is a first side view of some elements of the switch of figure 1;

Figure 5 is a second side view of some of the elements of the switch of figure 1;

- Fig.6, 7 and 8 are detailed views that show the first switching cycle of a circuit breaker in accordance with the present invention;

Figures 9 and 10 are detailed views that show a second switching cycle of a circuit breaker in accordance with the present invention;

11 is a General view of a second embodiment of a circuit breaker in accordance with the present invention;

Fig.12 is a functional diagram of the location of the switch of Fig.11;

Fig.13 is a General view of some elements of the switch of Fig.11;

DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to the attached drawings, the automatic low voltage switch 1 in accordance with the present invention, in its most general embodiment, relating to a bipolar switch, comprises a housing 10 of insulating material that includes a first pole 20 and a second pole 30. The rear part 11 of the housing 10, which is appropriately shaped, represents means for connecting to a DIN rail. The housing 10 involves the use of a cable by connecting to the special terminals of the respective conductors or buses. In addition, the front of the housing 10 involves connecting to a cover not shown in the drawing, so that this switch is completely closed.

The first pole 20 contains a first contact 21 and a second contact 22, which can be mutually connected / disconnected with each other, and the second pole 30 contains a third 31 and a fourth contact 32 (not shown), which can be mutually connected / disconnected with each other . Contacts 22 and 32 are in a fixed position, while contacts 21 and 31 are movable, acting between an open position in which they are not connected to their respective fixed contacts and a closed position in which they are connected to fixed contacts.

The switch also contains a kinematic mechanism 40 closing / opening, which is connected to the first and second poles 20, 30 to perform the action of connecting / disconnecting the first and second contacts 21, 22, as well as the third and fourth contacts 31, 32. More specifically, the kinematic mechanism 40 closing / opening contains levers that transmit contacts to the movement of the head 42, controlled by the user, to perform the operation of opening or closing the switch; in addition, the levers cause the contacts to open in the event of a malfunction in the electrical installation associated with this switch 1. To this end, the kinematic closing / opening mechanism 40 preferably comprises means for holding the movable contact in the closed position, as well as means for releasing the kinematic mechanism allowing automatic opening of the switch 1. In one embodiment, the kinematic closing / opening mechanism 40 includes, at least one pair of levers, for example a gripping lever 43 and a release lever 41, which, being coupled to each other, hold the contacts in a closed position lion. In the event of a malfunction, the release lever 41 is released from the capture lever 43 by rotation around the center 418, disengaging the kinematic mechanism so that an automatic opening operation can be performed using the mechanism, which will be described in more detail below.

The circuit breaker in accordance with the present invention is intended to protect electrical installations (such as residential, industrial or commercial installations), as well as the user himself, by automatically opening the circuit breaker and then cutting off the power supply in accordance with the first, second and third fault situations. Typically, these situations of malfunction refer to a short circuit, overload, and earth leakage.

To this end, the circuit breaker 1 in accordance with the present invention contains the first 50, second 60 and third 70 protective devices designed to activate the release of the kinematic mechanism 40 of the closing / opening and opening of the contacts 21, 22 and 31, 32 in accordance with the first, second or third fault situation related to switch 1.

Protective devices are typically devices of a known type. The first 50 and second 60 protective devices are usually combined together and form a magnetothermal device containing a magnetic drive mechanism (usually containing a coil, a movable core, a fixed core, a slider or, in general, a pin and spring), which provides protection against short circuits and a thermal drive a mechanism (usually consisting of a bimetallic strip) to provide protection against overload currents. The third protective device 70 is typically a differential drive mechanism that provides protection against earth leakage currents and typically includes a relay and a toroidal coil. Differential protection detects leakage current to earth as a result of an imbalance between the currents of two phases or between phase and neutral, depending on the situation.

The circuit breaker 1 in accordance with the present invention also comprises connection means 80, which connects the kinematic closing / opening mechanism 40 to the first 50, second 60 or third 70 protection device. Generally speaking, unlike conventional known circuit breakers, in the circuit breaker in accordance with this invention, the mechanical pulses of the protective devices 50, 60 and 70 are transmitted to the kinematic trip mechanism through a single mechanism that greatly simplifies the circuit breaker design compared to conventional solutions that require each protective circuit devices of special mechanical action.

A first embodiment of a circuit breaker 1 in accordance with the present invention, shown in FIG. from 1 to 5, provides protection for only one of the poles, thereby forming a typical configuration of the so-called 1P + N switches. In practice, in accordance with the present invention, the first 50 and second 60 protective devices are operatively connected to the first pole 20, forming magnetothermal protection (from short circuit currents and overload currents) of this pole, while the third device 70 provides differential protection of the circuit breaker.

A second embodiment of the circuit breaker 1 in accordance with the present invention, shown in FIG. from 11 to 13, provides protection for both poles, forming a switch configuration with two protected poles in two modules (2P2M).

Specifically, in accordance with this embodiment, the first 50 and second 60 protective devices are connected to the first pole 20, forming a thermo-thermal protection for this pole; the switch also contains a fourth 55 and a fifth 65 protective device connected to the second pole 30, while the fourth protective device 55 provides protection against short circuit currents, and the fifth protective device 65 provides protection against overload currents for the second pole 30. In this case, the third device 70 provides differential protection for circuit breaker 1.

6-10 are embodiments illustrating an automatic opening operation in a circuit breaker in accordance with the present invention.

As indicated above, an embodiment of the kinematic closing / opening mechanism 40 preferably comprises a first release lever 41 for disengaging the closing / opening mechanism 40 by releasing the third connecting lever 43 to enable opening of the contacts 21, 22 and 31, 32. Connecting the means 80 comprises, for example, a first trip shaft 81 that connects the kinematic closing / opening mechanism 40 to the first and second protective devices 50 and 60, as well as to the fourth and fifth protections devices 55 and 65 when they are installed. According to this embodiment, the connecting means 80 also comprises a second actuating lever 82, which connects the kinematic closing / opening mechanism 40 to the third protective device 70. The first trip shaft 81 and the second actuating lever 82 are connected to the first trip lever 41. In other words, the connecting means 80 forms a single mechanical interface, for example, by means of a first trip shaft 81 and a second acting lever 82, through which a mechanical impulse generated once ary protection devices 50, 55, 60, 65, 70 associated with the occurrence of the corresponding fault situation, is transmitted to the kinematic mechanism 40 closing / opening, such as effects on the release lever 41.

Figures 6 and 9 show an option when the switch is closed and there are no malfunctions, while the kinematic closing / opening mechanism 40 is maintained locked in the closed position by the interaction of the third connecting lever 43 with the first trip lever 41. In particular, in accordance with this embodiment one end of the lever 43 is engaged by means of a protrusion into the body of the lever 41, which prevents the rotation of the lever 43 counterclockwise (and the resulting disengagement ator).

The automatic opening operation in the event of a malfunction caused by a short circuit is shown in FIGS. 6 and 7. The first protective device 50 (and the fourth protective device 55, when present) comprises a slider 501 mounted on a movable core. Under normal conditions (see FIG. 6), a portion of the slider 501 is located near the first extension 810 of the first trip shaft 81.

In the event of a short circuit, the protective device 50 is activated by pulling the movable core inward and, as a result, moving the attached slider 501 (see Fig. 7, which shows the movement of the slider 501 in the right direction). Due to this change in position, the slider 501 acts on the first extension 810 of the shaft 81, which rotates clockwise around its own pivot point 815. Shaft 81 represents a second extension 811 associated with this shaft, which has been shaped accordingly. Due to the rotation of the shaft 81, the second extension 811 interacts with the first trip lever 41, causing it to rotate counterclockwise around its own center of rotation 418. As a result, the release lever 41 is released from the third connecting lever 43, allowing it to move and disengaging the kinematic closing / opening mechanism 40, which goes into the open position, disconnecting the movable contacts 21 and 31 from the respective fixed contacts 22 and 32.

6 and 8 illustrate an automatic opening operation in the event of faults associated with overload currents. The protective device 60 (and the fifth protective device 65, when present) contains a bimetallic strip, which, when passing through the overload current circuit, must bend. Under normal conditions (see FIG. 6), one portion of the strip 60 is located near the third extension 812 of the first trip shaft 81.

In the event of an overload current due to the bending of the bimetallic strip, the protective device 60 is activated (see Fig. 8, which shows the movement of the strip 60 in the downward direction). Due to this movement, the strip 60 acts on the extension 812 of the shaft 81, which rotates clockwise around its own pivot point 815. Due to this rotation, the second extension 811 of the shaft 81 interacts with the first trip lever 41, causing it to rotate and the previously described automatic opening of the contacts.

Magnetothermic protection has already been described in relation to a single-pole version. Obviously, in cases where both poles are protected, the design basically has a symmetrical shape corresponding to the two poles 20 and 30, respectively, and protective devices 50, 60 and 55, 65, which can act independently on the connecting means 80 ( and therefore on shaft 81) and cause the opening of switch 1.

Figures 9 and 10 show an automatic opening operation in the event of a malfunction associated with an earth leakage current. The protective device 70 includes a piston 701, made with the possibility of sliding when a leakage current to the earth, and therefore, when a current imbalance occurs in the conductors associated with the poles. Under normal conditions (see Fig. 9), one end of the piston 701 is located near the shoulder 822 of the second acting lever 82. The acting lever 82 is positioned properly on the axis at a point 820 with the possibility of rotation at this point and the corresponding springs are held at rest. The second actuating lever 82 is also equipped with means 821 for connecting to the first trip lever 41. In the case shown in the attached drawings, the actuating means is formed from a protrusion 821 intended to interact with the portion 410 of the trip lever 41.

In the event of a leakage current to earth, the protective device 70 is triggered, causing the piston 701 to move in the direction of the outer part of the relay (see Fig. 10, which shows the movement of the piston 701 in the right direction). Due to this movement, the piston 701 acts on the shoulder 822 of the lever 82, which rotates counterclockwise around its own pivot point 820. As a result of this rotation, the protrusion 821 of the operating lever 82 interacts with the portion 410 of the first trip lever 41, causing it to rotate counterclockwise and automatically open the contacts, as described previously.

In addition to significant simplifications from a mechanical point of view, the circuit breaker in accordance with the present invention can be made extremely compact with advantageous placement of its various components inside the housing 10.

For example, FIGS. 3 and 12 show that the first pole 20 and the second pole 30 are preferably symmetrically located to the left and right of the longitudinal axis 100 of the switch 1, when viewed from the front. Therefore, the kinematic closing / opening mechanism 40 may preferably be located in the center relative to the first and second poles 20 and 30.

In the case where only one pole is protected, FIG. 3 shows that the first and second protective devices 50 and 60 are located, for example, above the first pole 20 and are located next to the kinematic closing / opening mechanism 40. More specifically, the devices 50 and 60 for magnetothermic protection are usually grouped in a single unit (and for this reason they are shown in Fig. 3 as a single functional unit) and are located near the pole, in the forward position, when viewed from the front of the switch 1). Therefore, the devices 50 and 60 are connected to the pole 20 to provide protection against short circuits and overloads and are connected to the kinematic mechanism 40 of the circuit / opening to activate the action of automatic tripping.

In this configuration, a third protective device 70, which typically provides protection against earth leakage, is placed in the transverse position with respect to the longitudinal axis 100 and adjacent to the kinematic closing / opening mechanism 40. In other words, when viewed from the front of the circuit breaker, the third protective device 70 is located in a lower position relative to the first and second protective devices 50 and 60 and with respect to the kinematic mechanism 40 of the closing / opening.

In the same way as in the previous case, in cases where both poles are protected, the first and second protective devices 50 and 60 are located above the first pole 20 and adjacent to the kinematic closing / opening mechanism 40, while the fourth and fifth protective devices 55 and 65 are located above the second pole 30 and adjacent to the kinematic closing / opening mechanism 40 on the opposite side with respect to the first and second protective devices 50 and 60. In this case, the third protective device 70 is placed in the transverse position relative to contact to the longitudinal axis 100 and adjacent to the kinematic closing / opening mechanism 40, and therefore, when viewed from the front of the switch, it is in a lower position with respect to the first, second, third and fourth protective devices, as well as lower and with respect to to the kinematic mechanism 40 of the circuit / opening.

The resulting design is extremely rational and compact. The arrangement of the components inside the housing 1 is basically symmetrical and ensures optimal use of the internal space of the housing. Consequently, the dimensions of the circuit breaker can be kept very compact, in particular, the width is equal to two standard DIN modules (35 mm) with significant advantages in terms of modularity.

In accordance with the above description, it is obvious that the circuit breaker in accordance with the present invention has achieved all its goals and performs all tasks, as expected. Indeed, the circuit breaker in accordance with the present invention can provide a large number of functions with a reduced number of components and a reduced cost.

Moreover, when using a single mechanism between the protective devices and the kinematic closing / opening mechanism 40, it is possible to simplify the design of the circuit breaker while providing the entire protection range (magnetic, thermal and differential) at the same time on one or both poles.

In addition, unlike current-level circuit breakers, which require special mechanisms for each type of protection and / or the use of additional modules, the use of a single switching mechanism between the protective devices and the kinematic closing / opening mechanism 40 provides a significant reduction in production costs.

It should be noted that especially in the configuration option in which both poles are protected, the device in a single housing of the present invention can be endowed with a large number of functions, with subsequent savings in production and installation costs. Moreover, due to the extremely high compactness and rational placement of components inside the case, the external dimensions are significantly reduced. In particular, it is possible to make a switch with a width equal to two standard DIN-modules, with two protected poles with significant advantages in terms of modularity and rationality of installation.

In accordance with the description given here, those skilled in the art will appreciate the additional characteristics, changes, and improvements that they may make to the invention. These features, changes, and improvements should therefore be considered an integral part of the present invention. Almost all materials used, as well as dimensions and the associated shapes and contours, can be of any type in accordance with the requirements of the current level of technology and technology.

Claims (12)

1. Automatic low voltage switch (1), comprising a housing (10) of insulating material, including:
a first pole (20) comprising a first contact (21) and a second contact (22) configured to mutually connect / disconnect with each other;
a second pole (30) comprising a third contact (31) and a fourth contact (32) configured to mutually connect / disconnect with each other;
kinematic mechanism (40) of closing / opening connected with the first and second poles (20, 30) for connecting / disconnecting the first and second contacts (21, 22), and the third and fourth contacts (31, 32);
the first (50), second (60) and third protective devices (70) designed to activate the release of the kinematic mechanism (40) for closing / opening and opening contacts (21, 22; 31, 32) due to the corresponding first, second or third situation of malfunction in an electrical installation associated with a switch (1);
connection means (80) that connects the kinematic mechanism (40) of the closing / opening circuit with the first (50), second (60) and third protective devices (70),
characterized in that in the front view of the switch (1), the first (20) and second pole (30) are located symmetrically to the left and right of the longitudinal axis (100) of the switch (1), and the kinematic mechanism (40) of the closing / opening is located in the center relative to first and second poles (20, 30). 2. The circuit breaker (1) according to claim 1, characterized in that the first protective device (50) provides protection against short circuits, the second protective device (60) provides protection against overload currents, and the third protective device (70) provides protection against earth leakage currents. 3. The circuit breaker (1) according to claim 2, characterized in that the first and second protective devices (50, 60) are connected to the first pole (20). 4. The circuit breaker (1) according to claim 1, characterized in that the kinematic mechanism (40) for closing / opening contains a first trip lever (41) designed to release the kinematic mechanism (40) for closing / opening for the possibility of automatic opening of contacts (21 , 22; 31, 32). 5. A circuit breaker (1) according to claim 4, characterized in that the coupling means (80) comprises a first trip shaft (81) that connects the kinematic closing / opening mechanism (40) with the first and second protective devices (50, 60) and a second acting lever (82) that connects the kinematic mechanism (40) of the closing / opening circuit with the third safety device (70). 6. The circuit breaker (1) according to claim 5, characterized in that the first trip shaft (81) and the second acting lever (82) are connected to the first trip lever (41). 7. The circuit breaker (1) according to claim 3, characterized in that it contains a fourth (55) and fifth (65) protective devices connected to the second pole (30), while the fourth protective device (55) provides protection against currents short circuit, and the fifth protective device (65) provides protection against overload currents. 8. The circuit breaker (1) according to claim 3, characterized in that the first and second protective devices (50, 60) are located above the first pole (20) and placed adjacent to the kinematic mechanism (40) of the closing / opening. 9. The circuit breaker (1) according to claim 8, characterized in that the third protective device (70) is placed in the transverse position with respect to the longitudinal axis (100) and adjacent to the kinematic mechanism (40) of the closing / opening. 10. The circuit breaker (1) according to claim 7, characterized in that the first and second protective devices (50, 60) are located above the first pole (20) and adjacent to the kinematic mechanism (40) of the closing / opening, and the fourth and fifth protective devices (55, 65) are located above the second pole (30) and adjacent to the kinematic mechanism (40) of the closing / opening. 11. The circuit breaker (1) according to claim 10, characterized in that the third protective device (70) is placed in the transverse position with respect to the longitudinal axis (100) and adjacent to the kinematic mechanism (40) of the closing / opening. 12. The circuit breaker (1) according to claim 1, characterized in that it has the same width as the two standard DIN modules.

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