EP3525227B1 - Mains voltage-independent ground fault electrical switching apparatus and assembly method - Google Patents

Description

The invention relates to a mains voltage-independent residual current circuit breaker with an insulating material housing which has a first and a second current path area which are separated from one another by a housing partition. The residual current device has a first primary conductor, which is part of a first current path arranged in the first current path area, and a second primary conductor, which is part of a second current path arranged in the second current path area. In addition, the residual current protective switching device has a thermal release device for detecting an overload condition and - for detecting a residual current - a summation current transformer through which the two primary conductors are passed. The invention also relates to a method for assembling such a mains voltage-independent residual current circuit breaker.

Electromechanical protective switching devices - for example circuit breakers, miniature circuit breakers or residual current circuit breakers - are used to monitor and protect an electrical circuit and are used in particular as switching and safety elements in electrical power supply networks. To monitor and protect the electrical circuit, the protective switching device is connected in an electrically conductive manner via two or more connection terminals to an electrical line of the circuit to be monitored in order to interrupt the electrical current in the respective monitored line if necessary. For this purpose, the protective switching device has a switching contact which can be opened when a predefined state occurs, for example when a short circuit or a fault current is detected, in order to connect the monitored circuit from the electrical line network to separate. Such protective switching devices are also known as modular devices in the field of low-voltage technology.

A residual current circuit breaker is a protective device to guarantee protection against a dangerous residual current in an electrical system. Such a fault current - which is also referred to as differential current - occurs when a live part of the line has an electrical contact to earth. This is the case, for example, when a person touches a live part of an electrical system: in this case, the current flows as a fault current through the body of the person concerned to earth. To protect against such body currents, the residual current circuit breaker must quickly and safely disconnect all poles of the electrical system from the line network when such a residual current occurs. In general usage, instead of the term "residual current circuit breaker", the terms FI circuit breaker (short: FI switch), differential current circuit breaker (short: DI switch) or RCD (for "residual current protective device") are used equally.

In the case of residual current circuit breakers, a distinction is also made between line voltage-dependent and line voltage independent devices: while line voltage-dependent residual current circuit breakers have control electronics with a release that is dependent on an auxiliary or line voltage to fulfill their function, line voltage-independent residual current circuit breakers do not require an auxiliary or line voltage to implement the triggering function, but rather have for the implementation of the mains voltage-independent tripping, as a rule, a large summation current transformer with a so-called holding magnet coupled via the secondary winding of the summation current transformer.

In addition, there are also device designs in which the functionality of a residual current circuit breaker is combined with the functionality of a line circuit breaker: such combined circuit breakers are referred to in German as FILS or in English-speaking countries as RCBO (for residual current operated circuit breakers with overcurrent protection). Compared to separate residual current and line circuit breakers, these combination devices have the advantage that each circuit has its own residual current circuit breaker: Normally, a single residual current circuit breaker is used for several circuits. If a fault current occurs, all protected circuits are switched off as a result. By using RCBOs, only the affected circuit is switched off.

To detect a fault or differential current, residual current circuit breakers usually have a summation current transformer, which determines the differential current by adding the electrical currents flowing in several, for example two to four, primary conductors in the correct phase. For this purpose, the summation current transformer has a ring-shaped magnetic core through which the primary conductors (leading and returning lines) are passed. The magnetic core itself is wrapped with a secondary conductor. If the current flow in the electrical lines leading there and back is the same, no induction current is induced in the secondary conductor. On the other hand, if a fault current flows to earth, the currents flowing in the primary conductors no longer cancel each other out. As a result, a voltage proportional to the current difference is induced in the secondary winding, which, as a fault current signal, triggers the protective switching device after a predetermined value has been exceeded.

Since the available installation space - for example in an electrical installation distributor - is usually very limited in applications in electrical installation technology, there is a need to make the circuit breakers as compact as possible to design. On the other hand, more and more functionalities are being integrated into the devices or combination devices are being developed that cover the functional scope of several individual devices: for example, there are so-called FILS circuit breakers, which combine the functional scope of a conventional residual current circuit breaker (FI) with that of a line circuit breaker (LS) . Furthermore, ever higher nominal currents are to be realized. All of these developments mean that there is less and less space available inside the devices.

the DE 10 2014 208036 A1 describes a residual current circuit breaker and assembly method for a modular device for use in an electrical installation distributor. The residual current circuit breaker has an insulating material housing with a front side, a fastening side opposite the front side, and narrow and broad sides connecting the front and the fastening side.

the DE 10 2011 079593 A1 describes an electromechanical circuit breaker, in particular a line circuit breaker or circuit breaker, with a first triggering device for detecting and disconnecting a short circuit, a second triggering device for detecting and disconnecting an overload condition, a switching contact which has a fixed contact and a moving contact that is movable relative to it, and a trigger lever, which is coupled to the first triggering device in such a way that when the first triggering device and / or the second triggering device is triggered, the triggering lever is actuated and the switching contact is opened.

the EP 1 693 943 A2 describes a device for all-current sensitive detection of an electrical differential current. The special arrangement of the, in particular, cylindrical summation current transformer results in the possibility of a special space-saving and in particular also simple to manufacture construction of the device as a whole.

the DE 44 17 897 A1 describes a method for assembling a summation current transformer. The formation of assembly groups makes separate pre-assembly of individual functional parts superfluous and these groups can be handled in a closed manner.

The object of the invention is therefore to provide a mains voltage-independent residual current circuit breaker with a summation current transformer and an assembly method for such a mains voltage-independent residual current circuit breaker which, with a compact design of the residual current circuit breaker, enable high reliability with lower installation and manufacturing costs.

According to the invention, this object is achieved by the mains voltage-independent residual current protective switching device and the method for mounting the summation current converter according to the independent claims. Advantageous embodiments of the residual current circuit breaker according to the invention or the assembly method according to the invention are the subject matter of the dependent claims.

The mains voltage-independent residual current circuit breaker according to the invention has an insulating material housing with a first and a second current path area, which are separated from one another by a housing partition. A first primary conductor, which is part of a first current path, is arranged in the first current path area. A second primary conductor, which is part of a second current path, is arranged in the second current path area. Furthermore, the protective switching device has a summation current transformer, which is received in an opening in the housing partition, the first primary conductor and the second primary conductor through the summation current transformer are passed through. A first end of the first primary conductor is electrically conductively connected to a first contacting element of the protective switching device assigned to this end by means of a high-temperature-resistant joint, formed by welding or brazing, with a preassembled module through the summation current transformer with the first primary conductor passed through and the first contacting element attached to it is formed. Furthermore, a first and a second end of the second primary conductor are each electrically conductively connected to a contacting element of the protective switching device assigned to the respective end by means of non-high-temperature-resistant joint connections, formed by soft soldering.

The heat-resistant joint is formed by welding or brazing.

Welding and brazing are integral joining processes, which are characterized by high strength. In this way, the functionality - and thus the reliability of the protective switching device - can be guaranteed.

The joint connection, which is not highly heat-resistant, is formed by soft soldering.

Soft soldering differs from hard soldering or welding in that it has a significantly lower process temperature. With this method, the heat input into the insulating housing can be significantly reduced, whereby the risk of damage to neighboring components of the protective switching device is significantly reduced. Soft soldering is only mentioned here as an example for a joint connection that is not highly heat-resistant; in principle, however, any joining method can be considered in which the energy input into the device can be kept comparatively low.

The term "mains voltage independent" means that the protective switching device does not need a mains voltage in the event of a fault current to generate a trigger signal (for example to feed a trigger electronics), but that the trigger signal is generated from the detected fault current alone without an additional mains voltage - for example with With the help of a so-called holding magnet. Mains voltage-independent residual current circuit breakers are not dependent on any auxiliary or mains voltage to fulfill their function and therefore do not require any auxiliary or mains voltage to implement the tripping function.

The insulating housing is used to accommodate and hold the components and to attach the circuit breaker to a mounting or top hat rail, as used in common electrical installation distributors. It is essentially cuboid and has a front side, a fastening side opposite the front side, and narrow and broad sides connecting the front and fastening sides. The first and second current path areas are separated from one another in the width direction and electrically isolated from one another by the housing partition.

In the narrow design, the insulating material housing has a width of only one division unit (TE), which corresponds to a housing width of approx. 18 mm. The housing partition, which runs parallel to the broad sides of the insulating material housing, can be formed by a housing middle part, which can be closed on both sides with the aid of two housing cover parts after the individual components of the protective switching device have been installed. The cover parts thus represent housing covers which form the broad sides of the insulating material housing and cover the interior of the insulating material housing on these broad sides.

The summation current transformer is a ring-shaped magnetic core with a secondary winding, through which the primary conductors are passed. The summation current transformer is received in an opening formed in the housing partition so that the first primary conductor in the first current path area and the second primary conductor in the second current path area can be passed through the annular magnetic core. The functionality of a summation current transformer is based on the magneto-inductive principle: if the electrical current flowing in the first primary conductor is the same as the electrical current flowing back in the second primary conductor, if the two electrical currents are added with the correct sign, the magnetic fields generated by them cancel each other out - consequently, in the secondary winding does not induce an electric current. If, on the other hand, the electrical current flowing back and forth in the two primary conductors is different, the resulting magnetic field induces an induction current in the secondary winding, which then triggers the residual current device.

Since the establishment of a cohesive, highly heat-resistant joint connection between the first end of the first primary conductor and the first contacting element directly and clearly assigned to this end would involve a high input of energy into the insulating material housing, it is possible according to the invention to produce this joint connection outside the insulating material housing and to create the joint connection in this way Only insert components into the insulating housing after the joining process. The joint connections to be made between the two ends of the second primary conductor in the assembled state and a contacting element that is directly and clearly assigned to the respective end are made by means of joint connections that are not highly heat-resistant in order to keep the associated heat input into the insulating housing as low as possible. Thus, a safe and reliable assembly of the is in a simple manner Mains voltage-independent residual current circuit breaker can also be implemented with compact designs.

In addition to reducing the energy input into the insulating material housing by creating the highly heat-resistant joint (s) outside the insulating material housing, the pre-assembled module enables these assembly processes to be carried out without spatial restrictions (limited space) in parallel with the assembly of the protective switching device. The installation time, and thus the installation effort, can be significantly reduced in this way.

In an advantageous development of the protective switching device, the first contacting element is part of a thermal release device for detecting an overload condition.

The thermal release device is often part of a circuit breaker. With so-called combination devices, the functionality of a residual current circuit breaker is combined with that of a line circuit breaker: one then speaks of so-called FI / LS or LS / DI switches. In English-speaking countries, the term RCBO (for residual current operated circuit breaker with overcurrent protection) is common. The thermal release device can be formed by a bimetallic element or also by a shape memory element through which the electric current flows directly or indirectly and which heats up in the process. If the temperature is too great, the bimetallic element or the shape memory element deforms. This change in shape is transferred to a trigger mechanism - for example a switch lock of the protective switching device - whereby the protective switching device is triggered and the current in the electrical line to be monitored is interrupted.

In a further advantageous development of the protective switching device, there is also a second end of the first primary conductor electrically conductively connected by means of a further high-temperature-resistant joint connection to a second contacting element of the protective switching device assigned to this end.

The connection of the second end of the first primary conductor to the further, second contact-making element can also be produced by a high-temperature-resistant joint outside the insulating material housing. In this way, a reliable, materially bonded connection with high strength is produced - without the high energy input into the insulating housing which is usually associated therewith.

In a further advantageous development of the protective switching device, the second contacting element is formed by a connection terminal of the protective switching device.

Depending on the length of the first primary conductor and the position of the summation current transformer in the housing, it is possible to connect the second end of the first primary conductor directly - i.e. without further intermediate parts - to the connection terminal assigned to this current path in an electrically conductive manner.

In a further advantageous development of the protective switching device, the second primary conductor is also part of the preassembled assembly.

This results in the further advantage that the second primary conductor does not have to be threaded through the summation current transformer afterwards, but can be passed through the summation current transformer outside the insulating material housing without its spatial restriction. The assembly effort can thereby be further reduced.

In a further advantageous development of the protective switching device, the first primary conductor and / or the second primary conductor are designed as rigid conductors.

Rigid conductors have the advantage of dimensional stability and can be made more massive than flexible strands, which is particularly important for circuit breaker types that are intended for higher currents. In the case of a summation current transformer already installed in the insulating material housing, however, it is difficult or even impossible to thread the rigid conductors through the summation current transformer due to the limited space available. The advantage of rigid primary conductors therefore comes into play particularly during the pre-assembly of the module: in this case the assembly time - and thus the assembly effort - can be significantly reduced.

In a further advantageous development, the protective switching device is designed as an RCBO combination device which, in addition to the functionality of the residual current circuit breaker, has the functionality of a line circuit breaker.

As an RCBO combination device, the protective switching device also has the functionality - and thus the components - of a line circuit breaker, for example a thermal release device to detect an overload condition and an electrodynamic release device to detect a short circuit. Combination devices of this type have the advantage that they combine the functionality of several individual devices in a common housing - with generally the same or less structural volume, compared with the structural volumes of the individual devices.

In a further advantageous development of the protective switching device, the insulating material housing has a width of only one division unit.

Common single-pole miniature circuit breakers mostly have a housing width of one module (corresponds to approx. 18mm), as do common single-pole residual current circuit breakers. A single-pole residual current circuit breaker, which with a width of one division unit also has the functionality of a circuit breaker has completely or partially, is characterized by an extremely compact arrangement and represents a space-saving alternative to the use of the corresponding individual devices the first primary conductor and the thermal release device is exposed to a significantly higher thermal load.

This problem is far less pronounced with switching devices that have a larger installation space - for example FILS devices, which combine the functional scope of a conventional residual current circuit breaker (FI) with that of a line circuit breaker (LS) with a housing width of two modules. The same applies to mains voltage-dependent residual current circuit breakers, which, due to the smaller current transformers used there, offer more space and thus a greater distance between the joints and other device components as well as the insulating housing. In these cases, the joint connections can optionally also be produced by means of non-heat-resistant joining processes, for example by means of soft soldering.

1. a) Vormontieren einer Baugruppe bestehend aus dem Summenstromwandler, dem ersten Primärleiter sowie der thermischen Auslöseeinrichtung, wobei das erste Ende des ersten Primärleiters mittels einer hochwarmfesten Fügeverbindung, gebildet durch Schweißen oder Hartlöten, mit der thermischen Auslöseeinrichtung verbunden wird;
2. b) Einsetzen der vormontierten Baugruppe in die Öffnung der Gehäusetrennwand, wobei der erste Primärleiter und die thermische Auslöseeinrichtung im ersten Strompfadbereich positioniert werden;
3. c) Kontaktieren der beiden Enden des zweiten Primärleiters mittels nicht-hochwarmfester Fügeverbindungen, gebildet durch Weichlöten, mit einem dem jeweiligen Ende jeweils unmittelbar und eindeutig zugeordneten Kontaktierungselement.

The assembly method according to the invention for a mains voltage-independent residual current circuit breaker of the type described above has the following steps:

1. a) preassembling an assembly consisting of the summation current transformer, the first primary conductor and the thermal release device, the first end of the first primary conductor being connected to the thermal release device by means of a high-temperature joint, formed by welding or brazing;
2. b) inserting the preassembled assembly into the opening in the housing partition, the first primary conductor and the thermal release device being positioned in the first current path area;
3. c) Contacting the two ends of the second primary conductor by means of non-high-temperature-resistant joints, formed by soft soldering, with a contacting element that is directly and clearly assigned to the respective end.

By forming the preassembled module, the energy input into the insulating housing, which would occur when creating the high-temperature-resistant joint in the installation position in the insulating housing, i.e. in the assembled state, can be avoided. Any damage to the protective switching device that may be caused by this is also effectively avoided in this way. Since significantly lower temperatures occur when creating the non-high-temperature-resistant joints, these can be carried out in the installation position of the components to be joined, i.e. to be connected, in the second current path area of the insulating material housing without temperature-related damage to the protective switching device. This significantly improves the reliability of the assembly process. With regard to the further advantages of the assembly method according to the invention, reference is made to the above statements on the advantages of the protective switching device according to the invention.

In an advantageous development of the assembly method, the preassembled assembly also includes the electrical connection terminal to which the second end of the first primary conductor is connected by means of a further high-temperature joint before the assembly is inserted into the opening formed in the housing partition.

The advantages mentioned above are all the more bearable if the further highly heat-resistant joint connection is also carried out before the preassembled assembly is inserted into the opening formed in the housing partition. This joining process does not result in any corresponding heat input into the insulating material housing of the protective switching device, which significantly reduces the risk of damage.

In a further advantageous development of the assembly method, the preassembled assembly also contains the second primary conductor.

Since the threading of the second primary conductor through the opening of the summation current transformer, which is usually carried out manually, does not take place in the cramped conditions of a summation current transformer already installed in the housing, this assembly step can be carried out in a significantly simplified manner outside the insulating material housing before the pre-assembled assembly is inserted into the insulating material housing will. The assembly effort and the associated error rate can be significantly reduced as a result.

In summary, the advantage of the mains voltage-independent residual current circuit breaker according to the invention and the assembly method according to the invention is essentially based on the fact that the high-temperature-resistant joints are only made where greater strength is required due to the increased temperature stress on the joint during operation of the residual current circuit breaker. This higher thermal load occurs in particular at the joint between the first primary conductor and the thermal release. Since the high-temperature-resistant joint connections are produced outside the insulating material housing, no temperature input into the insulating material housing is connected, so that damage to the insulating material housing caused thereby or the other components of the residual current device included therein are effectively prevented.

Figuren 1 bis 3

schematische Darstellungen des netzspannungsunabhängigen Fehlerstrom-Schutzschaltgerätes in verschiedenen Ansichten;

Figur 4

eine schematische Darstellung einer vormontierten Summenstromwandler-Baugruppe in einer Seitenansicht;

Figur 5

eine schematische Darstellung der Summenstromwandler-Baugruppe vor dem Einsetzen in das Isolierstoffgehäuse in perspektivischer Ansicht;

Figuren 6 und 7

schematische Darstellungen der in das Isolierstoffgehäuse eingesetzten Summenstromwandler-Baugruppe in verschiedenen Seitenansichten;

Figur 8

eine schematische Detaildarstellung der nicht-hochwarmfesten Fügestellen im montierten Zustand;

Figur 9

eine schematische Darstellung der vollständig im Isolierstoffgehäuse montierten und gefügten Summenstromwandler-Baugruppe in perspektivischer Ansicht.

In the following, an embodiment of the mains voltage-independent residual current protective switching device is explained in more detail with reference to the accompanying figures. In the figures are:

Figures 1 to 3

schematic representations of the mains voltage-independent residual current circuit breaker in different views;

Figure 4

a schematic representation of a pre-assembled summation current transformer assembly in a side view;

Figure 5

a schematic representation of the summation current transformer assembly before insertion into the insulating housing in a perspective view;

Figures 6 and 7

schematic representations of the summation current transformer assembly used in the insulating housing in different side views;

Figure 8

a schematic detailed representation of the non-highly heat-resistant joints in the assembled state;

Figure 9

a schematic representation of the total current transformer assembly fully assembled and joined in the insulating housing in a perspective view.

In the various figures of the drawing, the same parts are always provided with the same reference numerals. The description applies to all drawing figures in which the corresponding part can also be recognized.

In the Figures 1 to 3 a residual current circuit breaker 1 is shown schematically in different views. While Figure 1 shows a view from below of the residual current circuit breaker 1 is shown in FIG Figure 2 a corresponding side view of the circuit breaker 1 is shown; Figure 3 shows a plan view corresponding to this in turn. The mains voltage-independent residual current circuit breaker 1 according to the invention has an insulating material housing 2 with a front side 4, a fastening side 5 opposite the front side 4 and narrow sides 6 and broad sides 7 connecting the front side 4 and the fastening side 5. The insulating material housing 2 has a first current path area 8 and a second current path area 9, which are separated from one another by a housing partition wall 10. The housing partition wall 10 runs parallel to the broad sides 7 from one narrow side 6 to the other narrow side 6 of the insulating material housing 2. The two current path areas 8 and 9 are thus arranged side by side in the width direction.

In the first current path area 8 there is a physical first current path 11 which runs from one narrow side 6 to the other narrow side 6 and is connected in an electrically conductive manner to the phase conductor of the electrical circuit to be monitored during installation. In the second current path area 9 there is accordingly a physical second current path 12, which also runs from one narrow side 6 to the other narrow side 6 and is connected in an electrically conductive manner to the neutral conductor of the electrical circuit to be monitored during installation. The protective switching device 1 thus has a phase conductor side (P side) in which the first current path is arranged and a neutral conductor side (N side) in which the second current path is arranged. In the area of the narrow sides 6, each of the two current path areas 8 and 9 has electrical connection terminals 30 - an input terminal and an output terminal. The respective input terminal of the relevant current path is via the two current paths 11 and 12, respectively 11 and 12 are electrically conductively connected to the respective output terminal of this current path.

On its front side 4, the mains voltage-independent residual current circuit breaker 1 according to the invention has an actuating element 3 for manual actuation. The protective switching device 1 can be fastened to a latching or top hat rail via the fastening side 5 opposite the front side 4. Such latching rails or top hat rails are used as standard in electrical installation distributors for the attachment of modular devices. The insulating material housing 2 advantageously has a width of only one division unit (1TE).

Figure 4 shows a schematic side view of a pre-assembled summation current transformer assembly 20. The assembly 20 has a summation current transformer 21, which is simply wrapped with a first primary conductor P, which is part of the first current path 11 arranged in the first current path area 8. A first end P1 of the first primary conductor P is electrically conductively connected by means of a highly heat-resistant joint connection to a first contacting element 27, which is part of a thermal release device 22. The thermal release device 22 also has a bimetal element 23, which is electrically conductively connected to the first contacting element 27, a moving contact 24, which is electrically conductively connected to the bimetal element 23 via a strand 28, as well as a blow loop 25 and an arc guide rail 26 . Via its second end P2, the first primary conductor P is electrically conductively connected to a connection terminal 30 of the protective switching device 1 by means of a further highly heat-resistant joint connection. The two highly heat-resistant joints between the first primary conductor P and the thermal release device 22 on the one hand and the connecting terminal 30 on the other hand can be formed, for example, by means of welding or brazing. Furthermore, the summation current transformer 21 is with a second Primary conductor N (see Figure 7 ), which is part of the second current path 12 arranged in the second current path area 9, is simply wrapped around it.

Figure 5 shows schematically the preassembled summation current transformer assembly 20 before it is installed in the housing partition wall 10 in a perspective view. The housing partition 10 is designed as part of the housing middle part 14, which contains the housing partition 10 and can be equipped with the components of the residual current circuit breaker 1 on both sides. After the assembly of the individual components, the housing middle part 14 is closed on both sides by means of two housing covers (not shown) which are fastened to the housing middle part 14. The two housing covers then cover the insulating housing 2 towards the broad sides 7 and thus form the outer broad sides 7 of the insulating housing 2. The housing cover can be fastened to the housing middle part 14, for example, by means of rivets and / or snap-in connections.

In the Figures 6 and 7 the summation current transformer assembly 20 inserted into the housing middle part 14 is shown schematically in various side views. It represents Figure 6 represents a side view of the phase conductor side (P-side) of the housing middle part 14, Figure 7 shows a side view of the opposite neutral conductor side (N side). Both on the P-side and on the N-side in the area of the narrow sides 6 there is a terminal receiving space 15 in which the electrical connection terminals 30 of the residual current circuit breaker 1 are received and held during assembly. From the Figures 6 and 7 it becomes clear that the space available in the interior of the insulating housing 2 is very limited. On the one hand, the width of the summation current transformer 21 essentially corresponds to the inside width of the insulating material housing 2 between the two broad sides 7. On the other hand, there is the opening 13 formed in the housing middle part 14 for receiving the summation current transformer 21 is not much larger than the summation current transformer 21 itself. For this reason, the two ends N1 and N2 of the second primary conductor N must be guided close to the summation current transformer 21 in order to still fit through the opening 13 when the pre-assembled summation current transformer assembly 20 is installed. For this reason, too, it makes sense to design the second primary conductor N as a rigid conductor.

Figure 8 shows schematically a to Figure 7 Corresponding detailed representation of the non-highly heat-resistant joints of the summation current transformer assembly 20 in the assembled state. The non-highly heat-resistant joints serve to connect the first end N1 or the second end N2 of the second primary conductor N with a contact element 16 or 17 (see FIG to connect electrically conductive.

In Figure 9 the summation current transformer assembly 20, which is completely mounted in the insulating housing 2, is shown schematically in a perspective view. Figure 9 shows again the N-side of the residual current circuit breaker 1, the non-heat-resistant joints of the summation current transformer assembly 20 with the contacting element 16 or 17 assigned to the respective end N1 or N2 have already been made. The first end N1 of the second primary conductor N is connected in an electrically conductive manner via a contacting element 16 to a connection terminal 30 assigned to this end N1. The second end N2 of the second primary conductor N is connected in an electrically conductive manner to the fixed contact 18 of the circuit breaker 1 via a further contacting element 17 which is molded onto the fixed contact carrier 19. The fixed contact 18 forms the N-side switching contact of the protective switching device 1 with a contact element arranged on the moving contact 24. The second end N2 is indirectly electrically conductively connected to the terminal associated with the second primary conductor N via the closed switching contact.

The assembly method according to the invention is described in more detail below with the aid of the figures:
In a first step, the assembly 20, consisting of the summation current transformer 21, the first primary conductor P and the thermal release device 22, is preassembled. For this purpose, the first primary conductor P is first passed through the summation current transformer 21. If necessary, the first primary conductor P can also be wound once or several times around the magnetic core of the summation current transformer 21. The first end P1 of the first primary conductor P is then electrically conductively connected to the first contacting element 27, which is part of the thermal release device 22, by means of a highly heat-resistant joint. As an alternative to this, it is also possible to first connect the first primary conductor P to the first contacting element 27 by means of the highly heat-resistant joint connection and only then to pass the first primary conductor P through the summation current transformer 21. This is particularly advantageous when the primary conductor P does not have to be wound around the magnetic core of the summation current transformer 21.

In this first step, the second end P1 of the first primary conductor P is advantageously also connected in an electrically conductive manner to the P-side connection terminal 30 of the protective switching device 1 assigned to this end by means of a further high-temperature-resistant joint. Furthermore, it is advantageous in the first step to already lead the second primary conductor N through the summation current transformer 21 and, if necessary, to wind it once or several times around its magnetic core. However, these two assembly steps do not necessarily have to be carried out in this order in order to carry out the assembly method according to the invention.

In a second step of the assembly method according to the invention, the pre-assembled assembly 20 is inserted on the P side into the opening 13 formed in the housing partition wall 10, wherein the thermal release device 22 is positioned in the first current path area 8 of the insulating material housing 2. A part of the summation current transformer 21 protrudes through the opening 13 into the second current path area 9 of the insulating material housing 2.

In the third step, the first end N1 and the second end N2 of the second primary conductor N become electrically conductive with the contacting element 16 or 17 directly and clearly assigned to the respective end N1 or N2 in their installation position in the second current path area 9 by means of non-high-temperature-resistant joints tied together. The connection terminal 30 assigned to the first end N1 is plugged onto the first end N1; Likewise, the fixed contact carrier 19 assigned to the second end N2 is plugged onto the second end N2. Both N-side joining connections are made with the help of a non-heat-resistant joining process, for example by means of soft soldering. Since this is associated with a lower heat input, no device contours or components of the residual current circuit breaker 1 are excessively stressed as a result. The joint connections that are not highly heat-resistant are sufficient at this point, since the thermal load on these joints during operation of the protective switching device 1 is not too great. As an alternative to soft soldering, only as an exemplary embodiment that does not belong to the invention, the non-heat-resistant joints can also be created using any other joining method, provided that the heat input into the device is low and the plastic walls of the insulating housing 2 are not damaged as a result.

With the above-described, inventive arrangement of a residual current circuit breaker 1 and the assembly method according to the invention, it is only possible to accommodate the significantly larger summation current transformer 21 required for mains voltage-independent FI technology in a compact RCBO device. Due to the small installation space, the primary conductors P and N in the device are arranged very close to the geometric contours and walls of the insulating housing 2, which, as a rule, cannot withstand the high thermal load (proximity to the thermal release device 22) of a high-temperature-resistant connection technology such as welding or brazing. Highly heat-resistant connections are required at this point, however, in order to prevent the strong heating of the thermal release device 22 from melting and thus destroying connections that are not highly heat-resistant, for example soft-soldered connections. For this reason, those joints that are exposed to high thermal loads due to the device-related technology and design are designed as high-temperature-resistant joints outside the device. On the other hand, those connections that are exposed to a lower thermal load in the device (closer proximity to the thermal release device 22) can accordingly be designed as less temperature-stable, not highly heat-resistant joint connections, for example by soft soldering. Since this is associated with a significantly lower heat input, these connections can also be made in the device, ie when the components to be joined are already installed in the insulating material housing 2. Due to the special design of the primary conductors P and N and their ends P1, P2, N1 and N2, it is not necessary to shape the primary conductors P and N after assembly in the insulating housing 2 by a further bending process. This further simplifies assembly.

The introduction of compact protective switching devices 1 significantly increases the demands and expectations on the customer side with regard to a space-saving design. The components and assemblies used are moving ever closer together, the comparatively large distances that originally still existed, for example between the summation current transformer 21 and the thermal release device 22, are significantly smaller or are almost completely eliminated. This increases the stability requirements for the joining connections used, which according to the invention is achieved by a high-temperature-resistant joining process (for example by brazing or welding) is characterized by a significantly higher thermal stability and is carried out in advance, ie already before the assembly of the components to be joined in the insulating material housing 2 of the protective switching device 1, is solved. It is necessary to integrate the summation current transformer 21 into both current paths 8 and 9 of the protective switching device 1, whereby not all connections can be established in advance, since the summation current transformer 21 always has to be mounted from one side. After the summation current transformer 21 has been installed, the remaining joint connections on the other side (N side) are produced using a joining process that takes place at lower temperatures, for example by soft soldering.

List of reference symbols:

1

Circuit breaker

2

Insulated housing

3

Actuator

4th

Front

5

Mounting side

6th

Narrow side

7th

Broadside

8th

first rung area

9

second rung area

10

Housing partition

11

first current path

12th

second current path

13th

opening

14th

Housing middle part

15th

Terminal receiving space

16

Contacting element

17th

Contacting element

18th

Fixed contact

19th

Fixed contact carrier

20th

module

21

Summation current transformer

22nd

thermal release device

23

Bimetal element

24

Moving contact

25th

Blow loop

26th

Guardrail

27

first contacting element

28

Strand

30th

Connection terminal

31

Clamping frame

32

Clamping screw

P.

first primary conductor
P1 first end
P2 second end

N

second primary conductor
N1 first end
N2 second end

Claims (11)

1. Grid-voltage-independent residual current protective switching device (1),

   - having an insulating-material housing (2), which has a first (8) and a second current path region (9), which are separated from one another by a housing partition (10),

   - having a first primary conductor (P), which is part of a first current path (11) arranged in the first current path region (8), and having a second primary conductor (N), which is part of a second current path (12) arranged in the second current path region (9), and

   - having a summation current transformer (21), which is received in an opening (13) of the housing partition (10), wherein the first primary conductor (P) and the second primary conductor (N) are fed through the summation current transformer (21),

   - wherein a first end (P1) of the first primary conductor (P) is electrically conductively connected to a first contact-connection element (27), associated with said end (P1), of the protective switching device (1) by means of a joining connection resistant to high temperature, formed by welding or hard soldering,
   characterized

   - in that the summation current transformer (21) together with the first primary conductor (P) fed through and the first contact-connection element (27) fastened thereto forms a preassembled component (20), and

   - in that a first (N1) and a second end (N2) of the second primary conductor (N) are electrically conductively connected in each case to a contact-connection element, associated with the respective end (N1, N2), of the protective switching device (1) by means of joining connections not resistant to high temperature, formed by soft soldering.
2. Protective switching device (1) according to Claim 1, wherein the first contact-connection element (27) is a constituent part of a thermal triggering device (22) for detecting an overload state.
3. Protective switching device (1) according to either of the preceding claims, wherein a second end (P2) of the first primary conductor (P) is electrically conductively connected to a second contact-connection element, associated with said end, of the protective switching device (1) by means of a further joining connection resistant to high temperature.
4. Protective switching device (1) according to Claim 3, wherein the second contact-connection element is formed by a connection terminal (30) of the protective switching device (1) .
5. Protective switching device (1) according to one of the preceding claims, wherein the second primary conductor (N) is also a constituent part of the preassembled component (20).
6. Protective switching device (1) according to one of the preceding claims, wherein the first primary conductor (P) and/or the second primary conductor (N) are designed as rigid conductors.
7. Protective switching device (1) according to one of the preceding claims, wherein the protective switching device (1) is designed as an RCBO combination device, which has the functionality of a line circuit breaker in addition to the functionality of a residual current circuit breaker.
8. Protective switching device (1) according to one of the preceding claims, wherein the insulating-material housing (2) has a width of one subdivision unit (TE).
9. Assembly method for a grid-voltage-independent residual current protective switching device (1) according to one of the preceding claims,
   having the steps of:

   - preassembling a component (20) consisting of the summation current transformer (21), the first primary conductor (P) and the thermal triggering device (22), wherein the first end (P1) of the first primary conductor (P) is connected to the thermal triggering device (22) by means of a joining connection resistant to high temperature, formed by welding or hard soldering;

   - inserting the preassembled component (20) into the opening (13) of the housing partition (10), wherein the first primary conductor (P) and the thermal triggering device (22) are positioned in the first current path region (8);

   - contact-connecting the two ends (N1, N2) of the second primary conductor (N) by means of joining connections not resistant to high temperature, formed by soft soldering, to a contact-connection element respectively associated with the respective end (N1, N2).
10. Assembly method according to Claim 9,
    wherein the preassembled component (20) comprises the electrical connection terminal (30) to which the second end (P2) of the first primary conductor (P) is connected by means of a further joining connection resistant to high temperature before the component (20) is inserted into the opening (13) formed in the housing partition (10).
11. Assembly method according to either of Claims 9 and 10, wherein the preassembled component (20) also contains the second primary conductor (N).

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