DE202021105500U1 - low voltage current transformer - Google Patents

Abstract

Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). characterized in that the pickup coil (32) is electrically conductively connected via at least two pickup lines (33) to at least two pickup contacts (40) which are arranged in the converter housing (20) and fitted from outside (24) of the converter housing (20). - And contactable and each as a lever clamp (41) are formed.

Description

The invention relates to a low-voltage current transformer.

Low-voltage current transformers generally have a transformer core that carries at least one pickup coil and spans a transformer core plane, and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane. In this case, a low-voltage busbar can then be arranged in the low-voltage busbar opening in the installed and intended state, as the designation of the opening already indicates, so that the low-voltage current transformer can then convert a current flowing under low voltage in the low-voltage busbar via the pickup coil or converts it accordingly. Such low-voltage current transformers are, for example, in DE 10 2019 115 404 A1 , the DE 101 31 739 A1 , the CN 201163573 Y and the U.S. 2013/0200971 A1 or in the as yet unpublished German patent application 10 2021 106 843.6 disclosed.

In addition to the aforementioned designations for the low-voltage busbar and the pickup coil, there are also the designations primary conductor or primary busbar for the low-voltage busbar and secondary conductor or secondary coil for the pickup coil. In exceptional cases, the term primary coil is even used for the low-voltage busbar, even though the busbar itself has no windings.

It is the object of the invention to provide a low-voltage current transformer which can be built as cost-effectively as possible or can be installed as cost-effectively as possible.

The object of the invention is achieved by low-voltage current transformers having the features of the independent claims. Further advantageous configurations, which may also be independent of this, can be found in the subclaims and the following description.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or can be installed as cost-effectively as possible, a low-voltage current transformer can be characterized by a transformer core that carries at least one pickup coil and spans a transformer core plane and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane that the pickup coil is electrically conductively connected via at least two pickup lines to at least two pickup contacts, which are arranged in the converter housing, can be equipped and contacted from outside the converter housing and are each designed as a lever-pull terminal.

In the present context, the “pick-up coil” can be understood to mean a coil which is designed as a wound conductor. In the present context, a coil is in particular an electrical component which has a wound conductor and is set up to generate an electromagnetic field or to be inductively excited by it, with the latter being particularly important for the function as pickup coil. Most coils consist of at least one winding of a conductor made of wire, enameled copper or aluminum wire, silver-plated copper wire, high-frequency stranded wire or ribbon, with the conductor usually being wound on a coil carrier. In the present context, if necessary, a transformer core itself can serve as a coil carrier. The winding arrangement and shape, the wire diameter, the winding material and the material of the transformer core determine the value of the inductance and other properties of the pickup coil.

A secondary signal, which corresponds to the magnetic flux in the converter core, can then be provided via the pick-up coil and which is then available as a secondary current, preferably for metrological purposes.

In the present context, the term "converter core", often colloquially also called armature, refers to an assembly that is set up to conduct magnetic flux. Here, the magnetic flux density is a physical quantity of electrodynamics. It is the areal density of the magnetic flux that passes perpendicularly through a specific surface element, in particular through a surface element of the transformer core.

A transducer core can preferably consist of a soft magnetic material with the highest possible saturation flux density, with the most linear characteristic possible and the highest possible magnetic permeability. As a result, the magnetic flux, which is induced by a primary current in the converter core, can be bundled or guided with low losses. This ensures that the primary current generates a course of the secondary current that is as linear as possible and the required hurdle performance is essentially guaranteed.

Furthermore, for example, a transformer core can be produced by pressing a suitable ferromagnetic powder in a tool. In this case, the pressed so-called green compacts are usually solidified in subsequent temperature treatments and, in the case of ferrite materials, sintered at high temperatures to form a ceramic.

A transformer core can in particular also be composed of several layers of a corresponding material, for example current transformer or transformer sheet metal. Depending on the specific configuration, the strip material is preferably equipped with a thin insulation layer to reduce eddy current losses. A large number of possibilities are known per se for such insulating layers, for example targeted oxidation via a coating with a lacquer and the like. In certain situations, for example with a corresponding material, the jump in material caused between the layers on the respective surfaces lying on top of one another can possibly already be sufficient to minimize the formation of current turbulence.

Advantageously, a converter core has a low hysteresis behavior when the magnetizing current is reversed, ie in particular the primary current, so that a small phase shift angle between the primary current and the secondary current and low heat generation in the converter core can be achieved.

In particular, the transformer core can be ring-shaped and have a central opening, which in the present context is referred to as a low-voltage busbar opening. Depending on the specific configuration, the transformer core can then be wound in particular as a toroidal tape core in the form of a strip material, in which case the low-voltage busbar opening can then be provided in a structurally simple manner by the winding core on which the strip material is wound.

In a specific embodiment, the transformer core may be split and have two or more transformer core parts, in which case, in the case of an annular transformer core, this then does not run in a purely radial plane, i.e. not in a plane that represents the low-voltage busbar opening or the transformer core plane or that is parallel thereto can be shared. In particular, such a divided transformer core can make it possible for a conductor for the primary current, referred to in the present context as the low-voltage busbar, not to be threaded through the low-voltage busbar opening in the transformer core, but for the divided transformer core to be fitted around the low-voltage busbar in the open state. With such an embodiment, it goes without saying that the associated housing can or should also have a corresponding division. On the other hand, the converter core can also be of undivided design.

In the present context, a “low-voltage current transformer” is understood to mean a current transformer which is specially adapted to the requirements of applications in the low-voltage range. The low-voltage range extends up to a voltage of 1,000 V, preferably up to a voltage of just 750 V or 720 V. In the constant effort to test the limits, there are also certain devices for the low-voltage range defined in this way that definitely have a Voltage up to 1,200 V or slightly above can be operated. Depending on the type of construction, however, such equipment is also not referred to as medium-voltage equipment, although it can still be operated in the lower limit range of the medium-voltage range to the low-voltage range.

In general, a current transformer as used herein is preferably an electrical or electrical device which converts a primary current, suitably referred to herein as low-voltage current, into a secondary current according to a fixed relationship. The secondary current can, in particular, be an electrical signal adapted for measurement electronics, so that a current transformer can enable or simplify the measurement of the primary current or the low-voltage current.

Corresponding low-voltage currents are conducted in low-voltage busbars, which can then be arranged in the low-voltage busbar opening of the respective converter core, so that these low-voltage busbars transport the primary current or the low-voltage current, by which the associated low-voltage current transformer is excited and which is then converted by it in a corresponding manner.

In this case, the low-voltage busbar opening accordingly defines a plane or the converter core plane, in which or parallel to which the magnetic flux runs through the converter core when a primary current flows in the low-voltage busbar.

In the present context, the width of the low voltage bus bar opening is preferably measured in the transformer core plane. In particular, the width can be measured parallel to the low-voltage busbars, which are often rectangular and flat, so that the Width can be measured along the flat side of the low voltage busbar.

In the present context, a “converter housing” is understood in particular to mean a solid casing for the low-voltage current transformer, which protectively surrounds the transformer core and is preferably not electrically conductive at room temperature conditions or under operating conditions. The converter housing is also preferably not made of metal, for example made of plastic. A converter housing can optionally be designed as a split converter housing, it being possible for the converter housing to consist of a plurality of, in particular two, converter housing parts.

In this case, the converter housing preferably has good thermal conductivity in order to dissipate any heat that arises in the converter cores or in the pick-up coils.

It is also conceivable here in particular for the converter housing to be cast, possibly even cast around the converter core and the other assemblies to be arranged within the converter housing.

In particular, however, the converter housing can be divided into housing parts, in particular in the plane of the converter core or in a plane parallel thereto, which serve to ensure that the desired assemblies, i.e. at least the converter core, the associated pickup coil or coils as well as contacts and lines, can be inserted into the converter housing. to assemble the low-voltage current transformer ready for use. The housing parts are then put together in a non-detachable or non-destructively detachable manner, with the non-detachability ultimately also serving to ensure operational safety. In order to be able to correct any construction errors that may occur after the ready-to-use assembly during the final inspection before the assembled low-voltage current transformer is handed over, measures may be taken by which - in individual cases and with a considerable expenditure of time - the two housing parts are non-destructively separated can be solved. This can be ensured, for example, by slow-hardening adhesives or cold welds that form themselves after a while, or by other special structural measures that allow the housing parts to be detached from one another without destroying them a certain time after assembly or under very difficult conditions, such as using very special tools, to correct any quality defects before delivery.

In particular, a distinction must therefore be made between converter housing parts, on the one hand, which make it easier to insert a low-voltage busbar into the low-voltage busbar opening or surround a mounted low-voltage busbar with the low-voltage current transformer, and housing parts themselves, which are only intended to enable the low-voltage current transformer to be installed. In this respect, a low-voltage current transformer can in particular have converter housing parts, which in turn are each composed of housing parts, with the latter serving to also insert parts of the converter core and the associated electrical and electronic as well as other components that are to be used in the converter housing part, while the former then serve to simplify assembly around a low-voltage busbar.

In particular, the converter housing can include a converter core holder, by means of which the converter core of the low-voltage current converter is held in the converter housing. Depending on the specific configuration, the converter core holder can also be designed as a fastening, so that the converter core is not only held but is firmly connected to the converter housing under normal operating conditions.

In the present context, the "pickup lines" preferably designate electrical lines to and from the pick-up coil, which can be electrically contacted via "pickup contacts", also called secondary contacts, which in turn are arranged in the converter housing. An electrical contact to the pickup coil or to the pickup coils can thus be established by the pickup contacts, which can be equipped and contacted from outside the converter housing.

By using lever-pull terminals as collector contacts, which are characterized in that they can be actuated with a lever, i.e. in particular to be opened and clamped against a train, a fast and reliable connection can then be guaranteed with a suitable design, which accordingly enables cost-effective assembly. Due to their clamping against tension, lever-pull contacts are specially designed lever-type terminals, which also include terminals in which a contact can only be opened or closed by the clamping effect.

In the present context, a “spring-loaded terminal” describes in particular an electrical clamping connection that is closed by a spring balancer, which must be opened with a tool to equip the terminal. In contrast, a "lever clamp" in particular closed by lever and/or spring force, the lever having to be opened for loading in order to insert a conductor into this type of connection terminal, as this then releases the lever force or lifts the spring. In the case of "push-in terminals", manual opening is preferably not necessary for assembly; here, a conductor can be inserted into the terminal against a spring force for contact and is then easily held there. To remove the conductor, a mechanical intervention must also take place here, which can be done, for example, by inserting a tool at a point provided for this purpose; In particular embodiments, a lever is provided for removing push-in clamps, through which the conductor can then be relieved of the spring force of the push-in clamp instead of using a separate tool, and the conductor can be removed. A mechanical intervention also takes place with spring-type terminals and lever-type terminals when a conductor is to be removed.

Two further collector contacts are preferably provided, which are arranged in the converter housing and are accessible from outside the converter housing and which are each connected to one of the two collector lines, with the two further collector contacts preferably being in the form of push-in terminals or likewise each in the form of lever-pull terminals . Push-in clamps in particular can be closed very quickly and easily, which accordingly also enables cost-effective assembly. Depending on the specific implementation, if, for example, protection against no-load voltages via the push-in terminals is to be provided, it is quick and easy to bring the low-voltage current transformer into a delivery configuration in which an no-load voltage bridge is inserted into the other consumer contacts, for example via the push-in terminals possible. Once the lower voltage current transformer has been installed, i.e. the first two collector contacts have been contacted with a measuring device or similar, the no-load bridge can be quickly removed when using lever-type terminals. In the case of push-in terminals, this can be more complex if a tool is required to open them. If the push-in terminals are designed as lever terminals, ie can be opened via a lever, the idle bridge can of course be easily removed by opening the lever. In particular, push-in clamps can also be configured as lever-pull clamps if they are pushed in to provide tensile stress for securing a cable, stranded wire or wire and the clamp can be opened and possibly closed by actuating a lever. Otherwise, the no-load jumper can also simply be severed if necessary.

Advantageously, at least one test opening is provided in the converter housing, through which a test contact is accessible without jamming, which is electrically conductively connected to a first of the two pickup lines. The test contact makes it possible to test the functionality and the operating parameters of the delivered widths or delivered low-voltage current transformers quickly and easily, in particular without having to laboriously close and open a terminal in order to be able to carry out the test. In particular, the actual consumer contact, for example in the form of a lever clamp, is then immediately freely accessible, e.g. for assembly purposes.

It is advantageous if a second test contact, which is electrically conductively connected to a second of the two pickup lines, is accessible through the test opening without pinching. As a result, the pick-up coil can then be tested in a correspondingly advantageous manner. The advantage of the one opening for both test contacts is the simple structure of the housing, with additional measures to avoid short circuits during the test may have to be provided.

It is advantageous if two test openings are provided in the converter housing, through which a test contact is accessible in a non-jamming manner, with a first of these two test contacts being electrically conductively connected to a first of the two pickup lines and a second of these two test contacts to a second of the two pickup lines is.

The test contact makes it possible to quickly and easily test the functionality and the operating parameters of the low-voltage current transformers that are ready for delivery or have been delivered, in particular without having to laboriously close and open a terminal in order to be able to carry out the test.

In particular, the actual consumer contact, for example in the form of a lever clamp, is then immediately freely accessible, e.g. for assembly purposes. The advantage of the two test openings or the separate test openings is their spatial separation, so that with a suitable design, any short circuits during testing can be avoided in a simple and reliable manner.

Alternatively, at least one test contact that is accessible without clamping can preferably be formed in one of the lever-pull terminals, which is electrically conductively connected to the pickup line, to which the corresponding lever-pull terminal is also electrically conductively connected. As a result, no separate test contact needs to be installed and be installed, as this is already integrated in the lever hoist clamp, which can usually be purchased as a part.

It goes without saying that a corresponding test contact can be provided in each lever-type terminal, but at least in one of the lever-type terminals that are electrically conductively connected to a common pickup line. The latter already enables an immediate check, while the former appears to be more complex, but then no different lever hoist clamps have to be installed.

Advantageously, the two collector contacts each have an assembly direction, in the opposite direction to which an electrical conductor can be fed into the respective collector contact or in which an electrical conductor can be led out of the respective collector contact, and the two collector contacts each have an identical assembly direction component in the converter housing with regard to their assembly directions arranged. In this way, the two collector contacts can be fitted from the same side, which can be defined as the component side, which means a corresponding simplification during assembly.

In order to be able to equip the two further collector contacts from the same side, which can be defined as a further assembly side, it is advantageous if the two further collector contacts each have an assembly direction against which an electrical conductor is introduced into the respective collector contact or in which a electrical conductors can be led out of the respective collector contact, and the two further collector contacts are each arranged with an identical assembly direction component in the converter housing with regard to their assembly directions.

It is advantageous if all collector contacts are arranged with an identical component in the converter housing in terms of their assembly directions, so that all collector contacts are assembled from the same side, which can be defined as the assembly side. A removal of an idle bridge is then easily possible if necessary.

Alternatively, a collector contact electrically conductively connected to a first of the two collector lines and a collector contact electrically conductively connected to a second of the two collector lines can each be arranged with an assembly direction component in the converter housing with regard to their assembly directions, which component is arranged perpendicularly or in the opposite direction to an assembly direction component , with which two further collector contacts are aligned, which are each electrically conductively connected to one of the two collector lines. In this way, loading from different sides is made possible, since the loading direction points in a different direction, so that multiple loading directions can also be defined if necessary. Opposite directions appear to be particularly advantageous when the respective assembly direction components are perpendicular to the transducer plane. With a suitable configuration, this enables universal installation or one that is more universal than configurations without this option.

Advantageously, the pinch-free access to the respective test contact occurs along a test direction, which is preferably arranged perpendicularly to the associated test opening, and the test direction of the two test contacts each have a common test direction component. As a result, the test can be carried out by guiding corresponding test probes in parallel, which then only need to be guided along the test direction component. Any deviations in direction can be compensated for by the opening or a guide inside the housing. If the distance is specified, a prefabricated test fork can even be used. In particular, a machine test or a test using a test robot is also conceivable in this way.

The two test directions are preferably identical, so that the test sequence can be designed to be more reliable and simple.

The perpendicular arrangement of the test direction to the associated test opening also makes it easier to insert and remove any test probes.

It is advantageous if a test direction component is identical to an assembly direction component, so that an assembly side can also be defined or used as a test side, ie as a housing side from which testing can take place.

In order to achieve the same advantages, the test direction component can in particular be identical to the placement direction component.

It is advantageous if a test direction component is perpendicular to an assembly direction component. In particular in the case of lever-pull terminals, but also in the case of push-in terminals designed and arranged in a specific way, the lever can then be closed in this way from a direction perpendicular to the assembly direction operate. A check can then also be carried out from the direction from which the lever is actuated.

In order to achieve the same advantages, the test direction component can also be perpendicular to the mounting direction component.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or can be installed as cost-effectively as possible, a low-voltage current transformer with at least one transformer core carrying a pick-up coil and spanning a transformer core plane and a transformer housing enclosing the transformer core, both of which have a low-voltage busbar opening penetrating the transformer core plane, can be characterized that the pickup coil is electrically conductively connected via at least two pickup lines to at least four pickup contacts, two of which are connected to one of the two pickup lines and which are arranged in the converter housing and can be fitted from outside the converter housing, and that the four pickup contacts are each used as pushin Terminal or are designed as a lever-pull terminal.

As already arranged above, the use of push-in terminals or lever-pull terminals is advantageous in such an embodiment, so that it is correspondingly advantageous to provide four collector contacts, all of which are designed accordingly. It is particularly advantageous here if at least two of the collector contacts are designed as identical terminals or are provided with the same terminals, so that these collector contacts can then each be operated in the same way. Particularly preferably, these two identical terminals are each provided on one of the two collector lines, so that the identical usability and the identical appearance, especially if the other two collector contacts are designed with different terminals, an identical use, for example the connection with one input to one Measuring device, suggest to the installer. On the other hand, all four customer contacts can also be provided with the same terminals, which can result in cost advantages, particularly when purchasing corresponding terminals as vendor parts.

Preferably, at least one test opening is provided in the converter housing, through which a test contact is accessible without pinching, which is electrically conductively connected to a first of the two pickup lines.

A test contact enables the functionality and the operating parameters of the delivery-ready or delivered low-voltage current transformers to be tested quickly and easily, in particular without having to laboriously close and open a terminal in order to be able to carry out the test.

In particular, the actual collector contact, for example in the form of a lever clamp, can then be arranged so that it is freely accessible, e.g. for assembly purposes.

A second test contact, which is electrically conductively connected to a second of the two pickup lines, is advantageously accessible through the test opening without pinching. As a result, the pick-up coil can then be tested in a correspondingly advantageous manner.

One advantage of the one opening for both test contacts is the simple structure of the housing, with additional measures to avoid short circuits during the test having to or should be provided if necessary.

It is advantageous if two test openings are provided in the converter housing, through which a test contact is accessible in a non-jamming manner, a first of these two test contacts being electrically conductive with a first of the two pickup lines and a second of these two test contacts with a second of the two pickup lines being electrically conductive are connected.

The advantage of the two test openings, or the separate test openings, is their spatial separation, so that with a suitable design, any short circuits during testing can be avoided in a simple and reliable manner.

On the other hand, it can be advantageous if at least one test contact that is accessible without jamming is formed in one of the lever-pull terminals and is electrically connected to the pickup line, to which the corresponding lever-pull terminal is also electrically connected. In this way, no separate test contact needs to be built in and installed, as this is then already integrated in the lever hoist terminal, which can usually be purchased as a part. It goes without saying that a corresponding test contact can be provided in each lever-type terminal, but at least in one of the lever-type terminals that are electrically conductively connected to a common pickup line. The latter already enables an immediate examination, while the former appears to be more complex; but then no different lever hoist clamps have to be installed.

Cumulatively or as an alternative to this, at least one test contact that is accessible without jamming can be formed in one of the push-in terminals, which is electrically conductively connected to a customer line to which the push-in terminal is also electrically conductively connected, so that no separate test contact needs to be built in and installed , since this is then already integrated in the push-in terminal, which can usually be obtained as a purchased part. It is also understood that a corresponding test contact can be provided in each push-in terminal, but at least in one of the push-in terminals that are electrically conductively connected to a common pickup line. The latter already enables an immediate examination, while the former appears to be more complex; however, no different Pushln terminals then have to be installed.

In order to be able to equip all collector contacts from the same side, which can then be defined as the assembly side, all four collector contacts can preferably each have an assembly direction in the opposite direction to which an electrical conductor is fed into the respective collector contact or in which an electrical conductor is led out of the respective collector contact can be, and the four pickup contacts are arranged with respect to their mounting directions, each with an identical mounting direction component in the converter housing.

Advantageously, a collector contact electrically conductively connected to a first of the two collector lines and a collector contact electrically conductively connected to a second of the two collector lines are each arranged with an assembly direction component in the converter housing with regard to their assembly directions, which is arranged perpendicularly or in the opposite direction to an assembly direction component, with which in each case two further customer contacts are aligned, which are each electrically conductively connected to one of the two customer lines. This enables loading from different sides, since the loading direction points in a different direction, so that multiple loading sides can be defined if necessary. Opposite directions appear to be particularly advantageous when the respective assembly direction components are perpendicular to the transducer plane.

It is advantageous if the pinch-free access to the respective test contact takes place along a test direction and the test direction of the two test contacts each have a common test direction component. As a result, the test can be carried out by guiding corresponding test probes in parallel, which then only need to be guided along the test direction component. Any directional deviations can be compensated for by the opening or a housing-internal guide. A prefabricated test fork can even be used for a given distance. In particular, a machine test or a test using a test robot is also conceivable in this way.

In a particularly advantageous embodiment, the test direction is arranged perpendicularly to the associated test opening in order to achieve the advantages mentioned above.

It is also advantageous if the two test directions are identical, since the test sequence can be designed to be operationally reliable and simple.

A test direction component is preferably identical to an assembly direction, so that an assembly side can also be defined or used as a test side, ie as a housing side from which testing can take place. In order to achieve the same advantages, the test direction component can in particular be identical to the placement direction component.

A test direction component is advantageously arranged perpendicular to an assembly direction component. Particularly in the case of lever-pull terminals, but also in the case of push-in terminals arranged in a certain way, the lever can be actuated from a direction perpendicular to the direction of assembly. A test can then be carried out from the direction from which the lever is actuated. For the same advantageous reasons, the test direction component can also be perpendicular to the mounting direction component.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or can be installed as cost-effectively as possible, a low-voltage current transformer can have a transformer core that carries at least one pick-up coil and spans a transformer core plane and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane. characterized in that the pickup coil is electrically conductively connected via at least two pickup lines to at least two pickup contacts, which are arranged in the converter housing, can be loaded from outside the converter housing and are each designed as a lever-type terminal, as a push-in terminal and/or as a spring-loaded terminal and that in the converter housing at least one test opening is provided through which is accessible without jamming by a test contact which is electrically conductively connected to a first of the two pickup lines. With a suitable configuration, both a final test before delivery of the low-voltage current transformer and a simple installation of the low-voltage current transformer that is then delivered and possibly even a follow-up test via the test contact can be carried out in this way in a simple and reliable manner. By arranging the test openings in the converter housing, they can be arranged and aligned in the desired position during the construction of the converter housing.

In the present case, a “spring-loaded terminal” is any electrically conductive terminal that can be used as an electrical contact, i.e. as a consumer contact, and which enables tension protection via spring force. It goes without saying that--depending on the specific design--here too there may be overlaps with lever pull contacts or push-in contacts.

A second test contact, which is electrically conductively connected to a second of the two pickup lines, is advantageously accessible through the test opening without pinching. As a result, the pick-up coil as a whole can then be tested in a correspondingly advantageous manner. The advantage of the one opening for both test contacts is the simple structure of the housing, with additional measures to avoid short circuits during the test may have to be provided.

It is advantageous if two test openings are provided in the converter housing, through which a test contact is accessible in a non-jamming manner, with a first of these two test contacts being electrically conductively connected to a first of the two pickup lines and a second of these two test contacts to a second of the pickup lines are.

The test contact enables the functionality and the operating parameters of the delivery-ready or delivered low-voltage current transformers to be tested quickly and easily, in particular without having to laboriously close and open a terminal in order to be able to carry out the test. In particular, the actual consumer contact, for example in the form of a lever clamp or another clamp, e.g. for assembly purposes, is then immediately accessible. The advantage of the two test openings or the separate test openings is their spatial separation, so that with a suitable design, any short circuits during testing can be avoided in a simple and reliable manner.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or can be installed as cost-effectively as possible, a low-voltage current transformer can have a transformer core that carries at least one pick-up coil and spans a transformer core plane and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane. characterized in that the pickup coil is electrically conductively connected via at least two pickup lines to at least two pickup contacts, which are arranged in the converter housing, can be loaded from outside the converter housing and are each designed as a lever-type terminal, as a push-in terminal and/or as a spring-loaded terminal and that a test contact that is accessible without clamping is formed in one of the lever pull, pushln or spring pull terminals, which is electrically connected to the collector line, with which the corresponding lever pull, pushln - or spring-loaded terminal is electrically conductively connected. With a suitable configuration, both a final test before delivery of the low-voltage current transformer and a simple installation of the low-voltage current transformer that is then delivered and possibly even a follow-up test via the test contact can be carried out in this way in a simple and reliable manner. The configuration of the test contacts in the respective clamps enables a particularly simple assembly of the respective low-voltage current transformers, since the test contacts can be provided by the clamps, which are generally used as purchased parts.

It is advantageous if a corresponding, non-clamping accessible test contact is provided in each of the lever-pull terminals that are electrically conductively connected to a common pickup line. This already enables an immediate test, while the test contacts appear to be more complex for all terminals, but then no different terminals have to be installed.

In order to achieve the same advantages, a corresponding, non-clamping accessible test contact can be provided in each of the lever-hoist terminals, which saves installing different lever-hoist terminals.

Cumulatively or alternatively to this, a corresponding test contact that is accessible without pinching can be provided in each of the push-in terminals that are electrically conductively connected to a common pickup line. This also enables an immediate test, while the test contacts on all terminals are seem more complex, but then no different terminals have to be installed.

In order to enable an immediate test, while the test contacts appear to be more complex for all terminals, but then no different terminals have to be installed, cumulatively or alternatively in one of the spring-loaded terminals, which are electrically connected to a common pickup line, a corresponding, non-jamming accessible test contact can also be provided. In order to achieve the advantages mentioned above, a corresponding test contact that is accessible without clamping can also be provided in each of the spring-loaded terminals, which appears to be more complex in terms of construction for the terminals, but no different terminals have to be installed here either.

Preferably, the two collector contacts each have an assembly direction in the opposite direction to which an electrical conductor can be fed into the respective collector contact or in which an electrical conductor can be led out of the respective collector contact, with the two collector contacts each being arranged with an identical assembly component in the converter housing with regard to their assembly directions are. In this way, the two collector contacts can be fitted from the same side, which can be defined as the component side.

The jam-free access to the respective test contact preferably takes place along a test direction and the test direction of the two test contacts each has a common test direction component. The test can then be carried out by guiding corresponding test probes in parallel, which then only need to be guided along the test direction component. Any deviations in direction can be compensated for by the opening or a guide inside the housing. A prefabricated test fork can even be used for a given distance. In particular, a machine test or a test using a test robot is also conceivable in this way. It is particularly advantageous if the test direction is arranged perpendicularly to the associated test opening in order to achieve the advantages mentioned above.

In a further advantageous embodiment, the two test directions can be identical, so that the test sequence can be designed to be reliable and simple.

It is advantageous if a test direction component is identical to an assembly direction component, so that an assembly side can also be defined or used as a test side, ie as a housing side from which testing can take place. In order to achieve the same advantages, the test direction component can preferably be identical to the mounting direction component.

As an alternative to this, a test direction component can be aligned perpendicular to an assembly direction component. In the case of lever-type terminals in particular, but also in the case of push-in or spring-loaded terminals arranged in a specific way, actuation, for example also for removing a line, can be carried out from a direction perpendicular to the direction of assembly. A check can then be carried out from the direction from which the actuation is also carried out. In particular, in order to achieve the same advantages, the test direction component can also be perpendicular to the mounting direction component.

It is advantageous if, in a transport configuration, between test contacts, protection against no-load voltage is arranged on open secondary contacts, which in each case extends through the test openings and connects the test contacts in an electrically conductive manner. In this way, protection against these no-load voltages, which can be quite dangerous, for example during storage or transport, can be implemented inexpensively. For example, voltages U of 50 V or 25 mA or more can already be dangerous; especially when it comes to alternating current. On the other hand, in the mounted state, for example, a load resistor, for example a measuring device, is then sufficient to dissipate the current.

In order to be able to achieve the advantages mentioned above in a particularly advantageous and structurally simple manner, the protection against no-load voltages can be designed in the form of an no-load bridge. This can then be removed after an electrical connection of the secondary contacts or the collector contacts, since sufficient protection is then usually ensured by the respective connection. Otherwise, the idle jumper can remain in place until adequate protection is provided. Remaining the no-load bridge makes no sense during the intended use of the low-voltage current transformer because this bridge ultimately short-circuits the consumer contacts or the secondary contacts.

In a particularly advantageous embodiment, the neutral bridge can be designed to be inherently rigid in order to achieve the advantages mentioned above, which in particular makes it easier to handle.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or assembled as cost-effectively as possible, a low-voltage current transformer can be provided with a transformer core that carries at least one pick-up coil and spans a transformer core plane, and with a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane characterized in that the pickup coil is electrically conductively connected via at least two pickup lines to at least two pickup contacts, which are arranged in the converter housing and can be equipped and contacted from outside the converter housing, and in that the two pickup lines each have one from outside the converter housing and are clamp-free accessible test contact is electrically conductively connected, wherein between the two test contacts in a transport configuration, the test contacts electrically conductively connecting open circuit fbrücke is arranged as protection against open circuit voltages on open secondary contacts. In this way, protection against no-load voltages, which can be quite dangerous, for example during storage or transport, can be implemented inexpensively. For example, voltages U of 50 V or 25 mA or more can already be dangerous; especially when it comes to alternating current. On the other hand, in the mounted state, for example, a load resistor, for example a measuring device, is then sufficient to dissipate the current.

Cumulatively or alternatively to this, a low-voltage current transformer with a transformer core that carries at least one pickup coil and spans a transformer core level and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane, can also be characterized in that the pickup coil is electrically conductive via at least two pickup lines at least two collector contacts are connected, which are arranged in the converter housing and can be equipped and contacted from outside the converter housing, and that on the converter housing there is a holder for an open-circuit bridge that electrically conductively connects the test contacts, the collector contacts or the collector lines as protection against open-circuit voltages on open secondary contacts is arranged to achieve the same advantages and to provide a low-voltage power converter that builds as inexpensively as possible or as inexpensively as possible can be mounted stig.

The bracket is intended to prevent the idle bridge from being accidentally lost due to vibration or displacement or the like, which is particularly advantageous for access without jamming, since the separate bracket can ensure a sufficiently secure fit.

In the present context, an “open circuit bridge” can be understood, for example, as preferably small plug-in bridges that are connected to the test contacts or also to the collector contacts as a form of short-circuit plugs. In particular, such idle bridges can be provided by short wires or strands. As a result, the secondary contacts or the collector contacts and also the corresponding test contacts are electrically connected to one another, ie bridged.

It is advantageous if the idler bridge is designed to be inherently rigid, as a result of which simple and operationally reliable handling of the respective idler bridge is possible.

In particular, the holder can be designed as a clamp holder. With a suitable configuration, the no-load bridge can then be held in a clamped manner by the holder and can therefore be inserted and removed quickly and easily.

In addition, the holder can be easily and cost-effectively molded directly onto the converter housing as a clamping mold, ie as a mold that clamps a suitable no-load bridge, as a result of which a corresponding mount can be provided in a correspondingly simple and reliable manner.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or can be installed as cost-effectively as possible, a low-voltage current transformer can be characterized by a transformer core that carries at least one pickup coil and spans a transformer core plane and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane that the pickup coil is electrically conductively connected via at least two pickup lines to at least two pickup contacts, which are arranged in the converter housing and can be fitted from outside the converter housing, with protection against no-load voltages on open secondary contacts being hard-wired between the two pickup lines being provided within the converter housing. In this way, protection against open no-load voltages, which can be quite dangerous, for example during storage or transport, can be implemented cost-effectively. For example, as already emphasized above, voltages U of 50 V or 25 mA or more can already be dangerous; before especially when it comes to alternating current. On the other hand, in the mounted state, for example, a load resistor, for example a measuring device, is then sufficient to dissipate the current.

The protection against no-load voltages above 60 V preferably intervenes. This still enables good and accurate measurements.

Good and accurate measurements are still possible when the protection against open secondary hardness at 55 V intervenes. It is conceivable that even if the protection against open secondary hardness intervenes above 50 V, good and accurate measurements are still possible.

The protection against no-load voltages is advantageously in the form of electronic overvoltage protection. Such a system is structurally easy to implement and reliable.

In the present context, “overvoltage protection” can preferably be understood to mean the protection of electrical and electronic devices from excessively high electrical voltages. Overvoltages can be caused by lightning, by capacitive or inductive coupling of other electrical systems, especially when the secondary contacts are open. Electrostatic discharges, which can arise even with simple handling, can also be caused by voltages. Any circuit of electronic components that avoids an overvoltage to a sufficiently operationally reliable extent can therefore be used as electronic overvoltage protection. Negative influences during regular operation can be effectively minimized by suitable additional measures known per se, such as high resistances or a suitable choice of characteristic curves.

For a structurally particularly simple implementation and operational safety, the electronic overvoltage protection can be formed by two oppositely connected Zener diodes between the pickup lines.

In the present context, the zener diode describes a diode that is designed to be operated permanently in the reverse direction in the range or above the breakdown voltage. In the forward direction they behave like normal diodes. In reverse bias, zener diodes are blocking at low voltages, just like normal diodes. By switching two Zener diodes against each other, the influences in the forward direction can be minimized or avoided. From a certain blocking voltage, the so-called breakdown voltage, the current increases by many orders of magnitude within a few hundred millivolts. As a rule, this process does not depend on the previous history, which means that this current also decreases again when the voltage is reduced. Zener diodes are therefore suitable for voltage stabilization and voltage limitation. Due to the low junction thickness, zener diodes have a large junction capacitance, they have a lot in common with varactor diodes. If such zener diodes are switched in the opposite direction, it can be ensured in this way that, once the respective breakdown voltage has been reached, a further increase in voltage can be ruled out or almost ruled out.

In order to provide a low-voltage current transformer that can be built as cost-effectively as possible or assembled as cost-effectively as possible, a low-voltage current transformer can have a transformer core that carries at least one pick-up coil and spans a transformer core plane, and a transformer housing that encloses the transformer core, both of which have a low-voltage busbar opening that penetrates the transformer core plane characterized in that the converter housing has at least two housing parts which are closed to one another by means of a housing closure and which each abut with an abutting edge, with a first of the two housing parts on a side of the abutting edge facing away from the exterior of the converter housing or on a side of the abutting edge facing towards the exterior of the converter housing a barrier-forming wall is provided, which absorbs closure forces of the housing closure. The wall thus offers a dual function.

In the present context, the “housing locks” can be understood to mean catches, conical plug-in connections that hold by friction and at the same time also absorb lateral locking forces, and the like. The housing parts that are to be connected to one another by means of the housing closure serve to provide the low-voltage current transformer and not to open the converter housing and the converter core as intended, as has already been explained above by the distinction between converter housing parts. Accordingly, it is advantageous if the housing closure or the housing closures are non-detachable or non-destructively detachable, with detachability directly after assembly possibly still being tolerated in order to be able to correct errors before delivery. Opening the housing locks after delivery of the respective low-voltage current transformer is not intended.

The abutting of the abutting edges is particularly advantageous since this leaves relatively little installation space and otherwise the housing has a predetermined breaking point due to age, stress, penetrating dirt, warping, etc.

A wall that forms a barrier can then at the same time form a creepage distance extension or a puncture protection device. This can then be used to extend the creepage distance to reduce the risk that any voltages or currents from the outside along the surface of the housing parts into the interior of the converter housing or from the inside of the converter housing to the outside can be provided, which can definitely be caused by dirt etc. also in the Age can then be favoured. Likewise, the risk of puncture, which can be aggravated by age-related distortion or the ingress of dirt, etc., can be effectively avoided.

It is advantageous if the wall forming a barrier absorbs closing forces acting perpendicularly to the extent of this wall and/or in a plane spanned by the abutting edges. In particular, these can be transverse or shearing forces which threaten to shift the housing parts in a plane spanned by the abutting edge, which is parallel to the plane of the transducer core, for example, or displace the two abutting edges of this plane against one another. In this way, a safety side for the connection of the two housing parts can be implemented in a structurally simple manner.

The wall forming a barrier can preferably absorb closing forces acting parallel to the extent of this wall and perpendicular to the extent of this wall in the second of the two housing parts. These are forces which separate the two housing parts from one another at right angles to sliding or shearing movements, for example by lifting one housing part, such as a cover, off the other housing part. Cumulatively or alternatively, in order to achieve the same advantages, the protruding wall serving as a puncture protection can absorb locking forces acting parallel to the extension of this wall and perpendicular to the extension of this wall perpendicular to a plane spanned by the abutting edges.

For a good closure effect, the housing closure can comprise an effective latching connection between the protruding wall serving as a barrier and the second of the two housing parts. With a suitable design, this is easy to close and can, also with a suitable design, be designed in such a way that it cannot be opened again non-destructively or can only be opened non-destructively with great effort, so that the housing parts can ultimately be closed by the snap-in connection in practice and in practice normal use are inextricably linked.

Cumulatively or alternatively to this, the housing closure can comprise an effective friction connection between the protruding wall serving as a barrier and the second of the two housing parts. Such a friction connection offers good protection against lateral or transverse or shearing forces and, in particular, also as a positioning aid when assembling the housing connection. In addition, this can be designed to be tight all around, so that dirt and dirt can only get into the housing with difficulty.

The frictional connection is advantageously a frictional connection. The frictional connection offers a particularly good protection against lateral or transverse or shearing forces and is also suitable as a positioning aid. In addition, this can be made very tight all around, so that it is very difficult for dirt to get into the housing.

It is advantageous if the wall forming a barrier takes over at least 90% of the closure forces of the housing closure that are required for reliable operation. The wall forming a barrier particularly preferably assumes all of the locking forces of the housing lock that are required for reliable operation. Here, in particular, a separation between the locking forces that point in different directions can take place, so that, for example, all lateral movements can be intercepted via the wall, while a separate locking mechanism is used against vertically acting forces. In particular, forces which are superfluous or which only serve as a reserve can also be absorbed by the wall. Overall, the more forces are absorbed by the corresponding wall, the fewer supplementary assemblies, such as internal guides, or additional latching tongues, which cost installation space and money, have to be provided. The pull-off forces for separating the two halves of the housing are preferably more than 100 N. In particular, they can also be selected to be less than 1000 N, so that corrections can still be made to the interior of the housing if necessary.

Alternatively, the locking lugs take over 100% of the holding force.

A low-voltage current transformer can also be spanned by at least one pick-up coil and a transformer core plane the transformer core and a transformer housing enclosing the transformer core, both of which have a low-voltage busbar opening penetrating the plane of the transformer core, characterized in that a busbar attachment for attaching the low-voltage current transformer to a low-voltage busbar is provided on the transformer housing, which has a housing-side attachment body and one that can be clamped between the attachment body and the low-voltage busbar Clamping body comprises, wherein the busbar fastening comprises a rapid positioning device for rapid positioning of the clamping body in relation to the fastening body and the low-voltage busbar and a clamping device and a clamping device for applying the intended clamping forces between the fastening body and the low-voltage busbar and the rapid positioning device and the clamping device by movements deviating from one another accordingly quickly act positioning or exciting to provide a low-voltage current transformer that builds as cheaply as possible or can be assembled as cheaply as possible. The design of the busbar attachment with rapid positioning and clamping devices that are separate from one another can significantly speed up the entire assembly process if the design is suitable. On the one hand, the quick positioning device can be used to quickly position the clamping body, which can then apply the clamping forces together with the clamping device. In particular, for example, a long turning operation for tightening screws can be minimized.

The movements that differ from one another include, in particular, different directions or types of movement and the movement of different assemblies.

The rapid positioning device and the clamping device preferably comprise assemblies that differ from one another. In this way, the rapid positioning device and the clamping device can be provided or replaced independently of one another, if necessary.

It can also be advantageous if the quick-positioning device and the clamping device are realized by identical subassemblies, if one subassembly then has a dual function and can provide both the quick-positioning device and the clamping device or parts thereof.

Advantageously, the rapid positioning device comprises a one-way sliding clamp. The one-way sliding clamp can be designed to be detachable or non-destructively detachable, with the former possibly being somewhat more expensive, while the latter leads to additional costs when opening because of the destruction, since correspondingly destroyed components then have to be replaced. Overall, however, the one-way sliding clamp offers the advantage that it is structurally simple to implement and can be operated quickly and reliably, such as in the form of a cable tie.

It is advantageous if the one-way sliding clamping is implemented by a spring element, since such a spring element is simple, inexpensive, and operationally reliable and, at the same time, durable.

It is particularly advantageous if such a spring element is realized, for example, by a resilient thread. Such a resilient thread could be a Starlock connection, for example. For quick positioning, the spring forces of the spring-loaded thread are then overcome with a sliding movement, while the tensioning then takes place via the screwing movement. A spring-loaded thread is particularly simple, inexpensive and durable.

The clamping body is preferably designed as a pressure stamp. Such is easy to implement. It is also conceivable that the clamping body is designed as a tension element, such as, among other things, in the form of a suitably attached cable tie.

Advantageously, the pressure stamp is designed as a threaded pin, since this entails a simple structural implementation and is also inexpensive.

It goes without saying that the features of the solutions described above or in the claims can also be combined if necessary in order to be able to cumulatively implement the advantages accordingly.

• 1 ein erstes Gehäuseteil eines Wandlergehäuses eines erstes Niederspannungsstromwandlers in perspektivischer Außenansicht ;
• 2 das erste Gehäuseteil nach 1 in perspektivischer Innenansicht;
• 3 ein zweites Gehäuseteil des Wandlergehäuses des ersten Niederspannungsstromwandlers nach 1 und 2 in perspektivischer Außenansicht;
• 4 das zweite Gehäuseteil nach 3 in perspektivischer Innenansicht;
• 5 eine erste Seite eines zweiten Niederspannungsstromwandlers in perspektivischer Außenansicht;
• 6 eine zweite Seite des zweiten Niederspannungsstromwandlers nach 5 in perspektivischer Außenansicht;
• 7 ein erstes Gehäuseteil des Wandlergehäuses des zweiten Niederspannungsstromwandlers nach 5 und 6 in perspektivischer Innenansicht;
• 8 ein zweites Gehäuseteil des Wandlergehäuses des zweiten Niederspannungsstromwandlers nach 5 bis 7 in perspektivischer Innenansicht;
• 9 eine schematische perspektivischer Explosionsansicht des zweiten Niederspannungsstromwandlers nach 5 bis 8;
• 10 eine Pushln-Klemme des zweiten Niederspannungsstromwandlers nach 5 bis 9 in einer Detailvergrößerung der 9;
• 11 eine erste Seite eines dritten Niederspannungsstromwandlers in perspektivischer Außenansicht;
• 12 ein erstes Gehäuseteil des Wandlergehäuses des dritten Niederspannungsstromwandlers nach 11 in perspektivischer Innenansicht und schematischer Darstellung einer Wandlerebene sowie aktiver Komponenten;
• 13 einen schematischen Schnitt entlang der Linie XIII-XIII in 11 durch eine Pushln-Klemme des dritten Niederspannungsstromwandlers nach 11 und 12;
• 14 die Anordnung nach 13 bei in die Prüföffnungen eingesetzter Leerlaufbrücke als Schutz gegen offene Sekundärkontakte;
• 15 eine Abwandlung der in 13 und 14 dargestellten Anordnung in identischer Ansicht mit einer Klemmungsanformung als Halterung für die Leerlaufbrücke;
• 16 die Anordnung nach 15 in einer Aufsicht in Prüfrichtung;
• 17 eine schematische Aufsicht auf als Hebelzugklemmen ausgebildete Abnehmerkontakte;
• 18 ein elektrisches Symboldiagramm für einen elektronischen Überspannungsschutz innerhalb des Wandlergehäuses;
• 19 eine Aufsicht auf eine geteilte Mutter für eine Stromschienenbefestigung;
• 20 eine erste alternative Stromschienenbefestigung mit der Mutter nach 19 in schematischer Seitenansicht;
• 21 die Anordnung nach 20 bei in eine Halteöffnung des gehäuseseitigen Befestigungskörpers eingesetztem Gewindestift bzw. Andruckstempel mit Mutter;
• 22 die Anordnung nach 20 und 21 bei angezogenem Gewindestift;
• 23 eine zweite alternative Stromschienenbefestigung mit der Mutter nach 19 in ähnlicher Darstellung wie 20 bis 23 (wobei ein Teil der geteilten Mutter bereits in der Halteöffnung vorpositioniert ist);
• 24 die Anordnung bei eingesetztem Gewindestift bzw. Andruckstempel und angezogener Mutter;
• 25 eine der Anordnung nach 5 bis 10 ähnliche, dritte alternative Stromschienenbefestigung in ähnlicher Darstellungsart wie 20 bis 24, wobei jedoch eine verlängerte Führung für den Gewindestift bzw. Andruckstempel vorgesehen ist;
• 26 eine vierte alternative Stromschienenbefestigung in ähnlicher Darstellungsart wie 20 bis 25 in einem Auslieferungszustand, bei welche der Andruckstempel aus Kunststoff gebildet ist und die Spanneinrichtung einen Führungskörper und eine Hebelanordnung umfasst, durch welche der Führungskörper axial in Richtung der Niederspannungsstromschiene verlagerbar ist;
• 27 die Anordnung nach 26 in ähnlicher Darstellungsart wie 20 bis 26 bei in Richtung der Niederspannungsstromschiene durch Eindrücken schnellverlagertem Andruckstempel ;und
• 28 die Anordnung nach 26 und 27 in ähnlicher Darstellungsart wie 20 bis 27 bei umgelegtem Spannhebel der Spanneinrichtung.

Further advantages, goals and properties of the present invention are explained using the following description of exemplary embodiments, which are also shown in particular in the attached drawing. Show in the drawing:

• 1 a first housing part of a converter housing of a first low-voltage current converter in a perspective external view;
• 2 the first housing part 1 in perspective interior view;
• 3 a second housing part of the converter housing of the first low-voltage current converter 1 and 2 in perspective external view;
• 4 the second housing part 3 in perspective interior view;
• 5 a first side of a second low-voltage current transformer in a perspective external view;
• 6 a second side of the second low voltage power converter 5 in perspective external view;
• 7 a first housing part of the converter housing of the second low-voltage current converter 5 and 6 in perspective interior view;
• 8th a second housing part of the converter housing of the second low-voltage current converter 5 until 7 in perspective interior view;
• 9 a schematic exploded perspective view of the second low-voltage power converter 5 until 8th ;
• 10 a push-in terminal of the second low-voltage current transformer 5 until 9 in a detailed enlargement of the 9 ;
• 11 a first side of a third low-voltage current transformer in a perspective external view;
• 12 a first housing part of the converter housing of the third low-voltage current converter 11 in a perspective interior view and schematic representation of a converter level and active components;
• 13 a schematic section along the line XIII-XIII in 11 through a push-in terminal of the third low-voltage current transformer 11 and 12 ;
• 14 according to the arrangement 13 with no-load jumper inserted in the test openings as protection against open secondary contacts;
• 15 a modification of the 13 and 14 shown arrangement in an identical view with a Klemmanformung as a holder for the idle bridge;
• 16 according to the arrangement 15 in a top view in test direction;
• 17 a schematic plan view of the customer contacts designed as lever pull terminals;
• 18 an electrical symbol diagram for an electronic surge protector within the converter housing;
• 19 a top view of a split nut for a busbar attachment;
• 20 a first alternative busbar fastening with the nut 19 in schematic side view;
• 21 according to the arrangement 20 with a threaded pin or pressure stamp with nut inserted into a holding opening of the fastening body on the housing side;
• 22 according to the arrangement 20 and 21 with the threaded pin tightened;
• 23 a second alternative busbar attachment with the nut 19 in a similar representation as 20 until 23 (with part of the split nut already pre-positioned in the retaining hole);
• 24 the arrangement with the threaded pin or pressure stamp inserted and the nut tightened;
• 25 one according to the arrangement 5 until 10 Similar, third alternative busbar attachment in a similar representation as 20 until 24 , but with an extended guide for the threaded pin or pressure stamp is provided;
• 26 a fourth alternative busbar attachment in a similar representation as 20 until 25 in a delivery state in which the pressure stamp is made of plastic and the tensioning device comprises a guide body and a lever arrangement, by which the guide body can be displaced axially in the direction of the low-voltage busbar;
• 27 according to the arrangement 26 in a manner similar to 20 until 26 with the pressure stamp quickly shifted in the direction of the low-voltage busbar by pressing in; and
• 28 according to the arrangement 26 and 27 in a manner similar to 20 until 27 with the clamping lever of the clamping device turned over.

In a first embodiment, a first housing part 21 of a converter housing 20, as shown in FIGS 1 and 2 shown, a low-voltage current transformer 10 side walls 27 and a bottom wall 28.

The housing part 21 also has a low-voltage busbar opening 11 , the low-voltage busbar opening 11 also comprising a side wall 27 . The side walls 27 and the bottom walls 28 enclose a space, these internally enclosing the interior 23 of the converter housing, respectively while the space outside of these walls represents the exterior 24 of the transducer housing 20 .

Lateral supplementary guides 90 are also arranged on the housing part 21, which serve to insert the corresponding counterpart, another housing part 21, as simply and precisely as possible in order to close the housing part 21 or to place it on the housing part 21.

In addition, the housing part 21 includes a collector contact molding 22 on one side, which provides appropriate space for the arrangement of collector contacts.

The low-voltage power converter 10 of this exemplary embodiment also includes an in 3 and 4 illustrated second housing part 21 of the converter housing 20, which also comprises two bottom walls 28, side walls 27, an interior 23 of the converter housing, an exterior 24 of the converter housing, a corresponding low-voltage busbar opening 11 as well as a collector contact molding 22 and a central lateral supplementary guide 90.

The two housing parts 21 can be closed to the converter housing 20 by a frictional connection 75, the supplementary guides 90 also having a positioning effect here.

In the present exemplary embodiment, the second housing part 21 includes latching lugs 73 in a wall 26 that forms a barrier 70, which can form a latching connection 72 with latching openings 74 in the side walls 27 of the first housing part 21, with this wall 26 being connected to the side wall 27 of the first housing part 21 the 1 and 2 can also serve as a positioning aid.

With a suitable configuration, this wall 26 with the side wall 27 of the first housing part 21 according to the 1 and 2 also form the frictional connection 75, which enables a very tight fit in addition to the latching connection 72. In addition, this increases the tightness.

It goes without saying that in deviating embodiments only the latching connection 72, which can be formed for example by a latching lug 73 or latching lugs 73 and a latching opening 74 or latching openings 74, or only the frictional connection 75 can be provided.

Irrespective of this, the barrier 70 essentially serves to extend the creepage distance to reduce the risk of any voltages or currents from the outside reaching the surface of the housing parts 21 into the interior 23 of the converter housing or from the interior 23 of the converter housing 23 to the outside 24 in this way.

The barrier can also serve as a breakdown protection to reduce the risk of voltages or currents of the converter housing 20 breaking through in the area of the seam between the housing parts 21 .

In a second embodiment of a low-voltage current converter 10 according to 5 until 10 the low-voltage current transformer 10 includes a transformer housing 20 which is composed of two housing parts 21 . Here, too, a housing closure 71 holds the housing parts 21 together, with the housing closure 71 being designed as a snap-in connection 72 and as a friction-locking connection 75 . In this case, the housing parts 21 lie on top of one another on their abutting edge 25, the structure corresponding in principle to the structure of the converter housing 20 according to the first exemplary embodiment.

In addition, the low-voltage current transformer 10 includes a low-voltage busbar opening 11, at the edge of which a busbar attachment 80 is arranged.

In the present exemplary embodiment, push-in terminals 42 with an identical mounting direction 49 of the collector contact 40 are used as collector connections or collector contacts 40, which are also accessible as test contacts 50 in this direction as the test direction 59 of the test contact 50.

In addition to the customer contacts 40 and test contacts 50 described above are in the 5 , 6 and 9 corresponding electrical conductors 19 for the electrical connection are also arranged in the collector contact molding 22, for example.

As protection 60 against no-load voltages on open secondary contacts or pickup contacts 40, an idle bridge 61 can be used in two of the push-in terminals 42, insofar as they are each located at one end of the pickup coil.

The converter housing 20 of the low-voltage current converter 10 of the present exemplary embodiment comprises two housing parts 21, as shown in FIGS 7 and 8th are shown.

A first in 7 The housing part 21 shown has a plurality of locking openings 74 in a side wall 27 .

A second housing part, as in the 8th is shown, includes locking lugs 73 in a barrier 70 forming walls 26, which can enter into a locking connection 72 with the locking openings 74, this wall 26 with the side wall 27 of the other housing part 21 after 7 can serve as a positioning aid.

With a suitable configuration, this wall 26 can follow the side wall 27 of the other housing part 21 7 also form a frictional connection 75, which enables a very tight fit in addition to the locking connection 72. The tightness can also be increased in this way.

It goes without saying that in different embodiments only the latching connection 72, which is formed for example by a latching lug 73 or latching lugs 73 and a latching opening 74 or latching openings 74, or only the frictional connection 75 can be provided.

Irrespective of this, the barrier 70 essentially serves to extend the creepage distance to reduce the risk of any voltages or currents from the outside reaching the surface of the housing parts 21 into the interior 23 of the converter housing 20 or from the interior 23 of the converter housing 20 to the outside 24 on this path .

The barrier can also serve cumulatively or alternatively as a breakdown protection to reduce the risk of voltages or currents entering the converter housing 20 in the area of the seam between the housing parts 21 .

The bus bar attachment 80 of the present embodiment includes, such as in FIG 9 shown, in addition to a fastening body 81 on the housing side, a quick-positioning device 83 or a clamping device 84. In the present exemplary embodiment, the busbar fastening 80 uses Starlocks 87 as spring-loaded threads 86 and pressure stamps 88 forming threaded pins 89 as clamping bodies 82 in order to implement a one-way sliding clamp 85, which acts as a quick-positioning device 83 and can serve as a tensioning device 84 . By overcoming the spring forces of the starlocks 87, the threaded pins can be easily pushed up to a low-voltage busbar located in the low-voltage busbar opening 11. The tension can then be increased by screwing on the threaded pins 89. To open, the threaded pin 89 must be unscrewed.

The threaded pins 89 also carry insulation 94, which is part of the pressure stamp 88.

In the present exemplary embodiment, two test openings 51 are provided as access to the test contacts 50 above the customer contact projection 22 .

The converter housing 20 also encloses a converter core 30 which also has a low-voltage busbar opening 11, which is ultimately the case in the exemplary embodiment according to FIG 1 until 4 also implemented in this way.

In addition, an external field shield 39 is arranged between the converter core 30 and the side wall 27 .

The push-in terminal 42 used in the present exemplary embodiment is inserted into the collector contact molding 22 with an assembly direction 49 . The placement direction 49 is also the same as the testing direction 59.

In addition, a holder 92 specifically serves to hold the push-in clamp 42. In addition, the holder 92 is secured by fastening hooks 91 in the converter housing. Two actuation slots 93 are used to open the push-in terminal 42. The collector contact 40 also includes a soldering point 46, to which a collector line is or can be soldered.

In a third embodiment of a third low-voltage current converter 10 according to 11 until 14 the converter housing 20 is also formed from two housing parts 21 which abut one another at an abutting edge 25 .

The converter housing 20 also has mounting directions 49 for collector contacts 40 or push-in terminals 42, which are perpendicular to a converter core plane 31 or to a parting plane of the housing parts 21, and test directions 59, which are parallel to these planes. In addition, the present exemplary embodiment includes two test openings 51 for the test contacts 50.

In addition, a pickup coil 32 consisting of a plurality of partial coils is wound around a transducer core 30 which spans the transducer core plane 31 . In the present exemplary embodiment, one, ie a total of four, partial coils of pickup coil 32 are wound around converter core 30 on each side.

A total of four extraneous field shields 39 are arranged between the transformer core 30 or the pick-up coil 32 and a wall 26 forming a barrier 70 .

The pickup coil 32 is electrically conductive via two pickup lines 33 with two pickups merkontakten 40 connected, which are arranged in the converter housing 20.

The two collector contacts 40 of the present exemplary embodiment are also realized here via PushIn clamp 42 between a holder 92 for the PushIn clamp 42 and a collector contact molding 22 in which the test opening 51 of the test contact 50 is arranged. The arrangement essentially corresponds to the arrangement of the previous exemplary embodiment with a different assembly direction 49.

In addition, in the present embodiment, as in the 14 is shown, an open circuit bridge 61 may be arranged in the test opening 51 as protection against open secondary contacts.

In a modified embodiment of the previous embodiment according to the 10 until 14 a Klemmanformung 63 of the converter housing 20 can be provided as a holder 62 for the idle bridge 61, such as in FIGS 15 and 16 is shown.

In a further exemplary embodiment 17 collector contacts 40 are designed as lever terminals 41 . These have mounting directions 49 lying perpendicular to a transducer core plane 31 or to a parting plane of the housing parts 21 and test directions 59 of the test contact 50 lying parallel to these planes. For this purpose, the lever-pull terminals 41 include test openings 51 in their levers 95 .

In an exemplary embodiment explained abstractly, which can be implemented, for example, in the exemplary embodiment explained above, protection 60 against open no-load voltages is designed as electronic overvoltage protection 65, with this being formed by two Zener diodes 66 connected in opposite directions between collector lines or between two solder points 34. These are connected to the pick-up coil 32 accordingly.

A split nut 96 with a first part 97 and a second part 97 of the split nut 96 can be used for a busbar attachment 80 to a low-voltage busbar 12 . This can be placed in a desired position around a thread, such as a threaded pin 89 serving as a pressure stamp 88, so that it does not have to be screwed for a long time. In deviating embodiments, an undivided nut can also be used, which is then more complicated to screw on.

In a first embodiment of a busbar attachment according to 20 until 22 with the mother 96 after 19 the divided nut 96 serve as quick positioning device 83 and are placed in a suitable position around the threaded pin 89 or the pressure stamp 88 so that not so much screwing has to be done. The threaded pin 89 or the pressure stamp 88 with its insulation 94 for the threaded pin 89 are then seated on the low-voltage busbar 12 and are arranged perpendicularly thereto.

A housing-side attachment body 81 on a converter housing 20 includes a guide 100 with a retaining opening 98 and with a recess 99. As in FIG 21 shown, the threaded pin 89 can be inserted into the holding opening 98 of the fastening body 81 on the housing side, as can the pressure stamp 88 with the split nut 96 .

In the present embodiment, as shown in FIG 22 shows, the threaded pin 89 must be tightened, whereby the associated split nut 96 is then drawn into the upper recess 99 of the retaining opening 98 and is thus secured.

In a further exemplary embodiment 23 and 24 a second alternative power rail attachment 80 is a similar arrangement as in the embodiment according to the 20 until 22 before, wherein in the present embodiment, a part 97 of the split nut 96 is already pre-positioned in the retaining opening 98.

By suitably offsetting the nut 96 and shaping the retaining opening 98, the second part 97 of the divided nut 96 snaps into the retaining opening 98, so that the nut 96 and the threaded pin 89 or pressure stamp 88 are then secured simply by tightening the threaded pin screw connection 89 still has to be braced.

In another, in 25 illustrated embodiment of a busbar attachment 80, which essentially the busbar attachment 80 of the embodiment according to 20 until 24 corresponds, an extended guide for the threaded pin 89 or for the pressure stamp 88 is provided. With a suitable design, the extended guide can stabilize the threaded pin 89 or, with a suitable design, also serve as protection against accidental contact and as protection against voltage or current, which is particularly advantageous when the threaded pin 89 is in contact with the low-voltage busbar 12 . Here, a Starlock 87 is provided so that the arrangement otherwise corresponds to the arrangement 5 until 10 is working.

In another, in the 26 until 28 illustrated embodiment, the pressure stamp 88 is made of plastic, so that in particular the insulation 95 can be dispensed with.

The clamping device 84 of this exemplary embodiment comprises a guide body 104 and a lever arrangement 101. The guide body 104 can be displaced axially in the direction of the low-voltage busbar 12 by the lever arrangement 101, which consists of clamping lever 102 and eccentric 103 and is mounted in the fastening body 81 on the housing. He then hits a Starlock 87.

The design of the pressure stamp made of plastic means that insulation is not required. Alternatively, however, a metallic pressure stamp 88 or one with a thread can also be provided.

The pressure stamp 88 of the present exemplary embodiment can be quickly displaced in the direction of the low-voltage busbar 12 by direct pressing in overcoming the latching forces of the starlock 87 .

By moving a clamping lever 102 of the clamping device 84 , the pressure pad 88 can be clamped accordingly via the starlock 87 .

It goes without saying that the exemplary embodiments described above can be combined in almost any way in terms of their individual features

reference list

10

low voltage current transformer

11

Low voltage busbar opening

12

low voltage busbar

19

electrical conductor

20

converter housing

21

housing part

22

Customer Contact Formation

23

Inside of the converter housing

24

Exterior of the converter housing

25

bumper edge

26

barrier 70 forming wall

27

sidewall

28

bottom wall

30

transducer core

31

transducer core level

32

pick-up coil

33

customer line

34

plumbing

39

external field shielding

40

customer contact

41

Lever Pull Clamp

42

pushln clamp

46

solder point

49

Equipping direction of the collector contact 40

50

test contact

51

Test contact opening 50

59

Test direction of the test contact 50

60

Protection against open circuit voltages

61

idle bridge

62

Bracket for idle bridge 61

63

clamping conformation

65

electronic surge protection

66

zener diode

70

barrier

71

case closure

72

snap connection

73

detent

74

detent opening

75

friction connection

80

power rail attachment

81

housing-side fastening body

82

clamping body

83

quick positioning device

84

clamping device

85

one-way sliding clamp

86

resilient thread

87

Starlock

88

pressure stamp

89

grub screw

90

lateral supplementary guide

91

fastening hook

92

Holder for PushIn clamp 42

93

Actuating slot for opening the push-in terminal 42

94

Insulation for threaded pin

95

Lever of the lever hoist clamp 41

96

shared mother

97

part of the shared mother

98

holding hole

99

recess

100

guide

101

lever arrangement

102

cocking lever

103

eccentric

104

guide body

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102019115404 A1 [0002]
• DE 10131739 A1 [0002]
• CN201163573Y[0002]
• US 2013/0200971 A1 [0002]
• DE 102021106843 [0002]

Claims (50)

Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). characterized in that the pickup coil (32) is electrically conductively connected via at least two pickup lines (33) to at least two pickup contacts (40) which are arranged in the converter housing (20) and fitted from outside (24) of the converter housing (20). - And contactable and each as a lever clamp (41) are formed. Low-voltage current transformer (10) after claim 1 , characterized in that two further collector contacts (40) are provided, which are arranged in the converter housing (20) and are accessible from outside (24) of the converter housing (20) and which are each connected to one of the two collector lines (33), the the two other customer contacts (40) are preferably each designed as a push-in terminal (42) or also each as a lever-pull terminal (41). Low-voltage current transformer (10) after claim 1 or 2 , characterized in that in the converter housing (20) at least one test opening (51) is provided, through which a test contact (50) is accessible without pinching, which is electrically conductively connected to a first of the two pickup lines (33). Low-voltage current transformer (10) after claim 3 , characterized in that a second test contact (50), which is electrically conductively connected to a second of the two pickup lines (33), is accessible through the test opening (51) without pinching. Low-voltage current transformer (10) after claim 3 , characterized in that two test openings (51) are provided in the converter housing (20), through which a test contact (50) is accessible without clamping, a first of these two test contacts (50) being connected to a first of the two pickup lines (33) and a second of these two test contacts (50) are electrically conductively connected to a second of the two pickup lines (33). Low-voltage current transformer (10) after claim 1 or 2 , characterized in that at least one test contact (50) that is accessible without clamping is formed in one of the lever-pull terminals (41) and is electrically conductively connected to the pickup line (33), with which the corresponding lever-pull terminal (41) is also electrically conductive connected is. Low-voltage current transformer (10) according to one of Claims 1 until 6 , characterized in that the two collector contacts (40) each have an assembly direction (49) against which an electrical conductor (19) is introduced into the respective collector contact (40) or in which an electric conductor (19) exits the respective collector contact (40) can be brought out, and the two collector contacts (40) are arranged with regard to their assembly directions (49) each with an identical assembly direction component in the converter housing (20). Low-voltage current transformer (10) after claim 2 and after claim 7 , characterized in that the two further collector contacts (40) each have an assembly direction (49) in the opposite direction to which an electrical conductor (19) is fed into the respective collector contact (40) or in which an electric conductor (19) emerges from the respective collector contact (40 ) can be brought out, and the two further collector contacts (40) are arranged with regard to their assembly directions (49) each with an identical assembly direction component in the converter housing (20). Low-voltage current transformer (10) after claim 7 and after claim 8 , characterized in that all collector contacts (40) are arranged with respect to their mounting directions (49) with an identical mounting direction component in the converter housing (20). Low-voltage current transformer (10) after claim 7 and after claim 8 , characterized in that a collector contact (40) electrically conductively connected to a first of the two collector lines (33) and a collector contact (40) electrically conductively connected to a second of the two collector lines (33) each have a assembly direction component are arranged in the converter housing (20), which is arranged perpendicularly or in the opposite direction to an assembly direction component, with which two further collector contacts (40) are aligned, which are each electrically conductively connected to one of the two collector lines (33). Low-voltage current transformer (10) according to one of Claims 4 until 6 , characterized in that the pinch-free access to the respective test contact (50) along a test direction (59) which is preferably arranged perpendicular to the associated test opening (51), and that the test direction (59) of the two test contacts (50) each have a common test direction component. Low-voltage current transformer (10) after claim 11 and after one of Claims 7 until 10 , characterized in that a test direction component, preferably the test direction component, is identical to an assembly direction component, preferably identical to the assembly direction component. Low-voltage current transformer (10) after claim 11 and after one of Claims 7 until 10 , characterized in that a test direction component, preferably the test direction component, is perpendicular to an assembly direction component, preferably perpendicular to the assembly direction component. Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). preferably also according to one of the preceding claims, characterized in that the pick-up coil (32) is electrically conductively connected via at least two pick-up lines (33) to at least four pick-up contacts (40), of which two each are connected to one of the two pick-up lines (33) are connected and which are arranged in the converter housing (20) and can be loaded from outside the converter housing (20), and that the four collector contacts (40) are each designed as a push-in terminal (42) or as a lever-pull terminal (41). Low-voltage current transformer (10) after Claim 14 , characterized in that in the converter housing (20) at least one test opening (51) is provided, through which a test contact (50) is accessible without pinching, which is electrically conductively connected to a first of the two pickup lines (33). Low-voltage current transformer (10) after claim 15 , characterized in that a second test contact (50), which is electrically conductively connected to a second of the two pickup lines (33), is accessible through the test opening (51) without pinching. Low-voltage current transformer (10) after claim 15 , characterized in that two test openings (51) are provided in the converter housing (20), through which a test contact (50) is accessible without clamping, a first of these two test contacts (50) being connected to a first of the two pickup lines (33) and a second of these two test contacts (50) are electrically conductively connected to a second of the two pickup lines (33). Low-voltage current transformer (10) after Claim 14 , characterized in that at least one test contact (50) that is accessible without pinching is formed in one of the lever-pull terminals (41) and/or in one of the push-in terminals (42) and is electrically conductively connected to the pickup line (33). which is also electrically conductively connected to the corresponding lever pull (41) or push-in clamp (42). Low-voltage current transformer (10) according to one of Claims 14 until 18 , characterized in that all four collector contacts (40) each have an assembly direction (49) against which an electrical conductor (19) is introduced into the respective collector contact (40) or in which an electric conductor (19) exits the respective collector contact (40) can be brought out, and the four collector contacts (40) are arranged with regard to their assembly directions (49) each with an identical assembly direction component in the converter housing (20). Low-voltage current transformer (10) according to one of Claims 14 until 18 , characterized in that a collector contact (40) electrically conductively connected to a first of the two collector lines (33) and a collector contact (40) electrically conductively connected to a second of the two collector lines (33) each have a assembly direction component are arranged in the converter housing (20), which is arranged perpendicularly or in the opposite direction to an assembly direction component, with which two further collector contacts (40) are aligned, which are each electrically conductively connected to one of the two collector lines (33). Low-voltage current transformer (10) according to one of Claims 16 until 18 , characterized in that the pinch-free access to the respective test contact (50) takes place along a test direction (59) which is preferably arranged perpendicularly to the associated test opening (51), and the test direction (59) of the two test contacts (50) each have one have a common test direction component. Low-voltage current transformer (10) after Claim 21 and after claim 19 or 20 , characterized in that a test direction component, preferably the test direction component, is identical to an assembly direction component, preferably identical to the assembly direction component. Low-voltage current transformer (10) after Claim 21 and after claim 19 or 20 , characterized in that a test direction component, preferably the test direction component, is perpendicular to an assembly direction component, preferably perpendicular to the assembly direction component. Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). preferably also according to one of the preceding claims, characterized in that the pickup coil (32) is electrically conductively connected via at least two pickup lines (33) to at least two pickup contacts (40) which are arranged in the converter housing (20) from outside the converter housing (20) and are each designed as a lever-pull clamp (41), as a push-in clamp (42) and/or as a spring-loaded clamp and that (i) at least one test opening (51) is provided in the converter housing (20). , through which a test contact (50) is accessible without clamping, which is electrically conductively connected to a first of the two pickup lines (33) i st, or (2) a test contact (50) that is accessible without clamping is formed in one of the lever pull, push-in or spring-type terminals, which is electrically conductively connected to the customer line (33), with which the corresponding lever pull, push-in - or spring-loaded terminal is electrically conductively connected. Low-voltage current transformer (10) after Claim 24 , characterized in that a second test contact (50), which is electrically conductively connected to a second of the two pickup lines (33), is accessible through the test opening (51) without pinching. Low-voltage current transformer (10) after Claim 24 , characterized in that two test openings (51) are provided in the converter housing (20), through which a test contact (50) is accessible without clamping, a first of these two test contacts (50) being connected to a first of the two pickup lines (33) and a second of these two test contacts (50) are electrically conductively connected to a second of the two pickup lines (33). Low-voltage current transformer (10) after Claim 24 , characterized in that in each case one of the lever pull (41), pushin (42) or spring-loaded terminals, which are electrically conductively connected to a common collector line (33), preferably in each of the lever pull (41), pushin - (42) or spring-loaded terminals, a corresponding test contact (50) that is accessible without clamping is provided. Low-voltage current transformer (10) according to one of claims 24 until 27 , characterized in that the two collector contacts (40) each have an assembly direction (49) against which an electrical conductor (19) is introduced into the respective collector contact (40) or in which an electric conductor (19) exits the respective collector contact (40) can be brought out, and the two collector contacts (40) are arranged with regard to their assembly directions (49) each with an identical assembly direction component in the converter housing (20). Low-voltage current transformer (10) after claim 28 and after one of Claims 25 until 27 , characterized in that the pinch-free access to the respective test contact (50) takes place along a test direction (59) which is preferably arranged perpendicularly to the associated test opening (51), and the test direction (59) of the two test contacts (50) each have one have a common test direction component. Low-voltage current transformer (10) after claim 28 and after claim 29 , characterized in that a test direction component, preferably the test direction component, is identical to an assembly direction component, preferably identical to the assembly direction component. Low-voltage current transformer (10) after claim 28 and after claim 29 , characterized in that a test direction component, preferably the test direction component, is perpendicular to an assembly direction component, preferably perpendicular to the assembly direction component. Low-voltage current transformer (10) according to one of claims 3 until 5 , 11 , 15 until 17 and 24 until 31 , characterized in that in a transport configuration between the test contacts (50) a respective test openings (51) penetrating, the test contacts (50) electrically conductively connecting protection (60) against no-load voltages open secondary contacts, preferably in the form of an idle bridge (61), which is in particular designed to be inherently rigid. Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). preferably also according to one of the preceding claims, characterized in that the pickup coil (32) is electrically conductively connected via at least two pickup lines (33) to at least two pickup contacts (40), which are arranged in the converter housing (20) and can be accessed from outside the converter housing (20) can be equipped and contacted, and that (i) a test contact (50) that is accessible from outside the converter housing (20) and without clamping is electrically conductively connected to the two pickup lines (33), with between the two test contacts (50 ) In a transport configuration, the test contacts (50) electrically conductively connecting idle brake gap (61) as protection (60) against open secondary contacts, and/or (ii) on the converter housing (20) a holder (62) for one of the test contacts (50), the pickup contacts (40) or the pickup lines (33 ) Electrically conductively connecting no-load bridge (61) is arranged as protection (60) against no-load voltages on open secondary contacts. Low-voltage current transformer (10) after Claim 33 , characterized in that the idling bridge (61) is designed to be inherently rigid. Low-voltage current transformer (10) after Claim 33 or 34 , characterized in that the holder (62) is designed as a clamping holder and is preferably formed as a clamping projection (63) in the converter housing (20). Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). preferably also according to one of the preceding claims, characterized in that the pickup coil (32) is electrically conductively connected via at least two pickup lines (33) to at least two pickup contacts (40), which are arranged in the converter housing (20) and can be accessed from outside the Transducer housing (20) can be equipped, wherein inside (23) of the transducer housing (20) between the two pickup lines (33) hard-wired protection (60) is provided against no-load voltages at open secondary contacts. Low-voltage current transformer (10) after Claim 36 , characterized in that the protection (60) against no-load voltages at 60 V, in particular over 55 V, intervenes. Low-voltage current transformer (10) after Claim 36 or 37 , characterized in that the protection (60) against no-load voltages is designed as electronic overvoltage protection (65), for example by two Zener diodes (66) connected in opposite directions between the pickup lines (33). Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). preferably also according to one of the preceding claims, characterized in that the converter housing (20) has at least two housing parts (21) which are closed to one another by means of a housing closure (71) and which each abut with an abutting edge (25), with a first of the in both housing parts (21) a barrier (70) forming wall (26) is provided on a side of the abutting edge facing away from an exterior (24) of the converter housing (20) or on a side of the abutting edge facing towards the exterior (24) of the converter housing (20), which locking forces of the housing lock (71). Low-voltage current transformer (10) after Claim 39 , characterized in that the wall (26) forming a barrier (70) absorbs closing forces acting perpendicularly to the extension of this wall (26) and/or acting in a plane spanned by the abutting edges (25). Low-voltage current transformer (10) after Claim 39 or 40 , characterized in that the wall (26) forming a barrier (70) acts parallel to the extension of this wall (26) and perpendicular to the extension of this wall (26) in the second of the two housing parts (21) and/or perpendicular to a through absorbs closing forces acting on the plane spanned by the abutting edges (25). Low-voltage current transformer (10) according to one of Claims 39 until 41 , characterized in that the housing closure (71) between the a barrier (70) forming wall (26) and the second of the two housing parts (21) effective latching connection (72) and/or between the wall (26) forming a barrier (70) and the second of the two housing parts (21) effective frictional connection, in particular a frictional connection (75 ), includes. Low-voltage current transformer (10) according to one of Claims 39 until 42 , characterized in that the wall (26) forming a barrier (70) takes over at least 90% and particularly preferably all the closing forces of the housing closure (71) that are required for reliable operation. Low-voltage current transformer (10) with a transformer core (30) carrying at least one pickup coil (32) and spanning a transformer core plane (31) and a transformer housing (20) enclosing the transformer core (30), both of which have a low-voltage busbar opening (11) penetrating the transformer core plane (31). preferably also according to one of the preceding claims, characterized in that a busbar fastening (80) for fastening the low-voltage current transformer (10) to a low-voltage busbar (12) is provided on the converter housing (20), which has a housing-side fastening body (81) and a between the fastening body (81) and the low-voltage busbar (12) clampable clamping body (82), wherein the busbar fastening (80) comprises a rapid positioning device (83) for rapid positioning of the clamping body (82) in relation to the fastening body (81) and the low-voltage busbar ( 12) and a clamping device device (84) for applying the intended tensioning forces between the fastening body (81) and the low-voltage busbar (12) and the rapid positioning device (83) and the tensioning device (84) have a correspondingly quick positioning or tensioning effect by movements that deviate from one another. Low-voltage current transformer (10) after Claim 44 , characterized in that the rapid positioning device (83) and the clamping device (84) comprise different assemblies. Low-voltage current transformer (10) after Claim 44 , characterized in that the rapid positioning device (83) and the clamping device (84) are at least partially realized by identical assemblies. Low-voltage current transformer (10) according to one of Claims 44 until 46 , characterized in that the rapid positioning device (83) comprises a one-way sliding clamp (85). Low-voltage current transformer (10) after Claim 47 , characterized in that the one-way sliding clamp (85) is realized by a spring element, for example by a resilient thread (86). Low-voltage current transformer (10) according to one of Claims 44 until 48 , characterized in that the clamping body (82) is designed as a pressure stamp (88). Low-voltage current transformer (10) according to one of Claims 44 until 49 , characterized in that the pressure stamp (88) is designed as a threaded pin (89).

Images