DE102018210925B4 - Electromechanical low-voltage protective switching device - Google Patents

Abstract

Electromechanical low-voltage protective switching device (1), with- an insulating housing (2), - a printed circuit board (10), which is accommodated and held at a predefined position in the insulating housing (2) and which has a processing unit, namely a microcontroller and a memory element, wherein the printed circuit board (10) has at least two contact points (11) which are designed to output and/or receive information, and- wherein the insulating material housing (2) has at least two openings (8) which with regard to their correlate spatial position with the position of the at least two contact points (11) of the printed circuit board (10) in such a way that the at least two contact points (11) can be contacted through the openings (8) from outside the insulating material housing (2), the insulating material housing (2) a front side (4), one of the front side (4) opposite fastening side (5), and the front and the Be has narrow and broad sides (6, 7) connecting the fastening side (4, 5) in order to arrange the protective switching devices next to one another in a series arrangement, with the openings (8) being formed in one of the two broad sides (7) of the insulating housing (2), so that the Openings are covered by an adjacent protective switching device, so that unauthorized contacting of the contact points is made significantly more difficult.

Description

The invention relates to an electromechanical low-voltage protective switching device with a housing made of insulating material and with a printed circuit board assembly which is received and held at a predefined position in the housing made of insulating material.

Protective switching devices - such as circuit breakers, miniature circuit breakers, residual current circuit breakers or arcing or fire protection switches - are used in particular as switching and safety elements in electrical power supply networks for monitoring and protecting an electrical circuit and are known in principle. Circuit breakers are specially designed for high currents. A circuit breaker (so-called circuit breaker), which is also known as a "miniature circuit breaker" (MCB), represents a so-called overcurrent protection device in electrical installations and is used in particular in the area of low-voltage networks. Circuit breakers and miniature circuit breakers guarantee safe shutdown in the event of a short circuit and protect consumers and systems from overload. In this way, for example, electrical lines are protected from damage due to excessive heating as a result of an excessively high electric current.

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

In electrical installation technology, the term "AFN" is understood to mean a protective device to protect against a fault current caused by an arc fault. Such accidental arc protection devices are used in low-voltage networks to protect the electrical installation technology from damage by a fault current due to an accidental arc and from its thermal consequences - for example cable fires. An arc fault can occur, for example, at a defective point in an electrical cable, e.g. a loose cable clamp or due to a cable break. If the accidental arc occurs electrically in series with an electrical consumer, the normal operating current is usually not exceeded because it is limited by the consumer. For this reason, the accidental arc is not detected by a conventional overcurrent protection device, such as a fuse or circuit breaker. This is particularly problematic in the case of high operating currents and in the case of arcing faults that have existed for a long time, since in these cases there is a risk of fire due to the high temperatures associated with the arcing.

To determine whether there is an arc fault, the arc fault detection device measures the voltage curve and the current curve over time and evaluates it using digital signal processing. In the event of an arc fault, the current curve in particular has characteristic, high-frequency components. During the evaluation, however, it should be noted that regular fluctuations in the current curve and harmonics or transient current curves that occur during normal operation, such as those that occur when an electrical consumer is switched on, do not lead to faulty tripping of the arc fault detection device. For this reason, AFD units have relatively complex algorithms for monitoring the electrical installation and for detecting possible arcing faults.

In the (English-language) specialist literature, such devices for detecting accidental arcs are referred to as "Arc Fault Detection Device" (abbreviated AFDD). In North America, where the so-called UL standard (underwriters laboratories, standard with 110 V mains voltage) prevails, the term "Arc Fault Circuit Interrupter" (abbreviated AFCI) is common. The principles used in these arc protection circuit breakers are exemplified in US patents U.S. 5,729,145 such as U.S. 6,031,699 described. In most European countries, which make the IEC standard (International Electrotechnical Commission, standard with a mains voltage of 230 V) mandatory, arc protection switches are not mandatory. Current circuits in IEC technology have so far mostly been secured with the help of residual current circuit breakers and miniature circuit breakers. However, protection against arcing faults cannot be implemented with the protective switching devices mentioned.

In principle, to monitor or protect an electrical circuit, the respective protective switching device is electrically conductively connected to an electrical line of the circuit to be monitored (e.g. via connection terminals) in order to interrupt the electrical current in the respective line if necessary. For this purpose, the protective switching device has a switching contact with a fixed contact and a moving contact that is movable relative thereto. The moving contact can be actuated via a switching mechanism of the protective switching device, so that the switching contact can be opened and closed. In this way, when a predefined condition occurs, for example a short circuit or an electrical overload, the switching mechanism is activated and the switching contact is thus opened in order to interrupt the electrical line and thus separate the monitored circuit from the electrical line network.

In low-voltage electrical installation technology, these protective switching devices - ie both miniature circuit breakers and residual current circuit breakers, as well as combination devices such as FI/LS or AFDD/AFCI - are also referred to as "series installation devices". This term comes from the fact that a large number of such DIN rail mounted devices are often arranged side by side “in a row” in an electrical distribution board. Such series installation devices are in principle from the publications DE 602 09 126 T2 or EP 1 939 912 B1 previously known.

Some of the protective functions provided by means of these protective switching devices, such as short-circuits, overloads or fault currents, are generally implemented purely mechanically, for example in the case of short-circuit tripping by means of a tripping coil and a movably mounted tripping armature. Other protective functions, such as detecting an arc fault, are more complex to implement and require a certain logic. For this purpose, the relevant protective switching devices usually also have a so-called printed circuit board, which is also referred to as a printed circuit board (“printed circuit board”). Measurement data can be recorded and processed with the aid of the printed circuit board assembly, which generally has at least one processing unit, for example a microcontroller, and a memory element. On the basis of this measurement data, a decision can then be made as to whether an interference event is present which requires the switching contact to be opened and thus the protective switching device to be triggered.

If changes are to be made to the software, for example as part of an update, the housing of the protective switching device must be opened to gain access to the printed circuit board. From the point of view of the device manufacturer, such software changes should only be able to be made by the relevant manufacturer himself or persons authorized by him in order to avoid errors and thus malfunctions of the protective switching device. Furthermore, a special tool is usually required to open the housing in order to avoid damage to the housing as far as possible. As a result, the effort associated with updating the software is so high that in most cases it is cheaper to replace the entire protective switching device.

In addition, the EP 2 728 690 B1 a voltage sensor contact for an electronic device. Furthermore, the U.S. 2016/0181026 A1 an improvement for accessory wiring on an overmolded circuit breaker housing. Furthermore, the DE 10 2017 125 308 A1 a switching device with an interface module. Finally revealed the DE 91 14 742 U1 a device for the detachable fastening of modular housings for auxiliary switches and/or electrical switching devices.

It is therefore the object of the present invention to provide an electromechanical low-voltage protective switching device which is distinguished by a lower maintenance outlay in the event of software changes or updates.

According to the invention, this object is achieved by the electromechanical low-voltage protective switching device according to the independent claim. Advantageous configurations of the protective switching device according to the invention are the subject matter of the dependent claims.

The electromechanical low-voltage protective switching device according to the invention has an insulating housing and a printed circuit board assembly, which is accommodated and held at a predefined position in the insulating housing. For its part, the printed circuit board has at least two contact points which are designed to output and/or receive information. Furthermore, the insulating housing has at least two openings which, in terms of their spatial position, correlate with the position of the at least two contact points of the printed circuit board assembly, i.e. interact in such a way that the at least two contact points can be contacted through the openings from outside the insulating housing.

Through the formed in the insulating material, ie arranged openings contacting the contact points of the printed circuit board - and so that software stored locally in the protective switching device can be updated - from the outside through the openings, without the insulating housing itself having to be opened for this purpose. Damage that can occur when the insulating housing is opened is thus avoided. Furthermore, the time required for updating the software is thereby significantly reduced, as a result of which the associated maintenance costs can also be significantly reduced.

The insulating housing of the low-voltage protective switching device has a front side, a fastening side opposite the front side, and narrow and broad sides connecting the front side and the fastening side. The openings are formed in one of the two broad sides of the insulating housing.

The arrangement of the openings in one of the two broad sides of the insulating housing has several advantages: on the one hand, easier access to the contact points is possible there, since the area of the narrow sides is mainly occupied by the connection terminals; This significantly simplifies the arrangement of the printed circuit board assembly inside the housing. On the other hand, if the protective switching devices are arranged next to one another in a series arrangement, the openings are covered by the protective switching device arranged adjacent, so that unauthorized contacting of the contact points is made significantly more difficult as a result.

In a further advantageous development of the low-voltage protective switching device, the openings are closed by means of a seal applied by the manufacturer.

The use of a seal or seal sticker has the advantage that the manufacturer can check whether the protective switching device has been tampered with in an unauthorized manner. As long as the seal is intact, it can be assumed that the device's internal software has not been modified by unauthorized third parties. This ensures that software updates are only carried out by the manufacturer himself or by a person authorized by him to do so.

In a further advantageous development of the low-voltage protective switching device, the printed circuit board has further contact points which correlate with further openings formed in the insulating material housing with regard to their spatial position.

The further openings correlate with the further contact points in terms of their position on the insulating material housing, so that contacting of the further contact points through the further openings from outside the insulating material housing is made possible. With the help of the other contact points, further functions are possible: for example, measured values or fault memories can be read out here.

A system consists of an electromechanical low-voltage protective switching device of the type described above and an adapter device which can be coupled to the protective switching device. The adapter device has at least two contact pins which, in terms of their spatial arrangement, correlate with the spatial arrangement of the at least two contact points. The at least two contact pins serve to make contact with the at least two contact points of the protective switching device, with the contact pins being able to be guided through the at least two openings formed in the insulating housing for making contact.

With regard to the advantages of the system, consisting of an electromechanical low-voltage protective switching device and a matching adapter device that can be coupled to the protective switching device, reference is made to the above-described advantages of the electromechanical low-voltage protective switching device according to the invention. In particular, if more than two contact points are to be contacted, the use of an adapter device results in a significant time advantage.

• 1 und 2 perspektivische Außenansichten des erfindungsgemäßen Schutzschaltgerätes;
• 3 eine schematische Darstellung des Schutzschaltgerätes mit teilweise transparentem Gehäuse;
• 4 eine schematische Detaildarstellung des in 3 dargestellten Schutzschaltgerätes.

An exemplary embodiment of the electromechanical low-voltage protective switching device according to the invention is explained in more detail below with reference to the attached figures. In the figures are:

• 1 and 2 Perspective external views of the protective switching device according to the invention;
• 3 a schematic representation of the protective switching device with a partially transparent housing;
• 4 a schematic detailed representation of the in 3 protective switching device shown.

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

In the 1 and 2 the low-voltage protective switching device 1 according to the invention is shown schematically in a perspective external view. The protective switching device 1 has an insulating material housing 2, which has a front side 4, a fastening side 5 arranged opposite the front side 4, and narrow sides 6 and broad sides 7 connecting the front side and the fastening side 4, 5. An actuating element 3 for manual actuation of the protective switching device 1 is arranged on the front side 4 . The insulating material housing 2 has a front housing half-shell 2-1 and a rear housing half-shell 2-2, which are connected to one another by means of several rivets 9. In the area of the narrow sides 6 there are connection terminals 14 (see 3 ) arranged, by means of which the protective switching device 1 is electrically conductively connected to an electrical circuit to be protected. However, the shell construction of the housing shown here is only to be understood as an example and is in no way essential to the invention.

A plurality of openings 8 are formed in the broad side 7 of the front housing half-shell 2-1 facing the viewer and are arranged in such a way that a suitable tool (not shown) - for example with the aid of suitable contact pins or contact pins - can be used to make contact from outside the insulating housing 2 through the openings 8 into the interior of the insulating material housing 2 is possible.

In the representation of 1 nine openings 8 are formed in the broad side 7 of the insulating material housing 2, which are arranged in the form of a 3×3 matrix. However, this embodiment is only to be understood as an example: it is necessary for the insulating material housing 2 to have at least two openings 8 which are designed in such a way that contact pins or contact pins can be inserted from the outside through the openings 8 into the insulating material housing 2 .

in the in 2 In the protective switching device 1 shown, the area formed in the broad side 7 with the openings 8 is closed with the aid of a seal 20 which is glued to the relevant area. In this way, it is possible for the manufacturer to check that unauthorized third parties cannot tamper with the protective switching device 1 . This ensures that software updates are only carried out by the manufacturer himself or by a person authorized by him to do so.

3 shows one to the 1 and 2 Corresponding representation of the protective switching device 1 with a partially transparent insulating housing 2, ie the front housing half-shell 2-1 is only indicated, so that a look inside the insulating housing 2 is possible. 4 provides a detailed representation of the in 3 represented protective switching device 1.

Inside the insulating material housing 2, the connection terminals 14 can be seen in the area of the narrow sides 6, via which the protective switching device 1 can be electrically conductively connected to the electrical circuit to be protected. In addition to the terminal 14 shown on the left, a short-circuit tripping device 15 and an arc quenching chamber 16 are accommodated in the insulating housing 2 . In the middle of the housing - below the actuating element 3 - there is a switching mechanism 17 with a movable switching contact which can be opened if necessary in order to interrupt the current flow in the electrical line to be monitored.

Furthermore, the protective switching device 1 has a printed circuit board assembly 10 which is accommodated and held in a predefined position inside the insulating housing 2 . Such printed circuit boards are used, for example, in arc fault protection switches (AFDD for “Arc Fault Detection Device”) in order to be able to map a complex triggering logic. For this purpose, the printed circuit board assembly 10 generally has a memory element 12 and a processing unit 13, for example a microcontroller, for example in order to acquire and process measurement data. Furthermore, the printed circuit board 10 can also have a communication unit (not shown) in order to be able to integrate the protective switching device 1 into a higher-level monitoring and control system and thus make it capable of communication.

According to the invention, the printed circuit board assembly 10 has a plurality of contact points 11 which are designed to output and/or receive information. These contact points 11, which are also referred to as contact pads, are used to make contact with the printed circuit board assembly 10 from the outside and, with regard to their spatial position in the insulating material housing 2, correlate with the position of the at least two openings 8 formed in the broad side 7 of the insulating material housing 2 such that a Contacting the at least two contact points 11 with the aid of a suitable tool through the openings 8 from outside the insulating material housing 2 is possible. If the contact pins are slim enough, they can be inserted through the openings 8 from the outside until their tips touch the contact points 11 assigned to these openings 8 . If more than two contact points 11 are to be contacted and, accordingly, more than two contact pins are required, it is helpful to arrange these multiple contact pins in an adapter device (not shown) that can be mechanically coupled to the protective switching device 1, with the multiple contact pins corresponding in terms of their spatial arrangement to the spatial Arrangement of the multiple contact points 11 correlate, so that when the Adap is coupled tergerätes to the protective switching device 1, the plurality of contact pins are passed through the openings 8 and contact them each directly and clearly associated contact points 11 of the printed circuit board assembly 10. In this way, data stored on the printed circuit board 10 can be read out without great effort or new data can be uploaded to the printed circuit board 10 without the protective switching device 1 having to be opened for this purpose. Accordingly, the mechanical tests that would be required after opening and closing the insulating housing 2 again are also eliminated. It is also possible for data to be transmitted to the adapter device by wire or wirelessly from a higher-level location—for example, a control room.

Reference List

1

protective switching device

2

insulating housing

2-1

front half shell

2-2

rear half shell

3

actuator

4

front

5

mounting side

6

narrow side

7

broadside

8th

opening

9

rivet

10

printed circuit board

11

contact point

12

storage element

13

processing unit

14

terminal block

20

seal

Claims (3)

Electromechanical low-voltage protective switching device (1), with - an insulating housing (2), - A printed circuit board assembly (10) which is received and held at a predefined position in the insulating housing (2) and which has a processing unit, namely a microcontroller and a memory element, wherein the printed circuit board (10) has at least two contact points (11) which are designed to output and/or receive information, and - wherein the insulating material housing (2) has at least two openings (8) which, in terms of their spatial position, correlate with the position of the at least two contact points (11) of the printed circuit board (10) in such a way that contact can be made between the at least two contact points (11) and the openings (8) from outside the insulating material housing (2) is possible, wherein the insulating material housing (2) has a front side (4), a fastening side (5) opposite the front side (4), and narrow and broad sides (6, 7) connecting the front side and the fastening side (4, 5) in order to Protective switching devices to be arranged side by side in series, with the openings (8) being formed in one of the two broad sides (7) of the insulating housing (2), so that the openings are covered by an adjacent protective switching device, so that unauthorized contacting of the contact points is made significantly more difficult. Low-voltage protective switching device (1) according to claim 1 , characterized in that the openings (8) are closed by means of a seal (20) applied by the manufacturer. Low-voltage protective switching device (1) according to one of the preceding claims, characterized in that the printed circuit board (10) has further contact points (11) which correlate with further openings (8) formed in the insulating material housing (2) with regard to their spatial position.

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