EP4620015A1

EP4620015A1 - Circuit breaker with current measuring capability

Info

Publication number: EP4620015A1
Application number: EP23809107.8A
Authority: EP
Inventors: Tomás Drábek; Petr Matousek; Jakub KOZDON; Pavel Dedourek
Original assignee: Eaton Intelligent Power Ltd
Current assignee: Eaton Intelligent Power Ltd
Priority date: 2022-11-16
Filing date: 2023-11-10
Publication date: 2025-09-24
Also published as: GB202217109D0; GB2624399A; WO2024104609A1; GB2624399A8

Abstract

A circuit breaker (1, 1 a..1 f, 1A..1 D') is disclosed, which comprises a housing (2), a switch unit (3a..3d), a latch (4a..4d), a trigger unit (6a..6c, 6a', 6a") with an electromagnetic trigger device (7) and/or a thermal trigger device (9) and a first voltage sensor (11a), which is arranged in the housing (2) and which is electrically connected to the trigger unit (6a..6c, 6a', 6a"). The first voltage sensor (11a) is designed to measure a first voltage drop (U1 ) at the first coil (L1 ) if the trigger unit (6a..6c, 6a', 6a") comprises an electromagnetic trigger device (7) and/or at the first heating element (R1 ) if the trigger unit (6a..6c, 6a', 6a") comprises a first thermal trigger device (9). Generally, the first voltage drop (U1 ) reflects a first current (I1) through the trigger unit (6a..6c, 6a', 6a").

Description

Circuit breaker with current measuring capability

TECHNICAL FIELD

The invention relates to a circuit breaker, which comprises a housing and one or more input terminals and output terminals reaching through the housing, wherein the input terminals are intended to be connected to a grid and wherein the output terminals are intended to be connected to a load. Moreover, the circuit breaker comprises a switch unit with at least a first switch, wherein the switch unit is arranged in the housing and wherein the first switch is electrically arranged between a first input terminal of the input terminals and a first output terminal of the output terminals. In addition, the circuit breaker comprises a latch, which is arranged in the housing and which upon a trigger signal opens the switch(es) of the switch unit and which keeps the same open after a trigger signal until manual on-site intervention or until remote intervention. The circuit breaker also comprises a) an electromagnetic trigger device with a first coil and/or b) a thermal trigger device with a first heating element. The electromagnetic trigger device is arranged in the housing and causes outputting the trigger signal in case of overcurrent through the first coil. The first coil is electrically arranged in series with the first switch or between a second input terminal of the input terminals and a second output terminal of the output terminals. The thermal trigger device is arranged in the housing as well and causes outputting the trigger signal in case of overcurrent through the first heating element. The first heating element is electrically arranged in series with the first switch or between a second input terminal of the input terminals and a second output terminal of the output terminals, too. The invention furthermore relates to an arrangement, which comprises a DIN rail and a first circuit breaker of the above kind mounted on the DIN rail.

BACKGROUND ART

A circuit breaker and an arrangement of the above kinds are generally known in prior art. In case of overcurrent, the circuit breaker disconnects the load from the grid. As is generally known in prior art, overcurrents with a fast current changing rate cause triggering the latch through the electromagnetic transducer, whereas overcurrents with a slow changing rate cause triggering the latch through the thermal trigger device. Modern applications desire for data being relevant for a circuit breaker, in particular for data about the current flowing over the circuit breaker. So, there is a need for a robust, cheap and reliable current measuring capability for a circuit breaker, which withstands unfavorable environmental conditions, in which circuit breakers are commonly used.

DISCLOSURE OF INVENTION

Accordingly, an object of the invention is the provision of an improved circuit breaker and the provision of an improved arrangement. In particular, a robust, cheap and reliable current measuring solution for a circuit breaker shall be provided, which withstands unfavorable environmental conditions, in which circuit breakers are commonly used.

The object of the invention is solved by a circuit breaker of the type disclosed in the opening paragraph, which additionally comprises a first voltage sensor, wherein the first voltage sensor is arranged in the housing, wherein the inputs of the first voltage sensor are electrically connected to the trigger unit, wherein the first voltage sensor is designed to measure a first voltage drop at the first coil if the trigger unit comprises an electromagnetic trigger device according to case a) and/or at the first heating element if the trigger unit comprises a first thermal trigger device according to case b) and wherein the first voltage drop reflects a first current through the trigger unit.

By use of these measures, a robust, cheap and reliable current measuring capability for a circuit breaker is disclosed, which withstands unfavorable environmental conditions, in which circuit breakers are commonly used. The measured voltage is proportional to a current flowing through the first coil and/or the first heating element and thus can be seen as an equivalent to said current. However, instead of a traditional (and additional) shunt, components of a circuit breaker are used for current measurement, which are often part of a circuit breaker anyway. Accordingly, technical complexity and costs are only slightly increased compared to prior art circuit breakers.

For the generation of the trigger signal, the electromagnetic trigger device can comprise an electromagnetic transducer, which is functionally coupled to the first coil and which transforms the electromagnetic field emitted by the first coil into a trigger signal. For example, the electromagnetic transducer can be formed of or can comprise an armature, which is attracted by the electromagnetic field emitted by the first coil. Accordingly, an overcurrent through the first coil can cause a movement of the armature and in turn outputting a mechanical trigger signal. However, although this is a proven method for triggering a latch, the electromagnetic transducer may also work on a different physical principle and for example generate an electric trigger signal. An example for such an electromagnetic transducer is a Hall sensor converting the electromagnetic field emitted by the first coil into a voltage.

The function of the thermal trigger device is similar to that of the electromagnetic trigger device, however, based on the temperature of the first heating element. For the generation of the trigger signal, the thermal trigger device comprises a thermal transducer, which is functionally coupled to the first heating element and which transforms a temperature generated by the first heating element into a trigger signal. In particular, the first heating element can be formed by or can comprise a first bimetal element. In this case, the output of the first heating element is not a temperature but a switching state or movement, which is fed to the latch. Strictly speaking, the first bimetal element also comprises the thermal transducer in this case. In other words, the functions of the first heating element and the thermal transducer are comprised of a single bimetal element. However, although this is a proven method for triggering a latch, the thermal transducer may also work on a different physical principle and for example generate an electric trigger signal. An example for such a thermal transducer is an electronic temperature sensor converting the temperature generated by the first heating element into a voltage.

The handle and the trigger unit are functionally coupled with the latch, and the latch is functionally coupled with the switch unit. For example, the functional coupling may be achieved by means of a mechanical connection. In such a case, the trigger signal can be formed by a movement of a part of the trigger unit, wherein said part is connected to the latch. Accordingly, such a movement triggers the latch, which in turn switches off the switch unit.

The latch keeps the first switch of the switch unit open after a trigger signal until manual on-site intervention or until remote intervention. Manual intervention can be a movement of the handle, which causes the first switch of the switch unit being closed again, as this is principally known. In addition, the first switch of the switch unit may also be closed remotely, for example by means of an electric signal fed to the latch.

Further advantageous embodiments are disclosed in the claims and in the description as well as in the figures.

Beneficially, the switch unit can comprise a second switch, which is electrically arranged between the second input terminal of the input terminals and the second output terminal of the output terminals. In this way, a multipole circuit breaker can be formed, which for example not only disconnects a phase line but also a neutral line in case of overcurrent.

In another beneficial embodiment of the circuit breaker, the electromagnetic trigger device in case a) comprises a second coil, wherein the electromagnetic trigger device causes outputting the trigger signal additionally in case of overcurrent through the second coil and wherein the second coil is electrically arranged in series with the second switch and/or the thermal trigger device in case b) comprises a second heating element, wherein the thermal trigger device causes outputting the trigger signal additionally in case of overcurrent through the second heating element, and wherein the second heating element is electrically arranged in series with the second switch.

In this way, reliable overcurrent detection and in succession disconnection of the load from the grid can be guaranteed also in case of unsymmetric loads in multi phase systems. There may be separate trigger units for each phase or a common trigger unit for all phases.

In another advantageous embodiment, the circuit breaker comprises a second voltage sensor, wherein the inputs of the second voltage sensor are electrically connected to the trigger unit, wherein the second voltage sensor is designed to measure a second voltage drop at the second coil if the trigger unit comprises an electromagnetic trigger device according to case a) and/or at the second heating element if the trigger unit comprises a thermal trigger device according to case b) and wherein the second voltage drop reflects a second current through the trigger unit. In this way, reliable current measuring can be guaranteed also in case of multi phase systems, in particular in case of unsymmetric loads. The first voltage sensor and the second voltage sensor can be part of a voltage measuring unit.

In one further embodiment, the circuit breaker can comprise an electronic circuit, which is arranged in the housing, which is connected to the voltage sensor(s) or which the voltage sensor(s) is/are part of and which comprises a data interface, wherein i) the data interface is embodied as a wired data interface, which is designed to transmit measurement data reflecting the measured voltage drop(s) out of the housing by wire and/or ii) the data interface is embodied as a contactless or wireless data interface, which is designed to transmit measurement data reflecting the measured voltage drop(s) out of the housing in a contactless or wireless manner.

In particular, the contactless data interface can be a radio interface (and comprises a radio sender) in case ii), in particular working according to the standard for Near-field communication, or can be an optical interface (and comprises a sender diode) in case ii), in particular working according to the standard for Infrared Data Association.

By use of the above measures, measurement data can be transmitted from the circuit breaker to other devices.

In yet another embodiment, the electronic circuit or the voltage sensor(s) can comprise an amplifier, which is designed to amplify the measured voltage drop(s), in particular before it is transmitted by the data interface. In this way, the voltage level can be raised to level, which is usable for downstream devices (e.g. for the data interface). In particular, the amplification may be chosen in a way that the output value directly reflects a current associated with a measured voltage drop. For example, 1 V output voltage can equal a first current of 1 A. However, 1 V output voltage can also equal a different first current, e.g. 10 A, 100 A and so on. Beneficially, the electronic circuit can comprise a microprocessor, which is designed to postprocess the measurement data reflecting the measured voltage drop(s), in particular after it has been amplified and before it is sent to the data interface. For example, data may be stored (e.g. with timestamp) for later use, measurement data can be averaged, etc. In yet another beneficial embodiment of the circuit breaker, the data interface in addition can be designed to receive commands and can be designed to transmit these commands to the microprocessor for execution. Commands for example can be used for clearing the memory, resetting an averaging algorithm, etc.

It is very advantageous, if the electronic circuit or the voltage sensor(s) comprise(s) a frequency compensation unit, which compensates a deviation of a real voltage drop from the associated measured voltage drop or deviations of real voltage drops from the associated measured voltage drops based on a deviation of a frequency of the current flowing over the electromagnetic trigger device from a reference frequency in case a) and/or a temperature compensation unit, which compensates a deviation of a real voltage drop from the associated measured voltage drop or deviations of real voltage drops from the associated measured voltage drops based on a deviation of a temperature of the first or second heating element from a reference temperature in case b).

In contrast to a traditional shunt for measuring a current via a voltage drop, which basically is invariant to a frequency of the current to be measured, the voltage drop at the first coil substantially depends on the frequency of the first current. Usually, the frequency can be assumed to be stable at 50 Hz or 60 Hz. However, if a very high measuring accuracy is desired, frequency variations around said nominal frequency of 50 Hz or 60 Hz can be taken into consideration by calculating the impedance of the first coil, which is Zu = j-o-L1 with © = 2- -f or by calculating a deviation of the real impedance from a nominal impedance at 50 Hz or 60 Hz. In case of a temperature compensation, the reference temperature can be measured by use of an ambient temperature sensor for example. Usually, the temperature, at which the circuit breaker is operated, can be assumed to be stable, for example at 20°. However, if a very high measuring accuracy is desired, temperature variations can be taken into consideration by measuring an ambient reference temperature and by accordingly taking into consideration the dependency of the resistance of the thermal trigger device from its temperature. Generally, it is advisable to do the compensation before measurement data is sent out by the data interface. In yet another very advantageous embodiment a compensation in case a) can be done based on the first current flowing through the first coil or based on currents flowing through each of the coils and/or a compensation in case b) can be done based on the temperature of the first heating element or based on temperatures of each of the heating elements.

If there are more coils in case a), compensation for all voltage drops can be based on a compensation based on the frequencies of each of the currents or can be based on just one of the currents. It may be sufficient to base the compensation on just one current if no or no substantial variation of the frequencies between the different currents is expected or possible. Similarly, if there are more thermal trigger devices in case b), compensation for all voltage drops can be based on the temperatures of each of the currents or can be based on a compensation based on the temperature of just one of the heating elements. It may be sufficient to base the compensation on just one temperature if no or no substantial variation of the temperatures between the different heating elements is expected.

In one further embodiment, the circuit breaker can comprise mounting means, which are arranged on a rear side of the circuit breaker, which are designed for mounting the circuit breaker on a DIN rail and which form or comprise a groove, a longitudinal extension of which coincides with a longitudinal extension of the DIN rail in the mounted state of the circuit breaker, the housing of the circuit breaker can comprise two side faces, which are orientated perpendicular the longitudinal extension of the groove of the mounting means and the data interface can be prepared for data transmission of the measurement data via one of the or via both side faces.

In the above context, an arrangement can comprise a DIN rail, a first circuit breaker of the disclosed kind mounted on the DIN rail and

I) a second circuit breaker of the disclosed kind mounted on the DIN rail side by side to the first circuit breaker and/or

II) a communication module mounted on the DIN rail side by side to the first circuit breaker, wherein the housing of the communication module comprises two side faces, which are orientated perpendicular the longitudinal extension of the DIN rail, wherein the communication module comprises one or more data interface(s) and wherein the communication module is prepared for data transmission through one or more data interface(s) via one of the or both side faces.

In this way, the circuit breaker can send own measurement data to a communication module or also to a neighbored circuit breaker or can receive foreign measurement data from a neighbored circuit breaker and can relay it to the communication module. By chaining a couple of circuit breakers, measurement data can be forwarded step by step through the chain. So, in principle a single common communication module can be used for a plurality of circuit breakers. Generally, the chained circuit breakers and communication module can be prepared for transmission in only one direction or in both opposite directions.

Beneficially, the data interface in addition can be designed to receive foreign measurement data or commands from an adjacent circuit breaker or communication module and can be designed to transmit this foreign measurement data from one side face to the other side face, to transmit these commands from one side face to the other side face or to transmit these commands to the circuit breaker’s microprocessor for execution.

In this way, the circuit breaker additionally can receive commands from the communication module and can transmit them to its own microprocessor for execution or can receive commands from the communication module and can relay them to a neighbored circuit breaker. So, by chaining a couple of circuit breakers also commands can be forwarded step by step through the chain.

In yet another embodiment, the circuit breaker can comprise mounting means, which are arranged on a rear side of the circuit breaker, which are designed for mounting the circuit breaker on a DIN rail and which form or comprise a groove, a longitudinal extension of which coincides with a longitudinal extension of the DIN rail in the mounted state of the circuit breaker, the housing of the circuit breaker can comprise a front face vis-a-vis of the rear face, a top face connecting the rear face and the front face on one end and a bottom face vis-a-vis of the top face connecting the rear face and the front face on another end and the data interface can be prepared for data transmission of the measurement data via the top face, bottom face and/or the front face.

In the above context, an arrangement can comprise a DIN rail, a circuit breaker of the disclosed kind mounted on the DIN rail, a communication rail, which is orientated parallel to the DIN rail and which comprises power conductors and communication conductors, a master communication module, which is connected to the power conductors and the communication conductors and which is designed to power the power conductors and to at least receive measurement data via the communication conductors, and a sub communication module,

-) which is mounted to the communication rail and which is arranged in the vicinity of the top face, bottom face and/or the front face of the circuit breaker,

-) which is connected to the power conductors and which is designed to receive power from the power conductors and

-) which is connected to the communication conductors and which is designed to fed measurement data received from the data interface of the circuit breaker into the communication conductors.

In this way, the circuit breaker can send own measurement data to a communication module or also to another circuit breaker. In this embodiment, the circuit breakers are not chained with regards to data transmission, but devices may directly communicate independent of whether they are neighbored or not.

The communication between the circuit breakers and the sub communication modules takes place through the data interface, and the communication between the sub communication modules and the master communication module takes place through the communication rail. Generally, the master communication module can be designed to provide communication between the circuit breakers and a superordinate control.

Beneficially, the data interface in addition can be designed to receive foreign measurement data or commands from another circuit breaker or a master communication module via the top face, bottom face and/or the front face and can be designed to relay this foreign measurement data, in particular to another circuit breaker via the associated sub communication modules, to relay this foreign measurement data, in particular via its sub communication module to the master communication module, to relay these commands, in particular to another circuit breaker via the associated sub communication module, or to transmit these commands to the circuit breaker’s microprocessor for execution.

In this way, the circuit breaker can send own measurement data to another circuit breaker or to the master communication module, can receive foreign measurement data from another circuit breaker and can relay it to the communication module or can receive commands from the master communication module and can transmit them to its own microprocessor for execution or can relay them to another circuit breaker. Again, it is noted that the circuit breakers are not chained with regards to data transmission, but devices may directly communicate independent of whether they are neighbored or not in this embodiment.

BRIEF DESCRIPTION OF DRAWINGS

The invention now is described in more detail hereinafter with reference to particular embodiments, which the invention however is not limited to.

Fig. 1 shows a schematic circuit diagram of a first example of a circuit breaker;

Fig. 2 shows a schematic circuit diagram of a first example of an electronic circuit with an amplifier and a data interface;

Fig. 3 shows a schematic circuit diagram of an example of an electronic circuit with an amplifier and a wired data interface; Fig. 4 shows a schematic circuit diagram of an example of an electronic circuit with an amplifier and a contactless data interface;

Fig. 5 shows an electronic circuit like in Fig. 4 but with a microprocessor with a memory and a post processing unit;

Fig. 6 shows an electronic circuit like in Fig. 5 but with a frequency compensation unit and a temperature compensation unit;

Fig. 7 shows a circuit breaker like in Fig. 1 but with the switch in an alternative position;

Fig. 8 shows a circuit breaker like in Fig. 1 but with a two pole switch;

Fig. 9 shows a circuit breaker like in Fig. 1 but without a thermal trigger device;

Fig. 10 shows a circuit breaker like in Fig. 1 but without an electromagnetic trigger device;

Fig. 11 shows a schematic circuit diagram of a three phase circuit breaker;

Fig. 12 shows an oblique view of an exemplary circuit breaker and a DIN rail;

Fig. 13 shows an arrangement with a couple of circuit breakers and a communication module communicating via their side faces;

Fig. 14 shows an oblique view of an exemplary circuit breaker, a DIN rail, a communication rail, and a sub communication module and

Fig. 15 shows an arrangement with a couple of circuit breakers and a communication module communicating via a communication rail.

DETAILED DESCRIPTION

Generally, same parts or similar parts are denoted with the same/similar names and reference signs. The features disclosed in the description apply to parts with the same/similar names respectively same/similar reference signs. Indicating the orientation and relative position is related to the associated figure, and indication of the orientation and/or relative position has to be amended in different figures accordingly as the case may be.

Fig. 1 shows a schematic circuit diagram of a first example of a circuit breaker 1a. The circuit breaker 1 a comprises a housing 2 and two input terminals TI1 , TI2 and two output terminals TO1 , TO2 reaching through the housing 2, wherein the input terminals TI1 , TI2 are intended to be connected to a grid and wherein the output terminals TO1 , TO2 are intended to be connected to a load (note: the grid and the load are not shown in Fig. 1 ). Moreover, the circuit breaker 1a comprises a switch unit 3a with a first switch S1 , wherein the switch unit 3a is arranged in the housing 2 and wherein the first switch S1 is electrically arranged between a first input terminal TI1 of the input terminals TI1 , TI2 and a first output terminal TO1 of the output terminals TO1 , TO2. In addition, the circuit breaker 1a comprises a latch 4a, which is arranged in the housing 2 and which upon a trigger signal opens the switch S1 of the switch unit 3a and which keeps the same open after a trigger signal until manual on-site intervention or until remote intervention. Additionally, the current breaker 1a comprises a handle 5 and a trigger unit 6a. The handle 5 and the trigger unit 6a are functionally coupled with the latch 4a, and the latch 4a is functionally coupled with the switch unit 3a. For example, the functional coupling may be achieved by means of a mechanical connection. In such a case, the trigger signal can be formed by a movement of a part of the trigger unit 6a, wherein said part is connected to the latch 4a. Accordingly, such a movement triggers the latch 4a, which in turn switches off the first switch S1 of the switch unit 3a. As said, the latch 3a keeps the first switch S1 of the switch unit 3a open after a trigger signal until manual on-site intervention or until remote intervention. Manual intervention can be a movement of the handle 5, which causes the first switch S1 of the switch unit 3a being closed again, as this is principally known. In addition, the first switch S1 of the switch unit 3a may also be closed remotely, for example by means of an electric signal fed to the latch 4a (not shown in Fig. 1).

In detail, the trigger unit 6a comprises an electromagnetic trigger device 7 with a first coil L1 , wherein the electromagnetic trigger device 7 is arranged in the housing 2 and causes outputting the trigger signal in case of overcurrent through the first coil L1 . In this embodiment, the first coil L1 is electrically arranged in series with the first switch S1 (case a). For generation of the trigger signal, the electromagnetic trigger device 7 comprises an electromagnetic transducer 8, which is functionally coupled to the first coil L1 and which transforms the electromagnetic field emitted by the first coil L1 (illustrated with the magnetic field strength H in Fig. 1 ) into a trigger signal. For example, the electromagnetic transducer 8 can be formed of or comprise an armature, which is attracted by the electromagnetic field emitted by the first coil L1 . Accordingly, an overcurrent through the first coil L1 can cause a movement of the armature and in turn outputting a mechanical trigger signal. However, although this is a proven method for triggering a latch 4a, the electromagnetic transducer 8 may also work on a different physical principle and for example generate an electric trigger signal. An example for such an electromagnetic transducer 8 is a Hall sensor converting the electromagnetic field emitted by the first coil L1 into a voltage.

The trigger unit 6a depicted in Fig. 1 in addition comprises a thermal trigger device 9 with a first heating element R1 , wherein the thermal trigger device 9 is arranged in the housing 2 and causes outputting the trigger signal in case of overcurrent through the first heating element R1 . In this embodiment, the first heating element R1 is electrically arranged in series with the first switch S1 as well (case b). The function of the thermal trigger device 9 is similar to that of the electromagnetic trigger device 7, however, based on the temperature T of the first heating element R1 . For generation of the trigger signal, the thermal trigger device 9 comprises a thermal transducer 10, which is functionally coupled to the first heating element R1 and which transforms a temperature T generated by the first heating element R1 into a trigger signal. In particular, the first heating element R1 can be formed by or comprise a first bimetal element. In this case, the output of the first heating element R1 is not a temperature but a switching state or movement, which is fed to the latch 4a. Strictly speaking, the first bimetal element also comprises the thermal transducer 10. In other words, the functions of the first heating element R1 and the thermal transducer 10 are comprised of a single device then. However, although this is a proven method for triggering a latch 4a, the thermal transducer 10 may also work on a different physical principle and for example generate an electric trigger signal. An example for such a thermal transducer 8 is an electronic temperature sensor converting the temperature T generated by the first heating element R1 into a voltage. As is generally known in prior art, overcurrents with a fast current changing rate cause triggering the latch 4a through the electromagnetic transducer 8, overcurrents with a slow changing rate through the thermal trigger device 9. It should also be noted that the latch 4a, the electromagnetic trigger device 7 and the thermal trigger device 9 may be part of a single module of the circuit breaker 1a. Accordingly, the various parts shown in Fig. 1 may be seen as functional groups, which may be embodied in one or more physical modules.

In addition to the parts cited above, the circuit breaker 1a comprises a first voltage sensor 11a, which is arranged in the housing 2 and whose inputs are electrically connected to the trigger unit 6a. In this example, the first voltage sensor 11a is designed to measure a first voltage drop U1 at the first coil L1 and at the first heating element R1 . Generally, the first voltage drop U1 reflects a first current 11 through the trigger unit 6a. In other words, the measured first voltage drop U1 is proportional to the first current 11 flowing through the first coil L1 and the first heating element R1 and thus can be seen as an equivalent to said first current 11 .

The circuit breaker 1a of Fig. 1 additionally comprises an optional electronic circuit 12, which is arranged in the housing 2, which is connected to the voltage sensor 11a and which comprises a data interface 13. Fig. 2 in this context shows a first embodiment of an electronic circuit 12a, which apart of the data interface 13 comprises an optional amplifier 14. The data interface 13 can be embodied as a wired data interface 13a, which is designed to transmit measurement data reflecting the first measured voltage drop U1 out of the housing 2 by wire (case i) like this is shown in Fig. 3. Alternatively or in addition, the data interface 13 can be embodied as a wireless or contactless data interface 13b, which is designed to transmit measurement data reflecting the first measured voltage drop U1 out of the housing 2 in a contactless manner (case ii) like this is shown in Fig. 4. For example, the contactless data interface 13b can be a radio interface (and thus can comprise a radio sender), in particular working according to the standard for Near-field communication (NFC). Alternatively, the contactless data interface 13b can be an optical interface (and thus comprise a sender diode), in particular working according to the standard for Infrared Data Association (IrDA). The optional amplifier 14 is designed to amplify the first measured voltage drop U1 before it is transmitted by the data interface 13, 13a, 13b. In particular, the amplification may be chosen in a way that the output value of the amplifier 14 directly reflects the first current 11 associated with the first measured voltage drop U1 , however, with a different magnitude as the case may be.

The electronic circuit 12 may also comprise a microprocessor 15a, which is designed to postprocess the measurement data reflecting the measured first voltage drop U1 , in particular after it has been amplified by the amplifier 14 and before it is sent to the data interface 13, 13a, 13b, like this is depicted in Fig. 5 by use of an electronic circuit 12d. In detail, the electronic circuit 12d comprises a post processing unit 16 and a memory 17 in this example. For example, data may be stored (e.g. with a timestamp) in the memory 17 for later use, measurement data can be averaged by use of the post processing unit 16, etc. In this context it should be noted that the data interface 13, 13a, 13b may additionally be prepared to receive commands and to transmit these commands to the microprocessor 15a for execution. Such commands may be used for clearing the memory 17, for resetting an averaging algorithm, etc.

Fig. 6 shows another example of an electronic circuit 12e, which in addition to the parts already cited before comprises an optional frequency compensation unit 18, which compensates a deviation of a real voltage drop from the associated measured first voltage drop U1 based on a deviation of a frequency f of the first current 11 from a reference frequency in case a). The frequency f of the first current 11 is measured by use of a frequency measuring unit 19 in this example. In contrast to a traditional shunt for measuring a current via a voltage drop, which basically is invariant to a frequency f of the current to be measured, the voltage drop at the first coil L1 substantially depends on the frequency f of the first current 11 . Usually, the frequency can be assumed to be stable at 50 Hz or 60 Hz. However, if a very high measuring accuracy is desired, frequency variations around said nominal frequency of 50 Hz or 60 Hz can be taken into consideration by calculating the impedance of the first coil L1 , which is Zu = j-co -l_1 with o = 2-jr-f or by calculating a deviation of the real impedance from a nominal impedance at 50 Hz or 60 Hz.

The electronic circuit 12e in addition comprises an optional temperature compensation unit 20, which compensates a deviation of a real voltage drop from the associated measured first voltage drop U1 based on a deviation of a temperature T of the first heating element R1 from a reference temperature Tr in case b). The reference temperature Tr is measured by use of an ambient temperature sensor 21 in this example. Usually, the temperature, at which the circuit breaker 1a is operated, can be assumed to be stable, for example at 20°. However, if a very high measuring accuracy is desired, temperature variations can be taken into consideration by measuring an ambient reference temperature Tr and by accordingly taking into consideration the dependency of the resistance of the thermal trigger device 9 from its temperature T.

In the embodiments of Figs. 2 to 6, the voltage sensor 11a is shown as a separate part being connected to the electronic circuit 12, 12a..12e. However, similarly, the voltage sensor 11 a may be part of the electronic circuit 12, 12a..12e. In this context, one should also note that the voltage sensor 11 a may comprise all or some of the parts of the electronic circuit 12, 12a..12e, such as the data interface 13, 13a, 13b, the amplifier 14 and/or the microprocessor 15a, 15b or its parts. One should also note that the parts of the electronic circuit 12, 12a..12e are not necessarily separate physic parts but can be seen as functional parts, which may be embodied in one or more physic devices. For example, the frequency compensation unit 18, the temperature compensation unit 20, the post processing unit 16 and the memory 17 may be embodied on one and the same chip, etc.

Fig. 1 shows an embodiment of a circuit breaker 1a, where the first coil L1 is electrically arranged in series with the first switch S1 and where the first heating element R1 is electrically arranged in series with the first switch S1 as well. However, this is not the only possibility. Fig. 7 shows an embodiment of a circuit breaker 1 b, which is similar to the circuit breaker 1a shown in Fig. 1 . In contrast, the first coil L1 is electrically arranged between a second input terminal TI2 of the input terminals TI1 , TI2 and a second output terminal TO2 of the output terminals TO1 , TO2, and the first heating element R1 is electrically arranged between the second input terminal TI2 and the second output terminal TO2 as well. However, in the operational state of the circuit breaker 1b, i.e. when the circuit breaker 1 b is connected to a grid via its input terminals TI1 , TI2 and to a load via its output terminals TO1 , TO2, the first coil L1 and the first heating element R1 are again switched in series with the first switch S1. So, the function of the circuit breaker 1 b basically equals the function of the circuit breaker 1a. Both, the circuit breaker 1a and the circuit breaker 1 b are single pole switches, which - if properly connected - disconnected a phase line in case of overcurrent (but not the neutral line).

Fig. 8 shows another example of a circuit breaker 1c, which basically is the combination of the circuit breakers 1a and 1b. Hence, the function of the circuit breaker 1c basically equals the function of the circuit breakers 1a and 1 b. In, detail the switch unit 3c comprises a second switch S2, which is electrically arranged between the second input terminal TI2 and the second output terminal TO2. So, both a neutral line and a phase line are disconnected in case of overcurrent.

Fig. 9 shows an embodiment of a circuit breaker 1 d, which again is similar to the circuit breaker 1a shown in Fig. 1. In contrast, the circuit breaker 1d does not comprise a first heating element R1 . Accordingly, the function of the circuit breaker 1d is similar to the function of the circuit breaker 1a but does not involve the function of the first heating element R1 . One should also understand, that in the embodiment of the circuit breaker 1 a shown in Fig. 1 , the voltage sensor 11 a can be clamped only to the first coil L1. In such a case, triggering would take place as outlined in the context of the circuit breaker 1a of Fig. 1 , whereas current measuring would take place like in the circuit breaker 1d of Fig. 9.

Fig. 10 shows an embodiment of a circuit breaker 1 e, which again is similar to the circuit breaker 1a shown in Fig. 1 . In contrast, the circuit breaker 1e does not comprise first coil L1 . Accordingly, the function of the circuit breaker 1e is similar to the function of the circuit breaker 1 a but does not involve the function of the first coil L1 . In other words, the function of the circuit breaker 1e equals the function of the circuit breaker 1d of Fig. 9, wherein the roles of the first coil L1 and the first heating element R1 are exchanged. One should also understand, that the in the embodiment of the circuit breaker 1a shown in Fig. 1 , the voltage sensor 11a can be clamped only to the first heating element R1 . In such a case, triggering would take place as outlined in the context of the circuit breaker 1a of Fig. 1 , whereas current measuring would take place like in the circuit breaker 1e of Fig. 10. Figs. 1 and 7 to 10 depict two pole circuit breakers 1a..1e. However, this is not the only possibility, and Fig. 11 depicts a circuit breaker 1f, which is embodied as four pole circuit breaker disconnecting a neutral line and three phase lines in case of overcurrent. For this reason, the circuit breaker 1f comprises additional switches S3 and S4. To detect overcurrent in all three phases even in case of unsymmetric load, the circuit breaker 1f can comprise three trigger units 6a..6a” as shown in Fig. 11 , which are each embodied like the trigger unit 6a of Fig. 1 and which each act on the latch 4d. There may also be a common trigger unit with a common electromagnetic trigger device and/or a common thermal trigger device. In this case, the common electromagnetic trigger device can comprise a second coil L2 and a third coil L3, wherein the electromagnetic trigger device causes outputting the trigger signal additionally in case of overcurrent through the second coil L2 or third coil L3 and wherein the second coil L2 is electrically arranged in series with the second switch S2 and wherein the third coil L3 is electrically arranged in series with the third switch S3. In addition, the common thermal trigger device can comprise a second heating element R2 and a third heating element R3, wherein the thermal trigger device causes outputting the trigger signal additionally in case of overcurrent through the second heating element R2 or third heating element R3, and wherein the second heating element R2 is electrically arranged in series with the second switch S2 and wherein the third heating element R3 is electrically arranged in series with the third switch S3. If the circuit breaker 1f is designed for symmetric load only, principally overcurrent detection in one of the current paths is sufficient. It should also be noted that the switch S4 can be omitted if the neutral line needs not to be disconnected in case of overcurrent.

The circuit breaker 1f is capable of measuring all three currents 11 .. I3 independently through the voltage sensors 11 a..11 c or by use of the measured voltages I11 .. U3 respectively. Concretely, the circuit breaker 1f comprises a second voltage sensor 11 b, wherein the inputs of the second voltage sensor 11 b are electrically connected to the trigger unit 6a’, wherein the second voltage sensor 11 b is designed to measure a second voltage drop U2 at the second coil L2 if the trigger unit 6a’ comprises an electromagnetic trigger device 7 according to case a) and/or at the second heating element R2 if the trigger unit 6a’ comprises a thermal trigger device 9 according to case b) and wherein the second voltage drop U2 reflects a second current 12 through the trigger unit 6a’. In addition, the circuit breaker 1f comprises a third voltage sensor 11 c, wherein the inputs of the third voltage sensor 11 c are electrically connected to the trigger unit 6a”, wherein the third voltage sensor 11 c is designed to measure a third voltage drop U3 at the third coil L3 if the trigger unit 6a” comprises an electromagnetic trigger device 7 according to case a) and/or at the third heating element R3 if the trigger unit 6a” comprises a thermal trigger device 9 according to case b) and wherein the third voltage drop U3 reflects a third current I3 through the trigger unit 6a”. As already said, the second coil L2, the third coil L3, the second heating element R2 and the third heating element R3 can also be part of a common trigger unit, which the current sensors 11 a..11 c are connected to.

For the above reasons, the function of the circuit breaker 1f is similar to the function of the circuit breaker 1a, wherein overcurrent triggering and current measuring is multiplied.

In view of a frequency compensation, a compensation in case a) can be done based on the first current 11 flowing through the first coil L1 or based on the currents 11 .. I3 flowing through each of the coils L1 ,.L3. If there are more coils L1 ,.L3 in case a), compensation for all voltage drops U1 ..U3 can be based on a compensation based on the frequencies f of each of the currents 11 .. I3 or can be based on just one of the currents 11 ,.I3. It may be sufficient to base the compensation on just one current if no or no substantial variation of the frequencies f between the different currents 11 .. I3 is expected or possible.

In addition, in view of a temperature compensation, a compensation in case b) can done based on the temperature T of the first heating element R1 or based on temperatures T of each of the heating elements R1 ,.R3. If, for example, there are more bimetal elements in case b), compensation for all voltage drops U1 ..U3 can be based on the ambient or reference temperatures Tr for each of the bimetal elements or can be based on a compensation based on the ambient or reference temperature Tr of just one of the bimetal elements. It may be sufficient to base the compensation on just one ambient or reference temperature Tr if no or no substantial variation of the ambient or reference temperatures Tr for the different bimetal elements is expected. Fig. 12 now shows an oblique view of an arrangement 22a having a circuit breaker 1 with mounting means 23 and with a DIN rail 24. In detail, the mounting means 23 are arranged on a rear side A of the circuit breaker 1 and are designed for mounting the circuit breaker 1 on the DIN rail 24. The mounting means 23 form or comprise a groove B, whose longitudinal extension coincides with a longitudinal extension or axis C of the DIN rail 24 in the mounted state of the circuit breaker 1 . The housing 2 of the circuit breaker 1 comprises two side faces D1 , D2, which are orientated perpendicular the longitudinal extension of the groove B of the mounting means 23. In this embodiment, the data interface 13, 13a, 13b is prepared for data transmission of the measurement data via one of the or via both side faces D1 , D2.

In this context, Fig. 13 shows an arrangement 22b with a plurality of circuit breakers 1 A..1 D mounted on a DIN rail 24 and with a communication module 25, which is mounted on the DIN rail 24 as well. In detail, the circuit breakers 1A..1 C are mounted on the DIN rail 24 side by side. Each of the circuit breakers 1A..1 D comprises two data interfaces 13, 13’, which preferably are embodied as contactless data interfaces 13b as illustrated in Fig. 4. Nevertheless, the data interfaces 13, 13’ may be embodied as wired data interfaces 13a as illustrated in Fig. 3 as well. The communication module 25 is mounted on the DIN rail 24 between the first circuit breaker 1 A and the fourth circuit breaker 1 D. The housing of the communication module 25 comprises two side faces, too, which side faces are orientated perpendicular the longitudinal extension or axis C of the DIN rail 24. Moreover, the communication module 25 comprises one or more data interfaces 26, 26’, wherein the communication module 25 is prepared for data transmission through one or more data interfaces 26, 26’ via one of the or both side faces. Generally, the communication module 25 can be designed to provide communication between the circuit breakers 1A..1 D and a superordinate control. Finally, Fig. 13 shows optional screws 27 for the terminals TI1 ..TI4, TO1 ..TO4.

One should note that the arrangement 22b shown in Fig. 13 is just exemplary and may look differently. For example, the communication module 25 can be the first or last device in a row of devices.

The data interfaces 13, 13’ in addition to their measurement data sending function can be designed to receive foreign measurement data or commands from an adjacent circuit breaker 1A..1 D or communication module 25. For example, the circuit breaker 1A can be designed to transmit this foreign measurement data from one side face D1 to the other side face D2, to transmit commands from one side face D1 to the other side face D2 or to transmit commands to its microprocessor 15a, 15b for execution.

In this way, the circuit breaker 1A can send own measurement data to the communication module 25 (or also to the circuit breaker 1 B), can receive foreign measurement data from the circuit breaker 1 B and can relay it to the communication module 25, can receive commands from the communication module 25 and can transmit them to its own microprocessor 15a, 15b for execution or can receive commands from the communication module 25 and can relay them to the circuit breaker 1 B. By chaining a couple of circuit breakers 1A..1 D, measurement data and/or commands can be forwarded step by step through the chain. So, in principle a single common communication module 25 can be used for a plurality of circuit breakers 1A..1 D. Generally, the chained circuit breakers 1A..1 D and communication module 25 can be prepared for transmission in only one direction or in both opposite directions.

Fig. 14 now shows an arrangement 22c, which is similar to the arrangement 22a shown in Fig. 12, and Fig. 15 shows an arrangement 22d, which is similar to the arrangement 22b shown in Fig. 13. Again, the circuit breaker 1 of Fig. 14 comprises mounting means 23, which are arranged on a rear side A of the circuit breaker 1 , which are designed for mounting the circuit breaker 1 on the DIN rail 24 and which form or comprise a groove B, whose longitudinal extension coincides with the longitudinal extension or axis C of the DIN rail 24 in the mounted state of the circuit breaker 1 . The housing 2 of the circuit breaker 1 comprises a front face E vis-a-vis of the rear face A, a top face F connecting the rear face A and the front face E on one end and a bottom face G vis-a-vis of the top face F connecting the rear face A and the front face E on another end. In this embodiment, the data interface 13, 13a, 13b is prepared for data transmission of the measurement data via the front face E, but data transmission via the top face F or bottom face G would be possible as well. For data transmission, the arrangement 22c comprises a communication rail 28, which is orientated parallel to the DIN rail 24 and which comprises power conductors 29 and communication conductors 30. Further on, the arrangement 22c comprises a sub communication module 31 , which is mounted to the communication rail 28 and which is arranged in the vicinity of the front face E of the circuit breaker 1 . Alternatively, the sub communication module 31 may also be arranged in the vicinity of the top face F or bottom face G depending on where data transmission shall take place. The sub communication module 31 is connected to the power conductors 29 and is designed to receive power from the power conductors 29. Moreover, the sub communication module 31 is connected to the communication conductors 30 and is designed to fed measurement data received from the data interface 13, 13a, 13b of the circuit breaker 1 into the communication conductors 30.

The arrangement 22d is similar to the arrangement 22b of Fig. 13 but is based on the configuration depicted in Fig. 14. Concretely, the arrangement 22d comprises a plurality of circuit breakers 1A’..1 D’ of the type depicted in Fig. 14 mounted on the DIN rail 24 side by side. Each of the circuit breakers 1A’..1 D’ comprises a data interface 13, which preferably is embodied as a contactless data interface 13b as illustrated in Fig. 4 or which alternatively may also be embodied as wired data interface 13a as illustrated in Fig. 3.

Moreover, the arrangement 22d comprises a number of sub communication modules 31 , each being mounted on the communication rail 28 and each being associated with one of the circuit breakers 1A’..1 D’. As is depicted in Fig. 15, each sub communication module 31 is connected to a different one of the communication conductors 30 by means of connectors 33.

In addition, the arrangement 22d comprises a master communication module 32 being mounted on the DIN rail 24 side by side to the circuit breaker 1A’. The master communication module 32 is designed to power the power conductors 29 and to at least receive measurement data via the communication conductors 30. For this reason, the master communication module 32 is connected to the communication conductors 30 by means of connectors 34. One should note that the power conductors 29 are not explicitly shown in Fig. 15 for the sake of brevity. The communication between the circuit breakers 1A’..1 D’ and the sub communication modules 31 takes place through the data interface 13, 13a, 13b, and the communication between the sub communication modules 31 and the master communication module 32 takes place through the communication conductors 30. Generally, the master communication module 32 can be designed to provide communication between the circuit breakers 1A’..1 D’ and a superordinate control.

One should note that the arrangement 22d shown in Fig. 15 is just exemplary and may look differently. For example, the master communication module 32 can be mounted between two of the circuit breakers 1 A’..1 D’.

The data interfaces 13, 13a, 13b in addition to their measurement data sending function can be designed to receive foreign measurement data or commands from another circuit breaker 1A’..1 D’ or the master communication module 32. For example the circuit breaker 1A’ can be designed to relay this foreign measurement data to another circuit breaker 1 B’..1 D’ via the associated sub communication modules 31 , to relay this foreign measurement data via its sub communication module 31 to the master communication module 32, to relay these commands to another circuit breaker 1 B’..1 D’ via the associated sub communication modules 31 or to transmit these commands to its own microprocessor 15a, 15b for execution.

In this way, the circuit breaker 1A’ can send own measurement data to another circuit breaker 1 B’..1 D’ or to the master communication module 32, can receive foreign measurement data from another circuit breaker 1 B’..1 D’ or can receive commands from the master communication module 32 and can transmit them to its own microprocessor 15a, 15b for execution or can relay them to another circuit breaker 1 B’..1 D’. In contrast to the arrangement 22b of Fig. 13, the circuit breakers 1 A’..1 D’ are not chained with regards to data transmission in this embodiment, but devices may directly communicate independent of whether they are neighbored or not. In reality, the circuit breakers 1 , 1a..1f, 1A..1 D’ and the arrangements 22a..22d may have more or less parts than shown in the figures. Moreover, the description may comprise subject matter of further independent inventions.

It should also be noted that the term "comprising" does not exclude other elements and the use of articles "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

LIST OF REFERENCE NUMERALS

1 , 1a..1f, 1A..1 D’ circuit breaker

2 housing

3a. ,3d switch unit

4a..4d latch

5 handle

6a..6c, 6a’, 6a” trigger unit

7 electromagnetic trigger device

8 electromagnetic transducer

9 thermal trigger device

10 thermal transducer

11 a..11 c voltage sensor

12, 12a..12h electronic circuit

13, 13’ 13a, 13b data interface

14 amplifier

15a, 15b microprocessor

16 post processing unit

17 memory

18 frequency compensation unit

19 frequency measuring unit

20 temperature compensation unit

21 ambient temperature sensor

22a..22d arrangement

23 mounting means

24 DIN rail

25 communication module 26, 26’ data interface of communication module

27 screw

28 communication rail

29 power conductor

30 communication conductor

31 sub communication module

32 master communication module

33 connector to sub communication module

34 connector to master communication module

A rear side of circuit breaker

B groove

C longitudinal extension or axis of DIN rail

D1 , D2 side face of circuit breaker housing

E front face

F top face

G bottom face

L1..L3 coil

R1..R3 heating element

S1..S4 switch

TI1..TI4 input terminal

TO1..TO4 output terminal

111 .. U3 measured voltage drop

11..13 current f frequency of current

H magnetic field strength

T temperature of heating element

Tr reference temperature

Claims

1. Circuit breaker (1 , 1 a..1f, 1A..1 D’), comprising a housing (2), one or more input terminals (TI1 ..TI4) and output terminals (TO1 ..TO4) reaching through the housing (2), wherein the input terminals (TI1 ..TI4) are intended to be connected to a grid and wherein the output terminals (TO1 ..TO4) are intended to be connected to a load, a switch unit (3a..3d) with at least a first switch (S1 ), wherein the switch unit (3a. ,3d) is arranged in the housing (2) and wherein the first switch (S1 ) is electrically arranged between a first input terminal (TI1 ) of the input terminals (TI1 ..TI4) and a first output terminal (TO1 ) of the output terminals (TO1..TO4), a latch (4a..4d), which is arranged in the housing (2) and which upon a trigger signal opens the switch(es) (S1 ..S4) of the switch unit (3a..3d) and which keeps the same open after a trigger signal until manual on-site intervention or until remote intervention, and a trigger unit (6a..6c, 6a’, 6a”) with an electromagnetic trigger device (7) with a first coil (L1 ), wherein the electromagnetic trigger device (7) is arranged in the housing (2) and causes outputting of the trigger signal in case of overcurrent through the first coil (L1 ) and wherein the first coil (L1 ) is electrically arranged in series with the first switch (S1 ) or between a second input terminal (TI2) of the input terminals (TI1..TI4) and a second output terminal (TO2) of the output terminals (TO1..TO4), and characterized by a first voltage sensor (11 a), wherein the first voltage sensor (11 a) is arranged in the housing (2), wherein the inputs of the first voltage sensor (11 a) are electrically connected to the trigger unit (6a..6c, 6a’, 6a”), wherein the first voltage sensor (11a) is designed to measure a first voltage drop (U1 ) at the first coil (L1 ), wherein the first voltage drop (U1 ) reflects a first current (11 ) through the trigger unit (6a. ,6c, 6a’, 6a”).

2. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in claim 1 , characterized in that the switch unit (3a..3d) comprises a second switch (S2), which is electrically arranged between the second input terminal (TI2) of the input terminals (TI1 ..TI4) and the second output terminal (TO2) of the output terminals (TO1 ..TO4).

3. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in claim 2, characterized in that the electromagnetic trigger device (7) comprises a second coil (L2), wherein the electromagnetic trigger device (7) causes outputting the trigger signal additionally in case of overcurrent through the second coil (L2) and wherein the second coil (L2) is electrically arranged in series with the second switch (S2).

4. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in claim 3, characterized by a second voltage sensor (11 b), wherein the inputs of the second voltage sensor (11 b) are electrically connected to the trigger unit (6a..6c, 6a’, 6a”), wherein the second voltage sensor (11b) is designed to measure a second voltage drop (U2) at the second coil (L2), wherein the second voltage drop (U2) reflects a second current (I2) through the trigger unit (6a..6c, 6a’, 6a”).

5. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in any one of claims 1 to 4, further comprising an electronic circuit (12, 12a..12h), which is arranged in the housing (2), which is connected to the voltage sensor(s) (11a..11c) or which the voltage sensor(s) (11 a..11c) is/are part of and which comprises a data interface (13) i) wherein the data interface (13, 13’ 13a, 13b) is embodied as a wired data interface (13a), which is designed to transmit measurement data reflecting the measured voltage drop(s) (U1 ..U3) out of the housing (2) and/or ii) wherein the data interface (13, 13’ 13a, 13b) is embodied as a contactless data interface (13b), which is designed to transmit measurement data reflecting the measured voltage drop(s) (U1 ..U3) out of the housing (2) in a contactless manner.

6. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in claim 5, characterized in that the electronic circuit (12, 12a..12h) or the voltage sensor(s) (11a..11c) comprises an amplifier (14), which is designed to amplify the measured voltage drop(s) (U1 ..U3).

7. Circuit breaker (1 , 1a..1f, 1 A..1 D’), as claimed in claim 5 or 6, characterized in that the electronic circuit (12, 12a..12h) comprises a microprocessor (15a, 15b), which is designed to postprocess the measurement data reflecting the measured voltage drop(s) (U1..LI3).

8. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in any one of claims 5 to 7, wherein the data interface is embodied as a contactless data interface (13b), and the contactless data interface is a radio interface or an optical interface.

9. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in any one of claims 7 to 8, characterized in that the data interface (13, 13’ 13a, 13b) in addition is designed to receive commands and which is designed to transmit these commands to the microprocessor (15a, 15b) for execution.

10. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in any one of claims 5 to 9, characterized in that the electronic circuit (12, 12a..12h) or the voltage sensor(s) (11a..11 c) comprise(s) a frequency compensation unit (18), which compensates a deviation of a real voltage drop from the associated measured voltage drop (U1 ..U3) or deviations of real voltage drops from the associated measured voltage drops (U1 ..U3) based on a deviation of a frequency (f) of the current (11 , I2) flowing over the electromagnetic trigger device (7) from a reference frequency, and, optionally, wherein a compensation is done based on the first current (11 ) flowing through the first coil (L1 ) or based on currents (11 , I2) flowing through each of the coils (L1 ,.L3).

11 . Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in any one of claims 5 to 10, characterized in that the circuit breaker (1 , 1a..1f, 1 A..1 D’) comprises mounting means (23), which are arranged on a rear side (A) of the circuit breaker (1 , 1 a..1f, 1A..1 D’), which are designed for mounting the circuit breaker (1 , 1a..1f, 1A..1 D’) on a DIN rail (24) and which form or comprise a groove (B), a longitudinal extension of which coincides with a longitudinal extension (C) of the DIN rail (24) in the mounted state of the circuit breaker (1 , 1a..1f, 1A..1 D’), the housing (2) of the circuit breaker (1 , 1a..1f, 1 A..1 D’) comprises two side faces (D1 , D2), which are orientated perpendicular the longitudinal extension of the groove (B) of the mounting means (23) and the data interface (13, 13’ 13a, 13b) is prepared for data transmission of the measurement data via one of the or via both side faces (D1 , D2).

12. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in claim 11 , characterized in that the data interface (13, 13’ 13a, 13b) in addition is designed to receive foreign measurement data or commands from an adjacent circuit breaker (1 B) or communication module (25) and which is designed to transmit this foreign measurement data from one side face (D1 ) to the other side face (D2), to transmit these commands from one side face (D1 ) to the other side face (D2) or to transmit these commands to the microprocessor (15a, 15b) of the circuit breaker (1 , 1a..1f, 1A..1 D’) for execution.

13. Arrangement (22b), comprising a DIN rail (24), a first circuit breaker (1A) as claimed in claim 11 or 12 mounted on the DIN rail (24) and

I) a second circuit breaker (1 B) as claimed in claim 11 or 12 mounted on the DIN rail (24) side by side to the first circuit breaker (1 A) and/or

II) a communication module (25) mounted on the DIN rail (24) side by side to the first circuit breaker (1A), wherein the housing of the communication module (25) comprises two side faces, which are orientated perpendicular the longitudinal extension (C) of the DIN rail (24), wherein the communication module (25) comprises one or more data interface(s) (26, 26’) and wherein the communication module (25) is prepared for data transmission through one or more data interface(s) (26, 26’) via one of the or both side faces.

14. Circuit breaker (1 , 1a..1f, 1A..1 D’), as claimed in any one of claims 5 to 10, characterized in that the circuit breaker (1 , 1a..1f, 1 A..1 D’) comprises mounting means (23), which are arranged on a rear side (A) of the circuit breaker (1 , 1 a..1f, 1A..1 D’), which are designed for mounting the circuit breaker (1 , 1a..1f, 1A..1 D’) on a DIN rail (24) and which form or comprise a groove (B), a longitudinal extension of which coincides with a longitudinal extension (C) of the DIN rail (24) in the mounted state of the circuit breaker (1 , 1a..1f, 1A..1 D’), the housing (2) of the circuit breaker (1 , 1a..1f, 1 A..1 D’) comprises a front face (E) vis-a-vis of the rear face (A), a top face (F) connecting the rear face (A) and the front face (E) on one end and a bottom face (G) vis-a-vis of the top face (F) connecting the rear face (A) and the front face (E) on another end and the data interface (13, 13’ 13a, 13b) is prepared for data transmission of the measurement data via the top face (F), bottom face (G) and/or the front face (E), and, optionally, wherein the data interface (13, 13’ 13a, 13b) in addition is designed to receive foreign measurement data or commands from another circuit breaker (1 B’..1 D’) or a master communication module (32) via the top face (F), bottom face (G) and/or the front face (E) and which is designed to relay this foreign measurement data, to relay these commands or to transmit these commands to its microprocessor (15a, 15b) for execution.

15. Arrangement (22d), comprising a DIN rail (24), a circuit breaker (1A’..1 D’) as claimed in claim 15 or 16 mounted on the DIN rail (24), a communication rail (28), which is orientated parallel to the DIN rail (24) and which comprises power conductors (29) and communication conductors (30), a master communication module (32), which is connected to the power conductors (29) and the communication conductors (30) and which is designed to power the power conductors (29) and to at least receive measurement data via the communication conductors (30), and a sub communication module (31 ), -) which is mounted to the communication rail (28) and which is arranged in the vicinity of the top face (F), bottom face (G) and/or the front face (E) of the circuit breaker (1 A’..1 D’),

-) which is connected to the power conductors (29) and which is designed to receive power from the power conductors (29) and

-) which is connected to the communication conductors (30) and which is designed to feed measurement data received from the data interface (13, 13’ 13a, 13b) of the circuit breaker (1 A’..1 D’) into the communication conductors (30).