Switching device with current-sensitive latching switch contact and second non-latching switch contact

Abstract

The invention relates to a device (1a.. 1j) comprising a circuit breaker (2a.. 2j) which opens a latched first switching contact (S1) when a current (I) at the first switching contact (S1) exceeds a first current threshold (TH1), said first switching contact (S1) being closed only by manual intervention in the field. The device (1a.. 1j) further comprises a series contactor or relay (3a.. 3j), a current sensor (8a.. 8b ') sensing the current (I), and an electronic threshold switch (9) outputting a current excess signal (CES) when the current (I) exceeds a second current threshold (TH2) lower than the first current threshold (TH1), and outputting a normal current signal (NCS) when the current (I) drops to a third current threshold (TH3) lower than the second current threshold (TH2) or less. A transition from the normal current signal (NCS) to the current excess signal (CES) opens the second switch contact (S2), and a switch-on pulse fed to the external switch-on terminal (T11) closes the second switch contact (S2). Furthermore, an overcurrent protection device (2b... 2g) and a residual current circuit breaker (2a... 2g) for the aforementioned arrangement (1a... 1j) are disclosed.

Description

Technical Field

[0001] The present invention relates to a device having a circuit breaker and a contactor or a relay. The circuit breaker comprises a first switch contact, a trigger unit and a latch, wherein the trigger unit is designed to disconnect the first switch contact when the current flowing through the first switch contact exceeds a first current threshold, and the latch is designed to keep the first switch contact disconnected until manual intervention on site. The contactor or the relay comprises a second switch contact connected in series with the first switch contact of the circuit breaker, and an actuating unit acting on the second switch contact.

[0002] Furthermore, the present invention relates to an overcurrent protection device comprising a first switch contact, a trigger unit and a latch, wherein the trigger unit is designed to disconnect the first switch contact when a load current flowing through the first switch contact exceeds a first load current threshold, and the latch is designed to keep the first switch contact disconnected until manual intervention occurs on site.

[0003] Finally, the invention relates to a residual current circuit breaker with overcurrent protection, comprising the above-mentioned overcurrent protection device and an additional trigger unit, which is designed to open the first switching contact also when the residual current flowing through the first switching contact exceeds a first residual current threshold. Background Art

[0004] A device, an overcurrent protection device and a residual current circuit breaker with the above-mentioned overcurrent protection are generally known in the prior art. In the case of an excessive load current (e.g. > 15 A) and / or in the case of a residual current (e.g. > 30 mA), the device triggers a first switching contact. In the first case, an abnormally high load leads to the triggering of the first switching contact. In the second case, an insulation fault is the reason for the triggering of the first switching contact. The first switching contact is latched, which means that the first switching contact remains open until manual intervention on site, for example, until someone operates a handle of the switching device coupled to the latch and the first switching contact.

[0005] Basically, this is standard for most electrical appliances and ensures a high level of safety. However, in some cases, the need for on-site manual intervention to switch the switchgear on again is also a disadvantage. For example, sockets or grid access points in public spaces can be used for various devices, at least some of which may cause excessive load currents and / or may have insulation faults. An example of this situation is a battery charging station for electric vehicles. Electric vehicles may cause quite high load currents and they may also have insulation faults. Even in the case where the load current and / or the residual current remain below the first current threshold, it is useful to keep them away from the sockets to avoid that small changes or fluctuations in the load current and / or the residual current lead to the triggering of the first switch contact and thus require on-site manual intervention. As a result, the downtime of the grid access point is relatively long, because the responsible person must go to the site to operate the handle on the switchgear. In this example, this means that no car can be charged for a relatively long time, which is a significant disadvantage considering the ratio of the number of electric vehicles to the number of charging stations. Summary of the invention

[0006] Therefore, the object of the present invention is to provide an improved arrangement, an improved overcurrent protection device and an improved residual current circuit breaker with overcurrent protection. In particular, a solution should be provided which overcomes the above-mentioned disadvantages and provides substantially uninterrupted power at the public grid access point.

[0007] The objects of the invention are solved by a device as disclosed in the opening paragraph, which device also comprises:

[0008] - a current sensor designed to sense the current flowing through the first switch contact (since the first switch contact and the second switch contact are connected in series, this current is equal to the current flowing through the second switch contact),

[0009] - an electronic threshold switch having an input and an output, wherein the input is connected to a current sensor, and wherein the output is functionally coupled to an actuation unit of a contactor or a relay, and

[0010] - External make-on terminal, which is functionally coupled to the actuating unit of the contactor or relay.

[0011] Electronic threshold switches are designed to

[0012] - providing a current excess signal if the current sensed by the current sensor exceeds a second current threshold, the second current threshold being lower than the first current threshold, and

[0013] - providing a normal current signal in case the current sensed by the current sensor drops below the second current threshold or drops below a third current threshold, the third current threshold being lower than the second current threshold.

[0014] - the transition from the normal current signal to the current excess signal causes the actuation unit to open the second switch contact, and

[0015] - A make pulse fed to the external make terminal causes the actuation unit to open the second switch contact.

[0016] Furthermore, the objects of the invention are solved by an overcurrent protection device disclosed in the opening paragraph (for example, implemented as a "miniature circuit breaker" or "MCB" for short, or implemented as a "molded case circuit breaker" or "MCCB" for short), which overcurrent protection device also includes:

[0017] - a current sensor designed to sense the load current flowing through the first switch contact (since the first switch contact and the second switch contact are connected in series, this current is equal to the current flowing through the second switch contact),

[0018] - An electronic threshold switch having an input and an output, wherein the input is connected to a current sensor, and wherein the output is connected to a terminal of an overcurrent protection device.

[0019] Electronic threshold switches are designed to

[0020] - providing a current excess signal if the load current sensed by the current sensor exceeds a second load current threshold, the second load current threshold being lower than the first load current threshold, and

[0021] - providing a normal current signal in case the load current sensed by the current sensor drops below a second load current threshold or drops below a third load current threshold, the third load current threshold being lower than the second load current threshold.

[0022] Finally, the objects of the invention are solved by a residual current circuit breaker with overcurrent protection ("RCBO" for short) as disclosed in the opening paragraph, which residual current circuit breaker comprises an overcurrent protection device as described above and an additional triggering unit designed to open the first switching contact also if the residual current flowing through the first switching contact exceeds a first residual current threshold value.

[0023] By means of the proposed measures, the grid is shut down with the aid of contactors or relays before the load current and / or residual current reaches a dangerous level. On the one hand, this means that the power supply is shut down even in situations that are not actually dangerous, such as when an electric vehicle requires considerable charging power or generates some residual current. On the other hand, it avoids situations in which small changes or fluctuations in the load current and / or residual current lead to the triggering of the first switch contact and thus require manual intervention on site. Instead, only the contactor or relay is turned off, which can be turned on again remotely or automatically after a short safety period. As a result, long downtimes at the grid access point are avoided, since there is no need for personnel to go to the site to operate the handle on the switch device.

[0024] The device can be constructed in different ways. In one embodiment, the circuit breaker has a circuit breaker housing, while the contactor or relay has a separate contactor or relay housing. Thus, the device can be combined very flexibly. In an alternative embodiment, the circuit breaker and the contactor or relay have a common housing. In this case, the device is very compact.

[0025] It should be noted that the term "load current" may refer to "AC load current", "DC load current" or "both AC and DC load current". The same is true for the term "residual current", which may refer to "AC residual current", "DC residual current" or "both AC and DC residual current". It should also be noted at this point that throughout the application, the term "residual current" may be replaced with "fault current", wherein the above definition also applies. Thus, the term "fault current" may refer to "AC fault current", "DC fault current" or "both AC and DC fault current".

[0026] In this context, it should also be noted that the current sensor can be implemented in different ways, namely as an AC load current sensor, a DC load current sensor, a combined AC / DC load current sensor, an AC residual current sensor, a DC residual current sensor, a combined AC / DC residual current sensor or any combination of these sensors. In particular, the term "current sensor" can also refer to a group of sub-sensors of the above-mentioned types.

[0027] When referring to the "current threshold", it should be noted that the current threshold is related to the load current or residual current. The residual current threshold is usually 30 mA or less, while the load current threshold is much higher and may even reach several kA.

[0028] Further advantageous embodiments are disclosed in the claims, the description and the drawings.

[0029] In one embodiment, the contactor or relay is a bistable contactor or relay, and the output of the electronic threshold switch and the external make-on terminal are fed to the actuation unit of the bistable contactor or relay (case a). In this case, the actuation pulse is fed directly to the actuation unit, which then holds the second switch contact in a given position. The bistable contactor or relay may have one coil or two coils for actuating the second switch contact.

[0030] In an alternative embodiment, the contactor or relay is a monostable contactor or relay, and the device includes an RS trigger, wherein the external make terminal is fed to the set input of the RS trigger, and the output of the electronic threshold switch is fed to the reset input of the RS trigger, or vice versa, and wherein the output of the RS trigger is fed to the actuation unit of the monostable contactor or relay (case b). The monostable contactor or relay usually has one coil for actuating the second switch contact, and has one switch position in which the coil is energized, and another switch position in which the coil is not energized. In order to keep the second switch contact in the desired position, it is recommended to use an RS trigger. If the second switch contact is closed in the energized state, the electronic threshold switch is fed to the reset input of the RS trigger, and the external make terminal is fed to the set input of the RS trigger. Therefore, an overcurrent event switches the second switch contact to its open position, and an external make pulse switches the second switch contact to its closed position. If the second switch contact is open in the energized state, the electronic threshold switch is fed to the set input of the RS flip-flop, and the external make terminal is fed to the reset input of the RS flip-flop. Thus, an overcurrent event switches the second switch contact to its open position again, while an external make pulse switches the second switch contact to its closed position. Typically, the RS flip-flop can be part of a circuit breaker, or can be part of a contactor or a relay.

[0031] Advantageously, the device comprises an external shutdown terminal and a logic OR function, wherein the output of the electronic threshold switch and the external shutdown terminal are fed to the input of the logic OR function, and the output of the logic OR function is fed to the actuating unit of the bistable contactor or relay in case a), or is fed to the reset input of the RS trigger (if the second switch contact is closed in the energized state) or the set input of the RS trigger (if the second switch contact is disconnected in the energized state) in case b). In this way, the contactor or relay can also be turned off by an external shutdown pulse. For this purpose, the device can particularly include an additional external shutdown terminal, which is connected to the input of the OR function. Typically, the OR function can be part of a circuit breaker, or can be part of a contactor or a relay. For example, the OR function can be implemented as an OR gate.

[0032] In one embodiment of the device, the circuit breaker can be designed as a residual current device (abbreviated as "ROD" - alternatively, "residual current circuit breaker" or "RCCB" for short, or "ground fault circuit interrupter" or "GFCI" for short), wherein

[0033] - The current flowing through the first switch contact is the residual current,

[0034] - the first current threshold is a first residual current threshold,

[0035] - the second current threshold is a second residual current threshold,

[0036] - The current exceeding limit signal is the residual current exceeding limit signal,

[0037] - The normal current signal is the normal residual current signal,

[0038] - the trigger unit is designed to open the first switch contact if a residual current flowing through the first switch contact exceeds a first residual current threshold value,

[0039] - the current sensor is designed as a residual current sensor for sensing a residual current flowing through the first switch contact,

[0040] - the electronic threshold switch is designed to provide a residual current excess signal at its output terminal if the residual current sensed by the current sensor exceeds a second residual current threshold value, wherein

[0041] - the electronic threshold switch is designed to provide a normal residual current signal if the residual current sensed by the current sensor falls below a second residual current threshold or falls below a third residual current threshold, the third residual current threshold being lower than the second residual current threshold, wherein

[0042] - the transition from a normal residual current signal to a residual current excess signal causes the actuation unit to open the second switch contact, and wherein

[0043] - A make pulse fed to the external make terminal causes the actuation unit to close the second switch contact.

[0044] In the present embodiment, the device comprises a residual current device. Thus, in the event of a residual current or a fault current, the device triggers the first switching contact.

[0045] In a very advantageous embodiment of the above arrangement,

[0046] - the first current threshold is a first DC residual current threshold,

[0047] - the second current threshold is a second DC residual current threshold,

[0048] - The current exceeding limit signal is the DC residual current exceeding limit signal.

[0049] - The normal current signal is a normal DC residual current signal,

[0050] - the trigger unit is designed to open the first switch contact when a DC residual current flowing through the first switch contact exceeds a first DC residual current threshold value,

[0051] - the circuit breaker comprises an additional trigger unit designed to open the first switching contact if an alternating residual current flowing through the first switching contact exceeds a first alternating residual current threshold value,

[0052] - the current sensor is designed as a DC residual current sensor designed to sense a DC residual current flowing through the first switch contact,

[0053] - the electronic threshold switch is designed to provide a DC residual current excess signal at its output terminal when the DC residual current sensed by the current sensor exceeds a second DC residual current threshold, wherein,

[0054] - the electronic threshold switch is designed to provide a normal DC residual current signal in the event that the DC residual current sensed by the current sensor drops below a second DC residual current threshold or drops below a third DC residual current threshold, the third DC residual current threshold being lower than the second DC residual current threshold, wherein

[0055] - the transition from the normal DC residual current signal to the DC residual current exceeding signal causes the actuating unit to open the second switch contact, and wherein

[0056] - A make pulse fed to the external make terminal causes the actuation unit to close the second switch contact.

[0057] In this embodiment, the additional trigger unit for the first switch contact is sensitive to AC residual current, while the current sensor senses DC residual current. Therefore, the electronic threshold switch and the second switch contact are sensitive to DC residual current. This embodiment is particularly useful for charging stations for electric vehicles, because electric vehicles mainly cause DC fault currents. As the car leaves again, the cause of the DC fault current also disappears. Therefore, it is beneficial to clear such conditions remotely. However, in alternative embodiments, the AC residual current and the DC residual current can change their roles in the above definition.

[0058] Advantageously, the above-mentioned residual current device of the arrangement can include an additional overcurrent protection switch connected in series with the first switching contact, which is then designed as a residual current circuit breaker with overcurrent protection ("RCBO" for short). The arrangement thus triggers the first switching contact both in the case of a residual current and in the case of an excessive load current. However, it should be noted that in this embodiment, the electronic threshold switch does not sense the load current, but is only sensitive to the residual current. Therefore, the second switching contact is only triggered in the case of a residual current.

[0059] In another embodiment of the device, the circuit breaker may be designed as an overcurrent protection device (for example, designed as a "miniature circuit breaker" or "MCB" for short, or designed as a "molded case circuit breaker" or "MCCB" for short), wherein

[0060] - The current flowing through the first switch contact is the load current,

[0061] - the first current threshold is a first load current threshold,

[0062] - the second current threshold is a second load current threshold,

[0063] - The current exceeding limit signal is the load current exceeding limit signal.

[0064] - Normal current signal is the normal load current signal,

[0065] - the trigger unit is designed to open the first switch contact if the load current flowing through the first switch contact exceeds a first load current threshold value,

[0066] - the current sensor is designed as a load current sensor designed to sense a load current flowing through the first switch contact,

[0067] - the electronic threshold switch is designed to provide a load current exceeding signal at its output terminal if the load current sensed by the current sensor exceeds a second load current threshold, wherein

[0068] the electronic threshold switch is designed to provide a normal load current signal if the load current sensed by the current sensor drops below a second load current threshold or drops below a third load current threshold, the third load current threshold being lower than the second load current threshold, wherein

[0069] - the transition from the normal load current signal to the load current exceeding signal causes the actuation unit to open the second switch contact, and wherein

[0070] - A make pulse fed to the external make terminal causes the actuation unit to close the second switch contact.

[0071] In this embodiment, the device comprises an overcurrent protection device. Thus, in case of excessive load current, the device triggers.

[0072] In a very advantageous embodiment of the above arrangement,

[0073] - the first current threshold is a first DC load current threshold,

[0074] - the second current threshold is a second DC load current threshold,

[0075] - The current over-limit signal is a DC load current over-limit signal.

[0076] - The normal load current signal is a normal DC load current signal,

[0077] - the trigger unit is designed to open the first switch contact when the DC load current flowing through the first switch contact exceeds a first DC load current threshold value,

[0078] - the circuit breaker comprises an additional trigger unit which is designed to open the first switching contact if the AC load current flowing through the first switching contact exceeds a first AC load current threshold value,

[0079] - the current sensor is designed as a DC load current sensor designed for sensing a DC load current flowing through the first switch contact,

[0080] - the electronic threshold switch is designed to provide a DC load current exceeding signal at its output terminal if the load current sensed by the current sensor exceeds a second DC load current threshold, wherein

[0081] the electronic threshold switch is designed to provide a normal DC load current signal if the DC load current sensed by the current sensor drops below a second DC load current threshold or drops below a third DC load current threshold, the third DC load current threshold being lower than the second DC load current threshold, wherein

[0082] - a change from a normal DC load current signal to a DC load current exceeding signal causes the actuation unit to open the second switch contact, and wherein

[0083] - A make pulse fed to the external make terminal causes the actuation unit to close the second switch contact.

[0084] In this embodiment, the additional trigger unit for the first switch contact is sensitive to the AC load current, while the current sensor senses the DC load current. Therefore, the electronic threshold switch and the second switch contact are sensitive to the DC load current. This embodiment is particularly useful for charging stations for electric vehicles, because electric vehicles (if any) mainly cause excessive DC load currents. As the car leaves again, the cause of the DC overload also disappears. Therefore, it is beneficial to clear such conditions remotely. However, in alternative embodiments, the AC load current and the DC load current can change their roles in the above definition.

[0085] Advantageously, the above-mentioned overcurrent protection device of the arrangement can include an additional residual current switch in series with the first switching contact and is then designed as a residual current circuit breaker (RCBO) with overcurrent protection. The arrangement thus triggers the first switching contact both in the case of a residual current and in the case of an excessive load current. However, it should be noted that in this embodiment, the electronic threshold switch does not sense the residual current but is only sensitive to the load current. Therefore, the second switching contact is only triggered in the case of a high load current.

[0086] In another embodiment of the proposed device, the circuit breaker may be designed as a residual current circuit breaker (RCBO) with overcurrent protection and may include, in addition to the features of the above-mentioned overcurrent protection device:

[0087] an additional triggering unit, which is designed to also open the first switching contact if the residual current flowing through the first switching contact exceeds a first residual current threshold value, and

[0088] - an additional current sensor which is designed as a residual current sensor designed for sensing a residual current flowing through the first switch contact and which is connected to an input of the electronic threshold switch.

[0089] The electronic threshold switch is also designed to

[0090] - providing a residual current excess signal if the residual current sensed by the additional current sensor exceeds a second residual current threshold, and

[0091] - providing a normal residual current signal in case the residual current sensed by the additional current sensor falls below a second residual current threshold value or falls below a third residual current threshold value, which is lower than the second residual current threshold value.

[0092] - causing the actuation unit to open the second switch contact if the electronic threshold value switch outputs a transition from a normal load current signal to a load current excess signal or a transition from a normal residual current signal to a residual current excess signal, and

[0093] - A make pulse fed to the external make terminal causes the actuation unit to close the second switch contact.

[0094] This is another embodiment of a device that triggers the first switch contact both in the case of a residual current and in the case of an excessive load current. Compared to other approaches disclosed previously, in this embodiment, the electronic threshold switch senses both the residual current and the load current. Thus, the second switch contact is triggered both in the case of a residual current and in the case of a high load current. It should also be noted that the electronic threshold switch outputs a dedicated current excess signal and a normal current signal for both the residual current and the load current.

[0095] In another embodiment of the proposed device, the circuit breaker may be designed as a residual current circuit breaker (RCBO) with overcurrent protection and may include, in addition to the features of the above-mentioned overcurrent protection device:

[0096] an additional triggering unit, which is designed to also open the first switching contact if the residual current flowing through the first switching contact exceeds a first residual current threshold value, and

[0097] - an additional current sensor which is designed as a residual current sensor designed for sensing a residual current flowing through the first switch contact and which is connected to an input of the electronic threshold switch.

[0098] The electronic threshold switch is also designed to

[0099] - providing a current excess signal in case the load current sensed by the current sensor exceeds a second load current threshold, or in case the residual current sensed by the additional current sensor exceeds a second residual current threshold, and

[0100] - providing a normal current signal when the load current sensed by the current sensor drops below a second load current threshold or drops below a third load current threshold and the residual current sensed by the additional current sensor drops below a second residual current threshold or drops below a third residual current threshold, the third load current threshold being lower than the second load current threshold, the third residual current threshold being lower than the second residual current threshold.

[0101] - the transition from the normal current signal to the current excess signal causes the actuation unit to open the second switch contact, and

[0102] - A make pulse fed to the external make terminal causes the actuation unit to close the second switch contact.

[0103] This is a further embodiment of a device that triggers the first switch contact both in the case of a residual current and in the case of an excessive load current. Also, in this embodiment, the electronic threshold switch senses both the residual current and the load current. Thus, the second switch contact is triggered both in the case of a residual current and in the case of a high load current. However, in this embodiment, the electronic threshold switch outputs a common current excess signal and a common normal current signal for the residual current and the load current.

[0104] In one embodiment, the residual current circuit breaker (RCBO) with overcurrent protection may include, in addition to the features of the above overcurrent protection device:

[0105] an additional triggering unit, which is designed to also open the first switching contact if the residual current flowing through the first switching contact exceeds a first residual current threshold value, and

[0106] - an additional current sensor which is designed as a residual current sensor designed for sensing a residual current flowing through the first switch contact and which is connected to an input of the electronic threshold switch.

[0107] The electronic threshold switch is also designed to

[0108] - providing a residual current excess signal if the residual current sensed by the additional current sensor exceeds a second residual current threshold, and

[0109] - providing a normal residual current signal in case the residual current sensed by the additional current sensor falls below a second residual current threshold value or falls below a third residual current threshold value, which is lower than the second residual current threshold value.

[0110] This is an embodiment of a residual current circuit breaker with overcurrent protection that triggers the first switch contact both in the case of residual current and in the case of excessive load current. In this embodiment, the electronic threshold switch senses both residual current and load current and outputs dedicated current excess signal and normal current signal for both residual current and load current, for example, to external terminals.

[0111] In another alternative embodiment, the residual current circuit breaker (RCBO) with overcurrent protection may include, in addition to the features of the above-mentioned overcurrent protection device:

[0112] - an additional triggering unit, which is designed to also open the first switching contact when the residual current flowing through the first switching contact exceeds a first residual current threshold value,

[0113] - an additional current sensor which is designed as a residual current sensor designed for sensing a residual current flowing through the first switch contact and which is connected to an input of the electronic threshold switch.

[0114] The electronic threshold switch is also designed to

[0115] - providing a current excess signal in case the load current sensed by the current sensor exceeds a second load current threshold, or in case the residual current sensed by the additional current sensor exceeds a second residual current threshold, and

[0116] - providing a normal current signal when the load current sensed by the current sensor drops below a second load current threshold or drops below a third load current threshold and the residual current sensed by the additional current sensor drops below a second residual current threshold or drops below a third residual current threshold, the third load current threshold being lower than the second load current threshold, the third residual current threshold being lower than the second residual current threshold.

[0117] This is an embodiment of a residual current circuit breaker with overcurrent protection that triggers the first switch contact both in the case of residual current and in the case of excessive load current. In this embodiment, the electronic threshold switch senses both the residual current and the load current, but unlike the above embodiments, the electronic threshold switch outputs a common current excess signal for the residual current and the load current, for example, to an external terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0118] The present invention will be described in more detail below with reference to specific embodiments, but the present invention is not limited thereto.

[0119] Figure 1 A schematic diagram of the device according to the invention used as a residual current device is shown;

[0120] Figure 2 An exemplary timing diagram showing the current flow through the switch contacts, the output of the electronic threshold switch and the state of the switch contacts;

[0121] Figure 3 A schematic diagram of the apparatus of the present invention used as an overcurrent protection device is shown;

[0122] Figure 4 A schematic diagram of the device of the invention used as a residual current circuit breaker with overcurrent protection is shown;

[0123] Figure 5 and Figure 4 Similar, but with an electronic threshold switch connected to the load current sensor;

[0124] Figure 6 and Figure 4Similar, but the electronic threshold switch is connected to both the load current sensor and the residual current sensor;

[0125] Figure 7 A schematic diagram of the device of the present invention with an additional external shutoff terminal is shown;

[0126] Figure 8 A schematic diagram of the device of the present invention is shown with an RS trigger coupled to a second switch contact;

[0127] Fig. 9 and Figure 8 Similar, but the circuit breaker and contactor or relay have a common housing;

[0128] Fig.10 A schematic diagram showing a device of the present invention having a DC residual current sensor and an AC residual current sensor; and

[0129] Fig.11 A schematic diagram of the device of the present invention having a DC load current sensor and an AC load current sensor is shown. DETAILED DESCRIPTION

[0130] In general, identical or similar parts are indicated by identical / similar names and reference numerals. The features disclosed in the specification apply to parts with identical / similar names and reference numerals. Indications of orientation and relative positions relate to the relevant figures, and indications of orientation and / or relative positions must be modified accordingly in different figures as appropriate.

[0131] Figure 1 A schematic diagram of an apparatus 1 a is shown, comprising a circuit breaker 2 a and a contactor or relay 3 a .

[0132] The circuit breaker 2a comprises a circuit breaker housing 4, a first switch contact S1, a trigger unit 5, a latch 6, a handle 7, a current sensor 8a, an electronic threshold switch 9, and five terminals T1..T5. Figure 1 In the example of , the neutral line N is connected to the terminals T1, T2, and one or more phases L1..L3 are connected to the terminals T3, T4. Figure 1 In FIG. 1 , only one conductor for each phase L1 .. L3 is shown symbolically, but in reality, there is a separate conductor for each phase L1 .. L3. Similar considerations can be made for the first switching contact S1. Figure 1 In FIG. 1 , only one first switching contact S1 of each phase L1 .. L3 is shown symbolically, but in reality, each phase L1 .. L3 may have a separate first switching contact S1 .

[0133] Current I LI..L3 From phases L1..L3 flows into terminal T3, and the current I NThe current sensor 8a is implemented as a residual current sensor in the present embodiment and senses a residual current or a fault current, which is a current I LI..L3 and current I N Both the trigger unit 5 and the electronic threshold switch 9 are connected to the current sensor 8a.

[0134] The trigger unit 5 is designed to open the first switch contact S1 when the current flowing through the circuit breaker 2a exceeds the first current threshold TH1. In this specific embodiment, the current is a residual current, and the first current threshold TH1 is a first residual current threshold TH1.

[0135] The latch 6 keeps the first switch contact S1 open until manual intervention occurs on site, that is, until someone closes the first switch contact S1 by operating the handle 7. Usually, the circuit breaker 2a also includes a test circuit and a test button, but for the sake of simplicity, Figure 1 Not shown.

[0136] The electronic threshold switch 9 has an input and an output, wherein the input is connected to the current sensor 8a, and wherein the output is connected to the terminal T5. The electronic threshold switch 9 is designed to provide a current excess signal at its output when the current sensed by the current sensor 8a exceeds a second current threshold TH2, wherein the second current threshold TH2 is lower than the first current threshold TH1. Furthermore, the electronic threshold switch 9 is designed to provide a normal current signal when the current sensed by the current sensor 8a drops below the second current threshold TH2 or drops below a third current threshold TH3, wherein the third current threshold TH3 is lower than the second current threshold TH2. The latter provides hysteresis if necessary.

[0137] The contactor or relay 3a in this embodiment includes a contactor or relay housing 10, a second switch contact S2, an actuating unit 11 acting on the second switch contact S2, and six terminals T6..T11. Figure 1 In the example of FIG. 1 , the neutral line N is connected to the terminals T6, T7, and one or more phases L1..L3 are connected to the terminals T8, T9. The second switching contact S2 is connected in series with the first switching contact S1 of the circuit breaker 2a. As in the case of the first switching contact S1, Figure 1, only one second switch contact S2 for phases L1 .. L3 is symbolically shown, but in practice, there may be one second switch contact S2 for each phase L1 .. L3. The output of the electronic threshold switch 9 is functionally coupled to the actuation unit 11 of the contactor or relay 3a. Specifically, the terminal T10 is connected to the actuation unit 11, and the output of the electronic threshold switch 9 is connected to the actuation unit 11 via the connection between the terminals T5 and T10. In addition, the terminal T11 forms an external make-up terminal, which is also functionally coupled to the actuation unit 11 of the contactor or relay 7. Specifically, the terminal T11 is connected to the actuation unit 11.

[0138] The actuation unit 11 is designed so that the transition from the normal current signal to the current exceeding signal causes the actuation unit 11 to open the second switch contact S2, and the on pulse fed to the external on terminal T11 causes the actuation unit 11 to close the second switch contact S2. For example, for this purpose, the contactor or relay 7 can be a bistable contactor or relay.

[0139] Now by using Figure 2 To explain the function of device 1a, Figure 2 At the very bottom a current-time diagram of the current I (in this example the residual current) is shown, above the diagram of the current signal CS the switching state S of the second switching contact S2 is shown. S2 , and the switching state S of the first switching contact S1 is shown at the top. S1 .

[0140] In normal operation, both the first switch contact S1 and the second switch contact S2 are closed and the load ( Figure 1 ) is conductively connected to the grid formed by the phases L1 .. L3 and the neutral conductor N. As long as the residual current (which is monitored by the residual current sensor 8a and is the current I LI..L3 and current I N The sum of the currents I and I) is lower than the second current threshold TH2, the switch contacts S1 and S2 remain closed. The electronic threshold switch 9 outputs a normal current signal NCS in this state. If the residual current I exceeds the second current threshold TH2 due to an insulation fault on the load side (which is the case at t1), the electronic threshold switch 9 changes its output from the normal current signal NCS to the current excess signal CES. This change causes the actuation unit 11 to open the second switch contact S2, thereby disconnecting the load from the grid. Since the second switch contact S2 cannot be opened in an infinitely short time, the load is disconnected from the grid when the current I LI..L3 There is some delay before it is indeed switched off at t2. Then, since the second switch contact S2 is open, the insulation fault is no longer valid and the electronic threshold switch 9 changes back to the normal current signal NCS.

[0141] It should be noted that in this first case of the functional description, the first switch contact S1 remains closed due to the fault or residual current I causing the second switch contact S2 to open not reaching the first current threshold TH1. Therefore, the trigger unit 5 is not activated.

[0142] The second switch contact S2 remains open until a make pulse is fed to the external make terminal T11 (this is the case at t3, and this causes the actuation unit 11 to close the second switch contact S2). Since the first switch contact S1 is still closed, the load is connected to the grid again. If the insulation fault no longer exists, the second switch contact S2 remains closed and the electronic threshold switch 9 outputs a normal current signal NCS. Therefore, in this case, the load remains connected to the grid.

[0143] If the insulation fault still exists and the residual current I exceeds the second current threshold TH2, the electronic threshold switch 9 immediately changes its output from the normal current signal NCS to the current excess signal CES, thereby disconnecting the second switch contact S2 again. Figure 2 In the switching state S2, the residual current remains low for a period of time and starts to rise rapidly from t4. At t5, the residual current I exceeds the second current threshold TH2, and the electronic threshold switch 9 changes its output from the normal current signal NCS to the current excess signal CES again. This change causes the actuator unit 11 to open the second switch contact S2, thereby disconnecting the load from the grid. S2 As shown in the figure, the second switch contact S2 cannot change its state immediately, so the residual current I also rises to the first current threshold TH1 at t6, causing the first switch contact S1 to be disconnected.

[0144] Therefore, if the residual current or fault current exceeds the first current threshold TH1, usually not only the second switch contact S2 will be opened, but also the first switch contact S1 will be opened by the trigger unit 5. In this case, only the switch-on pulse fed to the external switch-on terminal T11 will not connect the load to the grid again, but additional on-site manual intervention is required because the latch 6 keeps the first switch contact S1 open until someone operates the handle 7 and closes the first switch contact S1 again in this way.

[0145] In short, on the one hand, the device 1a provides the normal functionality of a residual current circuit breaker (RCD). In addition, less severe insulation faults also actually lead to disconnection of the load from the grid, but the switching on does not require manual intervention on site, but can be initiated remotely by feeding a switching on pulse to the external switching on terminal T11. This can be done by wire, but in principle it can also be done wirelessly if a suitable wireless receiver is connected to terminal T11 or even part of the device 1a and connected to the actuation unit 11.

[0146] It should be noted that Figure 2 A third current threshold value TH3 which is lower than the second current threshold value TH2 is also shown in FIG. In order to provide an optional hysteresis, the electronic threshold switch 9 can also be designed to provide a normal current signal NCS when the current I drops below the third current threshold value TH3.

[0147] Figure 3 Now a schematic diagram of an apparatus 1b is shown, which is similar to Figure 1 In contrast, the current sensor 8b of the circuit breaker 2b is implemented as a load current sensor in this embodiment and senses the load current, which is the current I LI..L3 (or alternatively the current I N ). Therefore, the circuit breaker 2b is designed as an overcurrent protection device (MCB or MCCB). Its functional principle is similar to Figure 1 The device 1a is basically the same. However, in Figure 1 and Figure 2 In the description of , the load current replaces the role of the residual current. In addition, there can be an optional thermal overload sensor 12, which also serves as a triggering unit for the first switching contact S1. Usually, such a thermal overload sensor 12 is used to detect lower overloads that act for a long time.

[0148] Figure 4 Now a schematic diagram of an apparatus 1c is shown, which is similar to Figure 1 and Figure 3 A combination of devices 1a and 1b. Figure 1 Device 1a starts with device 1c Figure 3 The device 1b also has a thermal overload sensor 12 for the same reason. In addition, the device 1c also has a load current sensor 8b, just like Figure 3 In addition, there is an additional trigger unit 13, which is connected to the load current sensor 8b. Therefore, the first switch contact S1 is not only triggered when the residual current exceeds the first residual current threshold TH1, but also when the load current exceeds the load current threshold (or when the thermal overload sensor 12 becomes overheated). Therefore, basically, Figure 4 The function of device 1c is equivalent to Figure 1 The function of the device 1a is added with the above-mentioned load current and thermal protection. It should be noted at this point that in this embodiment, the load current and thermal protection only act on the first switch contact S1, but not on the second switch contact S2.

[0149] Figure 5 A schematic diagram of an apparatus 1d is shown, which is similar to Figure 4In contrast, here the residual current sensor 8a is connected to the additional trigger unit 13 and the load current sensor 8b is connected to the trigger unit 5 and the electronic threshold switch 9. Figure 5 The function of device 1d is equivalent to Figure 4 The function of the device 1c is similar to that of the device 1c, but the roles of the residual current and the load current are changed. Nevertheless, the optional thermal overload sensor 12 still reacts to the load current and not to the residual current.

[0150] Figure 6 A schematic diagram of an apparatus 1e is shown, which is similar to Figure 3 In contrast, here both the residual current sensor 8a and the load current sensor 8b are connected to the trigger unit 5 and the electronic threshold switch 9. Figure 6 The function of device 1e is similar to Figure 4 The function of the device 1c. However, both the residual current and the load current can trigger the disconnection of the first switch contact S1 and the second switch contact S2. Basically, there is a logical OR between the residual current and the load current, which means that either the residual current or the load current can trigger the disconnection of the first switch contact S1 and the second switch contact S2. However, different first current thresholds TH1 and second current thresholds TH2 apply to the residual current and the load current (for example, the residual current threshold is 30 / 20 mA, while the load current threshold is 100 / 90 A). Figure 2 The relevant functional description also applies to Figure 6 In the present embodiment, the electronic threshold switch 9 outputs a common current exceeding signal and a common normal current signal for the residual current and the load current at the terminal T5. However, in an alternative embodiment, the electronic threshold switch 9 may also output a dedicated current exceeding signal and a normal current signal for both the residual current and the load current.

[0151] Figure 7 A schematic diagram of an apparatus 1f is shown, which is similar to Figure 4 1c. In contrast, the contactor or relay 3f comprises an additional OR function 14, which is implemented in this example as an OR gate, whose output is connected to the actuation unit 11 and whose input is connected to the terminals T10 and T12. Thus, the second switch contact S2 can be disconnected not only by the electronic threshold switch 9, but also by a pulse fed into the terminal T12. Thus, the second switch contact S2 can also be actively switched off remotely. It should be noted that the contactor or relay 3f can also be connected to Figure 1 , 3 , 5 and 6 are used in combination with the circuit breakers 2a, 2b, 2d and 2e. Finally, it should also be noted that the or function 14 can also be part of the circuit breaker 2f.

[0152] Figure 8 A schematic diagram of an apparatus 1g is shown, which is similar to Figure 7 Device 1f. In contrast, the contactor or relay 3f is a monostable contactor or relay, and the device 1g includes an RS trigger 15. The output of the RS trigger 15 is fed to the control input of the monostable contactor or relay, i.e., fed to the actuating unit 11. If the second switch contact S2 is closed in the powered-on state of the actuating unit 11, the external connection terminal T11 is fed to the set input of the RS trigger 15, and the output of the electronic threshold switch 9 is fed to the reset input of the RS trigger 15. If the second switch contact S2 is opened in the powered-on state of the actuating unit 11, the set input and the reset input change their roles. Therefore, a pulse fed into T10 or T12 causes the monostable second switch contact S2 to open, while a pulse fed into T11 causes the monostable second switch contact S2 to close. It should be noted that the OR gate 14 is only optional and can also be omitted. It should be noted that the contactor or relay 3g can also be connected with Figure 1 , 3 , 5 and 6 are used in combination with the circuit breakers 2a, 2b, 2d and 2e. Finally, it should also be noted that the RS trigger 15 can also be part of the circuit breaker 2g.

[0153] In the previously disclosed embodiments, the circuit breakers 2a..2g and the contactors or relays 3a..3g have separate housings 4 and 10. However, this is not a requirement, and Fig. 9 shows a device 1h, which is equivalent to Figure 8 The device 1h is similar to the device 1g, but has a common housing 16. Therefore, the terminals T2, T4, T5, T6, T8 and T10 are omitted in this embodiment. However, the function of the device 1h is the same as that of the device 1g. It should be noted that Figures 1 to 7 The devices 1a..1g can also use a common housing 16.

[0154] Fig.10 A schematic diagram of an apparatus 1i is shown, which is similar to Figure 4device 1c. In comparison, the additional residual current sensor 8a' replaces the load current sensor 8b. For example, the residual current sensor 8a can be implemented as a DC residual current sensor, while the additional residual current sensor 8a' can be implemented as an AC residual current sensor. In this way, the first switch contact S1 is triggered by the AC residual current or the DC residual current, while the second switch contact S2 is only triggered by the DC residual current. This embodiment is particularly useful for charging stations for electric vehicles, because electric vehicles mainly cause DC fault currents. As the car leaves again, the cause of the DC fault current also disappears. Therefore, it is beneficial to clear such conditions remotely. However, in an alternative embodiment, the AC residual current and the DC residual current can be in Fig.10 Change their roles in the arrangement 1i.

[0155] same, Fig.11 A schematic diagram of an apparatus 1j is shown, which is similar to Figure 5 device 1d. In comparison, the additional load current sensor 8b' replaces the residual current sensor 8a. For example, the load current sensor 8b can be implemented as a DC load current sensor, while the additional load current sensor 8b' can be implemented as an AC load current sensor. In this way, the first switch contact S1 is triggered by the AC load current or the DC load current, while the second switch contact S2 is only triggered by the DC load current. This embodiment is also particularly useful for charging stations for electric vehicles, because electric vehicles (if any) mainly cause excessive DC load currents. As the car leaves again, the cause of the DC overload also disappears. It is therefore beneficial to clear such conditions remotely. However, in an alternative embodiment, the AC load current and the DC load current can be in Fig.11 Change their roles in the device 1j.

[0156] It is worth noting that the present invention is not limited to the embodiments disclosed above, but different variants may be combined. In particular, additional and undescribed variants of the current sensors 8a..8b' and their use are possible. Moreover, in practice, the system may have more or fewer components than those shown in the figures. Furthermore, the description may include the subject matter of other independent inventions.

[0157] It should also be noted that the term "comprising" does not exclude other elements, and the use of the article "a" or "an" does not exclude a plurality. Elements described in connection with different embodiments may also be combined. It should also be noted that the reference signs in the claims should not be interpreted as limiting the scope of the claims.

[0158] Reference numerals list

[0159] 1a..1j Device

[0160] 2a..2j Circuit Breaker

[0161] 3a..3j Contactor or relay

[0162] 4 Circuit breaker housing

[0163] 5 Trigger unit

[0164] 6 Latch

[0165] 7. Handle

[0166] 8a, 8a' Residual current sensor

[0167] 8b, 8b' Load current sensor

[0168] 9 Electronic threshold switch

[0169] 10 Contactor or relay housing

[0170] 11 Actuation unit

[0171] 12 Thermal overload sensor

[0172] 13 Additional trigger unit

[0173] 14 OR function (OR gate)

[0174] 15 RS flip-flop

[0175] 16 Public Shell

[0176] CS current signal

[0177] CES current excess signal

[0178] NCS Normal Current Signal

[0179] I Current

[0180] I LI..L3 Current through the phase

[0181] I N Current through the neutral conductor

[0182] L1..L3 phase

[0183] N Neutral

[0184] S1 First switch contact

[0185] S2 Second switch contact

[0186] S S1 Switching state of the first switching contact

[0187] S S2 Switching state of the second switch contact

[0188] T Time

[0189] t i ..t6 time point

[0190] T1..T12 terminals

[0191] TH1 First current threshold

[0192] TH2 Second current threshold

[0193] TH3 The third current threshold

Claims

1. A device (1a..1j) comprising: - A circuit breaker (2a..2j) comprising a first switching contact (S1), a trigger unit (5, 13) and a latch (6), wherein the trigger unit (5, 13) is designed to open the first switching contact (S1) when the current (I) flowing through the first switching contact (S1) exceeds a first current threshold (TH1), and the latch (6) is designed to keep the first switching contact (S1) open until manual intervention on site, and - a contactor or relay (3a..3j) having a second switching contact (S2) and having an actuating unit (11) acting on said second switching contact (S2), said second switching contact (S2) being connected in series with said first switching contact (S1) of said circuit breaker (2a..2j), The features include: - a current sensor (8a..8b') designed to sense said current (I) flowing through said first switch contact (S1), - an electronic threshold switch (9) having an input and an output, wherein the input is connected to the current sensor (8a..8b'), and wherein the output is functionally coupled to the actuation unit (11) of the contactor or relay (3a..3j), and - an external make-on terminal (T11) functionally coupled to the actuation unit (11) of the contactor or relay (3a..3j), wherein - the electronic threshold switch (9) is designed to provide a current excess signal (CES) at its output terminal if the current (I) sensed by the current sensor (8) exceeds a second current threshold (TH2), the second current threshold (TH2) being lower than the first current threshold (TH1), wherein - the electronic threshold switch (9) is designed to provide a normal current signal (NCS) if the current (I) sensed by the current sensor (8) drops below the second current threshold (TH2) or drops below a third current threshold (TH3), the third current threshold (TH3) being lower than the second current threshold (TH2), wherein - the transition from the normal current signal (NCS) to the current excess signal (CES) causes the actuation unit (11) to open the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

2. The device (1a..1j) according to claim 1, characterized in that a) the contactor or relay (3a..3j) is a bistable contactor or relay, and the output of the electronic threshold switch (9) and the external make-on terminal (T11) are fed to the actuation unit (11) of the bistable contactor or relay (3a..3j), or b) the contactor or relay (3a..3j) is a monostable contactor or relay, and the device (1a..1j) comprises an RS trigger (15), wherein the external switch-on terminal (T11) is fed to the set input of the RS trigger (15) and the output of the electronic threshold switch (9) is fed to the reset input of the RS trigger (15), or vice versa, and wherein the output of the RS trigger (15) is fed to the actuation unit (11) of the monostable contactor or relay (3a..3j).

3. The device (1a..1j) according to claim 1 or 2, characterized in that The device (1a..1j) comprises an external shutdown terminal (T12) and a logic OR function (14), wherein the output of the electronic threshold switch (9) and the external shutdown terminal (T12) are fed to the input of the logic OR function (14), and the output of the logic OR function (14) is fed to the actuation unit (11) of a bistable contactor or relay (3a..3j) in case a) or to the reset input of an RS flip-flop (15) or to the set input of the RS flip-flop (15) in case b).

4. The device (1a..1j) according to any one of claims 1 to 3, characterized in that - the circuit breakers (2a..2j) are designed as residual current devices, - the current (I) flowing through the first switch contact (S1) is a residual current, - the first current threshold (TH1) is a first residual current threshold, - the second current threshold (TH2) is a second residual current threshold, - The current excess signal (CES) is a residual current excess signal, - The normal current signal (NCS) is a normal residual current signal, - the trigger unit (5, 13) is designed to open the first switch contact (S1) when the residual current (I) flowing through the first switch contact (S1) exceeds the first residual current threshold value (TH1), - the current sensor (8a, 8a') is designed as a residual current sensor for sensing the residual current (I) flowing through the first switching contact (S1), - the electronic threshold switch (9) is designed to provide the residual current excess signal (CES) at its output terminal if the residual current (I) sensed by the current sensor (8a, 8a') exceeds the second residual current threshold (TH2), wherein - the electronic threshold switch (9) is designed to provide the normal residual current signal (NCS) when the residual current (I) sensed by the current sensor (8a, 8a') drops below the second residual current threshold (TH2) or drops below a third residual current threshold (TH3), the third residual current threshold (TH3) being lower than the second residual current threshold (TH2), wherein - the transition from the normal residual current signal (NCS) to the residual current exceedance signal (CES) causes the actuation unit (11) to open the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

5. The device (1a..1j) according to claim 4, characterized in that - the first current threshold (TH1) is a first DC residual current threshold, - the second current threshold (TH2) is a second DC residual current threshold, - The current excess signal (CES) is a DC residual current excess signal. - The normal current signal (NCS) is a normal DC residual current signal, - the trigger unit (5, 13) is designed to disconnect the first switch contact (S1) when the DC residual current (I) flowing through the first switch contact (S1) exceeds the first DC residual current threshold (TH1), - the circuit breaker (2a..2j) comprises an additional trigger unit (13), which is designed to open the first switching contact (S1) when the AC residual current flowing through the first switching contact (S1) exceeds a first AC residual current threshold value, - the current sensor (8a, 8a') is designed as a DC residual current sensor designed to sense a DC residual current (I) flowing through the first switching contact (S1), - the electronic threshold switch (9) is designed to provide the DC residual current excess signal (CES) at its output terminal if the residual current (I) sensed by the current sensor (8a, 8a') exceeds the second DC residual current threshold (TH2), wherein - the electronic threshold switch (9) is designed to provide the normal DC residual current signal (NCS) when the DC residual current (I) sensed by the current sensor (8a, 8a') drops below the second DC residual current threshold value (TH2) or drops below a third DC residual current threshold value (TH3), wherein the third DC residual current threshold value (TH3) is lower than the second DC residual current threshold value (TH2), - the transition from the normal DC residual current signal (NCS) to the DC residual current excess signal (CES) causes the actuation unit (11) to open the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

6. The device (1a..1j) according to claim 4 or 5, characterized in that The circuit breaker (2a..2j) comprises an additional overcurrent protection switch connected in series with the first switching contact (S1) and is designed as a residual current circuit breaker with overcurrent protection.

7. The device (1a..1j) according to any one of claims 1 to 3, characterized in that - the circuit breakers (2a..2j) are designed as overcurrent protection devices, - the current (I) flowing through the first switch contact (S1) is the load current, - the first current threshold (TH1) is a first load current threshold, - the second current threshold (TH2) is a second load current threshold, - The current exceeding limit signal (CES) is a signal indicating that the load current exceeds the limit. - The normal current signal (NCS) is a normal load current signal, - the trigger unit (5, 13) is designed to open the first switch contact (S1) when the load current (I) flowing through the first switch contact (S1) exceeds the first load current threshold (TH1), - the current sensor (8b, 8b') is designed as a load current sensor designed to sense the load current (I) flowing through the first switch contact (S1), - the electronic threshold switch (9) is designed to provide the load current excess signal (CES) at its output terminal if the load current (I) sensed by the current sensor (8b, 8b') exceeds the second load current threshold (TH2), wherein - the electronic threshold switch (9) is designed to provide the normal load current signal (NCS) if the load current (I) sensed by the current sensor (8b, 8b') drops below the second load current threshold (TH2) or drops below a third load current threshold (TH3), the third load current threshold (TH3) being lower than the second load current threshold (TH2), wherein - a transition from the normal load current signal (NCS) to the load current excess signal (CES) causes the actuation unit (8) to open the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

8. The device (1a..1j) according to claim 7, characterized in that - the first current threshold (TH1) is a first DC load current threshold, - the second current threshold (TH2) is a second DC load current threshold, - The current excess signal (CES) is a DC load current excess signal. - The normal current signal (NCS) is a normal DC load current signal, - the trigger unit (5, 13) is designed to open the first switch contact (S1) when the DC load current (I) flowing through the first switch contact (S1) exceeds the first DC load current threshold (TH1), - the circuit breaker (2a..2j) comprises an additional trigger unit (13), which is designed to open the first switch contact (S1) when the AC load current flowing through the first switch contact (S1) exceeds a first AC load current threshold value, - the current sensor (8a, 8a') is designed as a DC load current sensor designed to sense a DC load current (I) flowing through the first switch contact (S1), - the electronic threshold switch (9) is designed to provide the DC load current exceeding signal (CES) at its output terminal if the load current (I) sensed by the current sensor (8a, 8a') exceeds the second DC load current threshold (TH2), wherein - the electronic threshold switch (9) is designed to provide the normal DC load current signal (NCS) when the DC load current (I) sensed by the current sensor (8a, 8a') drops below the second DC load current threshold (TH2) or drops below a third DC load current threshold (TH3), the third DC load current threshold (TH3) being lower than the second DC load current threshold (TH2), wherein - a transition from the normal DC load current signal (NCS) to the DC load current excess signal (CES) causes the actuation unit (11) to open the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

9. The device (1a..1j) according to claim 7 or 8, characterized in that The circuit breaker (2a..2j) comprises an additional residual current switch connected in series with the first switching contact (S1) and is designed as a residual current circuit breaker with overcurrent protection.

10. The device (1a..1j) according to any one of claims 7 to 9, characterized in that - the circuit breakers (2a..2j) are designed as residual current circuit breakers with overcurrent protection, - the circuit breaker (2a..2j) comprises an additional trigger unit (13), which is designed to open the first switching contact (S1) also when the residual current flowing through the first switching contact (S1) exceeds a first residual current threshold value, - the circuit breaker (2a..2j) comprises an additional current sensor (8a, 8a') which is designed as a residual current sensor designed to sense the residual current flowing through the first switching contact (S1) and is connected to an input of the electronic threshold switch (9), - the electronic threshold switch (9) is also designed to provide a residual current excess signal at its output terminal if the residual current sensed by the additional current sensor (8a, 8a') exceeds a second residual current threshold, wherein - the electronic threshold switch (9) is also designed to provide a normal residual current signal if the residual current sensed by the additional current sensor (8a, 8a') drops below the second residual current threshold or drops below a third residual current threshold, the third residual current threshold being lower than the second residual current threshold, wherein - if the electronic threshold switch (9) outputs a transition from the normal load current signal (NCS) to the load current excess signal (CES) or a transition from the normal residual current signal to the residual current excess signal, the actuation unit (11) opens the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

11. The device (1a..1j) according to any one of claims 7 to 9, characterized in that - the circuit breakers (2a..2j) are designed as residual current circuit breakers with overcurrent protection, - the circuit breaker (2a..2j) comprises an additional trigger unit (13), which is designed to open the first switching contact (S1) also when the residual current flowing through the first switching contact (S1) exceeds a first residual current threshold value, - the circuit breaker (2a..2j) comprises an additional current sensor (8a, 8a') which is designed as a residual current sensor designed to sense the residual current flowing through the first switching contact (S1) and is connected to an input of the electronic threshold switch (9), - the electronic threshold switch (9) is designed to provide a current excess signal (CES) at its output terminal if the load current sensed by the current sensor (8b, 8b') exceeds the second load current threshold (TH2) or if the residual current sensed by the additional current sensor (8a, 8a') exceeds a second residual current threshold, wherein - the electronic threshold switch (9) is further designed to provide a normal current signal (NCS) in the event that the load current sensed by the current sensor (8b, 8b') drops below the second load current threshold (TH2) or drops below a third load current threshold (TH3) and the residual current sensed by the additional current sensor (8a, 8a') drops below the second residual current threshold or drops below a third residual current threshold, the third load current threshold (TH3) being lower than the second load current threshold (TH2) and the third residual current threshold being lower than the second residual current threshold, wherein - the transition from the normal current signal (NCS) to the current excess signal (CES) causes the actuation unit (11) to open the second switch contact (S2), and wherein - A switch-on pulse fed to the external switch-on terminal (T11) causes the actuation unit (11) to close the second switch contact (S2).

12. An overcurrent protection device (2b..2g), comprising a first switch contact (S1), a trigger unit (5, 13) and a latch (6), wherein the trigger unit (5, 13) is designed to trigger a load current (I LI..L3 ) opens the first switch contact (S1) when the first load current threshold (TH1) is exceeded, and the latch is designed to keep the first switch contact (S1) open until manual intervention on site, Features include: - a current sensor (8b, 8b') designed to sense the load current (I LI..L3 ), - an electronic threshold switch (9) having an input and an output, wherein the input is connected to the current sensor (8b, 8b'), and wherein the output is connected to a terminal (T5) of the overcurrent protection device (2b..2g), wherein - The electronic threshold switch (9) is designed to be sensitive to the load current (I LI..L3 ) provides a current excess signal (CES) at its output terminal when the load current exceeds a second load current threshold (TH2), the second load current threshold (TH2) being lower than the first load current threshold (TH1), and wherein - The electronic threshold switch (9) is designed to be sensitive to the load current (I LI..L3 ) drops below the second load current threshold (TH2) or drops below a third load current threshold, wherein the third load current threshold is lower than the second load current threshold (TH2).

13. A residual current circuit breaker with overcurrent protection (2c..2g), characterized in that The overcurrent protection device (2b..2g) according to claim 12, wherein the residual current circuit breaker (2c..2g) comprises an additional trigger unit (5, 13), which is designed to also open the first switching contact (S1) when the residual current flowing through the first switching contact (S1) exceeds a first residual current threshold.

14. A residual current circuit breaker with overcurrent protection (2c..2g), characterized in that comprising an overcurrent protection device (2b..2g) according to claim 12, wherein - the residual current circuit breaker (2c..2g) comprises an additional triggering unit (13), which is designed to open the first switching contact (S1) also when the residual current flowing through the first switching contact (S1) exceeds a first residual current threshold value, - the residual current circuit breaker (2c..2g) comprises an additional current sensor (8a, 8a') which is designed as a residual current sensor designed to sense the residual current flowing through the first switching contact (S1) and is connected to an input of an electronic threshold switch (9), - the electronic threshold switch (9) is also designed to provide a residual current excess signal at its output terminal if the residual current sensed by the additional current sensor (8a, 8a') exceeds a second residual current threshold, wherein - the electronic threshold switch (9) is also designed to provide a normal residual current signal if the residual current sensed by the additional current sensor (8a, 8a') drops below the second residual current threshold or drops below a third residual current threshold, the third residual current threshold being lower than the second residual current threshold.

15. A residual current circuit breaker with overcurrent protection, characterized in that comprising an overcurrent protection device according to claim 12, wherein - the residual current circuit breaker (2c..2g) comprises an additional triggering unit (13), which is designed to open the first switching contact (S1) also when the residual current flowing through the first switching contact (S1) exceeds a first residual current threshold value, - the residual current circuit breaker (2c..2g) comprises an additional current sensor (8a, 8a') which is designed as a residual current sensor designed to sense the residual current flowing through the first switching contact (S1) and is connected to an input of an electronic threshold switch (9), - the electronic threshold switch (9) is designed to provide a current excess signal (CES) at its output terminal if the load current sensed by the current sensor (8b, 8b') exceeds a second load current threshold (TH2) or if the residual current sensed by the additional current sensor (8a, 8a') exceeds a second residual current threshold, wherein - the electronic threshold switch (9) is also designed to provide a normal current signal (NCS) when the load current sensed by the current sensor (8b, 8b') drops below the second load current threshold (TH2) or drops below a third load current threshold (TH3) and the residual current sensed by the additional current sensor (8a, 8a') drops below the second residual current threshold or drops below a third residual current threshold, the third load current threshold (TH3) being lower than the second load current threshold (TH2) and the third residual current threshold being lower than the second residual current threshold.

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