Protective switching device, system and procedure

Abstract

Protective switching device (G1) for a multi-conductor low-voltage circuit, - with a first protective switching function, - with a sensor unit for determining at least one variable of the low-voltage circuit to be monitored, - with a control unit (ST) connected to the sensor unit, for evaluating the monitored variable and triggering the activated protective switching function when a threshold value of the monitored variable is exceeded, - a power supply unit (PS) for supplying energy to the protective switching device, characterized in that a first communication unit (TRCV1) connected to the controller (ST) is provided, that both are designed in such a way that when the protective switching device is switched on, the first communication unit (TRCV1) sends out a transmission signal and the first protective switching function is only activated upon receipt of a corresponding reception signal.

Description

[0001] The invention relates to a protective switching device for a low-voltage circuit according to the preamble of patent claim 1, a connectable protective switching device for a low-voltage circuit, a system for a low-voltage circuit according to the preamble of patent claim 10 and a method for a low-voltage circuit according to the preamble of patent claim 11.

[0002] Low voltage refers to voltages up to 1000 volts AC and / or 1500 volts DC. Low voltage refers in particular to voltages greater than extra-low voltage, with values ​​of 25 or 50 volts AC and 60 or 120 volts DC.

[0003] Circuits, particularly low-voltage ones, refer to circuits for currents up to 6300 amps, and more specifically, currents up to 1600 amps, 1200 amps, 630 amps, 125 amps, 80 amps, 63 amps, 40 amps, 25 amps, or 16 amps. The current values ​​mentioned refer in particular to nominal and / or breaking currents, i.e., the maximum current that is normally carried through the circuit or at which the electrical circuit is usually interrupted, for example, by a protective device or a protective switching device.

[0004] The protective switching device includes in particular: - miniature circuit breaker or MCB for short; - Moulded Case Circuit Breaker, MCCB for short, or Air Circuit Breaker, ACB for short; - Residual current circuit breakers or residual current monitoring devices or residual current devices (RCDs for short) or residual current monitors (RCMs for short); - Fire protection switch or arc fault protection switch or Arc Fault Detection Device, AFDD for short.

[0005] Circuit breakers and power switches are protective devices that function similarly to a fuse. Circuit breakers and power switches monitor the current flowing through them via at least one conductor and interrupt the electrical current or energy flow to an energy sink or load. This is referred to as tripping when protective parameters, such as current limits or current time limits, are exceeded—i.e., when a current value is present for a certain period of time. The interruption occurs, for example, when the contacts of the circuit breaker or power switch are opened.

[0006] The difference between miniature circuit breakers and circuit breakers lies in the current level and the design.

[0007] For the purposes of the invention, circuit breakers refer in particular to switches used for currents from 63 to 6300 amperes. Closed circuit breakers are used more specifically for currents from 63 to 1600 amperes, especially from 125 to 630 or 1200 amperes. Open circuit breakers are used in particular for currents from 630 to 6300 amperes, more specifically from 1200 to 6300 amperes. Miniature circuit breakers are typically used for currents in the range from 6.3 amperes to 63 amperes, up to a maximum of 125 amperes.

[0008] The monitored variable is the current level in the electrical circuit. The protective function is overcurrent or short-circuit protection.

[0009] For the purposes of the invention, circuit breakers are particularly circuit breakers with an electronic trip unit, also known as an electronic trip unit (ETU).

[0010] Residual current circuit breakers measure the total current in an electrical circuit, which is normally zero, and interrupt the electrical circuit if a differential current value is exceeded—i.e., a total current other than zero that exceeds a certain (differential) current value or residual current value. The monitored variable is the total current in the electrical circuit. The protective function is residual current protection, i.e., protection against (dangerous) fault currents.

[0011] Arc fault circuit breakers or arc fault circuit breakers are relatively new types of protective switching devices. They monitor the electrical circuit for arc faults, i.e., arcs caused by a fault in the electrical circuit. This does not include arcs that occur during normal operation of the network or consumers. The monitored variable is the high-frequency spectrum in the electrical circuit or on the line. The protective function is arc fault protection or fire protection, i.e., protection against faults (or damage) or fires caused by arc faults.

[0012] A protective switching device is a device that activates a protective switching function when a threshold value of the monitored variable is exceeded. This does not, in particular, mean a direct interruption of the low-voltage circuit in the protective switching device. The interruption can also occur (indirectly) in another (protective switching) device to which the protective switching device is connected or coupled. A (direct) interruption in the protective switching device is also possible.

[0013] Circuit breakers are often combined to implement multiple circuit breaker functions. Often, one circuit breaker lacks a means for interrupting the low-voltage electrical circuit. The interruption is then performed by the other circuit breaker, which, for example, has contacts for interrupting the low-voltage circuit. Both devices are mechanically coded to ensure compatibility. Furthermore, a mechanical interface, such as a plunger, is provided for interruption. The circuit breaker without an interruption unit can use the mechanical interface to activate an interruption of the low-voltage circuit in the circuit breaker with an interruption unit; in this case, both circuit breakers are coupled.

[0014] Electrical coupling is also possible, for example by generating an artificial fault current in a coupled residual current device with an interruption unit using a fire protection switch without an interruption unit in order to cause an interruption (tripping) in the event of an arc fault.

[0015] Coupling two protective switching devices refers, in particular, to the grouping of two (or more) protective switching devices, where one protective switching device assumes a function, particularly the interruption function, of another protective switching device. This means, for example, that the low-voltage circuit is interrupted by the coupled protective switching device.

[0016] Common combinations in this sense are: - Residual current circuit breakers and miniature circuit breakers - Fire protection switches and circuit breakers - Circuit breakers and residual current devices

[0017] The problem here is that unauthorized combinations are possible. Furthermore, combinations with unauthorized copies, especially from the Far East, or non-certified products could be realized, which are not permitted.

[0018] The American patent US 6,356,426 B1 describes a residential circuit breaker with selectable current setting, load control, and power line carrier signaling. A residential circuit breaker is presented. The residential circuit breaker includes an electronic residential circuit breaker with a selectable current rating, allowing the user to easily set and reset the current rating depending on the desired use and the environment in which the circuit breaker is to be used. In another aspect, PLC (Common Power Line Carrier) communications are used to provide an effective signaling system for load control. In yet another aspect of the present invention, an interface between the electrical infrastructure and a cable automation system is provided for the purpose of load control.

[0019] The object of the present invention is to increase the use of only permissible combinations or certified devices. This object is achieved by a protective switching device having the features of patent claim 1, a connectable protective switching device having the features of patent claim 8, a system having the features of patent claim 10, or a method having the features of patent claim 11.

[0020] According to the invention, a protective switching device for a low-voltage circuit comprising several conductors is proposed, - with a first protective switching function, - with a sensor unit for determining at least one variable of the low-voltage circuit to be monitored, - with a control unit connected to the sensor unit for evaluating the monitored variable and triggering the activated protective switching function when a threshold value of the monitored variable is exceeded, - a power supply to supply energy to the protective switching device.

[0021] A first communication unit connected to the controller is provided; both are designed in such a way that when the protective switching device is switched on, the first communication unit sends out a transmission signal and the first protective switching function is only activated upon receipt of a corresponding reception signal.

[0022] This has the particular advantage that the protective switching function is only available if it has been coupled with a certified protective switching device or confirmed by a central unit. Activation or lack of activation can be signaled on the protective switching device, for example, by a visual or mechanical indicator, for example, by a lever for switching on being inoperable.

[0023] Advantageous embodiments of the invention are specified in the subclaims.

[0024] In an advantageous embodiment of the invention, the corresponding received signal is generated by a second, connectable protective switching device with a second protective switch function.

[0025] This has the particular advantage that only connectable protective switching devices can be combined or work with each other.

[0026] In an advantageous embodiment of the invention, the second, connectable protective switching device is a miniature circuit breaker or circuit breaker.

[0027] This has the particular advantage that the sophisticated contact systems for interrupting circuits of such switches can be used for new protective functions.

[0028] In an advantageous embodiment of the invention, the corresponding received signal is generated by a central unit, in particular without a circuit breaker function. This has the particular advantage that a central unit can enable the circuit breakers.

[0029] In an advantageous embodiment of the invention, the first communication unit is an RF transceiver; the corresponding received signal is generated by an RFID tag or a second communication unit.

[0030] This has the particular advantage that it is particularly easy to implement, especially with an RFID tag.

[0031] In an advantageous embodiment of the invention, the protective switching device is a residual current circuit breaker, in particular a mains voltage-dependent one, and the sensor unit has a summation current transformer.

[0032] This has the particular advantage that a mains voltage-dependent residual current device, which has a higher range of functions or a more extensive scope of protection, can be implemented in a compact, ie small, form with, for example, the sophisticated contact system of a circuit breaker or miniature circuit breaker.

[0033] In an advantageous embodiment of the invention, the protective switching device is a fire protection switch.

[0034] This has the particular advantage that the novel functionality for arc fault detection can be implemented compactly, ie in a small design, using, for example, the sophisticated contact system of a circuit breaker or miniature circuit breaker.

[0035] In an advantageous embodiment of the invention, the connectable protective switching device with a second protective switching function has an RFID tag for generating a transmission signal upon receipt of a corresponding reception signal.

[0036] This has the particular advantage that authentication is particularly easy to implement.

[0037] In an advantageous embodiment of the invention, the RFID tag is not visibly provided or attached to the connectable protective switching device.

[0038] This has the particular advantage that the type of authentication is not visible from the outside, thus preventing circumvention of the protection.

[0039] In an advantageous embodiment of the invention, a corresponding system and method are claimed.

[0040] All embodiments, both in dependent form referring back to patent claim 1, 8, 10 or 11, as well as referring back only to individual features or combinations of features of patent claims, bring about an improvement of a protective switching device for protection against unauthorized combinations.

[0041] The described properties, features and advantages of this invention and the manner in which they are achieved will become clearer and more clearly understandable in connection with the following description of the embodiments, which are explained in more detail in connection with the drawings.

[0042] The drawing shows: Fig. 1 a schematic representation of a first combination, Fig. 2 a schematic representation of a second combination, Fig. 3 a schematic representation of a third combination, Fig. 4 a schematic detailed representation.

[0043] Fig. Figure 1 shows a first protective switching device G1, in this example a residual current device RCD1, which is coupled, for example mechanically coupled, to a second protective switching device G2, in this example a miniature circuit breaker MCB1. Conductors L1 and N of a low-voltage circuit are connected to the miniature circuit breaker MCB1. According to the invention, the first protective switching device RCD1 has a controller ST connected to a first communication unit TRCV1, for example an RF transceiver or a transmitting / receiving device.

[0044] According to the invention, a second communication unit TRCV2 is provided or attached to the second circuit breaker MCB1. In the example, both communication units are arranged close to each other or on opposite sides of the circuit breakers.

[0045] Fig. 2 shows an arrangement or a section of Fig. 1, with the difference that the second protective switching device G2 has an RFID tag (Radio Frequency Identification - Tag) RT1 instead of the second communication unit TRCV2. The communication is also illustrated in more detail. The first communication unit TRCV1 sends out a first transmission signal. This is received by the RFID tag, which then sends out a second transmission signal that corresponds to the first transmission signal, i.e. is encoded accordingly or sends a response code. This second transmission signal is received by the first communication unit TRCV1. The contained code is compared with the expected code; if there is a match, a signal is sent to the control unit ST, whereupon the control unit ST activates at least one protective switching function of the first protective switching device, so that this at least one protective switching function is now available for monitoring at least one monitored variable.

[0046] In the example, the residual current protection function would now be available.

[0047] Fig. 3 shows an arrangement according to Fig. 1, with the difference that a third protective switching device G3 is provided, for example, an AFDD1 fire protection switch. The example shown is a combination of the first, second, and third protective switching devices G1, G2, and G3. Furthermore, a central unit ZE is provided.

[0048] The first and third protective switching devices G1, G3 each have a controller ST which is connected to the first RF transceiver TRCV1 and the third RF transceiver TRCV3, respectively.

[0049] The central unit ZE also has a communication unit, the central RF transceiver TRCVZE. This is connected to a central controller RF-ST.

[0050] Furthermore, communication is illustrated in more detail.

[0051] The first and third communication units TRCV1, TRCV3 each transmit a first and third transmission signal, respectively. This is received by the communication unit TRCVZE of the central unit. If the received information from the first and third protective switching devices is verified, e.g., if it matches stored values, a second and fourth transmission signal, corresponding to the first and third transmission signals, is then transmitted.

[0052] This second or fourth transmission signal is received by the first or third communication unit TRCV1, TRCV3, respectively. The code contained is compared with the expected code; if there is a match, a signal is sent to the respective control unit ST, which then activates at least one protective switching function of the first or third protective switching device.

[0053] In the example, the residual current protection function and fire protection switch function would now be available, with both protective switching devices corresponding or coupled to the second protective switching device G2 or MCB1.

[0054] Fig. 4 shows a detail or section according to Fig. 2. The first protective switching device G1 has a controller ST, which is connected on the one hand to a power supply PS and on the other hand to the first communication unit in the form of the first transceiver TRCV1. The first transceiver TRCV1 has a controller RFS, which is connected on the one hand to a transmitting unit TX, possibly to a transmitting amplifier, and on the other hand to a receiving unit RX, possibly to a receiving amplifier.

[0055] The transmitting and receiving units are connected to one or each an antenna Ant1, in the case of one antenna, for example, via a duplexer.

[0056] The second protective switching device G2 has an RFID tag RT1, which is shown in more detail. The RFID tag has an antenna Ant2 connected to a tag transceiver RFT2. This is connected to an energy storage device EP and a tag controller CPU. The tag transceiver RFT2, energy storage device EP, and tag controller CPU can be arranged on a single RF chip circuit.

[0057] In the following, the invention will be explained again in other words.

[0058] Use of RFID tags for secure assignment / authentication of combinations of different protective switching devices on the mechanical connecting surfaces.

[0059] For example, an "accessory device" or "accessory part" can be activated for a "base device." An RFID chip / tag can be attached to the accessory. The base device controls the RFID tag and receives a response for subsequent authentication.

[0060] The device with the communication unit must be actively designed with a control unit and power supply, e.g. with a supply voltage and a certain logic.

[0061] The RFID tag consists of an RFID chip coupled to an antenna (transponder), which is placed on a carrier medium.

[0062] The RFID tag can be applied as a sticker, laminate, plastic part, etc. In particular, an inconspicuous attachment, for example, inside or on the inside of the housing, can be advantageous so that the implemented protective measures are not visible.

[0063] In one variant, a so-called central unit, e.g., a data node / gateway, can serve as a "master" for central release or as a hub for further transport of information. The central unit can have a communication interface, e.g., in the form of a BI bus connection. Further communication can then be implemented via wires, e.g., via Modbus TCP, TCP / IP, etc.

[0064] The central unit, e.g. a data node, can be designed with an operating unit and a display.

[0065] The data node, e.g., in the form of a data concentrator, collects data from various devices, such as circuit breakers, measuring devices, and / or modular devices. The data node forwards the data via a higher-level bus to a central controller, e.g., for further processing, visualization, and / or archiving.

[0066] The G1 protective switching device contains a TRCV1 communication unit with an RF transceiver that can, for example, actively transmit data protocols wirelessly using an RF communication protocol (Tx Transmit Data) and wirelessly receive data protocols (RX Receive Data). The first protective switching device, as the "active participant," thus operates bidirectionally.

[0067] The RF transceiver can be implemented as an integrated circuit with an additional antenna.

[0068] The second protective switching device G2 can be equipped with an RFID tag, although this device then operates in a more "passive" manner. The RFID tag can, for example, consist of three components: a carrier medium, antenna, and circuit (RF chip). Since the tag does not have its own power supply (passive), it is supplied with data via the irradiated TEM wave (transverse electromagnetic wave) of the active transmitter. At the same time, it provides enough energy to process the received data and respond with a response telegram, depending on the control CPU or logic.

[0069] The invention has the advantage that flexibly permitted combinations of protective switching devices can be defined and manufactured in production and protection against misuse is provided.

[0070] This eliminates the possibility of unauthorized combinations by customers. Encoded RFID tags prevent the use of unauthorized counterfeits.

[0071] Furthermore, a devaluation function can be implemented by slowly devaluing an RFID tag or communication unit over its lifetime.

[0072] Although the invention has been illustrated and described in detail by the embodiment, the invention is not limited by the disclosed examples and other variations can be derived therefrom by a person skilled in the art without departing from the scope of the invention.

Claims

[1] Protective switching device (G1) for a low-voltage circuit comprising several conductors, - with a first protective switching function, - with a sensor unit for determining at least one variable of the low-voltage circuit to be monitored, - with a control unit (ST) connected to the sensor unit, for evaluating the monitored variable and triggering the activated protective switching function when a threshold value of the monitored variable is exceeded, - a power supply (PS) to supply power to the protective switching device, characterized by that a first communication unit (TRCV1) connected to the controller (ST) is provided, that both are designed in such a way that when the protective switching device is switched on, the first communication unit (TRCV1) sends out a transmission signal and the first protective switching function is only activated upon receipt of a corresponding reception signal. [2] Protective switching device (G1) according to claim 1, characterized by that the corresponding received signal is generated by a second, connectable protective switching device (G2) with a second protective switch function. [3] Protective switching device (G1) according to claim 2, characterized by that the second, connectable protective switching device (G2) is a miniature circuit breaker or circuit breaker. [4] Protective switching device (G1) according to claim 1, characterized by that the corresponding received signal is generated by a central unit (ZE), in particular without a circuit breaker function. [5] Protective switching device (G1) according to one of the preceding claims, characterized by , that the first communication unit (TRCV1) is an RF transceiver; that the corresponding received signal is generated by an RFID tag (RT1) or a second communication unit (TRCV2). [6] Protective switching device (G1) according to one of the preceding claims, characterized by , that the protective switching device (G1) is a residual current device (RCD1), in particular a mains voltage-dependent one, that the sensor unit has a summation current transformer. [7] Protective switching device (G1) according to one of the preceding claims 1 to 5, characterized by that the protective switching device is a fire protection switch (AFDD1). [8] A coupling protective switching device (G2) with a second protective switching function for a protective switching device (G1) according to one of claims 1 to 7, characterized by that the connectable protective switching device (G2) has an RFID tag (RT1) for generating a transmission signal upon receipt of a corresponding reception signal. [9] Connectable protective switching device according to claim 8, characterized by that the RFID tag (RT1) is not intended to be visible. [10] System for a low-voltage circuit comprising a first protective switching device (G1) with a first protective switching function and a second protective switching device (G2) with a second protective switching function, wherein the first protective switching function monitors a first physical quantity of the low-voltage circuit and the second protective switching function monitors a second physical quantity of the low-voltage circuit, characterized by , that the system is designed in such a way that the protective switching function of the first protective switching device (G1) is only activated if, after transmission of a first transmission signal by the first protective switching device (G1), a first corresponding reception signal is received by the first protective switching device (G1), wherein the second protective switching device (G2) receives the first transmission signal and, after checking the correspondence, transmits a second transmission signal which can be received as the first corresponding reception signal. [11] Method for a low-voltage circuit with a first protective switching device (G1) with a first protective switching function and a second protective switching device (G2) with a second protective switching function, wherein the first protective switching function monitors a first physical quantity of the low-voltage circuit and the second protective switching function monitors a second physical quantity of the low-voltage circuit, characterized by , that the protective switching function of the first protective switching device (G1) is only activated if, after transmission of a first transmission signal by the first protective switching device (G1), a first corresponding reception signal is received by the first protective switching device (G2), wherein the second protective switching device (G2) receives the first transmission signal and, after checking the correspondence, transmits a second transmission signal which is received as the first corresponding reception signal. [12] Method according to claim 11, characterized by that the second protective switching device (G2) uses an RFID tag (RT1), in particular an invisible one, for receiving and transmitting.

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