Circuit breaker device and method

Abstract

The invention relates to a circuit breaker device (SG) for protection of an electrical low-voltage circuit, having: - a mechanical isolator contact unit (MK) which is connected to an electronic disconnection unit (EU) in series, the serial circuit being connected to at least one grid-side and to at least one load-side connection, the mechanical isolator contact unit (MK) can be switched by opening contacts in order to prevent a current flow in the low-voltage circuit or closing the contacts in order to enable a current flow, - the electronic disconnection unit (EU) can be switched, by means of semiconductor-based switch elements, to a high-ohmic state of the switch elements in order to prevent a current flow in the low-voltage circuit, or to a low-ohmic state of the switch elements in order to enable a current flow, - the level of the current in the low-voltage circuit is ascertained and a process for preventing a current flow in the low-voltage circuit is initiated if current thresholds and / or current / time thresholds are exceeded, - and a high-ohmic or low-ohmic state of the electronic disconnection unit (EU) is signaled via a signalling output (SO).

Description

[0001] Description

[0002] Protective switching device and procedure

[0003] The invention relates to the technical field of a protective switching device for a low-voltage circuit with an electronic interruption unit and a method for a protective switching device for a low-voltage circuit with an electronic interruption unit.

[0004] Low voltage refers to voltages of up to 1000 volts AC or up to 1500 volts DC. Low voltage refers in particular to voltages greater than extra-low voltage, with values ​​of 50 volts AC or 120 volts DC.

[0005] The term “low-voltage circuit”, “network” or “system” refers to circuits with nominal or rated currents of up to 125 amperes, more specifically up to 63 amperes. The term “low-voltage circuit” refers in particular to circuits with nominal or rated currents of up to 50 amperes, 40 amperes, 32 amperes, 25 amperes, 16 amperes or 10 amperes. The current values ​​mentioned refer in particular to nominal, rated 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 such as a protective switching device, circuit breaker or circuit breaker. The rated currents can be further staggered, from 0.5 A to 1 A, 2 A, 3 A, 4 A, 5 A, 6 A, 7 A, 8 A, 9 A, 10 A, etc. up to 16 A.

[0006] Circuit breakers are long-established overcurrent protection devices used in low-voltage electrical circuits. They protect cables from damage caused by overheating due to excessive current and / or short circuits. A circuit breaker can automatically disconnect the circuit in the event of an overload and / or short circuit. A circuit breaker is a non-self-resetting fuse element.

[0007] Unlike miniature circuit breakers, circuit breakers are designed for currents greater than 125 A, and in some cases even as low as 63 A. Miniature circuit breakers are therefore simpler and more delicate in design. Miniature circuit breakers typically have a mounting option for mounting on a so-called top-hat rail (support rail, DIN rail, TH35).

[0008] Miniature circuit breakers are electromechanical in design. They contain a mechanical switching contact or shunt release in a housing to interrupt (trip) the electrical current. A bimetallic protective element or bimetallic element is usually used to trip (interrupt) the circuit in the event of a prolonged overcurrent (overcurrent protection) or thermal overload (overload protection). An electromagnetic release with a coil is used for brief tripping when an overcurrent limit is exceeded or in the event of a short circuit (short-circuit protection). One or more arc quenching chambers or devices for arc quenching are provided. There are also connection elements for conductors of the electrical circuit to be protected.

[0009] Protective switching devices with an electronic interruption unit are relatively new developments. These have a semiconductor-based electronic interruption unit. This means that the electrical current flow in the low-voltage circuit is conducted via semiconductor components or semiconductor switches, which interrupt the electrical current flow or can be made conductive. Protective switching devices with an electronic interruption unit also often have a mechanical isolating contact unit, in particular with isolating properties in accordance with the relevant standards for low-voltage circuits. The contacts of the mechanical isolating contact unit are connected in series to the electronic interruption unit, i.e. the current in the low-voltage circuit to be protected is conducted via both the mechanical isolating contact unit and the electronic interruption unit.

[0010] The present invention can be used for both low-voltage direct current circuits and low-voltage alternating current circuits. The invention particularly relates to low-voltage alternating current circuits with an alternating voltage, typically a time-dependent sinusoidal alternating voltage with frequency f. The time dependence of the instantaneous voltage value u(t) of the alternating voltage is described by the equation: u(t) = U * sin (2n * f * t). Where: u(t) = instantaneous voltage value at time t

[0011] U = amplitude of the voltage

[0012] A harmonic alternating voltage can be represented by the rotation of a pointer whose length corresponds to the amplitude (U) of the voltage. The instantaneous deflection is the projection of the pointer onto a coordinate system. One oscillation period corresponds to one full revolution of the pointer, and its full angle is 2n (2Pi) or 360°. The angular frequency is the rate of change of the phase angle of this rotating pointer. The angular frequency of a harmonic oscillation is always 2n times its frequency, i.e.: w = 2n*f = 2n / T = angular frequency of the alternating voltage (T = period of the oscillation). The angular frequency (w) is often preferred over the frequency (f), since many formulas in oscillation theory can be represented more compactly using the angular frequency due to the occurrence of trigonometric functions whose period is, by definition, 2n: u ( t ) = U * sin (wt)

[0013] In the case of angular frequencies that are not constant over time, the term instantaneous angular frequency is also used.

[0014] In the case of a sinusoidal, in particular temporally constant, alternating voltage, the time-dependent value of the angular velocity w and the time t corresponds to the time-dependent angle cp ( t ) , which is also referred to as the phase angle cp ( t ). This means that the phase angle cp ( t ) periodically passes through the range O...2n or 0°...360°. This means that the phase angle periodically assumes a value between 0 and 2n or 0° and 360° (cp = n* (0...2n) or cp = n* ( 0 °...360 ° ) , due to periodicity; in short: cp = O...2n or cp = 0°...360° ).

[0015] The instantaneous voltage value u(t) is therefore the instantaneous value of the voltage at time t, ie in the case of a sinusoidal (periodic) alternating voltage, the value of the voltage at the phase angle cp (cp = 0...2n or cp = 0°...360°, of the respective period).

[0016] The object of the present invention is to improve a protective switching device of the type mentioned above, in particular to achieve greater flexibility or a new feature for the protective switching device.

[0017] This object is achieved by a protective switching device having the features of patent claim 1 and by a method according to patent claim 13.

[0018] According to the invention, a protective switching device for protecting an electrical low-voltage circuit, in particular a low-voltage alternating current circuit, is proposed, comprising:

[0019] - a housing with at least one mains-side terminal and at least one load-side terminal, both for conductors of the low-voltage circuit to be connected to the protective device,

[0020] - a mechanical isolating contact unit connected in series with an electronic interruption unit, the series circuit being connected on the one hand to the at least one mains-side connection and on the other hand to the at least one load-side connection,

[0021] - that the mechanical isolating contact unit can be switched by opening at least one contact to prevent a current flow or closing the at least one contact for a current flow in the low-voltage circuit,

[0022] - that the electronic interruption unit can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent a current flow or a low-resistance state of the switching elements to allow current flow in the low-voltage circuit,

[0023] - a current sensor unit for determining the current level of the low-voltage circuit,

[0024] - a control unit which is connected to the current sensor unit, the mechanical isolating contact unit and the electronic interruption unit, whereby an avoidance of a current flow in the low-voltage circuit is initiated when current and / or current time limit values ​​are exceeded.

[0025] According to the invention, a signaling output is provided on the protective switching device. The signaling output is accessible, in particular, on the housing of the protective switching device. The signaling output is connected, in particular, to the control unit.

[0026] The protective switching device is designed in such a way that a high-impedance or low-impedance state of the electronic interruption unit can be or is signaled by means of the signaling output (signalable or is signaled means, among other things, communicability, transferability, transmittability; information about the state is transmitted).

[0027] This has the advantage of providing a signaling output integrated into or on the protective switching device, which can be used to explicitly signal the status of the electronic interruption unit without any further modifications or additions to the protective switching device or without an external additional device. This saves space in a distribution box of an electrical distribution system.

[0028] Further advantageous embodiments of the invention are specified in the subclaims and in the exemplary embodiment.

[0029] In an advantageous embodiment of the invention, the mechanical isolating contact unit is assigned to the load-side connection, and the electronic interruption unit is assigned to the mains-side connection. In particular, the mechanical isolating contact unit can be operated by a mechanical handle to switch the at least one contact to open or close.

[0030] This has the particular advantage that a structure for a protective switching device is provided in which the protective switching device can function even when the contacts of the mechanical isolating contact unit are open.

[0031] In an advantageous embodiment of the invention, two mains-side connections and at least one load-side connection are provided. In particular, a mains-side phase conductor connection, a mains-side neutral conductor connection, and a load-side phase conductor connection are provided.

[0032] This has the particular advantage that a structure for a protective switching device is provided which, on the one hand, provides an energy supply for the protective switching device and, on the other hand, enables a space-saving design by only having one switched pole.

[0033] In an advantageous embodiment of the invention, two mains-side connections and two load-side connections are provided. In particular, a mains-side neutral conductor connection, a mains-side phase conductor connection, a load-side neutral conductor connection, and a load-side phase conductor connection are provided.

[0034] This has the particular advantage that a structure for a two-pole protective switching device is provided, so that phase and neutral conductors can be connected directly and, for example, additional neutral conductor rails can be omitted.

[0035] In an advantageous embodiment of the invention, the signal output has a, in particular safe, galvanic isolation.

[0036] Safe galvanic isolation can be achieved, for example, by means of an optocoupler or relay. Alternatively, by inductive or capacitive galvanic isolation. This has the particular advantage that the signal output can be used universally in a potential-free manner and that safe galvanic isolation is provided from the phase conductors (or the control unit). Since the phase conductors (or the control unit) are at mains voltage (e.g. 230 V (AC)) during operation, this galvanic isolation enables safe use of the signal output. In particular, this provides protection against electric shock or so-called "voltage carryover" to a connected electrical line and the devices connected to it. In the case of voltage carryover, an electrical potential is unintentionally transferred to an electrical line or another device.

[0037] In an advantageous embodiment of the invention, the signal output also signals an open or closed state of at least one contact of the mechanical isolating contact unit.

[0038] This has the particular advantage of providing further flexibility and expanding the functionality of the protective switching device. In an advantageous embodiment of the invention, the signaling output is accessible from the housing. In particular, the signaling output has a plurality of connection terminals, in particular two or three connection terminals, wherein the connection terminals are connected internally in the protective switching device to at least one optocoupler / to the output side of the optocoupler. The input side of the optocoupler is connected, for example, to the control unit, which emits a corresponding signal. Alternatively, the connection terminals or additional connection terminals are connected to, in particular, a potential-free relay contact.

[0039] This has the particular advantage of providing a simple option for a potential-free connection of the signal output.

[0040] In an advantageous embodiment of the invention, a display unit connected to the control unit is provided, which has display means visible on the protective switching device for displaying the high-resistance or low-resistance state of the electronic interruption unit.

[0041] This has the particular advantage that the status of the electronic interruption unit is visualized.

[0042] In an advantageous embodiment of the invention, the protective switching device is designed such that the signaling output is configurable. More specifically, the signaling output, in addition to signaling a high-impedance or low-impedance state of the electronic interruption unit, or alternatively, also signals: a) the presence of an (electrical) fault at the load-side connection and / or b) the presence of a fault within the protective switching device.

[0043] This has the particular advantage of providing further flexibility and functional expansion of the protective switching device. (Electrical) faults include, among other things:

[0044] - Short circuit

[0045] - Overload / overcurrent

[0046] - Fault current

[0047] - Serial arc

[0048] (depending on the design and / or configuration of the protective switching device).

[0049] A fault internal to the protective switching device includes, among other things:

[0050] - Defect in the electronic interruption unit

[0051] - Defect in the current sensor unit or voltage sensor unit

[0052] - Defect in electronic components outside the control unit.

[0053] In addition to signaling a high-impedance or low-impedance state of the electronic interruption unit, the signal output can also provide an indication of a device status (ON or OFF or Standby).

[0054] In addition to signalling a high-impedance or low-impedance state of the electronic interruption unit, the signal output can also display a configured warning, such as:

[0055] - Overvoltage, undervoltage,

[0056] - Overtemperature, undertemperature,

[0057] - Overcurrent (exceeding a specified current value or a current value that can be set by a user)

[0058] - Exceeding a fault current threshold (earth fault current monitoring / ROM function).

[0059] In an advantageous embodiment of the invention, the protective switching device is designed in such a way that an (electrical) fault at the load-side connection is: a) a short circuit (of the consumer / of the (external) conductors of the low-voltage circuit connected to the protective switching device) or / and b) an overload (of the consumer / of the (external) conductors of the low-voltage circuit connected to the protective switching device).

[0060] Alternatively or additionally a c) earth fault current is .

[0061] Alternatively or additionally a d) serial arc fault is .

[0062] That an internal fault in a protective switching device is: a) a device overtemperature and / or b) a defect in a component of a unit of the protective switching device and / or c) exceeding (or falling below) an (internal) current threshold and / or d) falling below (or exceeding) an (internal) voltage threshold.

[0063] A defect in a component of a circuit breaker unit can, for example, be an (internally) detected defect in the electronic interruption unit. This can be determined, for example, by briefly switching the device on and off, or switching it off and on while simultaneously measuring electrical quantities such as current and voltage.

[0064] An error can, for example, be the undershooting of an (internal) voltage threshold, for example if the voltage (effective value) at the mains-side connections (or at the power supply of the protective switching device / power supply unit) is so low that the proper functioning of the protective switching device can no longer be ensured.

[0065] This has the particular advantage of providing further flexibility and functional expansion of the protective switching device, in particular enabling better signaling (or communication) of different states (or faults).

[0066] This increases and simplifies the device's communication capabilities. Furthermore, this signaling output provides a wired communication interface (in particular a two-pole / two-wire wired communication interface), enabling virtually delay-free signaling via the signaling output (latency-free). Virtually delay-free means direct signaling (signaling contact closed / open or low-impedance / high-impedance), i.e., without overhead-related information processing, such as that inherent in LAN / WLAN connections, using communication protocols such as MAC addresses, TCP / IP communication, or OSI communication. Depending on the area of ​​use or application of the protective switching device, the signaling output can be adapted and used for various functions.

[0067] In an advantageous embodiment of the invention, the protective switching device is designed such that the signaling output can assume two switching states (switching states), which can also be output as a (switching) sequence, so that several items of information can be output via the signaling output, which in particular has two poles / two connection terminals.

[0068] This has the particular advantage that a further functional extension of the protective switching device is provided, in particular an extended signaling of different states is enabled.

[0069] For example, a permanent logical zero level (logical zero level typically means that the signaling output is at zero volts or has a low resistance) can signal that the protective switching device is in the on state (ON).

[0070] A continuous logical one level (a logical one level typically means that the signal output is at 12 volts or 5 volts (or other typical signal voltages) or is high-impedance) signals that the protective switching device is in the standby or off state. If the signal levels change, for example, at a frequency of 0.5 Hz, this can signal an error. In this case, it no longer signals a device status, but rather an external error / error at the load-side connection or an internal error within the protective switching device.In an advantageous embodiment of the invention, checking functions on the circuit breaker side which a) switch the electronic interruption unit in the high-resistance state to the low-resistance state for a first period of time or (and) b) switch the electronic interruption unit in the low-resistance state to the high-resistance state for a second period of time are not signalled by the signal output.

[0071] This means that the check functions that cause a (temporary) change in the state of the electronic interruption unit are not signaled via the signaling output. This means that the change in the state of the electronic interruption unit (caused by the check function) is not signaled via the signaling output.

[0072] This has the particular advantage of preventing "flickering" of the signaling output ("flickering" of the (signaled) state of the signaling output) of the protective switching device. This prevents subsequent evaluation units connected to the signaling output from being "confused" by such (short-term) state changes, i.e., the connected devices do not receive incorrect information about the device state or status, and in particular, the status of the electronic interruption unit. The checking functions can be performed regularly or irregularly. The checking functions cause, among other things, a brief change in state of the electronic interruption unit, i.e., a brief low-resistance or high-resistance state of the electronic interruption unit. The checking functions are intended to ensure the functional reliability of the protective switching device, particularly during (regular) operation of the protective switching device.

[0073] The first time period is, for example, a short time period in the range of ps or ms up to one second, such as 100ps ... 200ps ... 300ps ... 600ps ... 700ps ... 800ps ... 1ms ... 10ms ... 20ms ... 40ms ... 50ms ... 100ms ... 200ms ... 500ms ... 1s (any value in between is possible). The second time period is, for example, a short time period in the range of ps or ms up to one second, such as 10ms ... 20ms ... 40ms ... 50ms ... 1s (any value in between is possible). l O Ops ... 200ps ... 300ps ... 600ps ... 700ps ... 800ps ... 1ms ... 10ms ... 20ms ... 40ms ... 50ms ... 100ms ... 200ms ... 500ms ... 1 s ( any intermediate value possible ).

[0074] According to the invention, a corresponding method for a protective switching device for a low-voltage circuit with electronic (semiconductor-based) switching elements with the same and further advantages is claimed.

[0075] The method for a protective switching device for protecting a low-voltage electrical circuit with :

[0076] - a mechanical isolating contact unit connected in series with an electronic interruption unit, the series circuit being connected on the one hand to at least one mains-side connection and on the other hand to at least one load-side connection,

[0077] - that the mechanical isolating contact unit can be switched by opening contacts to prevent current flow or closing contacts to allow current flow in the low-voltage circuit,

[0078] - that the electronic interruption unit can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent current flow or a low-resistance state of the switching elements to allow current flow in the low-voltage circuit,

[0079] - that the current level of the low-voltage circuit is determined and, if current and / or current-time limit values ​​are exceeded, the prevention of current flow in the low-voltage circuit is initiated,

[0080] - that a high-resistance or low-resistance state of the electronic interruption unit is signalled via a signalling output.

[0081] In an advantageous embodiment of the invention, the signaling output can assume (at least) two states, which can in particular also be output as a switching sequence, so that several items of information can be output via the signaling output, which in particular has two poles / two connection terminals.

[0082] All embodiments, both in dependent form referring back to the independent patent claim 1 or 13, and referring back only to individual features or combinations of features of patent claims, in particular also a reference of the dependent arrangement claims to the independent method claim, bring about an improvement of a protective switching device, in particular an improvement of the functionality and provide a new concept for a protective switching device.

[0083] The described properties, features and advantages of this invention as well as the manner in which these 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 drawing.

[0084] The drawing shows:

[0085] Figure 1 shows a first representation of a protective switching device,

[0086] Figure 2 shows a second representation of a protective switching device,

[0087] Figure 3 shows a representation of a signal output,

[0088] Figure 4 shows a representation of a functional grouping,

[0089] Figure 5 shows a representation of a configuration,

[0090] Figure 6 shows a first representation of switching states over time,

[0091] Figure 7 shows a representation of a status signal function, Figure 8 shows a second representation of switching states over time.

[0092] Figure 1 shows a representation of a protective switching device SG for protecting an electrical low-voltage circuit, in particular a low-voltage alternating current circuit, with a housing GEH, comprising:

[0093] - a grid-side neutral conductor connection NG, a grid-side phase conductor connection LG, a load-side neutral conductor connection NL, a load-side phase conductor connection LL of the low-voltage circuit; an energy source is usually connected to the grid side Grid, and a consumer is usually connected to the load side Load;

[0094] - a (two-pole) mechanical isolating contact unit MK with load-side connection points APLL, APNL and mains-side connection points APLG, APNG, whereby a load-side connection point APNL is provided for the neutral conductor, a load-side connection point APLL for the phase conductor, a mains-side connection point APNG for the neutral conductor and a mains-side connection point APLG for the phase conductor. The load-side connection points APNL, APLL are connected to the load-side neutral and phase conductor connections NL, LL, so that the contacts KKN, KKL can be opened to prevent current flow or the contacts can be closed to allow current flow in the low-voltage circuit. The mechanical isolating contact unit can also be designed as a single-pole mechanical isolating contact unit, i.e.with one contact, whereby the contact KKL is preferably arranged in the phase conductor L, a neutral conductor N passing through the protective switching device SG is then not provided.

[0095] - an electronic interruption unit EU, in particular a single-pole one (which in the case of a single-pole version is arranged in particular in the phase conductor L), with a mains-side connection point EUG, which is electrically connected to the mains-side phase conductor connection LG, and a load-side connection point EUL, which is electrically connected or connected to the mains-side connection point APLG of the mechanical isolating contact unit MK, wherein the electronic interruption unit has a high-resistance state of the switching elements to prevent a current flow or a low-resistance state of the switching elements to allow current flow in the low-voltage circuit by means of semiconductor-based switching elements,

[0096] - a current sensor unit SI for determining the level of the current in the low-voltage circuit, which is arranged in particular in the phase conductor L,

[0097] - a control unit SE which is connected to the current sensor unit SI, the mechanical isolating contact unit MK and the electronic interruption unit EU, whereby if current and / or current time limit values ​​are exceeded, the avoidance of a current flow in the low-voltage circuit is initiated.

[0098] According to the invention, the protective switching device SG is designed such that a signaling output SO is provided, accessible on the housing GEH of the protective switching device SG. The signaling output SO is connected, in particular, to the control unit SE. The protective switching device is designed such that the signaling output SO signals a high-impedance or low-impedance state of the electronic interruption unit EU.

[0099] Furthermore, a first voltage sensor unit SUA connected to the control unit SE can be provided, which determines the voltage level, in particular instantaneous values ​​of the voltage level, of the low-voltage circuit, in particular at the network-side connections LG, NG, specifically between the network-side neutral conductor connection NG and the network-side phase conductor connection LG.

[0100] In general, the mechanical isolating contact unit MK and the electronic interruption unit EU form a series circuit. The series circuit is connected, on the one hand, to at least one mains-side connection and, on the other hand, to at least one load-side connection. The mechanical isolating contact unit MK can advantageously be assigned to the load-side connection and the electronic interruption unit EU to the mains-side connection, as shown in Figure 1.

[0101] The mechanical isolating contact unit MK can be operated by a mechanical handle HH in order to switch the contacts open or close, as with a classic circuit breaker or miniature circuit breaker (MCB).

[0102] The control unit SE can have a microcontroller MP (microcontroller unit) (as shown in Figure 2).

[0103] Furthermore, a second voltage sensor unit SUB connected to the control unit SE can be provided, which determines the level of the voltage between the network-side connection point EUG and the load-side connection point EUL of the electronic interruption unit EU.

[0104] A measuring impedance ZM can be connected between the mains-side connection points APLG, APNG of the mechanical isolating contact unit MK. The measuring impedance ZM can, for example, be an electrical resistor and / or capacitor. The measuring impedance can also be an inductance. In particular, the measuring impedance can be a series or parallel connection of a resistor and / or capacitor and / or inductance.

[0105] In the example according to Figure 1, the electronic interruption unit EU is single-pole, in the example in the phase conductor. The mains-side connection point APNG for the neutral conductor of the mechanical isolating contact unit MK is connected to the mains-side neutral conductor connection NG of the housing GEH. In a single-pole variant, this connection can be omitted, as can the neutral conductor contact KKN of the mechanical isolating contact unit. The protective switching device SG is advantageously designed in such a way that the contacts of the mechanical isolating contact unit MK can be opened but not closed by the control unit SE, which is indicated by an arrow from the control unit SE to the mechanical isolating contact unit MK.

[0106] The mechanical isolating contact unit MK can be operated by a mechanical handle HH on the protective switching device SG to manually open or close the contacts KKL and KKN. The mechanical handle HH indicates (specifically through a mechanical connection between the contacts and the handle) the switching state (open or closed) of the contacts of the mechanical isolating contact unit MK on the protective switching device.

[0107] The mechanical isolating contact unit MK is advantageously designed in such a way that (manual) closing of the contacts by the mechanical handle is only possible after an enable, in particular an enable signal. This is also indicated by the arrow from the control unit SE to the mechanical isolating contact unit MK. This means that the contacts KKL, KKN of the mechanical isolating contact unit MK can only be closed by the handle HH when the enable or the enable signal is present (from the control unit). Without the enable or the enable signal, the handle HH can be operated, but the contacts cannot be closed ("continuous slipping").

[0108] The protective switching device SG has a power supply NT, for example a power supply unit. In particular, the power supply NT is provided for the control unit SE, which is indicated by a connection between the power supply NT and the control unit SE in Figure 1. The power supply NT is (on the other hand) connected to the mains-side neutral conductor connection NG and the mains-side phase conductor connection LG. A fuse SS, in particular a melting fuse, and / or a switch can advantageously be provided in the connection to the mains-side neutral conductor connection NG (and / or phase conductor connection LG).

[0109] In the case of a purely single-pole protective switching device, the power supply is provided by an external power source / additional connections.

[0110] The low-voltage circuit can be a three-phase alternating current circuit with a neutral conductor and three phase conductors. The protective switching device can be designed as a three-phase variant for this purpose and, for example, have additional mains-side and load-side phase conductor connections. Electronic interruption units and current sensor units (if necessary, additional first voltage sensor units) according to the invention are provided in a similar manner between the additional mains-side and load-side phase conductor connections. Likewise, contacts of the mechanical isolating contact unit.

[0111] The signaling output can then be used to communicate the states of one, two, or all three electronic interruption units. Specifically, the device state (ON / OFF / Ready / Standby) of the protective switching device; in this case, the states of all electronic interruption units are taken into account together in the signaling signal at the signaling output.

[0112] High-resistance refers to a state in which only a negligible current flows. In particular, high-resistance refers to resistance values ​​greater than 1 kiloohm, preferably greater than 10 kiloohms, 100 kiloohms, 1 megaohm, 10 megaohms, 100 megaohms, 1 gigaohm, or greater.

[0113] Low-resistance means a state in which the current value specified on the protective switching device could flow. In particular, low-resistance means resistance values ​​that are less than 10 ohms, preferably less than 1 ohm, 100 milliohms, 10 milliohms, 1 milliohm or less. In a first variant, the mechanical isolating contact unit MK can interrupt in a single pole. This means that only one conductor (of the two / several) conductors, in particular the active conductor or phase conductor, is interrupted, i.e. it has a mechanical contact. The neutral conductor is then contact-free, i.e. the neutral conductor is directly connected.

[0114] If additional active conductors / phase conductors are provided, in a second variant, the phase conductors have mechanical contacts of the mechanical isolating contact unit. The neutral conductor is directly connected in this second variant. For example, for a three-phase AC circuit. In a third variant of the mechanical isolating contact unit MK, the neutral conductor also has mechanical contacts, as shown in Figure 1.

[0115] The term mechanical isolating contact unit MK refers in particular to a (standard-compliant) isolating function implemented by the isolating contact unit MK. The isolating function includes the following points: - minimum air gap according to the standard (minimum distance between the contacts), - contact position indicator of the contacts of the mechanical isolating contact unit, - trip-free operation, i.e. actuation to interrupt the contacts of the mechanical isolating contact unit by the handle or control unit is always possible, so that no (permanent) blocking of the contacts in the closed state by the handle is possible.

[0116] The minimum clearance between the contacts of the isolating contact unit is essentially voltage-dependent. Other parameters include the degree of contamination, the type of field (homogeneous, inhomogeneous), and the air pressure or altitude above sea level.

[0117] There are corresponding regulations or standards for these minimum clearances or creepage distances. For example, these regulations specify the minimum clearance for an inhomogeneous and a homogeneous (ideal) electric field for air, depending on the degree of contamination, for surge voltage resistance. Surge voltage resistance is the resistance when a corresponding surge voltage is applied. Only if this minimum length (minimum distance) is present does the isolating contact unit or protective switching device exhibit an isolating function (isolating property).

[0118] For the purposes of the invention, the DIN EN 60947 or IEC 60947 series of standards is particularly relevant for the isolating function and its properties, to which reference is made here.

[0119] The isolating contact unit is advantageously characterized by a minimum clearance between the open isolating contacts in the open position (open position, open contacts) depending on the rated impulse withstand voltage and the degree of pollution. The minimum clearance is, in particular, between 0.01 mm and 14 mm (at least). In particular, the minimum clearance is advantageously between 0.01 mm at 0.33 kV and 14 mm at 12 kV, especially for pollution degree 1 and especially for inhomogeneous fields.

[0120] Advantageously, the minimum air distance can have the following values:

[0121] E DIN EN 60Ä47-1 (VDE 0C60-100)12018-06

[0122] Table 13 - Minimum clearances

[0123] The pollution levels and field types correspond to those defined in the standards. This advantageously allows for a standard-compliant protective switching device dimensioned according to the rated impulse withstand voltage.

[0124] With a mechanical isolating contact unit, in particular, no

[0125] Relay contact meant.

[0126] Figure 2 shows an illustration according to Figure 1, wherein further or other units are shown.

[0127] In Figure 2, the power supply NT is part of the control unit SE. Furthermore, a (particularly wireless) communication unit COM is provided, which is connected to the control unit SE or is part of it.

[0128] Furthermore, a display unit AE is provided. The display unit AE can be designed as a combined display and input unit. The display unit AE (display and input unit) is connected to the control unit SE or is a part of it. The display unit has visible display means on the protective switching device, in particular for displaying the high-resistance or low-resistance state of the electronic interruption unit EU.

[0129] The electronic interruption unit EU is, as shown in Figure 2, part of the control unit SE.

[0130] According to Figure 2, the control unit SE can have a microcontroller MP (microcontroller unit). The microcontroller can have various functions or routines / procedures, such as a configuration function KE, a status signal function SS, an error status function FS, and a device status function DS.

[0131] Furthermore, a position sensor unit PD can be provided, which signals the position of the contacts of the mechanical isolating contact unit (open, closed). The position sensor unit PD is advantageously connected to the control unit SE.

[0132] The protective switching device SG, for example, operates in principle in such a way that when the contacts of the mechanical isolating contact unit and the low-resistance interruption unit are closed and

[0133] - when a current is detected which exceeds a first current value, in particular when the first current value is exceeded for a first time limit, the electronic interruption unit EU becomes high-resistance and the mechanical isolating contact unit MK remains closed, or / and

[0134] - (or / and) in the case of a determined current which exceeds a higher second current value, in particular for a second time limit, the electronic interruption unit EU becomes high-resistance and the mechanical isolating contact unit MK is opened, or / and

[0135] - if the detected current exceeds an even higher third current value, the electronic interruption unit becomes high-impedance and the mechanical isolating contact unit MK is opened. An external control or display unit (ECU) or management system can be connected to the signaling output SO, as shown in Figure 2.

[0136] Figure 3 shows the basic structure of a galvanically isolated signal output SO in connection with an external control unit ECU.

[0137] Figure 3 shows a signal output SO, which is accessible from the housing. It has several connection terminals, in the example two connection terminals AKI, AK2, whereby the two connection terminals AKI, AK2 are connected internally to at least one optocoupler OPK or relay (with the switched relay contacts) in the circuit breaker. The optocoupler OPK is also controlled by an (internal) signal signal MSI, in particular from the control unit SE or its microcontroller MP. The signal signal MSI can alternate between a logical zero and one signal or zero and one level {0,1}. The zero signal 0 can be, for example, zero volts / 0 volts 0V. The one signal can be, for example, 3.3 volts 3.3V. In this way, at one connection, zero volts 0V (e.g. ground connection) and at the other connection, it is possible to alternate between zero volts 0V and 3.3 volts 3.3V, i.e. {0V; 3.3V}, the logic signal alternates between zero and one {0,1} .

[0138] The two connection terminals AKI, AK2 are connected, for example, on the outside of the housing with a two-wire cable comprising a first conductor LT1 and a second conductor LT2. The two-wire cable is also connected to an external control unit (ECU). The external control unit (ECU) can, for example, determine the signal state / switching state of the signal output SO (low-impedance or high-impedance optocoupler output or closed or open relay contact) via a current flow Ix (current source or voltage source).

[0139] Figure 4 shows a further embodiment of the invention, a functional grouping for the microcontroller MP. The microcontroller MP has a connection to the signal output SO, to which the internal signal MS I is fed. This comes from the status signal function SS. The status signal function SS, in turn, receives information from the error status function FS and the device status function DS.

[0140] The device status function DS, for example, provides the high-resistance or low-resistance state of the electronic interruption unit EU. It can also provide the open or closed state of the contacts of the mechanical isolating contact unit MK. The device status function DS thus provides the device status (ON / OFF / Ready / Standby) of the protective switching device.

[0141] The fault status function FS can, for example, provide further states of the low-voltage electrical circuit, such as the presence of an overcurrent condition, short-circuit condition, earth fault current, overvoltage or undervoltage condition.

[0142] Furthermore, a device warning function (DW) can be provided. This can provide additional device warnings, such as an elevated temperature of the protective switching device (exceeding the first and / or second temperature limit values).

[0143] The configuration function KF can be used to specify or configure which information is signaled and how.

[0144] Test functions on the circuit breaker side which a) switch the electronic interruption unit in the high-resistance state to the low-resistance state for a first period of time or (and) b) switch the electronic interruption unit in the low-resistance state to the high-resistance state for a second period of time are not signalled by the signalling output SO.

[0145] These short switching operations can be used, for example, to test the electronic interruption unit, in particular its semiconductor-based switching elements, or to check the functionality of the current sensor unit. These short switching operations are prioritized by the control unit SE in such a way that they are not signaled by the signaling output SO. This means that the internal signal MS I does not signal this. For example, only the "regular" state of the electronic interruption unit or the state of the protective switching device derived from it is signaled, without the short switching operations of the (internal) testing functions on the protective switching device side.

[0146] Alternatively or additionally, this can also be applied to external protection functions where, for example, load or line parameters are determined by brief switching operations of the electronic interruption unit.

[0147] Figure 5 shows an example of the signaling of the states of the protective switching device SG using the signaling output SO. Due to the electronic interruption unit EU and the mechanical isolating contact unit MK, the protective switching device can essentially assume three states:

[0148] 1. Mechanical isolating contact unit MK opened (at least one contact is open) (state of the electronic interruption unit high-resistance or low-resistance) - state Off OFF

[0149] 2. Mechanical isolating contact unit MK closed (at least one contact is closed) and the electronic interruption unit is high-resistance - Ready Standby state

[0150] 3. Mechanical isolating contact unit MK closed (at least one contact is closed) and the electronic interruption unit is low-resistance - state ON (OFF, Standby, ON are reference symbols in the drawings)

[0151] Using the signaling output SO, for example, a physical-static information status signal in the form of a one (1) or zero (0) {1; 0} can be communicated. In this way, two switching states or device states (On ON / Off OFF / Ready Standby) can be communicated. For example, it can be configured which information should be signaled. Depending on the configuration, for example, the signaling output SO can: in the upper illustration of Figure 5: -Off OFF state - for example, switching state zero (0) -On ON and Ready Standby state - for example, switching state one (1) (classic, similar to a circuit breaker)

[0152] Zero 0 and one 1 could also be used inversely. In the middle representation of Figure 5:

[0153] -Off state OFF and Ready Standby - for example switching state zero 0

[0154] -State One ON - for example switching state One 1 (Zero 0 and One 1 could also be used inversely.) in the lower illustration of Figure 5:

[0155] -Off state OFF- for example switching state zero 0 -On state ON - for example switching state one 1 -Ready standby state - for example a sequence of zero 0 and one 1

[0156] (Zero 0 and one 1 could also be used inversely.)

[0157] For the lower illustration of Figure 5, the switching state of the signal output SO over time t is again visualized / illustrated in Figure 6 (sequence examples).

[0158] In the upper illustration of Figure 6 :

[0159] -Off state OFF - for example zero 0 or zero percent 0% In the middle illustration of Figure 6 :

[0160] -State One ON - for example One 1 or 100 percent 100% In the lower illustration of Figure 6 :

[0161] Ready / Standby state - for example, a sequence of switching states zero (0) and one (1), where the duration of zero and one is equal. e.g., 50 percent (50%).

[0162] For example, additional states or information can be communicated using the SO signal output. This is indicated in Figure 7. Figure 7 shows the status signal function SS, which receives the status "On ON", "Ready Standby", "Off OFF", "Error Status 1 FS1", "Error Status 2 FS2", and "Device Warning 1 DW1".

[0163] The error status FS 1 or FS2 can be, for example: -Short circuit condition KS reached -Overcurrent condition US reached -Fault current condition reached -Overvoltage condition reached -Undervoltage condition reached

[0164] The device warning 1 DW1 can be, for example: -Over temperature condition reached -Self-test of the protective switching device negative

[0165] The signaling of these switching states or statuses by means of the signaling output SO is shown as an example in Figure 8. Figure 8 shows a representation according to Figure 6, with the difference that additional signaling sequences are shown, which are characterized by specific pulse-pause ratios PPV between zero and one signals or zero and one levels.

[0166] For example, Figure 7 shows a further switching state / sequence 25 percent 25%, in which the one signal represents 25 percent of a time unit and the zero signal represents 75 percent of the time unit, as shown in Figure 8. Linked to this sequence is, for example, a fault status 1 FS 1, which signals, for example, the reaching of a short-circuit condition KS of the conductors of the low-voltage circuit, for example more specifically at the load-side connections. For example, a short-circuit condition can be the current exceeding a (predetermined / set) short-circuit current value.

[0167] Furthermore, Figure 7 shows another switching state / sequence 75 percent 75%, in which the one signal is 75 percent of the time unit and the zero signal is 25 percent of the time unit, as shown in Figure 8. Linked to this sequence, for example, is a fault status 2 FS 2, which signals, for example, the reaching of an overcurrent condition US of the conductors of the low-voltage circuit, for example, more specifically at the load-side terminals. For example, an overcurrent condition can be the exceeding of a current threshold (rms value or instantaneous threshold).

[0168] This means that the signal output SO, for example, has two (static) switching states, which, depending on the information to be signaled, can be output quasi-statically or as an alternating sequence of states, i.e., a (switching) sequence. Alternatively or in addition to the static switching state, a (switching) sequence with a specific pulse-pause ratio PPV can be output, so that more than two pieces of information can be signaled (output).

[0169] In the following the invention is presented again in other words.

[0170] In innovative electronic circuit breakers, a mechanical isolating contact unit (isolating contacts) is used in combination with an electronic interrupting unit (electronic switch). Furthermore, a programmable microcontroller is used to execute the circuit breaker functions and, if necessary, additional device functions. Such a new circuit breaker can perform many functions, protect against various faults, and assume multiple states. According to the invention, this is to be communicated or signaled using a (parameterizable) signaling contact.

[0171] The protective switching device performs various protective functions, such as short-circuit protection, overload protection, residual current protection (RCD, additional residual current measurement not shown), protection against overvoltage, undervoltage or overtemperature (additional temperature measurement, not shown). A handle (for opening and closing the isolating contact unit), a detection of the handle (or better, the isolating contact) - position sensor unit, a current measurement, a voltage measurement and a power supply are, for example, present. According to the invention, a signaling output (signaling contact), in particular a galvanically isolated one, is provided. This signaling output can be constructed like a potential-free switch that is controlled via the control unit or the microcontroller.Via this signaling output (signaling contact), the protective switching device can provide information about the switching state of the device, in particular the electronic interruption unit, in a simple digital form (0, 1).

[0172] The galvanically isolated signal output can be implemented using, for example, an optocoupler with appropriate galvanic isolation. An external (remote) control unit (ECU) can query the switching state of the signal output (switching state at the optocoupler output) via a current or voltage source, for example.

[0173] The signal output can signal several types of information. In addition to the familiar states of Off and On, the Ready state can also be used. In addition to the aforementioned states, an error status or a (device) warning from the protective switching device can also be signaled (sent) via the signal output.

[0174] The information is stored in the MP microcontroller. Depending on the (configured) configuration, the desired information can be transmitted, and the type of information transmitted (status, sequence) can also be configured.

[0175] In addition to basic switching states, further information can be signaled (communicated) via the signal output. For example, fault types such as short circuits, overloads, or fault currents can be signaled.

[0176] The sequences can be specified or varied both in terms of the pulse-pause ratio (PPV) (duty cycle) and in terms of frequency and signal sequence. Thus, according to the invention, a simple signaling output (signaling contact) integrated into the protective switching device is advantageously provided, which can be used and configured for various information, such as device states. The signaling output can advantageously be configured so that, in particular, fault states at the load-side connection can be signaled (communicated) using definable sequences.

[0177] 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

Patent claims 1 . Protective switching device (SG) for protecting a low-voltage electrical circuit, comprising: - a housing (GEH) with at least one mains-side connection and at least one load-side connection for conductors of the low-voltage circuit, - a mechanical isolating contact unit (MK) connected in series with an electronic interruption unit (EU), the series circuit being connected on the one hand to the at least one mains-side connection and on the other hand to the at least one load-side connection, - that the mechanical isolating contact unit (MK) can be switched by opening at least one contact to prevent a current flow or closing at least one contact for a current flow in the low-voltage circuit, - that the electronic interruption unit (EU) can be switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent a current flow or a low-resistance state of the switching elements to allow current flow in the low-voltage circuit, - a current sensor unit ( ST ) for determining the current level of the low-voltage circuit, - a control unit (SE) connected to the current sensor unit (ST), the mechanical isolating contact unit (MK) and the electronic interruption unit (EU), whereby if current and / or current time limit values ​​are exceeded, the prevention of current flow in the low-voltage circuit is initiated, - that an alarm output (SO) accessible on the housing of the protective switching device is provided, - that the protective switching device is designed in such a way that the signaling output (SO) signals a high-resistance or low-resistance state of the electronic interruption unit (EU). 2 . Protective switching device (SG) according to claim 1 , characterized in that that the mechanical isolating contact unit (MK) is assigned to the load-side connection and the electronic interruption unit (EU) is assigned to the network-side connection, in particular that the mechanical isolating contact unit (MK) can be operated by a mechanical handle in order to switch the opening or closing of contacts.

3. Protective switching device (SG) according to claim 1 or 2, characterized in that two mains-side connections and at least one load-side connection are provided.

4. Protective switching device (SG) according to claim 1 or 2, characterized in that two mains-side connections and two load-side connections are provided.

5. Protective switching device (SG) according to one of the preceding claims, characterized in that the signaling output (SO) has a, in particular safe, galvanic isolation.

6. Protective switching device (SG) according to one of the preceding claims, characterized in that the signaling output (SO) also signals an open or closed state of at least one contact of the mechanical isolating contact unit (MK).

7. Protective switching device (SG) according to one of the preceding claims, characterized in that the signaling output (SO) has a plurality of connection terminals, in particular two or three connection terminals, wherein the connection terminals are connected internally in the protective switching device to at least one potential-isolating switching element, in particular an optocoupler or relay contact.

8. Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device is designed in such a way that the signaling output (SO) is configurable and, in addition to signaling a high-resistance or low-resistance state of the electronic interruption unit (EU) or alternatively also: a) signals the presence of a, in particular electrical, fault at the load-side connection and / or b) signals the presence of a fault internal to the protective switching device.

9. Protective switching device (SG) according to claim 8, characterized in that a fault at the load-side connection is: a) a short circuit and / or b) an overload and / or c) an earth fault current; that a fault internal to the protective switching device is: a) a device overtemperature and / or b) an exceeding or falling below a current threshold value and / or c) an exceeding or falling below a voltage threshold value.

10. Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device is designed in such a way that the signaling output (SO) can assume two switching states, which can also be output as a sequence, so that several items of information can be output via the signaling output, which in particular has two connection terminals.

11. Protective switching device (SG) according to claim 10, characterized in that the protective switching device is designed in such a way that the switching states or sequences are configurable, in particular in such a way that a switching state or a sequence can be assigned a state of the electronic interruption unit, the mechanical isolating contact unit, a fault on the load-side connection or a fault internal to the protective switching device.

12. Protective switching device (SG) according to one of the preceding claims, characterized in that testing functions on the protective switching device side which a) switch the electronic interruption unit in the high-resistance state to the low-resistance state for a first period of time or b) switch the electronic interruption unit in the low-resistance state to the high-resistance state for a second period of time are not signaled by the signaling output (SO). 13 . Method for a protective switching device (SG) for protecting a low-voltage electrical circuit with : - a mechanical isolating contact unit (MK) connected in series with an electronic interruption unit (EU), the series connection being connected on the one hand to at least one mains-side connection and on the other hand to at least one load-side connection, - that the mechanical isolating contact unit (MK) can be switched by opening contacts to prevent current flow or closing contacts to allow current flow in the low-voltage circuit, - that the electronic interruption unit (EU) is switched by semiconductor-based switching elements into a high-resistance state of the switching elements to prevent a current flow or a low-resistance state of the switching elements to Current flow in the low-voltage circuit can be switched, - that the current level of the low-voltage circuit is determined and, if current and / or current-time limit values ​​are exceeded, the prevention of current flow in the low-voltage circuit is initiated, - that a high-resistance or low-resistance state of the electronic interruption unit (EU) is signalled via a signalling output (SO).

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