EP4377986A1

EP4377986A1 - Circuit breaker

Info

Publication number: EP4377986A1
Application number: EP22785717.4A
Authority: EP
Inventors: Marvin TANNHÄUSER; Manfred Heindl; Jörg Hußmann
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2021-09-28
Filing date: 2022-09-16
Publication date: 2024-06-05
Also published as: DE102021210816A1; CN118020128A; WO2023052148A1

Abstract

The invention relates to a circuit breaker for protecting an electric low-voltage circuit, having: - a housing with grid-side connections and load-side connections for conductors of the low-voltage circuit; - a series circuit consisting of a mechanical separating contact unit and an electronic interruption unit, wherein - the separating contact unit is paired with the grid-side connections, and the interruption unit is paired with the load-side connections, and - the mechanical separating contact unit has a handle for closing and opening contacts; and - a current sensor unit, which is arranged in a conductor between the separating contact unit and the interruption unit, for ascertaining the level of the current of the low-voltage circuit. The circuit breaker is designed such that when current thresholds and/or current/time thresholds are exceeded, a process for preventing a current flow in the low-voltage circuit is initiated, and a power supply unit for supplying energy to the circuit breaker is provided, said power supply unit being connected to conductors of the low-voltage circuit between the grid-side connection and the separating contact unit.

Description

protection switching device

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

By low voltage is meant voltages of up to 1000 volts AC or up to 1500 volts DC. Low voltage refers in particular to voltages that are greater than extra-low voltage, with values of 50 volts AC or 60 volts DC, are .

With low-voltage circuit or network or system are circuits with rated currents or Rated currents of up to 125 amps, more specifically up to 63 amps. Low-voltage circuits are circuits with rated currents or Rated currents of up to 50 amps, 40 amps, 32 amps, 25 amps, 16 amps or 10 amps are meant. The current values mentioned mean in particular nominal, rated and/or cut-off currents, i. H . the maximum current that is normally conducted through the circuit or where the electrical circuit is usually interrupted, for example by a protective device such as a protective switching device, miniature circuit breaker or circuit breaker. The rated currents can be scaled further, 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.

Miniature circuit breakers have long been known overcurrent protection devices that are used in electrical installation technology in low-voltage circuits. These protect lines from damage caused by heating due to excessive current and/or short circuits. A circuit breaker can switch off the circuit automatically in the event of an overload and/or short circuit. A circuit breaker is a non-automatically resetting safety element. In contrast to miniature circuit breakers, circuit breakers are intended for currents greater than 125 A, sometimes even from 63 amperes. Miniature circuit breakers are therefore simpler and more filigree in construction. Miniature circuit breakers usually have a mounting option for mounting on a so-called top-hat rail (mounting rail, DIN rail, TH35).

Miniature circuit breakers are built electromechanically. In a housing, they have a mechanical switching contact or Shunt trip for interrupting (tripping) the electrical current on . A bimetallic protective element or Bimetallic element used for tripping (interruption) in the event of prolonged overcurrent (overcurrent protection) or in the event of thermal overload (overload protection). An electromagnetic release with a coil is used for short-term release when an overcurrent limit value is exceeded or used in the event of a short circuit (short circuit protection). One or more arc quenching chamber(s) or Arc extinguishing devices are provided. Furthermore, connection elements for conductors of the electrical circuit to be protected.

Protective switching devices with an electronic interrupting unit are relatively new developments. These have a semiconductor-based electronic interruption unit. D. H . the flow of electrical current in the low-voltage circuit is routed via semiconductor components or semiconductor switches, which interrupt or switch off the flow of electrical current. can be switched to be conductive. Protective switching devices with an electronic interrupting unit also often have a mechanical isolating contact system, in particular with isolating properties in accordance with relevant standards for low-voltage circuits, the contacts of the mechanical isolating contact system being connected in series with the electronic interrupting unit, i. H . the current of the low-voltage circuit to be protected is carried both via the mechanical isolating contact system as well as via the electronic interrupting unit.

The object of the present invention is to improve a protective switching device of the type mentioned at the outset, in particular to specify or to provide a new, improved architecture for such a protective switching device. a concept with increased safety for a protective switching device or Specify the low voltage circuit to be protected.

This problem is solved by a protective switching device with the features of patent claim 1 .

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, having:

- a housing with network-side and load-side connections for conductors of the low-voltage alternating current circuit, in particular a network-side phase conductor connection, a network-side neutral conductor connection, a load-side phase conductor connection, a load-side neutral conductor connection,

- A mechanical isolating contact unit (MK) connected to the mains-side connections, which is connected on the other hand to an electronic interruption unit (EU), which is connected to the load-side connections (L2, N2) on the other hand, so that through closed contacts of the isolating contact unit and a low-impedance state semiconductor-based switching elements of the electronic interrupting unit enable a current flow in the low-voltage circuit or open contacts of the isolating contact unit enable galvanic isolation while avoiding a current flow in the low-voltage circuit or/and a high-impedance state of the switching elements avoids a current flow in the low-voltage circuit, d . H . a series connection of a mechanical isolating contact unit and an electronic interruption unit, wherein the mechanical isolating contact unit on the mains side and the electronic interruption unit is arranged on the load side.

- that the mechanical isolating contact unit has a handle for manually closing and opening the contacts,

- a current sensor unit, which is arranged in a conductor between the isolating contact unit and the interrupting unit, for determining the magnitude of the current in the low-voltage circuit,

- A control unit, which is connected to the current sensor unit, the electronic interruption unit and the mechanical isolating contact unit, the protective switching device being designed in such a way that when current and/or current time limit values are exceeded, avoidance of a current flow in the low-voltage circuit is initiated,

- A power supply unit for supplying power to the protective switching device, in particular the control unit, the power supply unit being connected to conductors of the low-voltage circuit between the mains-side (LI, NI) connections and the mechanical isolating contact unit (MK), d. H . is arranged on the mains side.

According to the invention, a protective switching device is proposed, the electronic interruption unit being assigned to the load-side connections (consumer, energy sink) and the mechanical isolating contact unit being assigned to the network-side connections (energy source). The power supply unit is electrically connected to the conductors of the low-voltage circuit at the mains-side terminals, ahead of the mechanical isolating contact unit. D. H . Normally, the power supply unit is constantly supplied with energy (voltage) from the low-voltage circuit, regardless of the switching position of the contacts of the mechanical isolating contact unit or the high or low resistance state of the electronic interrupting unit (the low voltage circuit/power source is assumed to supply power/voltage under normal conditions) . Thus, the protective switching device, in particular the control unit, protective or Execute monitoring functions, even if the contacts of the mechanical isolating contact unit are open or the electronic interrupting unit is in a high-impedance state to prevent current flow.

Advantageous refinements of the invention are specified in the dependent claims and in the exemplary embodiment.

In an advantageous embodiment of the invention, a voltage sensor unit connected to the control unit is provided. The voltage sensor unit is provided for determining the magnitude of the voltage between the conductors of the low-voltage circuit, the voltage sensor unit being connected in particular to the conductors between the isolating contact unit and the interrupting unit.

This has the particular advantage that the voltage of the low-voltage circuit can be monitored and, if necessary, the circuit can be disconnected in the event of overvoltage or undervoltage. Thus, the architecture of the invention supports increased operational reliability of the protective switching device or. in the circuit.

In an advantageous embodiment of the invention, the mechanical isolating contact unit has a position indicator unit. The position indicator unit shows the position of the contacts, i .e . H . the contact position (open, closed) is signalled. The position display unit is z. B. a mechanical position indicator unit.

This has the particular advantage that information about the contact position (open, closed) is available. Furthermore, in the case of a mechanical position display unit, this information can also be displayed when the power is off.

In an advantageous embodiment of the invention, the protective switching device has a display unit connected to the control unit. This has the particular advantage that (status) information about the protective switching device can be displayed, e.g. B. about switching and/or error states.

In an advantageous embodiment of the invention, the protective switching device has a communication unit which is connected to the control unit and which, in particular, enables wireless communication.

This has the particular advantage that (status) information, such as switching and error states, can be sent to another protective switching device or monitoring or Management system can be transmitted.

In an advantageous embodiment of the invention, a residual current determination unit connected to the control unit is provided for determining a residual current in the conductors of the low-voltage circuit. This has the particular advantage that the protective switching device also has residual current monitoring (residual current monitoring) and thus has additional functionality.

In an advantageous embodiment of the invention, the protective switching device is designed in such a way that when the mechanical isolating contact unit is actuated by the handle before the contacts are opened, a signal is sent to the control unit, so that it puts the semiconductor-based switching elements of the electronic interruption unit into a high-impedance state .

This has the particular advantage that currentless (powerless) switching of the mechanical isolating contact unit is supported, in particular arcing or contact erosion is avoided.

In an advantageous embodiment of the invention, the mechanical isolating contact unit is designed in such a way that the contacts can be opened by the control unit but cannot be closed. Specifically, the contacts can be opened even if the handle is blocked. This has the particular advantage that increased operational reliability is achieved, since the contact/contacts cannot be accidentally closed by the control unit. Because the contacts are opened even if the handle is blocked, a so-called free tripping/free tripping is achieved, i. H . even if the handle is blocked, the low-voltage circuit is safely protected.

In an advantageous embodiment of the invention, the protective switching device, in particular the mechanical isolating contact unit, is designed in such a way that the mechanical isolating contact unit can be placed in a blocked state, so that the contacts are prevented from being closed by the handle. In particular, the control unit can put the mechanical isolating contact unit into a blocked state.

In an advantageous embodiment of the invention, the protective switching device, in particular the mechanical isolating contact unit, is designed in such a way that the mechanical isolating contact unit can be set to an unblocked state, with the contacts, in particular from the control unit, not being closed. In the unblocked state, the contacts can be closed (again) using the handle. In particular, the control unit can put the mechanical isolating contact unit into an unblocked state.

In particular, the unblocked state is resumed after a blocked state.

In an advantageous embodiment of the invention, the protective switching device, in particular the mechanical isolating contact unit, is designed in such a way that a bistable blocking state is provided, so that the blocked state or the unblocked state of the mechanical isolating contact unit is maintained even in the event of a power failure in the low-voltage circuit.

This has the particular advantage that after z. B. an application of a blocking signal, in particular from the control unit, closing of the contacts by the handle is prevented. After, for example, an unlocking signal has been received, in particular from the control unit, the contacts can again be closed by the handle.

I.e. the mechanical isolating contact unit has a blocking function or a blocking state that can be reset again, in particular is configured as bistable.

This has the particular advantage that before the end of the checking function or after a fault, especially in the control unit, of the protective switching device, which specifically endangers the functionality of the protective switching device, the power supply to the low-voltage circuit to be protected is prevented (by avoiding a current flow and not being able to close the Contacts) . Thus, the security of the low-voltage circuit is increased, since the contacts cannot be closed and consequently an unprotected load is not supplied with energy.

In an advantageous embodiment of the invention, the power supply unit is preceded by a protective element, in particular a fuse and/or a switch.

This has the particular advantage that the power supply unit or the control unit can be switched off, e.g. for insulation measurements. Furthermore, the power pack or the control unit can be secured in order to achieve increased security of the protective switching device against further faults.

In an advantageous embodiment of the invention, the power supply unit has a galvanic isolation. In particular, a transformer is provided. Further, the power supply unit may have reinforced insulation such as double insulation.

This has the particular advantage that the power supply unit has isolating properties in accordance with those for open contacts in order to achieve isolation between the network side and the load side in accordance with the standard. Thus, a standard-compliant protective switching device is made available, its particular control unit is normally constantly active ( switched on ) .

In an advantageous embodiment of the invention, the protective switching device is designed in such a way that when the protective switching device is put into operation for the first time in the de-energized (i.e. de-energized) state of the low-voltage circuit, the switching elements of the electronic interruption unit are in the high-impedance state and the mechanical isolating contact unit is in a blocked state. In the event of an energy supply (usually a voltage supply) in the low-voltage circuit, the protective switching device is supplied with energy by the power supply unit. The protective switching device, in particular the control unit, carries out a first checking function of the protective switching device. If the result of the first check function is positive, the mechanical isolating contact unit is unblocked, so that the contacts of the mechanical isolating contact unit can be closed by the handle.

This has the particular advantage that a very safe protective switching device is made available. Only when the first verification functions have been completed positively, which include a self-test in particular, so that the protective switching device is properly functional and can monitor the circuit, is it possible to open the circuit or to supply the load-side lines with energy, so that a load or consumer or the load-side circuit or the load-side lines are safely protected.

In an advantageous embodiment of the invention, after a positive result of the first checking function and unblocked mechanical isolating contact unit, the mechanical isolating contact unit is also unblocked after a power outage. This has the special advantage that the protective switching device can be switched on immediately after a power failure. In an advantageous embodiment of the invention, after a positive first check function and an unblocked mechanical isolating contact unit, after the contacts of the mechanical isolating contact unit have been closed by means of the handle, the switching elements of the electronic interruption unit are in a high-impedance state.

A second verification function is performed. If the result of the second checking function is positive, the switching elements of the electronic interruption unit are switched to a low-impedance state.

In particular, this step completes the switch-on process.

This has the particular advantage that a very safe protective switching device and circuit is made available. Only in the case of positively completed second check functions, which can include in particular a self-test of the electronic interrupting unit and special load-side and/or network-side parameters, so that the protective switching device is properly functional and the circuit to be protected is checked with regard to its selected parameters, in particular that the protective switching device is suitable for the circuit to be protected and the circuit is OK with regard to its tested parameters, the load-side lines are supplied with energy so that a load or consumer or the load-side circuit or the load-side lines are safely protected.

In an advantageous embodiment of the invention, the first (or second) checking function has a self-test of the functionality of the protective switching device. During the self-test of the functionality of the protective switching device: at least one component, in particular several components, a unit, in particular several units, of the protective switching device is checked.

If the at least one component, in particular several components, of a unit, in particular several units, is functional, the first (or second) checking function ends with a positive result.

This has the particular advantage that only one protective switching device with functioning units is switched on or monitors the circuit to ensure safety in the low-voltage circuit.

In an advantageous embodiment of the invention, if the result of the first check function is negative, the contacts of the mechanical isolating contact unit remain in a blocked state, so that they cannot be closed by the handle.

If the result of the second checking function is negative, the contacts of the mechanical isolating contact unit can be opened and placed in a blocked state, depending on the error. Alternatively, depending on the error, only the electronic interruption unit can remain high-impedance.

This has the particular advantage that a defective protective switching device that cannot perform its monitoring functions can (accidentally) supply power to a load or of the load-side lines is not allowed, so that unprotected circuits are avoided, which increases safety massively.

In an advantageous embodiment of the invention, the checking functions include checking at least one electrical parameter of the load-side or network-side connection. In particular, the checking function carries out a check of at least one, in particular several or all, of the following parameters:

- checking whether a first overvoltage value and/or second overvoltage value and/or third overvoltage value, in particular on the network side, has been exceeded,

- Checking for falling below a first undervoltage value, in particular on the mains side,

- Checking for exceeding a first temperature limit value and/or second temperature limit value and/or third temperature limit value, Checking for parameters of the load-side connection, in particular for falling below a load-side first and/or second resistance value or load-side first and/or second impedance value.

With overvoltage or Overvoltage value means that the valid operating voltage is exceeded. Not meant are the heights of overvoltage dips, for example with so-called bursts or Surges, which can typically be around 4 kV or 8 kV (in a 230 volt or 400 volt network), so-called network overvoltages (i.e. e.g. ten times the normative voltage of the low-voltage circuit).

In particular, the first overvoltage value can be a certain percentage higher than the normative voltage value. For example, with a normative voltage value of 230 volts, for example 10% higher, 230V + 10%.

In particular, the second overvoltage value can be a certain higher percentage higher than the normative voltage value. For example, with a normative voltage value of 230 volts, for example 20% higher, 230V + 20%.

In particular, the third overvoltage value can be a certain even higher percentage higher than the normative voltage value. For example, with a normative voltage value of 230 volts, for example 30% higher, 230V + 30%.

This has the particular advantage that e.g. B. a protective switching device is not connected to a network with a deviating normative voltage (operating voltage) or to a load with incorrect parameters. So e.g. B. A lack of protection in the event of incorrect connection of e.g. B. a 230 volt protective switching device to e.g. B. the two phases with a voltage of 400 volts can be detected and avoided, and an incorrect supply of a load with too high a voltage can be avoided. A related potential destruction of the protective switching device can also be avoided. In an analogous manner, switching on after a short circuit can be detected and avoided before the full supply voltage is switched on. Similarly, if the voltage is too low (a 230 volt device in a 115 volt network), problems can arise and lack of protection can be avoided. In this way, increased operational reliability is achieved in the low-voltage circuit. Furthermore, this has the particular advantage that not only the protective switching device itself is checked, but also the circuit/lines connected to the protective switching device, i. H . specifically the energy source the energy sink / consumer . This represents a new functionality for a protective switching device. Errors on the web side can be caused by e.g. B. connecting the protective switching device to the wrong conductor (400 volts instead of 230 volts) o. uh . be recognized and avoided. Likewise, possible faults on the load side, e.g. B. smooth short circuits can be detected in good time and switching on to the short circuit can be avoided.

In an advantageous embodiment of the invention, depending on the parameters checked: if the first overvoltage value is exceeded, overvoltage information is output, if the second overvoltage value is exceeded, the electronic interrupter unit is prevented from becoming low-resistance, if the third overvoltage value is exceeded, the contacts open If the voltage falls below the first undervoltage value, undervoltage information is issued and/or the electronic interruption unit remains at high resistance, in particular if the voltage level is greater than a second undervoltage value, if the first temperature limit value is exceeded, temperature information is issued, if the second temperature limit value is exceeded, the electronic interruption unit remains at high resistance If the third temperature limit value is exceeded, the contacts open, if the value falls below the first resistance value on the load side or the first impedance value on the load side, impedance information is output, if the temperature falls below the second value on the load side Resistance value or second impedance value on the load side, the electronic interruption unit remains highly resistive. This has the particular advantage that graded defined measures - warning - remain high-impedance - galvanic isolation - are carried out, depending on the over- or Falling below certain defined parameters. This achieves a graded protection concept and increased operational safety in the low-voltage circuit.

In an advantageous embodiment of the invention, the protective switching device is designed in such a way that when the handle is actuated to open the contacts, a signal is sent to the control unit before the contacts are opened, so that the switching elements of the electronic interruption unit are placed in a high-impedance state become . Furthermore, that the control unit has at least one current value or Stores current-time value of the current flow in the low-voltage circuit in a mains voltage-independent memory. This has the particular advantage that currentless (powerless) switching of the mechanical isolating contact unit is supported, in particular arcing or contact erosion is avoided. Furthermore, that the amount of current before the z. B. initiated opening is recorded and can be read afterwards. This supports the determination of the cause of the error.

In an advantageous embodiment of the invention, the protective switching device is designed such that when a current and/or current time limit value is exceeded, the switching elements of the electronic interruption unit are switched to a high-impedance state to prevent current flow in the low-voltage circuit. Furthermore, depending on the adjustable configuration of the protective switching device:

- the contacts of the mechanical isolating contact unit are opened or

- The switching elements remain in a high-impedance state and this state is displayed. In particular, the switching elements can become low-impedance as a result of an input be initiated. Or

- That the switching elements become low-impedance after a first period of time or after a test of the load-side connection, in particular a test of at least one electrical parameter of the load-side connection, more specifically that the electrical parameter falls below or exceeds a threshold value.

This has the particular advantage that the behavior of the protective switching device can be configured. In particular, various measures can be configured to avoid current flow, depending on the application. In addition, switching on the circuit again can be configured. Thus, the area of application and the functionality are increased by a protective switching device.

In an advantageous embodiment of the invention, the protective switching device is designed in such a way that when a fault is detected in a unit of the protective switching device, the switching elements of the electronic interruption unit are placed in a high-impedance state to prevent a current flow in the low-voltage circuit, so that the contacts of the mechanical isolating contact unit are also opened and the mechanical isolating contact unit is placed in a blocked state, so that the contacts are prevented from being closed by the handle, that the detection of the fault is communicated by the communication unit.

This has the particular advantage that a protective switching device detects faults itself and, if a fault is detected, automatically creates a safe state in the low-voltage circuit, also prevents it from being switched on again and communicates the fault, with the latter being constantly supplied with energy, in particular due to the inventive architecture of the protective switching device supplied power supply unit allows or is supported.

In an advantageous embodiment of the invention, this is

Protective switching device designed in such a way that with a In the event of a power failure in the electrical low-voltage circuit, the mechanical isolating contact unit remains in its switching state, so that when the contacts are closed and there is a subsequent power failure after the power supply has been restored, the contacts remain closed.

This has the particular advantage that after a power failure, the protective switching device does not have to be switched on again (manually), so that a renewed power supply is ensured.

In an advantageous embodiment of the invention, the control unit has a microcontroller.

This has the particular advantage that the functions according to the invention for increasing the safety of a protective switching device or of the low voltage electrical circuit to be protected can be realized by a (customizable) computer program product. Furthermore, changes and improvements to the function can be loaded individually onto a protective switching device, for example via the communication unit.

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 additional advantages is claimed.

A method for operating a protective switching device according to one of the patent claims in question, in particular according to patent claims 14 to 23, is claimed.

The method is directed, for example, to the operation of a protective switching device with a series connection of a mechanical isolating contact unit and an electronic interrupting unit, the mechanical isolating contact unit being arranged on the line side and the electronic interrupting unit being arranged on the load side (in the protective switching device). The mechanical isolating contact unit has a handle for closing and opening contacts. By closed contacts Isolating contact unit and a low-impedance state of semiconductor-based switching elements of the electronic interruption unit, a current flow in the low-voltage circuit can be enabled OR open contacts of the isolating contact unit enable galvanic isolation while avoiding a current flow in the low-voltage circuit and/or a high-impedance state of the switching elements avoids a current flow allowed in the low-voltage circuit. The magnitude of the current in the low-voltage circuit is determined (in the protective switching device) and if current and/or current time limit values are exceeded, a current flow in the low-voltage circuit is avoided (by means of the mechanical isolating contact unit and/or the electronic interrupting unit).

A power supply unit for supplying energy to the protective switching device is provided, which is connected to conductors of the low-voltage circuit in the housing on the network side, d. H . is/is connected in the area from the mains connections to the isolating contact unit (in the protective switching device).

When the protective switching device is started up for the first time in the de-energized state of the low-voltage circuit, the switching elements of the electronic interruption unit are in the high-impedance state and the mechanical isolating contact unit is in a blocked state. When power is supplied to the low-voltage circuit, the protective switching device is supplied with power by the power supply unit. A first checking function of the protective switching device is carried out. If the result of the first checking function is positive, the mechanical isolating contact unit is unblocked, so that the contacts of the mechanical isolating contact unit can be closed by the handle.

Further methods (designs) can be derived from the specific design, patent claims and the exemplary embodiment. All configurations, both in a dependent form referring back to patent claim 1 or 25, as well as referring back only to individual features or combinations of features of patent claims, bring about an improvement in a protective switching device, in particular a new architecture and an improvement in the safety of a protective switching device or of the electrical circuit , and provide a new concept for a protective switching device .

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

The drawing shows:

Figure 1 is a block diagram of a protective switching device.

FIG. 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 having:

- a housing GEH with line-side LI, NI and load-side L2, N2 connections for conductors of the low-voltage AC circuit, the line-side connections comprise a line-side neutral conductor connection NI and a line-side phase conductor connection LI, the load-side connections comprise a load-side neutral conductor connection N2 and a load-side phase conductor connection L2 the mains connections or an energy source is connected to the grid side, for example, to the load-side connections or the load side Load is, for example, (at least) a consumer or load connected,

- A mechanical isolating contact unit MK connected to the mains-side LI, NI connections, which on the other hand is connected to a electronic interruption unit EU , which on the other hand is connected to the load - side terminals L2 , N2 , d. H . a series connection of a mechanical isolating contact unit MK and an electronic interrupting unit EU, the mechanical isolating contact unit MK being connected to the line-side connections LI, NI or is assigned to the grid side and the electronic interruption unit EU is connected to the load-side connections L2, N2 or is assigned to the load side Load,

- So that through closed contacts KL, KN of the isolating contact unit MK and a low-impedance state of semiconductor-based switching elements TI, T2 of the electronic interruption unit EU allows a current flow in the low-voltage circuit or through open contacts KL, KN of the isolating contact unit MK a galvanic isolation while avoiding a current flow in Low-voltage circuit and/or a high-impedance state of the switching elements TI, T2 of the electronic interruption unit EU makes it possible to avoid a current flow in the low-voltage circuit,

- The mechanical isolating contact unit MK has a handle for closing and opening the contacts KL, KN, which is accessible on the outside of the housing, so that it can be operated manually by an operator,

- a current sensor unit S I, which is arranged in a conductor between the isolating contact unit MK and the interruption unit EU, for determining the level of the current in the low-voltage circuit, in the example the current sensor unit S I is arranged in the phase conductor,

- A control unit SE, which is connected to the current sensor unit SI, the electronic interruption unit EU and the mechanical isolating contact unit MK, the protective switching device SG being designed in such a way that when current and/or current time limit values are exceeded, a current flow of the low-voltage circuit is initiated, This can be done by switching elements TI, T2 of the electronic interruption unit EU becoming highly resistive and/or by opening the contacts KL, KN of the mechanical isolating contact unit MK,

- A power supply unit NT for powering the protective switching device SG, in particular the control unit SE, which is connected to conductors of the low-voltage circuit between the mains-side (LI, NI) connections and the mechanical isolating contact unit (MK). This includes a connection that requires a direct connection to the line-side (LI, NI) connections or the mechanical isolating contact unit (MK) includes. Electrically, the NT power supply unit is connected before the mechanical isolating contact unit (MK), so that it is supplied with energy from the mains-side connections regardless of the switching state of the contacts of the mechanical isolating contact unit (MK) (provided the mains-side connections supply energy/voltage).

In this way, the power pack unit (power pack) is constantly supplied with energy in the normal case (provided the mains side or energy source supplies energy). In this way, protective and monitoring functions can be (virtually) constantly installed in the protective switching device or be carried out by the control unit.

A protective element, in particular a fuse S ICH (as shown in FIG. 1), and/or a switch can be connected upstream of the power supply unit.

In the example, the protective switching device SG also has a voltage sensor unit SU connected to the control unit SE for determining the magnitude of the voltage between the conductors of the low-voltage circuit between the isolating contact unit MK and the interruption unit EU.

In the example, the protective switching device SG has a residual current determination unit ZCT connected to the control unit, which is arranged on the conductors of the low-voltage circuit between the isolating contact unit MK and the interruption unit EU, for determining a residual current in the conductors of the low-voltage circuit.

In the example, the protective switching device SG has a display unit AE connected to the control unit SE, for Display of status information of the protective switching device, in particular the control unit SE.

In the example, the protective switching device SG has a communication unit COM connected to the control unit SE. This can enable a wired or wireless communication option, as well as both.

The control unit SE has a microcontroller MCU for controlling the protective switching device. The microcontroller MCU or the control unit SE can have a computer program product CPP. The computer program product CPP includes commands which, when the program is executed by the microcontroller MCU, cause the latter to initiate the functions mentioned for a protective switching device.

A computer-readable storage medium on which the computer program product CPP is stored can be provided.

A data carrier signal that transmits the computer program product CPP can also be provided. The computer program product CPP or a new computer program product CPP reach the protective switching device through the communication unit COM.

In the example according to FIG. 1, the control unit SE includes the microcontroller MCU together with the computer program product CPP, the display unit AE, the communication unit CPP, the current sensor unit S I , the voltage sensor unit SU and the residual current determination unit ZCT. This is just an example , the units can also be separate resp . be grouped differently.

In the example according to FIG. 1, the electronic interruption unit EU has two semiconductor-based switching elements TI, T2, such as transistors, field effect transistors, IGBT, or the like. uh .

The semiconductor-based switching elements TI, T2 can be driven by a driver unit Drv. In the example, the driver unit Drv is in turn controlled by the control unit SE. The electronic interruption unit EU can have an energy absorber EA to avoid destructive voltage spikes or. the absorption of switching energy. In the example, the electronic interruption unit EU is single-pole (for one conductor of the low-voltage circuit). In the example, the electronic interruption unit EU is arranged in the phase conductor.

The mechanical isolating contact unit MK has two poles in the example (in both conductors of the single-phase AC circuit in the example). Safe electrical isolation is possible with a two-pole design, provided that the mechanical isolating contact unit MK is designed with isolating properties in accordance with the standard (distances, minimum air gaps, etc.).

The mechanical isolating contact unit MK has a position indicator unit POSA, which indicates the (switching) position of the contacts of the mechanical isolating contact unit MK. The position display unit is designed mechanically so that the contact position can be displayed even when there is no voltage (no energy from the grid side).

The protective switching device or the mechanical isolating contact unit MK is designed such that when the mechanical isolating contact unit MK is actuated by the handle HH before the contacts KL, KN are opened, an (actuating) signal AS is sent to the control unit SE. The protective switching device SG or the control unit SE is designed in such a way that the semiconductor-based switching elements TI, T2 of the electronic interruption unit EU are then put into a high-impedance state, so that power-free switching with the mechanical isolating contact unit MK is made possible.

The protective switching device or the mechanical isolating contact unit MK is designed in such a way that the contacts KL, KN can be opened by the control unit SE, for example by means of an opening signal OPEN, but cannot be closed. In particular, the contacts can be opened even if the handle is blocked (e.g. contrary to the usual use is permanently set to "On" / closing the contacts) .

The protective switching device or In one embodiment, the mechanical isolating contact unit MK is designed in such a way that in particular the control unit SE can put the mechanical isolating contact unit MK into a blocked state, so that the contacts are prevented from being closed by the handle.

Furthermore, that in particular the control unit SE can put the mechanical isolating contact unit MK into an unblocked state, the contacts, in particular from the control unit, not being closed, but the contacts can be closed by the handle. Furthermore, that the protective switching device, specifically the mechanical isolating contact unit MK, is designed in such a way that a bistable blocking state is provided, so that the blocked state or the unblocked state of the mechanical isolating contact unit MK is retained even in the event of a power failure in the low-voltage circuit.

Further units can be provided, such as a switching lock unit SS or a combined opening blocking unit O/B.

The new protective switching device SG according to the invention is designed in such a way that when the protective switching device is started up for the first time when the low-voltage circuit is de-energized (i.e. de-energized), the switching elements of the electronic interruption unit are in the high-impedance state and the mechanical isolating contact unit is in a blocked state. In the event of an energy supply (usually a voltage supply) in the low-voltage circuit, the protective switching device is supplied with energy by the power supply unit. The protective switching device, in particular the control unit, carries out a first checking function of the protective switching device. If the result of the first check function is positive, the mechanical isolating contact unit is unblocked, so that a Closing the contacts of the mechanical isolating contact unit is possible through the handle.

After a positive first check function and unblocked mechanical isolating contact unit, after a (now possible) closing of the contacts of the mechanical isolating contact unit by means of the handle, the switching elements of the electronic interruption unit (as before) are in a high-impedance state.

In particular, this step completes the switch-on process.

The first and second checking function includes, for example, a self-test of the functionality of the protective switching device. During the self-test of the functionality of the protective switching device: at least one component, in particular several components, a unit, in particular several units, of the protective switching device is checked.

If the at least one component, in particular a plurality of components, or a unit, in particular a plurality of units, is functional, the first (or second) checking function is ended with a positive result.

For example, the first checking function is aimed specifically at a self-test of the control unit SE, since this is supplied with energy.

The second checking function can, for example, be aimed specifically at a self-test of the electronic interruption unit EU, since it is now being supplied with energy/voltage is present.

If the result of the first check function is negative, the contacts of the mechanical isolating contact unit remain in a blocked state so that they cannot be closed by the handle.

The checking functions include checking at least one electrical parameter of the load-side or grid-side connection. In particular, the checking function carries out a check of at least one, in particular several or all, of the following parameters:

- Checking for exceeding a first temperature limit value and/or second temperature limit value and/or third temperature limit value,

Checking for parameters of the load-side connection, in particular for falling below a load-side first and/or second resistance value or load-side first and/or second impedance value.

The first checking function can include checking whether a network-side first overvoltage value and/or second overvoltage value and/or third overvoltage value is exceeded. Furthermore, a check for falling below a first undervoltage value on the network side. The second checking function can include checking parameters of the connection on the load side, in particular whether the value falls below a first and/or second resistance value on the load side or a first and/or second impedance value on the load side. In this way, switching on after a short circuit can be avoided.

Furthermore, depending on the checked parameters: if the first overvoltage value is exceeded, overvoltage information is issued, if the second overvoltage value is exceeded, the electronic interruption unit is prevented from becoming low-resistance, if the third overvoltage value is exceeded, the contacts open, if the first undervoltage value is not reached, undervoltage information is issued and/or the electronic Interruption unit remains high-impedance, in particular if the voltage level is greater than a second undervoltage value, if the first temperature limit value is exceeded, temperature information is output, if the second temperature limit value is exceeded, the electronic interruption unit remains high-impedance, if the third temperature limit value is exceeded, the contacts open, if the temperature falls below this limit of the first resistance value on the load side or first impedance value on the load side, impedance information is output, if the value falls below the second resistance value on the load side or second impedance value on the load side, the electronic interruption unit remains at high resistance.

When the handle is actuated to open the contacts before the contacts are opened, a signal is sent to the control unit, so that the switching elements of the electronic interruption unit are put into a high-impedance state. Furthermore, that the control unit has at least one current value or Stores current-time value of the current flow in the low-voltage circuit in a mains voltage-independent memory.

If a current and/or current time limit value is exceeded, the switching elements of the electronic interruption unit are in a high-impedance state to prevent a current flow in the low-voltage circuit shifted . Furthermore, depending on the adjustable configuration of the protective switching device:

- the contacts of the mechanical isolating contact unit are opened or

- The switching elements remain in a high-impedance state and this state is displayed. In particular, the switching elements can become low-impedance by an input. Or

When an error is detected in a unit of the protective switching device, the switching elements of the electronic interruption unit are placed in a high-impedance state to prevent a current flow in the low-voltage circuit. Furthermore, the contacts of the mechanical isolating contact unit are opened and the mechanical isolating contact unit is placed in a blocked state, so that the contacts are prevented from being closed by the handle. In addition, the detection of the error is communicated by the communication unit.

The first/second checking function can be implemented by the control unit, specifically the microcontroller MCU, in cooperation with the computer program product CPP.

If it is not functional, the contacts of the mechanical isolating contact unit can be opened. If there is no functionality after a renewed (or a certain number of further, e . The protective switching device can be designed in such a way that in the event of a power outage in the electrical low-voltage circuit, the mechanical isolating contact unit remains in its switching state, so that when the contacts are closed and there is a subsequent power outage after the power supply has been restored, the contacts remain closed.

High resistance means a state in which only a negligible current flows. In particular, by high resistance is meant resistance values greater than 1 kilohm, more preferably greater than 10 kilohms, 100 kilohms, 1 megohm, 10 megohms, 100 megohms, 1 gigaohm, or greater.

Low-impedance means a condition in which the current value specified on the protective switching device could flow. In particular, low-impedance means resistance values that are less than 10 ohms, better less than 1 ohm, 100 milliohms, 10 milliohms, 1 milliohm or less.

In the following, the invention is to be described or described again in other words. be summarized.

In electronic protective switching devices according to the invention, mechanical switching contacts in combination with an electronic switch will assume the switching functions.

1 . ) New concept :

-Mechanical break contacts in both poles

-One pole (in particular phase conductor L) is connected by an electronic interruption unit with semiconductor-based switching elements, e.g. B. Power semiconductor, protected - discharge network (energy absorber) over the switching elements

-A mechanical actuation of the handle, which is constructed in such a way that before the contacts are opened, a signal is sent to the control unit and this causes the interrupter unit to become highly resistive -The mechanical isolating contact unit can be opened by the control unit, but not closed -The mechanical isolating contact unit can only be closed manually using the handle -Measuring technology:

0 Voltage measurement between L and N

0 Current measurement in the protected pole (L)

0 Total current measurement across L and N

-The voltage supply (= power supply unit) for the control unit picks up the voltage at L and N before the contacts of the mechanical isolating contact unit

The power supply (= power supply unit) has a galvanic isolation (e.g. via a transformer voltage converter) in order to maintain the isolation function of the mechanical contacts in the overall concept. The galvanic isolation should meet standard requirements, e.g. double isolation.

The power supply (= power supply unit) has a protected connection to L (e.g. fuse) - The control unit can put the mechanical isolating contact unit in a blocked state. It is then no longer possible to close the contacts using the handle. The control unit can return the mechanical isolating contact unit to an unblocked state. -The device has a communication interface (preferably wireless) -The contact position of the (mechanical) contacts is displayed mechanically. (E.g. with green: off and red: on -The device has a display unit that shows the status of the device. E.g. with light-emitting diodes / LEDs, e.g. as follows: o Red: on-state o Green: off-state, unlocked o Yellow: Control state, high impedance

2.) Behavior when switching on:

When switching on, the device is switched on via the handle. a) The device is connected to the mains voltage. b) Power supply unit begins to power the device, specifically the control unit. c) The device, especially the control unit, carries out an initial check function / self-test (especially of the electronic components). d) If the conclusion is positive, the mechanical isolating contact unit, eg the switching mechanism, is "switched" from the blocked to the unblocked state (manual mechanical switching on by handling the main current path is now possible).

Preferably bistable states: It remains in the respective state even when there is no voltage, switching is actively controlled by the control unit. e) The contacts are closed by the handle. f) Contacts close g) The output on the load side is still dead because the interrupter unit is high-impedance / in the blocked state. h) Second check function, e.g. load is checked for e.g. short circuit i) If the test is positive, the interruption unit becomes low-impedance (without further (manual) actuation). j) Load side receives energy, load / consumer is supplied.

3.) Behavior when switching off:

When switching off, the device is switched off using the handle (manual operation). a) Handle is set to Off (contacts to open) b) The actuation is sent to the control unit before the contacts open c) The interrupting unit becomes high-impedance immediately (or intelligently at zero crossing) d) The contacts open e) The power supply for the electronics remain intact even when disconnected (released). i. If necessary, the control unit is supplied with a corresponding safety extra-low voltage from the power supply unit, e.g. B. 3V or 5V ii. The power supply includes safe galvanic isolation from the mains voltage (e.g. through double or extra reinforced isolation in the transformer voltage converter) iii. The power supply could be separated from the mains via a small switch.

4.) Behavior in the event of a fault in the load: short circuit or overload:

Occurs on a device e.g. B. Short-circuit in the load, the device reacts as follows. a) Exceeding a current limit value is detected by the corresponding units b) The interrupting unit is switched to the high-impedance state, so that the load / consumer is no longer supplied with energy / voltage c) Then the device can decide depending on the configuration (due to Error type and/or error current) which of the following (two) states, for example

1) The device automatically opens the mechanical contacts and the load is completely disconnected

2) The device remains in the high-impedance state (the contacts of the isolating contact unit remain closed - the device does not switch off) Automatic switching on is possible again from this state.

5.) Behavior in the event of (internal) device errors:

If an error occurs in the protective switching device, in particular the control unit, the device goes into a safe state from which the device cannot be switched on again. The prerequisite is the detection of the defect by the protective switching device. a) The error in the protective switching device is detected. b) The device switches the interruption unit to high resistance. c) The device opens the contacts of the isolating contact unit and blocks the isolating contact unit (e.g. the switching mechanism) to such an extent that it is no longer possible to close the contacts with the handle. d) The error is reported via the communication unit.

6.) Behavior in the event of a power failure / power failure:

If a power failure occurs, the protective switching device is no longer supplied with energy. The contacts remain closed / in the previous position. This means that when the mains voltage is restored, the device can switch to the previous switching state without manual operation.

Although the invention has been illustrated and described in more detail by the exemplary 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 protective scope of the invention.

Claims

33 patent claims

1 . Protective switching device (SG) for protecting an electrical low-voltage circuit having:

- a housing (GEH) with line-side (LI, NI) and load-side (L2, N2) connections for conductors of the low-voltage AC circuit,

- A mechanical isolating contact unit (MK) connected to the mains-side (LI, NI) connections, which is connected on the other hand to an electronic interruption unit (EU), which is connected to the load-side connections (L2, N2) on the other hand, so that closed contacts of the isolating contact unit and a low-impedance state of semiconductor-based switching elements of the electronic interrupting unit allows a current flow in the low-voltage circuit or through open contacts of the isolating contact unit a galvanic isolation is made possible while avoiding a current flow in the low-voltage circuit or/and through a high-impedance state of the switching elements avoiding a current flow in the low-voltage circuit,

- that the mechanical isolating contact unit has a handle for closing and opening the contacts,

- a current sensor unit (SI), which is arranged in a conductor after the isolating contact unit, for determining the level of the current of the low-voltage circuit,

- a control unit (SE), which is connected to the current sensor unit (SI), the electronic interruption unit (EU) and the mechanical isolating contact unit (MK), the protective switching device (SG) being designed in such a way that when the current and/or Current-time limits avoidance of a current flow of the low-voltage circuit is initiated,

- A power supply unit (NT) for the energy supply of the protective switching device (SG), which is connected to conductors of the low-voltage circuit between the mains-side (LI, NI) connections and the mechanical isolating contact unit (MK). 34

2. Protective switching device (SG) according to claim 1, characterized in that one with the control unit (SE) connected voltage sensor unit (SU) is provided to determine the level of the voltage between the conductors of the low-voltage circuit between isolating contact unit and interruption unit.

3. Protective switching device (SG) according to claim 1 or 2, characterized in that the mechanical isolating contact unit has a position display unit for the position of the contacts, in particular a mechanical position display unit.

4. Protective switching device (SG) according to Patent Claim 1, 2 or 3, characterized in that the protective switching device has a display unit (AE) connected to the control unit (SE), in particular for displaying the high-impedance or low-impedance state of the electronic interruption unit.

5. Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device has a control unit (SE) connected to the communication unit (COM), which in particular enables wireless communication.

6. Protective switching device (SG) according to one of the preceding claims, characterized in that one with the control unit (SE) connected residual current determination unit (ZCT) is provided for determining a residual current of the conductors of the low-voltage circuit.

7. 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 when the mechanical isolating contact unit is actuated by the handle before the contacts open, a signal is sent to the control unit (SE), so that this puts the semiconductor-based switching elements of the electronic interruption unit (EU) in a high-impedance state.

8. Protective switching device (SG) according to one of the preceding claims, characterized in that the mechanical isolating contact unit (MK) is designed such that the contacts of the control unit (SE) can be opened but not closed, in particular that the contacts are opened even if the handle is blocked.

9. 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, in particular the control unit (SE), the mechanical isolating contact unit (MK) can be put into a blocked state, so that the contacts close prevented by the handle.

10. Protective switching device (SG) according to Patent Claim 9, characterized in that, in particular the control unit (SE), the mechanical isolating contact unit (MK) can be put into an unblocked state, the contacts, in particular from the control unit, not being closed, the contacts but can be closed by the handle.

11. Protective switching device (SG) according to claim 9 or 10, characterized in that that the mechanical isolating contact unit (MK) is designed such that a bistable blocking state is provided, so that the blocked state or the unblocked state of the mechanical isolating contact unit (MK) is retained even in the event of a power failure in the low-voltage circuit.

12 . Protective switching device (SG) according to one of the preceding claims, characterized in that the power supply unit (NT) is preceded by a protective element (S ICH), in particular a fuse, or a switch.

13 . Protective switching device (SG) according to one of the preceding claims, characterized in that the power supply unit (NT) has a galvanic isolation, in particular has a transformer.

14 . Protective switching device (SG) according to one of the preceding claims, characterized in that the protective switching device (SG) is designed in such a way that when the protective switching device is first put into operation in the de-energized state of the low-voltage circuit, the switching elements of the electronic interruption unit (EU) are in the high-impedance state and the mechanical isolating contact unit (MK) in a blocked state is that when there is a power supply in the low-voltage circuit, the protective switching device is supplied with energy by the power pack unit (NT), the control unit (SE) carries out an initial check function of the protective switching device, with a positive result of the checking function the mechanical isolating contact unit is unblocked, so that closing the contacts of the mechanical isolating contact unit is possible through the handle. 37

15. Protective switching device (SG) according to claim 14, characterized in that after a positive result of the first check function and unblocked mechanical isolating contact unit (MK) the mechanical isolating contact unit (MK) is unblocked even after a power failure.

16. Protective switching device (SG) according to claim 14 or 15, characterized in that after a positive first check function and unblocked mechanical isolating contact unit after closing the contacts of the mechanical isolating contact unit by means of the handle, the switching elements of the electronic interruption unit are in a high-impedance state, that a second check function is carried out that after a positive result of the second checking function, the switching elements of the electronic interruption unit are placed in a low-impedance state.

17. Protective switching device (SG) according to Patent Claim 14, 15 or 16, characterized in that the first checking function has a self-test of the functionality of the protective switching device, in which at least one component, in particular a plurality of components, of a unit, in particular a plurality of units, of the protective switching device is checked , and if the at least one component, in particular a plurality of components, of a unit, in particular a plurality of units, is functional, the first checking function is terminated with a positive result.

18. Protective switching device (SG) according to claim 14, 15, 16 or 17, characterized in that the first verification function is a verification 38 includes at least one electrical parameter of the grid-side connection, in particular the magnitude of the voltage of the grid-side connection, in particular that if an overvoltage value is exceeded, the first checking function is ended negatively.

19 . Protective switching device (SG) according to claim 16, 17 or 18, characterized in that the second checking function has a self-test of the functionality of the protective switching device according to the first checking function and/or includes a check of at least one electrical parameter of the load-side connection.

20 . 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 when the contacts are opened by means of the handle before the contacts are opened, a signal is sent to the control unit so that the switching elements of the electronic interruption unit can be put into a high-impedance state, and in particular that the control unit has at least one current value or Stores current-time value of the current flow in the low-voltage circuit in a mains voltage-independent memory.

21 . 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 when a current and/or current time limit value is exceeded, the switching elements of the electronic interruption unit (EU) go into a high-impedance state to avoid a Current flow offset in the low-voltage circuit 39 that, depending on the adjustable configuration of the protective switching device:

- the contacts of the mechanical isolating contact unit are opened or

- The switching elements remain in a high-impedance state and this state is displayed, in particular that the switching elements can be initiated to become low-impedance by an input, or

22 . Protective switching device (SG) according to one of the preceding patent claims, characterized in that the protective switching device is designed in such a way that when a fault is detected in a unit of the protective switching device, the switching elements of the electronic interruption unit are put into a high-impedance state to prevent a current flow in the low-voltage circuit, that furthermore the contacts of the mechanical isolating contact unit are opened and the mechanical isolating contact unit is placed in a blocked state, so that the contacts are prevented from being closed by the handle, the detection of the error is communicated by the communication unit.

23 . 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 in the event of a power failure in the electrical low-voltage circuit, the mechanical isolating contact unit remains in its switching state, so that when the contacts and 40 subsequent power failure after restoring the

power supply the contacts remain closed.

24. Protective switching device (SG) according to one of the preceding patent claims, characterized in that the control unit (SE) has a microcontroller (MCU).

25. Method for operating a protective switching device (SG) according to one of the preceding claims.