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DE3902416A1 - Overcurrent-sensitive circuit breaker - Google Patents

Overcurrent-sensitive circuit breaker

info

Publication number
DE3902416A1
DE3902416A1DE19893902416DE3902416ADE3902416A1DE 3902416 A1DE3902416 A1DE 3902416A1DE 19893902416 DE19893902416 DE 19893902416DE 3902416 ADE3902416 ADE 3902416ADE 3902416 A1DE3902416 A1DE 3902416A1
Authority
DE
Germany
Prior art keywords
switch
overcurrent
evaluation
sensor
current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
DE19893902416
Other languages
German (de)
Inventor
Manfred Fischer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB AG Germany
ABB AB
Original assignee
Asea Brown Boveri AG Germany
Asea Brown Boveri AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Asea Brown Boveri AG Germany, Asea Brown Boveri ABfiledCriticalAsea Brown Boveri AG Germany
Priority to DE19893902416priorityCriticalpatent / DE3902416A1 / en
Publication of DE3902416A1publicationCriticalpatent / DE3902416A1 / en
Withdrawnlegal-statusCriticalCurrent

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Classifications

    • H-ELECTRICITY
    • H02 GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H — EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3 / 00 — Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection; integrated protection
    • H02H3 / 08 — Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection; integrated protection responsive to excess current
    • H02H3 / 085 — Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection; integrated protection responsive to excess current making use of a thermal sensor, e.g. thermistor, heated by the excess current
    • H-ELECTRICITY
    • H02 GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H — EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1 / 00 — Details of emergency protective circuit arrangements
    • H02H1 / 0007 — Details of emergency protective circuit arrangements concerning the detecting means

Abstract

Description

The invention relates to an overcurrent-sensitive self-switch for the protection of electrical components, in particular motor or circuit breaker, with at least one contact arrangement, with a switching mechanism engaged with a switch lock for actuating the contact arrangement and with an overcurrent-sensitive trigger part which is in operative connection with the switch lock The invention relates to an overcurrent-sensitive self switches for protecting electrical components, in particular motor or circuit breaker, with at least a contact arrangement, with one with a key switch engaged switching mechanism for actuating the contact arrangement as well as with an overcurrent sensitive tripping part that is operatively connected to the switch lock stands and when the respective nominal current is exceeded its shutdown by triggering the key switch brin gs about.
Electrical circuit breakers, especially overcurrent sensitive circuit breakers, have the task of connecting downstream electrical components and systems, such as. B. electrical cal machines (motors, transformers, chokes), lines or electronic switching devices to protect against damage caused by overcurrents by automatically causing its interruption when such an overcurrent occurs. Furthermore, electrical circuit breakers are used to protect supply lines from excessive heating that results from pending overcurrents that, if not switched off, lead to permanent damage to the insulation, e.g. Electrical automatic switches, in particular overcurrent sensitive tive auto switches, have the task of downstream electrical components and systems such. B. electrical machines (motors, transformers, chokes), lines or electronic switching devices from damage protect due to overcurrents by occur such an overcurrent automatically its un bring about break. Furthermore, electrical Automatic switch to protect supply lines inadmissible warming used, which from upcoming Overcurrent results when not turned off become permanent damage to the insulation, e.g. B. due to excessive aging, can lead or but at worst can start a fire.
Known electrical auto switches therefore have an overcurrent-sensitive triggering part for automatic triggering, which works together with the switch mechanism and the switching mechanism and, when an overcurrent occurs, triggers it, whereby the contact arrangement is opened and the power supply is interrupted overcurrent-sensitive tripping part, which with the switch lock and the rear derailleur works together and if an overcurrent occurs causes its triggering, causing the contact arrangement open and the power supply is interrupted.
Such an automatic switch is known from DE-PS 23 36 916, which is used as a line circuit breaker and has an electromagnetic short-circuit release as a release part and a bimetal release that can be acted upon by Joule heat. While the electromagnetic short-circuit release responds exclusively to short-circuit currents that are a multiple of the respective nominal current, the bimetal release is used to protect against currents that occur as a result of an overload and exceed the nominal current. The bimetal release is connected in series with the elec tromagnetic short-circuit release so that both releases carry exactly the current that flows in the line to be protected. Such a self-switch is from the DE-PS 23 36 916 become known as the line circuit breaker is used and as a trigger part electromagnetic short-circuit release and a through Joule'sche heatable bimetallic release points. During the electromagnetic short-circuit release exclusively on short-circuit currents that are a multiple of the respective nominal current, responds, serves the bimetal release to protect against currents that occur due to an overload and the rated current above stride. The bimetallic release with the elec tromagnetic short-circuit release connected in series, so that both triggers each conduct exactly the current, that flows in the line to be protected.
Here and in the following, overcurrents should only be understood to mean currents that result from an overload that has been present for a long time and lead to a moderate but impermissible excess of the rated current. Although short-circuit currents are also included in the overcurrents, they do not result from such an overload and are many times higher than the rated current. They should therefore not be considered in more detail unless they are explicitly discussed. Overflows are said to be only here and below che currents are understood to be from a long time pending overload and result in a moderate, but lead to inadmissible exceeding of the nominal current. Short-circuit currents are also too overcurrents calculate, but they do not result from such an overload and are many times higher than the nominal electricity. They should therefore not be considered in more detail unless explicitly mentioned.
The selection of the bimetallic release depends on the nominal currents to be mastered, whereby the thermally caused deflection of the bimetal strip clamped on one side starts when the nominal current is exceeded and, in the event of an overcurrent, triggers the switching mechanism after a certain period of time. The tripping characteristic of such a circuit breaker follows a tripping characteristic, which prescribes the shorter the tripping times, the higher the rated current is exceeded, whereby from a certain limit current the characteristic shows a kink, which results from the disconnection by the electromagnetic short-circuit release release depends on the to master nominal currents, the thermal caused deflection of the unilaterally clamped bime tallstreifens with exceeding the nominal current uses and if there is an overcurrent after a be agreed the triggering of the key switch leads. The trigger characteristic of such the circuit breaker follows a tripping characteristic that the shorter the tripping times, the higher the rated current is exceeded, being from a certain limit current, the characteristic curve has a kink that the shutdown by the electromagnetic short final trigger results .
The course of the characteristic curve shows that with low overcurrents, i. H. if the nominal current is slightly exceeded, the duration until shutdown by the overcurrent release (bimetal release) can assume large values ​​of up to an hour or that there is no shutdown at all. The tripping characteristics specified in the relevant regulations are based on the use of thermal bimetals as overcurrent releases, with which only such a tripping characteristic can be implemented. On the other hand, especially when using electronic components (semiconductors) there is the problem that the current limit value and / or the temperature are already slightly exceeded and the temperature in question can be destroyed and the electrical device in question permanently unusable. The course of the characteristic curve shows that at low over stream, i.e. H. if the nominal current is slightly exceeded mes, the time until shutdown by the overcurrent triggers (bimetallic triggers) large values ​​up to one hour can take or that there is no ab circuit comes. The stipulated in relevant regulations tripping characteristics are based on the use of thermal bimetals as overcurrent releases, with which only such a tripping characteristic can be realized. On the other hand, there is electro in particular African components (semiconductors) the problem that be slightly exceeding the current limit value and / or the temperature of their destruction and thus permanent uselessness of the electrical device concerned.
Furthermore, stresses can occur that are not or only insufficiently covered with conventional automatic switches. For example, when switching on electrical devices such. B. electric motors, for a short time a very high current value that can reach the switching current strength of the short-circuit release can be permitted. On the other hand, overcurrents can result as a result of overload, which, based on the valid tripping characteristics, do not or only very late lead to the disconnection of the current, so that the electrical device loaded in this way also suffers permanent damage or is destroyed. In other words, the valid tripping characteristics do not cover all known protection goals equally well. Furthermore, stresses can occur with the conventional auto switches not or only insufficiently are covered accordingly. For example, at On switching operations of electrical devices, e.g. B. Electro motors, for a short time a very high current value of the Ab reach the switching current of the short-circuit release may be permissible. On the other hand, as a result of over load overcurrents result, based on of the valid tripping characteristics not or only very late lead to the shutdown of the current, so that be so electrical device also burdened a permanent one damage is suffered or destroyed . In other words, the valid tripping characteristics do not cover all known protection goals equally well.
The tripping characteristics mentioned are made up of two Be rich, the first area is almost linear and the tripping within fractions of a second share after reaching or exceeding a limit value by the electromagnetic short-circuit release shows. The second area follows on from the first area, with the duration until tripping increases disproportionately with decreasing overcurrent and approaches a limit value asymptotically, which depends on the respective defined tripping characteristic (e.g. K or L.) is more or less above (1.05 to 1.5 times) the rated current. The tripping characteristics mentioned are composed of two ranges, the first area of ​​which is almost linear and shows the tripping within a fraction of a second after reaching or exceeding a limit value by the electromagnetic short-circuit release. The second area connects to the first area, whereby the duration until tripping increases with decreasing overcurrent and approaches asymptotically a limit value, which is more or less above (depending on the tripping characteristic defined (e.g. K or L. ) 1.05 times to 1.5 times the nominal current.
The tripping characteristic implemented in this way in the known electrical self-switches means that with such self-switches, electrical devices are not or only insufficiently protected against exceeding the nominal current. Particularly if one takes into account the permitted tolerance range, the result is insufficient protection against overcurrents for certain applications. Such in the known electrical self tripping characteristics are achieved with that secured with such automatic switches electrical devices or not adequately Rated current overshoots are protected. In particular if you have the permitted tolerance range in the Be Including consideration results in one for certain purposes inadequate protection against overcurrents.
Based on the prior art described above, it is therefore the object of the invention to create an overcurrent-sensitive circuit breaker of the type mentioned, with which a trigger sensitivity adapted to the respective requirements is guaranteed. Starting from the prior art described above it is therefore an object of the invention an overcurrent sensor tive auto switch of the type mentioned create with which one to the respective requirements Adapted trigger sensitivity guaranteed is.
According to the invention, he achieves the object is sufficient that the trigger part means for detection and definable time limit of overcurrents depending on the species.
According to the invention, the means of a current-sensitive sensor member and an electronic evaluation member electrically connected to this are gebil det, the sensor member depending on the configuration described below, each overcurrent detected indirectly or directly, d. H. a reference value valid for the respective overcurrent or the overcurrent itself, and the parameter obtained in this way is transmitted to the evaluation element, which evaluates the overcurrents with regard to size and duration and, when a respective limit value is reached, opens the contact arrangement and thus causes the current to be interrupted invention, the means are made from a current-sensitive sensor element and one with this electrically connected electronic evaluation element det, the sensor member depending on the following be written design any overcurrent indirectly or directly detected, d. H. one for the respective over current reference quantity or the overcurrent itself, and the parameter obtained in this way to the evaluation element which transmits the overcurrents in terms of size and evaluates duration and when a respective one is reached Limit the opening of the contact arrangement and so the Electricity interruption causes.
Due to the sensitivity of the sensor element provided, it is possible to define any current value as a limit value. It is due to the sensitivity of the intended NEN sensor element possible, any current value to be set as a limit. There is also the possibility by setting the evaluation element accordingly Limit the duration of the pending overcurrent as desired.
Depending on other requirements for the overcurrent-sensitive circuit breaker, an NTC resistor (NTC thermistor) or a thermocouple can optionally be provided as a sensor element, which is heated by this while retaining the conventionally provided thermal bimetal, its temperature serving as a reference value for the respective current. Depending on other overcurrent requirements sensitive auto switch can optionally be used as a sensor element an NTC resistor (thermistor) or a thermocouple be provided, which while maintaining the convention Lich provided thermal bimetal heated by this with its temperature as a reference for serves the respective current.
According to another embodiment it can be provided that the sensor element is designed as a current or voltage converter. The resulting measured variables serve as an input signal for the evaluation element, which evaluates the size and duration of the overcurrent in the same way as described above and triggers the shutdown of the self-switch when a limit value for the duration or for the current is reached Another embodiment, it can be provided that the sensor element as a current or voltage converter is trained. The resulting measurands serve as an input signal for the evaluation element, which in the same way as described above evaluation of the size and duration of the overcurrent and when a limit for the duration or for the current the shutdown of the self triggers switch.
A further embodiment of the sensor element can be included that the thermistor already mentioned in a Voltage divider circuit is arranged and its span drop as a reference variable the input signal for the evaluation element forms.
In particular, in the two first-mentioned Ausgestal lines of the sensor element, namely as a thermocouple or as a temperature-dependent resistor (thermistor) according to the invention, the sensor element is assigned a compensation element, whereby the setpoint setting for the limit value of the overcurrent is achieved. Such a compensation element can, for example, be designed as a Wheatstone measuring bridge. Especially in the first two configurations lines of the sensor element, namely as a thermocouple or as a temperature-dependent resistor (thermistor) is ge according to the invention the sensor element a compensation element assigned, whereby the setpoint setting for the overcurrent limit is reached. Such a thing Compensation element can, for example, as a Wheatstone measurement bridge be formed.
The evaluation element is constructed as an amplifier circuit which strengthens the measured values ​​transmitted by the sensor element. Preferably, the evaluation member is as adjustable, d. H. adjustable, operational amplifier forms. In addition, the evaluation element has a time element which is used to evaluate the duration of the pending overcurrent. The evaluation element is constructed as an amplifier circuit, ver the measured values ​​transmitted by the sensor element strengthens. The evaluation element is preferably set as cash, i.e. H. adjustable, operational amplifier out forms. In addition, the evaluation element has a time link which is used for the evaluation of the duration of the first overcurrent.
The evaluation element is in operative connection with the switching mechanism and causes it to be actuated in the event of an impermissible overcurrent, as a result of which the contact arrangement is opened. Since the amplifier circuit is arranged in the evaluation element provides an electrical output signal which may be unsuitable for direct loading of the switching mechanism, an electromechanical converter is also assigned to the evaluation element in an advantageous development of the invention, which converts the output signal of the amplifier circuit into an evaluation element converts mechanical output variable. Such an electromechanical converter can, for example, be a suitably sized magnetic drive that works together with the switch lock and, for example, acts on its release lever. But it can also be an electromechanical relay which, when responding as a result of an overcurrent, closes a circuit which, for example, causes the short-circuit release to be actuated. Instead of the electro-magnetic drive, a magnetic coil can also be provided which works together with a reed contact, which activates the short-circuit release or a shunt release in the same way as the electromechanical relay. The evaluation element is in operative connection with the Rear derailleur and performs Its operation in the event of an impermissible overcurrent, causing the opening of the contact arrangement takes place. As indicated in the evaluation element arranged amplifier circuit an electrical output signal delivers which for an immediate Beauf Impact of the rear derailleur may be unsuitable advantageous development of the invention the evaluation member also assigned an electromechanical transducer, the the output signal of the amplifier circuit in the off value element converted into a mechanical output variable. Such an electromechanical transducer can, for example an appropriately dimensioned magnetic drive be who works with the key switch and at for example, its trigger lever is applied. It can but also be an electromechanical relay, which a current when responding due to an overcurrent circle closes, for example the operation of the short-circuit triggers. Instead of the electro magnetic drive can also featured a solenoid be seen working with a reed contact the same way as the electromechanical relay the short-circuit release or a shunt release brings into action.
Instead of an electromechanical transducer, too an electronic switch can be provided, the Be opening of the rear derailleur can be provided instead of an electromechanical transducer by the short-circuit release water or caused by the shunt release.
In view of the cramped space conditions in a commercially available miniature circuit breaker with a modular structure, it may be necessary to install the inventive overcurrent-sensitive release part in an attachment with z. B. 1/2 module housing width, in such a case both the mechanical triggering of the switching mechanism of the circuit breaker can be done via a mechanical coupling and also in the manner described using the already existing NEN short-circuit release or the aforementioned Ar beitsstromauslösers.Considering the limited space in one commercially available circuit breakers with modular It may be necessary to build the inventive overcurrent sensitive tripping part in an attachment with eg B. to accommodate 1/2 module housing width, being in such a case, both the mechanical triggering of the circuit breaker of the circuit breaker via a mechanical coupling can be done as well as in the be written way using the already existing NEN short -circuit release or the already mentioned Ar positive current release.
When using electrical circuit breakers that are provided with the release part according to the invention, in consumer networks that are not secured by residual current protection measures, it is advantageous to keep the thermal release (Thermobime tall) available in commercially available miniature circuit breakers and motor protection switches in order to keep them in this way even if the neutral conductor fails, e.g. B. as a result of breakage to ensure adequate over current protection. In such a case, despite the lack of a return possibility via the neutral conductor, a current could flow via earth that would not be detected by the trip element according to the invention, since it requires the neutral conductor for its power supply and would therefore fail in such a case the trigger part according to the invention are provided, in Ver consumer networks that are not men are secured, it is advantageous to use the standard circuit breakers and motor protection switches existing thermal triggers (Thermobime tall), in this way even in the event of failure of the neutral conductor, eg B. due to breakage, sufficient excess to ensure current protection. In such a case could namely despite the lack of a return possibility a current can flow off the earth via the neutral conductor would not be caught by the trigger element according to the invention, since this needs the neutral conductor for its power supply and would therefore fail in such a case.
The mode of operation of the circuit breaker according to the invention is based on the fact that the sensor element can be preset to a certain limit current value, at which it transmits a signal to the evaluation element, which in turn evaluates the duration of the signal valid as a reference value for the overload current and when a time limit value is reached The mode of operation of the automatic switch according to the invention is based on the fact that the sensor element is connected to a specific one Limit current value can be preset at which it is a Signal transmitted to the evaluation element , which of its the duration of the as a reference value for the upcoming Overload current evaluates the signal and if Errei Chen a time limit the shutdown of the Automatic switch triggers.
The level of an overcurrent and its duration are thus recorded independently of one another and compared with predetermined limit values. If the limit values ​​are exceeded, the automatic switch is switched off. So the amount of one becomes independent of each other Overcurrent and its duration detected and compared with predetermined limit values. Are the limits above steps the automatic switch is switched off.
The inventive design of electrical circuit breakers with an overcurrent-sensitive release part, which includes a sensor element and an evaluation element, lends itself to the aforementioned device protection switch, but also LS / DI switches and FI / LS switches can be designed in this way The inventive design of electrical Automatic switches with overcurrent-sensitive tripping part, which comprises a sensor element and an evaluation element, lends itself to the device protection already mentioned switches, but also LS / DI switches can also be used as FI / LS switches can also be designed in this way, where the line protection part with the inventions appropriate trigger part is connected.
The range of use of the self-switch according to the invention therefore also extends to the known combination with fault current (FI) or differential current (DI) circuit breakers, in which case the evaluation element sends its trigger signal to the tripping components of the FI or DI switch sets up. So there is no problem without the possibility of using the test circuit required for these devices to periodically check whether the DI or FI switch is ready to be triggered. Not unlike in such a periodic check, the evaluation element closes the test circuit by means of an electromechanical or electronic relay, which immediately triggers and cuts off the current be known combination with residual current (FI) - or difference current (DI) circuit breakers, in which case the Evaluation element sends its trigger signal to the trigger components the FI or DI switch. So there is pro the opportunity that is required for these devices test circuit for periodic inspection of the readiness for tripping of the DI or FI switch move. No different from such a period The check is carried out by the evaluation element by means of an electromechanical or electronic relay of the test circuit closed, causing it to shutdown immediately solution and power cut comes.
When using thermally responsive sensor elements, it can be advantageous to maintain the thermobi metal which is present in conventional self-switching devices and act as an overcurrent release and to connect the release part according to the invention in parallel. When using thermally reacting sensor elements it may be advantageous with conventional self-scarf existing thermobi acting as overcurrent release Maintain metal and the trigger according to the invention to be connected in parallel . Thereby the Thermobime serves tall also as a heat source for the thermal reactive sensor element.
Instead of a thermal bimetal, however, any other bi metal that is heated by electrical current flow, e.g. B. heating resistor may be provided. Instead of a thermal bimetal, however, any other bi warming up by electric current flow metal, e.g. B. heating resistor may be provided.
Another option for setting the sensor element in relation to the desired triggering characteristic is to choose a different, preferably more sensitive, thermal bimetal. This shifts both the characteristic curve that applies to the thermal bimetal and the overcurrent-sensitive triggering part according to the invention that interacts with it. Another setting option of the sensor element in relation to the desired tripping characteristic is the Choosing a different, preferably more sensitive thermo bimetallic. This shifts both the for that Thermobimetal characteristic curve as well as that for the overcurrent according to the invention cooperating with it sensitive trigger part.
Due to the achievable high disconnection accuracy in the event of overload currents, the self-switch according to the invention are also available as a tariff monitor for the electricity supply company (EVU), since this effectively prevents the current from being drawn beyond the respective consumer connection value. Taking the circuit breaker according to the invention as a basis, the current reserve previously required can thus be reduced, since overcurrents that occur with conventional circuit breakers for up to an hour and longer and up to 1.45 orup to 1.9 times the respective nominal current, can no longer occur, because they are switched off immediately.Due to the high switch-off accuracy that can be achieved The self according to the invention offers overload currents switch also as tariff guard for the electricity utilities (EVU), since this is the electricity withdrawal via the respective consumer connection value is virtually prevented. Using the self-switch according to the invention can thus the previously required power reserve can be reduced because over currents with conventional automatic switches up to egg queue for an hour or more and up to 1.45 or up to 1.9 times the respective nominal current can wear , can no longer occur because they vice versa be switched off.
By means of the circuit breaker according to the invention, it is possible to secure lines depending on the type of installation and the resulting heating. By means of the automatic switch according to the invention is about this is a protection of lines depending on their method of laying and the resulting heating possible. The previous rough grid of electricity values ​​can be omitted in the future, as the targeted adjustment is given.
These and other advantageous refinements are specified in the subclaims. These and other advantageous configurations are shown in the specified in the subclaims.
Based on an execution shown in the drawing example, the invention, advantageous Ausgestal lines and special advantages of the invention tert and be described.
Fig. 1 A schematic diagram of an automatic switch with the release part according to the invention,Fig. 1 is a schematic diagram of an automatic circuit breaker according to the invention with the trigger member,
Fig. 2 a schematic diagram of a sensor element according to the invention,Fig. 2 is a schematic diagram of a MAESSEN sensor member according to the invention,
Fig. 3 shows the principle of the detail "X" out Fig. 1,Fig. 3 is a schematic illustration of the detail "X" from Fig. 1,
Fig. 4 to 8 further examples of a sensor element according to the invention,Fig. 4 to 8 show further examples of a inventive sensor element wherein,
Fig. 4 a pair of thermocouples,Fig. 4 is a thermocouple pair,
Fig. 5 a current transformer,Fig. 5 is a current converter,
Fig. 6 a voltage converter,Fig. 6 shows a voltage converter,
Fig. 7 a voltage divider,Fig. 7 is a voltage divider,
Fig. 8 a thermocouple pair as wellFig. 8 is a pair of thermocouples and
Fig. 9 show a diagram for explaining the triggering behavior. Fig. 9 is a diagram showing sever holding for explaining the trigger.
Fig. 1 shows the basic circuit structure of a circuit breaker 10, the one with an overcurrent-sensitive release part 12 is provided. Such an auto switch 10 can be both a line circuit breaker and a motor protection switch. In addition, it can also be a combined LS / DI or an FI / LS switch, in which case the in Fig. 1 detail shown "X" is provided.Fig. 1 shows the basic circuit structure of a circuit breaker 10 , which is provided with an overcurrent-sensitive trigger part 12 . Such a circuit breaker 10 can be both a circuit breaker and a motor protection switch. In addition, it can also be a combined LS / DI or FI / LS switch, in which case the detail "X" shown in FIG. 1 is provided.
In the main current path 11 of the automatic switch 10 is a single pole contact arrangement 12, consisting of a fe most and a movable contact piece, arranged as an electromagnetic short-circuit release shown here only with its circuit symbol 14. The electro-magnetic short-circuit release 14 is in active connection with a key switch 16, which in turn works together with a switching mechanism not shown here. When the key switch is triggered 16, e.g. B. by the electromagnetic release 14, This acts on the switching mechanism, whereby the moving contact piece of the contact arrangement 12 is opened as shown by the line of action shown in dashed lines 11 of the circuit breaker 10 is a single-pole contact arrangement 12 , consisting of a fe most and a movable contact piece, arranged as an electromagnetic short-circuit release 14 shown here only with its circuit symbol. The electro-magnetic short-circuit release 14 is in active connection with a switch 16 , which in turn works with egg nem switching mechanism not shown here. When the key switch 16 , e.g. B. by the electromagnetic trigger 14 , this acts on the switching mechanism, whereby the movable contact piece of the contact arrangement 12 is opened, as shown by the dashed line of action who is supposed to.
It is also in the main current path 11 of the automatic switch 10 an overcurrent-sensitive release part 18 switched on, which also with the key switch 16 is in operative connection. The trigger part 18 is from a sensor element 20 and an evaluation element connected to it 22 formed. While the sensor member 20, as in Fig. 1 represents Darge, in operative connection with the main current path 11 stands, acts on the evaluation element electrically connected to it 22 the key switch 16 or when installing in a combined LS / DI or FI / LS switch in Fig. 1 with "X" designated release element, which enables the immediate release of the switching mechanism 16 and thus the opening of the contact arrangement 12 has the consequence. The circuit arrangement of the with "X" named component is in Fig. 3 shown and explained in more detail. Furthermore, an overcurrent-sensitive tripping part 18 is switched on in the main current path 11 of the circuit breaker 10 , which is also in active connection with the switching mechanism 16 . The trigger part 18 is formed from a sensor element 20 and an evaluation element 22 connected. While the sensor element 20 , as shown in FIG. 1, is in operative connection with the main current path 11 , the evaluation element 22, which is electrically connected to it, acts on the switching mechanism 16 or when installed in a combined LS / DI or FI / LS switch in Fig. 1 with "X" tripping member, which has the un prompt triggering of the switch lock 16 and thus the opening of the contact arrangement 12 result. The circuit arrangement of the component labeled "X" is shown and explained in more detail in FIG. 3.
The evaluation element 22, which is shown here only by means of a circuit symbol as an adjustable operational amplifier, has a timing element, not shown here, which the duration of one of the sensor element via the double connecting line 21 transmitted signal is detected and compared with a predetermined limit value. The evaluation element 22 , which is represented here only by means of a circuit symbol as an adjustable operational amplifier, has a time element, not shown here, which detects the duration of a signal transmitted by the sensor element via the double connecting line 21 and compares it with a predetermined limit value.
Furthermore, the evaluation can 22 have an electromechanical transducer, which is used to send an elec trical trigger signal to the switch lock 16 to implement in order to actually trigger this. This converter, which is also not shown here, can be, for example, a simple electromechanical drive for acting on a release lever that belongs to the switch lock. Further, the evaluation gate 22 may have an electromechanical converter which serves to convert an electrical trigger signal to the switching mechanism 16 in order to actually trigger it. This converter, which is also not shown here in more detail, can be, for example, a simple electromechanical drive for actuating a release lever which belongs to the switch lock.
Fig. 2 shows an embodiment for the sensor member 20, the one in a known manner in the current path 11 switched on thermal bimetal 24 as well as an NTC resistor in thermal contact with this 26 (Hot wire ter) has.Fig. 2 shows an embodiment of the sensor member 20 which has a bimetallic 24 switched on in the current path 11 in a known manner and an NTC resistor 26 (Hot conductor) which is in thermal contact therewith.
To the NTC resistor 26 The NTC resistor has to be calibrated with regard to tripping in the event of overcurrent and, if necessary, the required tripping current must be set 26 with a measuring bridge circuit 28 combined, which is designed here as a Wheatstone measuring bridge. With the help of this adjustment and measuring arrangement 28that at the envisaged operating temperature, z. B. room temperature, is in equilibrium, it is possible to end the line at the Lei 30, 31 evaluation element to be connected 22 in the case of an impermissible excess of the in the main current path 11 to control the flowing current in such a way that the switching mechanism is triggered immediately 16 and thus the interruption of the contact arrangement 12 is brought about. In order to calibrate the NTC resistor 26 in relation to tripping in the event of an overcurrent and, if necessary, to set the required release current strength, the NTC resistor 26 is combined with a measuring bridge circuit 28 , which is designed here as a Wheatstone measuring bridge. With the help of this adjustment and measuring arrangement 28 , which at the provided temperature, e.g. B. room temperature is in equilibrium, it is possible to control the line ends 30 , 31 to be connected to evaluation element 22 in the event of an inadmissible exceeding of the current flowing in the main current path 11 current so that the triggering of the switching mechanism 16 and thus the interruption immediately the contact arrangement 12 is brought about.
Since measuring bridges, like the one in Fig. 2 Wheat stone measuring bridge shown 28 are known per se, will only be discussed here insofar as it is designed here in a special way with a temperature-dependent NTC resistor 26 and three other resistances 32, 33, 34at the intended use temperature with the temperature-dependent NTC resistor 26 are in equilibrium, so that at the tapping point of the lines 30, 31 no electricity flows from a single source of electricity 27 into the measuring bridge 28 is fed in. The power source 27 can in this case be expediently formed by tapping the supply network. If necessary, one of the resistors 32, 33, 34 be designed to be adjustable in order to switch in this way the adjustment in the bridge circuit at the operating temperature of the self-switch 10 Since measuring bridges, as the Wheat stone'sche measuring bridge 28 shown in Fig. 2 are known per se, will only be discussed here insofar as it is designed here in a special way with a temperature-dependent NTC resistor 26 and three other opponents 32 , 33 , 34 , which are in the intended use temperature with the temperature-dependent NTC resistor 26 in equilibrium, so that no current flows at the tap of the lines 30 , 31 , which is fed from a current source 27 into the measuring bridge 28 . The current source 27 can be expediently formed by tapping the supply network. If necessary, one of the resistors 32 , 33 , 34 can be designed to be adjustable in order to facilitate the adjustment in the bridge circuit at the operating temperature of the auto switch 10 .
In Fig. 3 is the detail "X" out Fig. 1 represents. This is a test circuit that is present in every FI or DI circuit breaker 36having a resistance 37 and an interruption point 38by means of a manually actuated test button 39 can be closed. When closing the test circuit 36 the flow of a current from phase to earth is simulated and checked here by the readiness of the DI or FI protection switch Fig. 3 the detail "X" from Fig. 1 is Darge. It is a test circuit 36 which is present in every RCD or DI circuit breaker and has a resistor 37 and an interruption point 38 which can be closed by means of a test button 39 which is actuated by hand. When the test circuit 36 is closed, the outflow of a current from phase to earth is simulated and checked here by the responsiveness of the DI or FI protection switch.
According to the invention it is now provided that when using combined LS / DI or FI / LS switches that of the evaluation element 22, which is designed as an adjustable Operationsver stronger, not on the switch lock 16 to switch, but to switch to a terbauteil terbauteils terbauteils to the test circuit of the respective residual current or residual current circuit with interruption point. It is provided that the interrupt point to be operated by hand 38 of the test circuit through an electromechanical switching component 40, as in Fig. 3 shown, or an electronic switch is switched bypassable, so that the previously described triggering of the fault current or differential current component takes place by closing the interruption point of the parallel circuit. The connection with the tripping part 18 takes place via the in Fig. 1 line shown 191, with an additional operative connection with the switch lock 16 can exist, as indicated by the dash-dotted line 192 According to the invention it is now provided, when using combined LS / DI or FI / LS switches, that of the evaluation element 22 , which is more strongly designed as an adjustable Operationsver, not to switch to the switching mechanism 16 , but to one to the test circuit of the respective residual current or residual current circuit breaker component to connect the parallel circuit with an interruption point. It is provided that the manually operated interruption point 38 of the test circuit by an electromechanical switching component 40 , as shown in Fig. 3, or an electronic switch is bridged, so that by closing the interruption point of the parallel circuit, the previously described triggering of the residual current or differential current component takes place. The connection to the trigger part 18 is in this case via the line 191 shown in FIG. 1, wherein there may additionally be an operative connection with the switching mechanism 16 , as indicated by the dash-dotted line 192 .
In the Fig. 4 to 7 are further design examples for the in Fig. 1 shown sensor element 20.In Figs. 4 to 7 further Ausgestaltungsbei are games for the system depicted in FIG. 1, sensor element 20.
In Fig. 4 is the sensor element 20 from a thermocouple 42 formed that is in thermal contact with the already in Fig. 2 described electrothermal release 24 stands. Just like the in Fig. 2 treated NTC resistors 26 is also the thermocouple 42 to a Wheat Stone bridge circuit 44 connected to the equation for the normal operating state of the self switch 10 to guarantee. The bridge circuit 44 also has four resistors, one over the thermocouple 42 and on the other hand via the connection line 30, 31 to the evaluation element 22 are bridged. The four resistors are in a known manner 46, 47, 48, 49 so coordinated that in normal operation of the automatic switch 10 at the junction of the to the evaluator 22 leading ladder 30, 31 no electricity flows. If necessary, one of the resistors, as in Fig. 4 for resistance 47 shown, be designed to be adjustable in order to achieve a more precise adjustment. In Fig. 4, the sensor member 20 is formed from a thermocouple element 42 which is in thermal contact with the electrothermal trigger 24 already described in Fig. 2. As well as the treated in FIG. 2 NTC resisting stand 26 and the thermocouple 42 stone to a Wheatstone bridge circuit 44 is connected to the From equation for the normal operation state of the self switch 10 to ensure. The bridge circuit 44 also has four resistors, which are bridged via the thermocouple 42 and the other via the connecting line 30 , 31 to the evaluation element 22 . In known manner, the four resistors 46 , 47 , 48 , 49 are matched to one another so that during normal operation of the circuit breaker 10 at the connection point of the conductor 30 , 31 leading to the evaluator 22 , no current flows. If necessary, one of the resistors, as shown in FIG. 4 for resistor 47 , can be designed to be adjustable in order to achieve a more precise adjustment.
Depending on the type and suitability of the evaluation element, the interconnection of the compensation bridge 44 dispensed with and the thermocouple 42 directly to the input of the evaluation element 22 be connected as in Fig. 8.Depending on the type and suitability of the evaluation element, there is no need to interpose the compensation bridge 44 and the thermocouple 42 is connected directly to the input of the evaluation element 22 , as shown in FIG. 8.
As a material pairing for the thermocouple 42 is provided here with preferably iron constantan. However, a copper-constantan pairing or any other common pairing is also possible. The gain of the evaluation element depends on the selected material pairing and the resulting thermal voltage 22 The material pairing for the thermocouple 42 is preferably iron constantan. Likewise, however, copper-constantan is also possible as a pair or depending on the other usual pairing. Depending on the selected material pairing and the resulting thermal voltage, the gain of the evaluation element 22 is to be set .
Fig. 5 shows a current transformer which, instead of the sensor members discussed above, i.e. H. of the NTC resistor 26 and the thermocouple 42, both the presence of a heating element, here the thermal bimetal 24, require, with the main current path 11 is in operative connection.Fig. 5 shows a current transformer, instead of the previously treated sensor elements, ie the NTC resistor 26 and the thermocouple 42 , both of which require the presence of a heating element, here the thermobimetal 24 , with the main current path 11 in operative connection.
The size of the current transformer, i.e. H. its number of turns depends on the current strength for which the self switch 10 is provided, as well as after the input signal for the evaluation element 22 The size of the current transformer, ie its number of turns, depends on the current for which the auto switch 10 is provided, and on the signal strength required for the input signal of the evaluation element 22 .
In Fig. 6 is an arrangement similar to that in FIG Fig. 5 shown here, however, as a voltage converter 52 is formed. The voltage dropping across the inductive resistor designed as a choke serves as an input signal for the one at the terminal ends 30, 31 evaluation element to be connected 22. In Fig. 6 is a similar arrangement as shown in Fig. 5, but here is formed as a voltage converter 52 . The voltage drop across the inductor designed as a choke serves as an input signal for the evaluation element 22 to be connected to the connection ends 30 , 31 .
This in Fig. 7 sensor element shown 20, is as a voltage divider circuit 54 designed with an NTC resistor 56