TEMPERATURE-CONTROLLED CIRCUIT BREAKER

The present invention relates in general to improving the protection of electrical supply lines in terms of thermal overload, and in particular to improving the miniature circuit breakers required for this purpose.

State of the Art

When electrical current flows through an electric line, the latter heats up due to its resistance. Here, the power loss converted into heat increases with the square of the flowing current, which further increases the resistance of the metallic line as well as the heat which builds up simultaneously along the entire length of the wire. This can eventually lead to cable fires with fatal outcomes, if this process proceeds and no suitable precautionary measures are taken against it.

Miniature circuit breakers, or shortly circuit breakers, have been arranged as a relatively reliable safeguard against cable fires.

Detailed information on currently used circuit breakers can be found on the Internet under [01]: Free online encyclopedia Wikipedia:Leitungsschutzschalter,

http://de.wikipedia.org/wiki/Leitungsschutzschalter, (entered on 19.02.2013, accessed on 05.03.2013). Accordingly, the circuit breaker was invented as a "reusable fuse element which is not self-resetting" [01] already "in 1924 in the company of Hugo Stotz in Mannheim" [01].As a fuse element "it can switch off the circuit automatically in case of overloads and short circuits." [01]

In terms of the mode of operation of "tripping in the event of an overload", it is explained in [01] that "switch ing-off takes place when the predetermined nominal value of the current flowing through the circuit breaker is remarkably exceeded for a long time. The time to trip depends on the intensity of the overcurrent; it is shorter at higher overcurrents than when the rated current is exceeded slightly.

A bimetal is used for tripping, which bends upon heating by the current flowing through it and actuates the trip mechanism". As further trip mechanisms, [01] describes "electromagnetic tripping in the event of a short circuit", "manual trip mechanism", "tripping via additional modules" and "trip-free mechanism", wherein the latter ensures that "in the event of a short circuit, an immediate trip also takes place if the switch lever is actuated or held in the ON position." [01] Circuit breakers operating according to this principle are very safe and reliable in terms of operation. They do not require an additional power supply in the form of smaller batteries for instance, but work completely self-sufficient and are therefore always ready to operate. They are also very inexpensive by mass production, and circuit breakers with a retail price of less than two Euros are presently available for the end user. There are numerous manufacturers for a plurality of circuit breakers which only differ slightly in details and numerous patents and utility models with marginal improvements are available, all of which operate according to the same principle in terms of tripping in the event of an overload:

Anytime conduction current flows through a bimetallic strip, it releases the latch in a delayed manner in the event of an impermissibly high permanent current due to the heating-induced bending of the bimetallic strip.

Since it has been focused on the rated current through the protected line instead of monitoring directly the temperature increase of the line, possibly as a consequence of the historical developments -anyhow, the so-constructed first circuit breaker has run outstandingly- many temporary measures and regulations have been established until today to cope with the shortcomings of conventional circuit breakers, which correspond to the today's state of the art, by means of numerous compromises.

A shortcoming is based on that the instantaneous effective current initially has very little significance in terms of the temperature increase of the line. What are decisive for the temperature increase, are, among other things, the exposure time to higher currents, the assembly-related heat dissipation of the installed line and the ambient temperature.

However, since there is a basic correlation between the conductor cross-section and the current flowing through it for the heating of an electric line, a large selection of circuit breakers for different rated currents has been established for the field of electric installations. Thus, a total of 13 different rated-currents, for example, are listed as standard for the field of electric installations in [01]:"Circuit breakers with characteristic B are available as standard for the following rated currents:6 / 10 / 13 / 16 / 20 / 25 / 32 / 40 / 50 / 63 / 80 / 00 / 125 Ampere."

This selection is required when the current flowing in the electric line is used as the primary selection criterion. According to these different specifications for each circuit breaker, the respective conductor cross-sections must be assigned by the practitioner during the domestic installation. Here, mistakes can be made. Therefore, this diversity of the different types can also be considered as a shortcoming against an equivalent solution with a significantly reduced number of different types of circuit breakers.

However, this is not enough. There are numerous regulations that must be taken into account as to how the respective power cables are laid, because an electric line freely mounted on the wall heats up less strongly than a plurality of adjacent lines, which are placed together in a narrow cable channel behind heat insulation.

Thus, for example, DIN VDE 0298-4/2003 specifies a total of 9 different types of installation procedures with the appropriate assignment of the current load, namely:"A1 , A2, B1 , B2, C, D, E, F, and G".Here, differences will also be based on the number of each loaded core in the cable and the expected ambient temperature.

Accordingly, the types of circuit breakers used differ also according to the installation type. During selection, further mistakes can be very easily made. Also this can be considered as a shortcoming, which is based on that the current and not the temperature increase or heating-up of the electric line is chosen as the primary selection criterion for line protection.

Therefore, an extensive domestic installation, e.g. for multi-family apartment buildings or for a hotel, requires a large number of different circuit breakers, very high level of expertise, knowledge of regulations to be met and pronounced logistics capabilities in the design of switch cabinets.

Nevertheless, a permanent safety is not always possible, since, e.g. when the intended use of a room is changed over the decades and the originally free running line on the brickwork of a storage cellar disappears in the thermal insulation material behind the wood paneling of the space which is subsequently reconstructed in the form of a cellar bar. In such a situation, even a correctly arranged installation at the beginning can cause a risk of damage due to cable fire. Some sort of prior art documents is discussed below to provide better understanding. On the other hand no documents could be found during the prior art search neither disclosing nor implying the idea of the present invention.

CN2456299 discloses a temperature controlled circuit breaker which is composed of a socket, a plug, a box body, a supporting block, a connecting rod, a pull rope, motor, lead wires, a sensor and a supporting point. Furthermore it has an oblong-shaped sensor thereof is arranged at the bottom of the box body in the square shape. However there is no hint within this disclosure to solve the technical problem defined here.

WO2006085829 discloses a low-loss electric automatic switch for the protection of electric current consumer devices and electric circuits. The switch of the invention is conceived in a way that it contains a magnetic yoke (4), in which a leading bushing (5) is positioned between both free ends of the magnet yoke (4), whereas a coil (6) is positioned on the bushing (5) and at one end of the bushing (5) there is a core (7), and at the opposite end of it there is a large anchor (8) and between the core (7) and the large anchor (8) and within the large anchor (8) there is a small anchor (9), whereas in the core (7) there is a bar (10) that moves along its axle anf leans at one end on the small anchor (9).

US5119260 discloses a method for operating a circuit-breaker by means of which one is able by using a vacuum circuit-breaker, to interrupt inductive circuits without causing disturbing overvoltages. The switching operation of the vacuum circuit-breaker is influenced by a tripping control device, which is supplied with a measured value of the tripping delay of the vacuum circuit-breaker from the instant the tripping signal is output to the instant the contact members are separated as a correcting quantity, in the case of an opening operation that occurred previously. The temperature of the actuator unit of the vacuum circuit-breaker, the standstill time of the circuit-breaker, as well as the operating voltage and temperature of a tripping solenoid can be used as further correcting quantities. However the temperature mentioned here is not directly usable by the circuit breaker because of lack of mechanic structure disclosed by that invention.

Short Description and Advantages of the Present Invention

Based on the above-described shortcomings and drawbacks of the state of the art, the underlying problem of the present invention is to further improve the protection of electric lines against damages due to impermissibly high temperature increases and to significantly reduce the number of different circuit breakers with respective different rated currents. This problem is solved by the features specified in the claims.

Advantageous embodiments and appropriate further modifications of the present invention are given in the respective subclaims.

The advantages achieved with the invention are based particularly on that an assignment of the maximal permissible rated current to the conductor cross-section is effected automatically, so that an overheating of the lines due to installation errors is excluded.

Another advantage achieved with the invention is particularly based on that only fewer different types of circuit breakers are used instead of a plurality of different circuit breakers for different expected rated currents, at the same design size, as it has been the standard until now.Thus, for a typical domestic installation for instance, only a single type of the novel circuit breaker according to the invention is required, which makes the stockpiling and the logistics considerably simpler during the installation of a switch cabinet.

A further advantage achieved with the present invention is particularly based on that an overheating of electric lines can be detected and prevented in the event of an error which may take place afterwards due to an impermissible increase in the number of current- carrying cables in the cable channel, due to impermissible subsequent/additional structural thermal insulation measures, or due to a reduction of the conductor cross- section through an inadvertent drilling during the installation of a wall closet.

Brief Description of the Figures Figures described in more detail below are given for explaining the invention.Among the figures,

Figure 1 schematically illustrates the typical configuration of a conventional circuit breaker with the respective functional units, as defined here as the state of the art, on which the invention described here is based, Figure 2 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units, as an additional complementary protective element in electric installations,

Figure 3 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units, as a complete replacement for conventional circuit breakers, Figure 4 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units, as a complete replacement for conventional circuit breakers and with additional complementary safety elements, Figure 5 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units with an alternatively modified form of the latch, as a complete replacement for conventional circuit breakers,

Figure 6 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units in an electronically-modified alternative form in terms of the arc- free latch, as a complete replacement for conventional circuit breakers,

Figure 7, representative of the state of the art, explains the geometric relations in an ellipse, Figure 8, representative of the state of the art, schematically illustrates two circles having different radii and central points at a common axis,

Figure 9, representative of the state of the art, schematically illustrates the intersection of the contours of an ellipse and two circles having different radii and central points at a common axis, Figure 10 schematically illustrates an optimal cross-sectional form or contour for receiving circular conductor cross-sections with different diameters,

Figure 11 is a schematic front view of the main body (22) of a heat flow clamp terminal (7) with a special opening (24) according to the optimal cross-sectional form or contour illustrated in figure 10 for receiving circular conductor cross-sections with different diameters,

Figure 12 is a schematic lateral top view of the circular opening (25) for receiving the set screw (23) for the heat flow clamp terminal (7),

Figure 13 is a schematic top view of the main body (22) of a heat flow clamp terminal (7), Figure 1 gives schematic lateral and front views of an elliptically formed set screw (23), Figure 15 schematically illustrates the positions of the set screw (23) and the main body (22) before the set screw (23) is screwed into the circular opening (25) of the main body (22) of a heat flow clamp terminal (7),

Figure 16 schematically illustrates the positions of the set screw (23) and the main body (22) of a heat flow clamp terminal (7) after the set screw (23) is partially screwed into the circular opening (25) of the main body (22),

Figure 17 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a set screw (23) screwed in up to the outer periphery of the protected electric line (12) inserted into the specially formed opening (24), the electric line having a minimal conductor cross-section intended for this heat flow clamp terminal (7),

Figure 18 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a screwed-in set screw (23) and a protected electric line (12) inserted into the specially formed opening (24), the electric line having a minimal conductor cross-section intended for this heat flow clamp terminal (7), wherein the set screw is screwed so tightly that the inserted electric line (12) to be protected is pressed against the wall of the specially formed opening (24) of a heat flow clamp terminal (7) and is thus deformed and partly assumes the contour of the opening and thus a maximal large-area heat contact is produced,

Figure 19 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a set screw (23) screwed in up to the outer periphery of the protected electric line (12) inserted into the specially formed opening (24), the electric line having a maximal conductor cross-section intended for this heat flow clamp terminal (7),

Figure 20 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a screwed-in set screw (23) and a protected electric line (12) inserted into the specially formed opening (24), the electric line having a maximal conductor cross-section intended for this heat flow clamp terminal (7), wherein the set screw is screwed so tightly that the inserted electric line (12) to be protected is pressed against the wall of the specially formed opening (24) of the heat flow clamp terminal (7) and is thus deformed so that it partly assumes the contour of the specially formed opening (24) and thus a maximal large-area heat contact is produced,

Figure 21 schematically illustrates an alternative contour of the specially formed opening (24) of the heat flow clamp terminal (7), wherein the contour illustrated in figure 10 is reproduced via easily-machined polygonal lines, Figure 22 schematically illustrates an alternative contour of the specially formed opening (24) of the heat flow clamp terminal (7), wherein the contour illustrated in figure 10 is reproduced by approximation using easily-machined trapezoid cut-outs,

Figure 23 schematically illustrates an alternative contour of the specially formed opening (24) of the heat flow clamp terminal (7), wherein the contour illustrated in figure 10 is reproduced by approximation using easily-machined circular cut-outs,

Figure 24 schematically illustrates an easily-machined alternative form of the set screw (23) with numerous cross-sectional contours of a circular-cylindrical form,

Figure 25 schematically illustrates an easily-machined alternative form of the set screw (23) with a few cross-sectional contours of a circular-cylindrical form,

Figure 26 schematically illustrates an easily-machined alternative form of the set screw (23) with a few circular-cylindrical cross-sectional contours and a rounded tip,

Figure 27, as a representative embodiment, is a schematic top view of the principle structure of a full mechanical heat-controlled functional unit (8) for controlling the tripping device (3) of the temperature-controlled circuit breaker,

Figure 28, as a representative embodiment, is a schematic lateral view of the principle structure of a full mechanical heat-controlled functional unit (8) for controlling the tripping device (3) of the temperature-controlled circuit breaker,

Figure 29, as a representative embodiment, schematically illustrates the principle structure of a modified main body (22) of a heat flow clamp terminal (7) for using a full mechanical heat-controlled functional unit (8) for controlling the tripping device,

Figure 30, as a representative embodiment, is a schematic top view of the principle structure of a modified main body (22) of a heat flow clamp terminal (7) with an assembled full mechanical heat-controlled functional unit (8) for controlling the tripping device (3), Figure 31 , as a representative embodiment, is a schematic lateral view of the principle structure of a modified main body (22) of a heat flow clamp terminal (7) with an assembled full mechanical heat-controlled functional unit (8) for controlling the tripping device (3),

Figure 32, as a representative embodiment, is a schematic lateral view of the principle structure of a modified main body (22) of a heat flow clamp terminal (7) with an assembled alternative electronic heat-controlled functional unit (8) for controlling an electronic tripping device (3),

Figure 33, as a representative embodiment, is a schematic front view of a selective clamp terminal (42) with exemplary illustrated three selection options and a respective clamp screw (45),

Figure 34, as a representative embodiment, is a schematic front view of a selective clamp terminal (42) with three selection options and a respective clamp screw (45), which presses an inserted wire (56) against the terminal bar 2 (53), for instance,

Figure 35, as a representative embodiment, schematically illustrates the multi-tapped coil for the electromagnetic selective short-circuit detector (43) with an exemplary designed, movable, partially circular cylindrical ferromagnetic core (61 ) and partially different radii for generating a selective short-circuit signal (44), and

Figure 36 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units, as a complete replacement for conventional circuit breakers and for a plurality of switching characteristics.

List of Reference Numbers

(1) Latch with trip-free mechanism

(2) Means for manual actuation

(3) Tripping device

(4) Switch contact

(5) Arc extinguishing device

(6) Clamp terminal

(7) Heat flow clamp terminal

(8) Heat-controlled functional unit

(9) Line current

(10) Heat flow

(11 ) Distribution network of the consumer installation

(12) Electric line to be protected

(13) Activation signal

(14) Short-circuit detector

(15) Short-circuit signal

(16) Overcurrent detector (17) Overcurrent signal

(18) Button for switching-on

(19) Button for switching-off

(20) Electromagnet

(21) Electronic switch

(22) Main body

(23) Set screw

(24) Specially formed opening

(25) Circular opening

(26) Internal thread

(27) Turning head with external thread

(28) Notch

(29) Guide portion

(30) Pressing portion

(31) Adjustment screw

(32) Carrier plate

(33) Fixation dome

(34) Hole

(35) Outer thread

(36) Bimetallic spiral

(37) Switch lug

(38) Bolt

(39) Support lug

(40) Temperature sensor

(41) Heat-conductive paste

(42) Selective clamp terminal

(43) Selective short-circuit detector

(44) Selective short-circuit signal

(45) Clamp screw

(46) Clamp screw thread

(47) Clamp housing

(48) Insulating material

(49) Threaded hole

(50) Option 3

(51 ) Terminal bar 3

(52) Option 2 (53) Terminal bar 2

(54) Option 1

(55) Terminal bar 1

(56) Inserted wire

(57) Hole 3

(58) Hole 2

(59) Guide 1

(60) Guide 2

(61) Ferromagnetic core

(62) Coil terminal 1

(63) Coil terminal 2

(64) Coil terminal 3

(65) Tie point

(66) Coil field range 1

(67) Coil field range 2

(68) Coil field range 3

Detailed Description

In order to describe the invention, figure 1 schematically illustrates the typical configuration of a conventional miniature circuit breaker with the respective functional units, as defined here as the state of the art, on which the present invention is based.

The typical distribution network of a consumer installation (11) starts generally behind the domestic main fuses in the electricity meter cabinet with a built-in consumer unit, i.e. distribution board.

Here is provided, for example, a meter support plate with a fastening and contacting unit. Here, the respective circuit breakers are aligned side by side and mounted by means of top-hat rails in an advantageous manner.

First of all, an electrically conductive connection to the distribution network of the consumer installation (11) is prepared. For this purpose, a clamp terminal (6) is used, which connects either a connection cable or a phase bar to the outer conductors of the main line using the respective circuit breaker electrically and mechanically, so that the line current (9) is transmitted in a non-dissipative manner.

A central component of the circuit breaker is the latch with trip-free mechanism (1), which is described in detail above in connection with the free online encyclopedia Wikipedia [01] already used in the search of the prior art. Accordingly, there is provided a latch lever, as a means for manual actuation (2), with which the switch contact (4) can be closed and opened in addition to and independently of the tripping device (3).An arc extinguishing device (5) ensures a safe interruption of the electrical connection, after the opening of the switch contact (4).

By actuating the latch lever into the switching-off (A) position, the switch contact (4) is opened and the current is interrupted.

By actuating the latch lever into the switching-on (E) position, the switch contact (4) is closed, unless the tripping device (3) prevents this, e.g. in the event of a short circuit, by means of its integral trip-free mechanism. Explanatory information related to the trip-free mechanism can be found in [01] for the manual actuation of the latch lever into the switching-on (E) position:"An important feature of circuit breakers is the insusceptible trip- free mechanism. It ensures that, in case of a short circuit, immediate tripping also takes place when the latch lever is actuated to or held in the on position. After an overload trip, the bimetallic strip must first cool down before a switching-on is possible again. Thus, the user is alerted to a possible error as it has to be switched on again by a manual switching action."

These respective errors in the form of a short circuit or in the form of an overload are detected in two different functional units of the circuit breaker which are connected in series to each other, and therefore, the same effective amperage of the line current (9) flows through these units, which also flows through the protected electric line (12).

In terms of the basic structure, the short-circuit detector (14) can be viewed as an electromagnet which delivers a mechanical short-circuit signal (15) to the tripping device (3) under very high overcurrents, such as may occur only in a short circuit case due to a very low mains impedance, whereby the tripping device interrupts the flow of the line current (9) almost without any delay by abruptly opening the switch contact (4).

In practice, this electromagnet will typically have less than ten turns of a thick wire, the center of which is provided with a small iron pin which is moved very rapidly with a relatively high force in case of a short circuit so that the pretensioned latch with trip-free mechanism (1 ) is released by means of a lever mechanism.

In industrial plants, the standard value for the breaking capacity in case of short circuit corresponds to a considerable value of 10000 A according to [01]. By contrast, the overcurrent detector (16) monitors both the amount and the period of the respective amperage of the line current (9). When an excessive current flows continuously, the overcurrent detector (16) supplies an overcurrent signal (17) to the tripping device (3), which then opens the switch contact (4). In practice, a small piece of bimetal is used for this purpose, of which one side is fixed and the other freely movable side, once deformed by heating, actuates a lever mechanism of the tripping device (3) and thus releases the pretensioned latch with trip-free mechanism

(1).

In contrast to the temperature-controlled circuit breaker according to the present invention, in which the heat flow emanating from the protected current-carrying electric line (12) is monitored directly without having to detour through the amperage of the line current (9), in the prior art for generating the overcurrent signal (17) in conventional circuit breakers, a small piece of bimetal is connected in series to the circuit to be monitored so that the entire line current (9) flows there through. The disadvantage of this method according to the prior art is that the small piece of bimetal through which the line current (9) flows and which serves as a core component of the overcurrent detector (16) must be correspondingly matched, dimensioned, and, if possible, differently positioned in each case for each different rated current, wherein typically a small set screw fixed in a manner hardly accessible by ordinary people is currently used for positioning.

Thus, in principle, a different internally-matched circuit breaker is required for one particular rated current, respectively. This requires a huge stock-keeping and a demanding planning before the electrical installation of a large house, for instance.

Another disadvantage is that this small piece of bimetal heats up quite considerably by the current flow of the line current (9). Measurements have proven that there are circuit breakers of which the small piece of bimetal serving as an overcurrent detector (16) through which the line current (9) flows must be heated over 90 degrees Celsius before the small piece of bimetal can be bent a distance of typically 3 mm, as caused by the current flow and the effective power acting on the bimetal and converted into heat by electrical losses, so that the bending thereof acting as a mechanical overcurrent signal (17) displaces the tripping lever as a component of the tripping device (3) of the latch with trip-free mechanism (1) to the extent that the tripping device (3) effects an abrupt opening of the switch contact (4). In an individually mounted conventional circuit breaker according to the prior art, this local internal heat source in the form of the current-carrying bimetal is not a problem.

If, however, numerous conventional circuit breakers are installed in a cabinet, this may result in a considerable problem in some circumstances. To understand this, the thermodynamics of each current-carrying bimetal must be observed:

The bimetal of a circuit breaker according to the prior art acts as an ohmic resistance because of the specific conductivity of the metal from which it is made. The electrical power is converted into heat in the bimetal with the square of the amperage, of the line current (9) flowing through it. This physical process heats up the bimetal. If the small piece of bimetal would be thermally insulated to a full extent, it would eventually be heated also at a very low amperage to such an extent that it would be bent and activate the tripping device (3).

In doing so, the tripping process would be independent of the magnitude of the current in an absurd manner, because the current would only determine the timing of the release, which would occur in any case. As a matter of course, such a circuit breaker would be completely useless.

Therefore, the small piece of bimetal in a conventional circuit breaker is so mounted that it can emit its heat back in the housing again. By mounting the fixed side of the bimetal onto wide metal pieces and welding the movable side thereof to a thick stranded copper wire, the heat originating from the bimetal is dissipated in the housing and released into the environment of the conventional circuit breaker, causing the bimetal to cool off again.

Thus, a thermal equilibrium is established between heating and cooling.

Therefore, a reliable circuit breaker is an inexpensive product of a laborious and elaborate development work, remarkably long-lasting series of empirical tests, and of a low- tolerance precise manufacturing technology.

However, if numerous circuit breakers are mounted e.g. to a top-hat rail in a close side-by- side relation in a poorly ventilated cabinet, the thermal equilibrium required for a proper operation of the circuit breaker can be severely disturbed under certain circumstances.

Because of the additional heating due to the adjacent circuit breakers which also heat up during operation, it may be the case that the conventional circuit breakers trip earlier even when the permissible rated current of the protected electric line (12) is still not exceeded, since additional heating takes place by adjacent circuit breakers. Therefore, the small piece of bimetal cannot rapidly cool down in a normal manner. Therefore, the thermal equilibrium shifts towards lower possible rated currents than originally planned and intended. This, in turn, provides an active cooling in closely installed switch cabinets under certain circumstances.

This can definitely become a problem in a poorly ventilated meter cabinet of domestic installations, which can anyhow be solved in principle by the practitioner.

When all conventional circuit breakers are mounted on top-hat rails, they are connected to the respective electric lines (12) to be protected by means of clamp terminals (6).

Here, the conductor cross-section of the electric line (12) to be protected must strictly be assigned to the rated current of the respective conventional circuit breaker which is connected therewith in a completely accurate manner. Otherwise, an accidental interchange could cause a cable fire at some time point with potentially fatal outcomes. Here, a wakeful and responsible work is absolutely required by the practitioner during installation.

However, risks can occur even with a fully accurate installation due to the overheating of the electric line in particular when modifications are made in the basic building structure afterwards. In this respect, for example, electric lines which originally extend freely on the wall are subsequently covered using a wooden panel having a heat-insulating material, or still further current-carrying lines for a subsequently-built annex are laid in the cable channel of the original individual electric lines.

A trader supplies power cables with cross-sections reduced at critical values, which then even with minor line disturbances such as notching or squeezing may lead to local increases of the current density and therefore to overheating as a result of this further reduction of the cross section.

Cases such as the partial drilling of an in-wall cable during the mounting of a wall cabinet, the slackness of the contact pressure in the clamp in a plug socket which has not been refurbished for decades and possibly installed by an ordinary person, the replacement of a very frequently-tripping circuit breaker by a version with medium switch characteristics and possibly "slightly" higher amperage on behalf of an annoyed buyer of a used real estate with an undocumented electrical installation etc. can still result in cable fires with partly appalling consequences nowadays.

Many years of practical experience have led to the consideration that the detection of the amperage of the line current (9) of the electric line (12) to be protected is not always an adequate approach for avoiding the overheating of electric wires.

The right approach for an improved solution to the problem of overloading of electric lines is to monitor the actual temperature of the line in a direct and continuous manner and to eventually interrupt the current flow, once the protected electric line (12) is threatened by overheating.

Accordingly, these considerations consequently lead to the direct method for the prevention of thermal overloads of electric lines, which is described here as a novel invention and is basically different, and which can prevent an overheating in a reliable way without having to detour through the actually-flowing amperage of the line current (9).A temperature-controlled circuit breaker which is newly constructed in part, and is described below in different versions serves as a means for carrying out this method, without which this method would not have been possible to implement.

The typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units is schematically illustrated in figure 2.

At first glance like the functional units of a conventional circuit breaker, the functional units used in this embodiment consist of a latch with trip-free mechanism (1), comprising a latch lever as a means for manual actuation (2), a tripping device (3), a switch contact (4) and an arc extinguishing device (5). By actuating the latch lever into the switching-on (E) position, the latch with the trip-free mechanism (1) is mechanically pretensioned by means of a spring mechanism for reducing the force required to trigger the switching operation on the one hand, and the switch contact (4) is closed on the other hand. The flow of the line current (9) is thus made possible.

By actuating the shift lever into the switching-off (A) position or when the tripping device (3) is activated, the spring mechanism is relaxed again and at the same time, the switch contact (4) is opened back. A further flow of the line current (9) is thus prevented. During this switching process, an arc extinguishing device (5) suppresses the arcing which otherwise would possibly take place and which also would probably sustain the current flow in spite of the opened switch contact (4).

The switch contact (4) can be realized both in a mechanical form, e.g. by a contact spring with reinforced contact electrodes, and in an electronic form, e.g. by a robust semiconductor switch. However, the mechanical form is presently remarkably more robust, more compact and significantly less expensive than a semiconductor-based electronic form and therefore will still remain the preferred form of implementing the switch contact (4) for a long time. As is the case with conventional circuit breakers, there is also provided a clamp terminal (6), which is connected to the latch with trip-free mechanism (1) on the one hand, and to the distribution network of the consumer installation (11) on the other hand.

As the functional units, which have not been known so far, are completely novel, and on which the invention is based in a characterizing way are provided both a heat flow clamp terminal (7) and a heat-controlled functional unit (8).

The heat flow clamp terminal (7) is connected, on the one hand, to the latch with trip-free mechanism (1 ) in an electrically conductive manner, and to the protected electric line (12) in an electrically and thermally conductive way, on the other hand. It is so constructed that it mechanically fixes the protected electric line (12), and both carries the line current (9) without loss, and transfers the heat flow (10) from the protected electric line (12) further to the heat-controlled functional unit (8) without loss.

As a significant difference to all applied methods known so far for protecting electric lines, attention must be paid in that in the invention introduced here, no line current (9) flows directly through the heat-controlled functional unit (8), but the latter is coupled in a thermally-conductive manner only to the heat flow (10) originating from the heat flow clamp terminal (7) and generates, as an activation signal (13) which is transmitted to the tripping device (3), either a mechanically acting control movement, e.g. in the form of an exactly defined and reproducible movement of a bimetallic spiral, or an electrically acting control signal, e.g. caused by the change of the resistance value of a semiconductor- based temperature sensor or an electromechanical tripping procedure, e.g. by means of a temperature-controlled switch relay with a correspondingly adapted or shaped switch tongue or a similarly designed electromagnetic component or auxiliary element, once an adjustable temperature threshold is exceeded, by which the tripping device (3) is activated, which in turn causes the switch contact (4) to open so that the line current (9) is interrupted.

A temperature-controlled circuit breaker with these functional units is particularly suitable as an additional protection element which acts in a complementary fashion. It is typically operated in series connection between the protected electric line (12) and the respective conventional circuit breaker and is connected so that the respective line current (9) from the conventional circuit breaker flows through the temperature-controlled circuit breaker and is then first transferred further to the protected electric line. This is necessary such that the current flow of the line current (9) can be interrupted by the temperature- controlled circuit breaker, as the case may be, if the temperature of the respective protected electric line (12) continuously monitored by the temperature-controlled circuit breaker is exceeded.

Instead of the functional units such as the second clamp terminal (6), short-circuit detector (14) with the respective shot-circuit signal (15), and overcurrent detector (16) with the respective overcurrent signal (17) used in conventional circuit breakers according to the prior art as shown in figure 1 , functional units which have not been known until today, e.g. heat flow clamp terminal (7) and heat-controlled functional unit (8) with the respective activation signal (13) are used in the invention presented here in the form of a temperature-controlled circuit breaker, wherein the heat flow clamp terminal (7) and the heat-controlled functional unit (8) are closely connected to each other both mechanically and thermally in order to provide the necessary heat flow (10) there between. These functional units are the characteristic features of this invention and are therefore elaborated below by way of examples.

A temperature-controlled circuit breaker designed this way is able to continuously monitor the temperature of the protected electric line (12) and interrupts the current flow when an arbitrarily selectable temperature threshold is exceeded, such that the temperature of the protected electric line (12) cannot be increased further by the flow of line current (9).

The incidence of cable fires due to the problems exemplified above can thus be effectively reduced. Because of the very high thermal conductivity of copper wires, heat which generates locally at interfering sites is distributed up to the connected heat flow clamp contact. Here, the amperage of the line current (9) is less important than the respective temperature of the protected electric line (12). If such a temperature-controlled circuit breaker is e.g. mounted in series between the respective protected electric line (12) and the conventional circuit breaker as an additional safety element to reduce the risks which are caused by overheated electrical wires, temperature-controlled circuit breakers which are completely identical in design can be used in principle for all protected electric lines independent from the rated currents of the conventional circuit breaker connected upstream.

However, the disadvantage of this use would be the space requirements. Since the typical size of a temperature-controlled circuit breaker approximately corresponds to the size of a conventional circuit breaker, the space required in the cabinet would be twofold. This problem can be solved for many applications by means of a simple expansion described below.

Accordingly, the functional units illustrated in figure 2 first define only the basic expansion step of the temperature-controlled circuit breakers introduced here.

The temperature-controlled circuit breakers are used in this basic expansion step as additional safety elements in combination with conventional circuit breakers within an electrical installation.

Retrofitting an existing installation is possible if sufficient space is available for mounting the additional thermally-controlled circuit breaker.

The problem that already-mounted switch cabinets may possibly not have sufficient space to install thermally-controlled circuit breakers afterwards can be solved in a relatively simple manner by expanding the functional units as already described above.

By adding a short-circuit detector (14) which has been known from conventional circuit breakers and generates an additional short-circuit signal (15) for activating the tripping device (15) in the event of a short-circuit fault, as is exactly the case with a conventional circuit breaker, the temperature-controlled circuit breaker is turned into a fully-adequate complete device which can completely replace conventionally constructed circuit breakers.

Thus, no further circuit breakers would be needed such that the required space would be reduced by 50%. However, a type classification of temperature-controlled circuit breakers would be required, which would be made according to current regulations for the permissible maximum short-circuit currents, because the current required for tripping the latch with trip-free mechanism (1 ) in the event of a short-circuit is based on a multiple of the rated current according to the regulations currently in force.

Therefore, a variety of types would then be differentiated again, which is not desired in the context of the problem described here. The optimal solution of this problem will be discussed further below. However, the problem can be significantly restricted even without additional measures.

Figure 3 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units, as a complete replacement for conventional circuit breakers.

Figure 3 is almost identical to figure 2, it is only supplemented with the short-circuit detector (14) functional unit and it is shown as to how the short-circuit signal (15) generated in the event of a fault is transmitted further for activating the tripping device (3).

The thus-constructed temperature-controlled circuit breaker comprises, in addition to the version described above in connection with figure 2, a short-circuit detector connected in series, which is connected so that the line current (9) flows through it and supplies a shot- circuit signal (15) to the tripping device (3) without delay once a predetermined current is exceeded. The tripping device (3) is thus activated, whereby the line current (9) is interrupted since the switch contact (4) is opened by the tripping device. Here, it is irrelevant in principle whether the short circuit detector (14) is connected in series between the heat flow clamp terminal (7) and the latch (1 ), or in series between the clamp terminal (6) and the latch (1 ).lt is only important that the total flowing line current (9) flows through the short circuit detector (14). Thus, a series connection must definitely be realized. At this point, it should be explained again in detail why the temperature-controlled circuit breaker, in particular in the field of domestic installations, can be used in a very advantageous and universal fashion, and why the direct detection of the line temperature is not only of the same worth, but functions more reliably than the detection of temporally flowing current, as is the present case. The two primary tasks of a circuit breaker are to switch-off the line from the power network in the event of a short-circuit on the one hand, and on the other hand, in the event of a long-lasting overload, which causes the line to overheat. Here, both in conventional circuit breakers and in the temperature-controlled circuit breaker described in connection with figure 3, the respective tripping mechanisms act for the short-circuit case and the overheating case, respectively, in a completely self- sustaining and independent fashion. Releasing the latch with trip-free mechanism (1) for a fault case due to a short-circuit takes place in exactly the same manner as it takes place in conventional circuit breakers.

However, in terms of protecting the line against overloads, the temperature of the protected electric line (12) is directly determined and taken as a criterion for switching off the circuit by activating the tripping device (3). Lines composed of plastic-coated copper wires are predominantly used for the electrical installation.

The value of the electrical resistance of such a wire can be determined in a relatively easy manner.

Detailed information in this regard can be found, for example, on the Internet under [02]:Free online encyclopedia Wikipedia:Elektrischer Widerstand, http://de.wikipedia.org/wiki/Elektrischer_Widerstand,

(entered on 26.02.2013, accessed on 14.03.2013).

Accordingly, the following relation applies to the resistance R of a line of length / , a material-dependent specific electrical resistance p , and a cross-sectional area A [02]:

Therefore, in an electric line with a constant, circular-cylindrical cross-sectional area A , the resistance per length / can be stated as follows: (1.2)

l A

[02] further states that:"When current flows through a resistor", "electrical energy" will be "converted into thermal energy" as follows,

P = R - I ² (1.2)

where P represents the electrical energy converted to thermal energy and / the actual value of the current intensity of the line current (9). Thus, as a result of a simple substitution, the thermal energy per unit length can be defined as follows:

Therefore, the thermal energy per unit length / depends on the typically constant material-dependent specific electrical resistance p .\\ increases with the square of the effective value of the current / and decreases with increasing cross-sectional area A of the respective line.

There is a clear relation between the diameter d and the cross-sectional area A in wires with a circular-cylindrical form. Detailed information in this regard can be found on the Internet under [03]: Free online encyclopedia Wikipedia: Kreis, http://de.wikipedia.org/wiki/Kreis,

(entered on 07.03.2013, accessed on 14.03.2013).

Accordingly, the following applies to cross-sectional area A [03]: Α = π λ - (1.4)

2 and the following is applicable for diameter d by an arithmetic conversion:

The actual temperature 3 of an electric line is given according to the inflow and outflow principle based on a thermal equilibrium which sets itself as a result of the sum of the action time of the raising thermal energy, reduced by the thermal energy with cooling action, dissipated to the environment of the electric line.

Since, in principle, the detection and evaluation of the respective characteristic parameters are possible only in a new installation at a sufficiently accurate level, proximity tables are often employed for the common use of individual lines for a safe estimation, these tables, taking into consideration both DIN VDE 0298 part 4, and, as a precautionary measure, adverse cases such as a multi-core wire which is laid in a duct within a heat- insulated wall and carries a direct current at an ambient temperature of 3 = 30 ⁰ C.

Thus, safety is ensured even if the electric lines transmit often more electrical energy at a given conductor cross-section.

A typical proximity table from the practice, given here as an example, provides the following protection with a rated current 7 as a function of the cross-sectional area A and the respective wire diameter d of the installed electric lines:

7 = 13,0 A A = \,5 mm ² d = 1 ,38 mm

I = 16,0 A v4 = 2,5 mm ² c/ = 1 ,78 mm

I = 20,0 A A = 4,0 mm ² d = 2,26 mm

7 = 25,0 A A = 6,0 mm ² d = 2 Q mm

7 = 32,0 A A = \ 0,0 mm ² d = 3,57 mm

7 = 50,0 A A = 16,0 mm ² d = 4,51 mm 7 = 63,0 A A = 25,0 mm ² d = 5,64 mm

I - 80,0 A = 35,0 mm ² rf = 6,68 mm

Measurements of temperature increases of the copper wires simply sheathed with PVC, as insulated single wires, which are typically combined in cables in the form of three or five wires, always result in a temperature of the conductor wire of 3 = 40 ° C under current load according to this table at a wire length / of one meter for all cases expressed there after a current flow time of one hour at room temperature with good approximation.

Here, the heating of the copper wire takes place in each single volume element of the wire. Since, according to equation (1.3), the thermal energy per unit length / at any point of the protected electric line (12) is generated by the flowing line current (9), the thermal energy per unit length / is also effective directly within the connection terminal in the cross-sectional area of the conductor.

This means that, when the current is selected as the primary criterion for the protection against overloads, eight different circuit breakers must be used for different rated currents, respectively, in order to protect the electric lines against overheating by permanently too high current densities according to the proximity table shown above for eight different cross-sectional areas A .

If, in contrast, the actual conductor wire temperature Θ of each protected electric line (12) is selected as the switching-off criterion, only a few types of temperature-controlled circuit breakers are required for different electric lines in terms of a total of eight different conductor cross-sections, wherein the differentiation of the types is based only on the currently applicable regulations for switching-off the current flow when a short circuit takes place. In contrast, concerning the protection against overloads no differentiation would be made.

At this point, the complicated problematic in a short circuit fault should not be discussed taking into account the materials and the loop impedances, for instance. Rather, as a matter of principle, brainstorming should be used for a type classification of temperature- controlled circuit breakers only on the basis of the already-established conditions.

The delayed thermal tripping for overload protection provided in conventional circuit breakers is completely the same in the temperature-controlled circuit breaker for all conductor cross-sections, without exception, given in the table above. Thus, in this respect, no differentiation must be made, since not the current, but the respective conductor heating is used as a criterion for switching off.

The regulations for electromagnetic tripping in the event of a short circuit, however, presently refer, inter alia, to the respective rated currents of conventional circuit breakers. This makes quite sense, since the line impedance is high for electric lines with a low conductor cross-section, which results in a short-circuit current which is lower than that of those electric lines with a higher conductor cross-section. This means that the line impedances are lower at the same line length there, making higher short-circuit currents possible. Additionally, there is also a classification according to the so-called switching characteristics.

In simpler terms, a C-characteristic which is chosen here as an example means that tripping in case of short-circuit must necessarily take place within a period of one tenth of a second when the short-circuit current is larger than or equal to ten times the rated current, but tripping can not take place when a current surge with a value five times the rated current takes place for a period of less than a tenth of a second.

In doing so, the circuit breaker should be prevented from tripping off prematurely and unnecessarily by a starting current surge during the start-up of a larger machine or of a welding transformer, for instance. On the other hand, the circuit breaker must trip off safely, if a short-circuit is caused by an electrically-operated defective device.

In the example given above, this would mean that for circuit breakers with the circuit characteristic C and rated currents of 13 A, 16 A, 20 A and 25 A, they all should necessarily trip off, in case of short-circuit, at a current of 130 A in one tenth of a second at the latest. With strict compliance with this requirement, all other requirements given below would be met at the same time:

All circuit breakers do not trip off prematurely, neither at 65 A, nor at 80 A or 100 A or 125 A, andall circuit breakers trip off timely at 130 A, and therefore also at 160 A or 200 A or 250 A. Thus, if the short-circuit detector could be successfully produced so precise that it would trip off exactly at a current of 130 A after a tenth of a second despite the production- related tolerances, then a corresponding type of the innovative temperature-controlled circuit breaker could replace four conventional circuit breakers at once according to the examples discussed here.

Alternatively, a hybrid solution between the two solutions described above can be provided. Here, both a conventional circuit breaker and a temperature-controlled circuit breaker are placed to a common housing. Then, a space which is no substantially larger than of a conventional circuit breaker will be required in a significantly expanded protection behavior by the common use of the respective functional elements.

Figure 4 schematically illustrates the typical configuration of a representative embodiment according to the invention for a hybrid temperature-controlled circuit breaker with the respective functional units, as a complete replacement for conventional circuit breakers with additional complementary safety elements in the form of an additional conventional overcurrent detector (16), which generates an additional overcurrent signal (17) in case of a threatening overload of the line and thus effects the switching-off by the activation of the tripping device (3) independently of other functional units.

Further embodiments and modifications can be conceived. Thus, a button for switching-on (18) and a button for switching-off (19) can alternatively be used in place of the latch lever typically used in conventional circuit breakers as a means for manual actuation (2).These buttons can either act mechanically on the latch (1 ), or can be arranged as electrical contacts and control an electromagnet (20), for instance, similar to the case of a contactor in a self-holding circuit.

The advantage of buttons is that the switch positions can clearly be assigned in an easily recognizable fashion by special shaping for instance. Thus, the switch state can immediately be recognized in a safe manner from a distance even when mounted 180 degrees offset. This, for example, also makes the switching-on difficult to such an extent that an accidental switching-on is less easily possible.

However, one such modified temperature-controlled circuit breaker would probably require a space which is larger than that of a conventional circuit breaker, which would be disadvantageous. Figure 5 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units with an alternatively modified form of the latch, as a complete replacement for conventional circuit breakers. This is about a temperature-controlled circuit breaker as already described in connection with figure 3.However, there is a difference in the latch with trip-free mechanism (1 ), which now comprises a means for manual actuation in the form of a button for switching-on (18), a means for manual actuation in the form of a button for switching-off (19), a tripping device (3), a switch contact (4), and an arc extinguishing device (5).

In this case, the switch contact (4) is closed by pressing the button for switching-on (18) mechanically or by means of an electromagnet (20) so that the flow of line current (9) is enabled.

The switch contact (4) is opened either by pressing the button for switching-off (19) or by means of the activated tripping device (3), mechanically or by means of an electromagnet (20), so that the flow of line current (9) is prevented, wherein the arc extinguishing device (5) suppresses any arcing during this switching process.

As a further alternative possibility, it could be considered to replace the switch contact (4) by an electronic switch (21 ). This electronic switch could be operated very easily both by a button for switching-on (18) and a button for switching-off (19). The advantage of the electronic switch could be that it would not give rise to arcing during switching-off. An arc extinguishing device (5) could therefore be omitted and the circuit breaker could also advantageously be used in hazardous areas.

Therefore, for the sake of completeness, figure 6 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units in an electronically-modified alternative form in terms of the arc-free latch, as a complete replacement for conventional circuit breakers.

This is thus about a temperature-controlled circuit breaker as already described in connection with figure 3 and 5, respectively. However, there is a difference in the latch with trip-free mechanism (1), which now comprises a means for manual actuation, a tripping device (3) and an electronic switch (21), wherein the electronic switch (21 ) is closed and thus the flow of line current (9) is enabled by actuating the means for manual actuation, and wherein the electronic switch (21 ) is opened and thus the flow of line current (9) is blocked by actuating the means for manual actuation.

On the other hand, the realization of a fully-electronic latch with trip-free mechanism (1) using currently available semiconductors is neither technically nor economically feasible at the moment in view of the immense switching capacity of present circuit breakers of 10000 A, for example, in terms of size and particularly in comparison to the low cost of conventional switch contacts (4), but this fundamental alternative should rather be considered as a future development possibility.

In the construction of circuit breakers, the always-effective viewpoint and a very substantial aspect is the functional reliability.

Therefore, the representative embodiments discussed here and introduced below focus almost exclusively on mechanical realizations. Mechanical realizations have no semiconductor components that could malfunction. They also do not require operating voltage and are therefore always ready-to-use. As a very important functional element of the temperature-controlled circuit breaker, it was mentioned on the heat flow clamp terminal (7) in connection with the description of figure 2. Since the heat flow clamp terminal (7) must be suitable with sufficiently good results for all electric lines and conductor cross-sections given by way of example in the proximity table shown above, a specially shaped opening (24) is required for the heat flow clamp terminal to receive the respective electric line or wire with a suitable conductor cross- section.

For describing the geometric relations, figure 7 illustrates the geometric relations in an ellipse, representative of the state of the art.

Detailed information in this regard can be found on the Internet under [04]:Free online encyclopedia Wikipedia: Ellipse, http://de.wikipedia.org/wiki/Ellipse,

(entered on 26.02.2013, accessed on 14.03.2013).

Accordingly, it can be generally said [04]:"An ellipse is a special closed oval curve."

The ellipse shown in figure 7 intersects the x-axis on two major vertices A and C, and the y-axis on the minor vertices B and D. The two focal points d and e lie on the major axis.A part of the semi-major axis (here designated "a") and a complete semi-minor axis (here designated "b") form a right-angled triangle with the line (here designated "c") between the focal point "d" and the upper vertex "B". This is the known state of the art. It is also known, what is shown in figure 8 as the state of the art, that two circles can be plotted with different radii (here designated "R1 " and "R2") and having central points on a common axis.

It is also known that the position of the central points can be selected and the radii of the circles can be chosen so that both circular contours can match to the contour of an ellipse over a relatively wide range.

Figure 9, representative of the state of the art, schematically illustrates the intersection of the contours of an ellipse and two circles with different radii "R1" and "R2" and with the respective central points at a common axis. The best match of the contour of the ellipse to the smallest of the two circles, i.e. to the circle having the radius "R1 ", is achieved when the central point of the circle is placed in the focal point of the ellipse, and the radius "R1 " is as large as the distance between the major vertex and the adjacent focal point of the ellipse in length.

The best match of the contour of the ellipse to the largest of the two circles, i.e. to the circle having the radius "R2", is achieved when the central point of the circle is placed in the center of the ellipse and the radius "R2" is as large as the semi-minor axis in length.

In inspiration from this known state of the art, the contour of the specially shaped opening (24) of the heat flow clamp terminal (7) can now be determined.

Figure 10 schematically illustrates an optimal cross-sectional form or contour of an opening for receiving circular conductor cross-sections with different diameters. The respective circular cylindrical conductor cross-sections with the radii "R1" and "R2" are illustrated using dashed lines in the contour of the optimal cross-sectional form.

On the left side of the schematic illustration in figure 10, i.e. in the range of negative x- values, one half of the opening is realized according to the above-described contour of a semi-ellipse.

On the right side of the schematic illustration in figure 10, i.e. in the range of the positive x- values, the other half of the opening is formed from a semi-square with an edge length of "2b".Here, the half of the edge length "b" of the square is exactly equal to the length "b" of the semi-axis of this ellipse. When combined, the two respective halves form together the contour of the specially shaped opening (24) according to the present invention for introducing the protected electric line (12).Accordingly, this has a contour in its cross-section, which consists, on the one hand, of a semi-ellipse and on the other hand, of a semi-square in place of the other half of the ellipse, wherein the double length of the shortest distance of the central point of the ellipse to its outer contour is equal to the edge length of the square, and is dimensioned so that it is equal to the maximum diameter (here designated "R2") of the cross-section of the protected electric line (12) and wherein the length difference between the major vertex and the adjacent focal point of the ellipse is sized such that it is equal to the minimum diameter (here designated "R1") of the cross-section of the protected electric line (12). Figure 1 schematically illustrates the front of the main body (22) of a heat flow clamp terminal (7) with a special opening (24) according to the optimal cross-sectional form or contour illustrated in figure 10 for receiving circular conductor cross-sections of different diameters. The main body (22) of the heat flow clamp terminal (7) is made of a good heat- conducting material such as copper or aluminum. This figure further shows a circular opening (25) staying buried in the metal for receiving the respective set screw (23) for pressing the protected electric line (12). This circular opening (25) is provided with an internal thread (26), so that the set screw (23) can be screwed in as intended.

Figure 12 is a schematic lateral top view of the circular opening (25) for receiving the set screw (23) for the heat flow clamp terminal (7). This lateral top view clearly shows how the special opening (24) provided in the metal extends across the entire depth of the main body (22) of the heat flow clamp terminal (7).

In figure 13, another perspective shows the top view of the main body (22) of a heat flow clamp terminal (7). Here, both the progression of the circular opening (25) with an internal thread (26) within the metal for receiving the respective set screw (23), and the progression of the special opening within the metal for receiving the protected electrical wires ( 2) having different diameters according to the cross-sectional areas are shown.

The corresponding diameters for the typical and commonly-used conductor cross-sections of A = 1,5 mm ² to A = 35 mm ² given in the proximity table above are around d - 1 ,4 mm to d = 6,7 mm respectively. However, it must be taken into consideration that from a diameter of above d = 3 mm, the respective conductor can be made from typically 7 single wires having the same, but smaller diameters. This ensures a better flexibility of the cable. This means that if copper rods with e.g. d = 6,7 mm would be used, this would require extremely high forces for laying the cable e.g. around a corner or for bending the same.

However, the outer contour of such a combined cable is likewise almost circular with good approximation. The set screw (23) required for pressing the protected electric line (12) inserted into the special opening (24) is illustrated in figure 14.This gives the schematic lateral and front views of a set screw (23) formed elliptically at its tip.

The set screw (23) has a turning head with an external thread (27) which is shaped to match the internal thread (26) of the circular opening (25) in the main body (22) of the heat flow clamp terminal (7). A notch (28) in the turning head with the external thread (27) enables one to rotate the same using a screwdriver in the exemplary embodiment shown here. However, other solutions for turning the head would be better. Particularly the use of hexagonal cut-outs for receiving Allen keys or Torx wrenches allow to apply very high pressing forces and therefore are to be used here very advantageously. The turning head with the external thread (27) merges into a smooth circular-cylindrical guide portion (29), with which the pressing section (30) joins. The outer contour of the pressing section (30) is shaped to match the contour of the special opening (24). When the set screw (23) is fully screwed into the circular opening (25) of the main body (22) of the heat flow clamp terminal (7), the special opening (24) is completely filled in cross-section by means of the set screw (23).

Figure 15 schematically illustrates the positions of the set screw (23) and the main body (22) before the set screw (23) is screwed into the circular opening (25) of the main body (22) of a heat flow clamp terminal (7) in detail. For receiving the conductors having initially-undetermined diameters, the set screw (23) is first brought into a ready-to-screw position within the main body (22).

Figure 16 schematically illustrates the positions of the set screw (23) and the main body (22) of a heat flow clamp terminal (7) after the set screw (23) is partially screwed into the circular opening (25) of the main body (22).

The set screw (23) can be further turned in once the protected electric line (12) is inserted into the special opening (24) of the main body (22) of a heat flow clamp terminal (7). Only low turning forces will be required until the set screw (23) strikes the outer periphery of the protected electric line (12), since the set screw (23) is only to be moved through the circular opening (25) of the main body (22).

In terms of this case, figure 17 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a set screw (23), which is screwed in up to the outer periphery of a protected electric line (12) inserted into the specially formed opening (24), the electric line having a minimal conductor cross-section intended for this heat flow clamp terminal (7). The originally circular-cylindrical-shaped cross-section deforms only when the set screw (23) is screwed in further, wherein the contour of the specially formed opening (24) and the contour of the pressing section (30) of the set screw (23) are partly assumed by the part of the protected electric line (12) which is present in the specially formed opening (24) depending on pressing force. Here, the extent of deformation depends on the exerted force, by which the set screw (23) is tightened and thus acts on the protected electric line (12).

Figure 18 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a screwed-in set screw (23) and a protected electric line (12) inserted into the specially formed opening (24), the electric line having a minimal conductor cross-section intended for this heat flow clamp terminal (7), wherein the set screw is screwed so tightly that the inserted electric line (12) to be protected is pressed against the wall of the specially formed opening (24) of a heat flow clamp terminal (7) and is thus deformed and partly assumes the contour of the opening and thus a maximal large-area heat contact is produced. However, the contour changes as deformation takes place, but the overall cross-sectional area of the protected electric line (12) is not changed in size, i.e. the heating-up due to the line current (9) at this point is of exactly the same magnitude as in the undeformed line and therefore no notching or wearing takes place in the conductor material as a result of pressing and the deformation occurring thereby.

In principle, the same conditions apply for electric lines (12) which are to be protected and have larger cross-sectional areas.

Figure 19 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a set screw (23), which is screwed in up to the outer periphery of a protected electric line ( 2) inserted into the specially formed opening (24), the electric line having a maximal conductor cross-section intended for this heat flow clamp terminal (7). Even with such a relatively large cross-sectional area, the changing contour of the boundary remains unchanged in its size, because no material is removed from the wire. Figure 20 schematically illustrates the main body (22) of a heat flow clamp terminal (7) with a screwed-in set screw (23) and a protected electric line (12) inserted into the specially formed opening (24), the electric line having a maximal conductor cross-section intended for this heat flow clamp terminal (7), wherein the set screw is screwed so tightly that the inserted electric line (12) to be protected is pressed against the wall of the specially formed opening (24) of the heat flow clamp terminal (7) and is thus deformed so that it partly assumes the contour of the specially formed opening (24) and thus a maximal large-area heat contact is produced.

Attention is to be paid in the manufacture of the main body (22) of the heat flow clamp terminal (7), that the optimal form of the contour of the specially formed opening (24) illustrated in the figures discussed so far may cause manufacture-related problems particularly in the region of the semi-ellipse.This contour corresponds to an optimum ideal contour, which can be reproduced with simply-produced contours in terms of functionality with very good approximation. Figure 21 shows an alternative contour of the specially formed opening (24) of the heat flow clamp terminal (7), wherein the contour shown in figure 10 is reproduced by polygonal lines which are simply machined and figure 22 shows an alternative contour of the specially formed opening (24) of the heat flow clamp terminal (7), wherein the contour shown in figure 0 is reproduced by approximation using simply-machined trapezoidal cut- outs. Both contours are examples for possible compromises that can be made in terms of production costs and functionality during production.

Regarding the temperature-controlled circuit breakers manufactured for a defined number of conductor cross-sections in terms of types, it is further possible to provide circular approximations of the optimal contour for the contour of the specially formed opening (24), wherein the diameter of the cut-outs are matched with the diameters of the conductor cross-sections of the protected electric line intended for these types of temperature- controlled circuit breakers.

Figure 23 schematically illustrates an alternative contour of the specially formed opening (24) of the heat flow clamp terminal (7), wherein the contour illustrated in figure 10 is reproduced by approximation using easily-machined circular cut-outs.

Also the costs of manufacture of the set screw (23) can be reduced by using a revised contour for production. Since the material, e.g. copper, used for the protected electric line (12) is relatively soft, other forms for the contour of the pressing section (30) are also possible without significant losses in function. However, as illustrated in the following examples, the alternative contours are generally less expensive to produce.

Figure 24 schematically illustrates an easily-machined alternative form of the set screw (23) with many circular-cylindrical cross-sectional contours and figure 25 schematically illustrates an easily-machined alternative form of the set screw (23) with a few circular- cylindrical cross-sectional contours, which can also be produced with a few circular- cylindrical cross-sectional contours and a rounded tip as an easily-machined alternative form of the set screw (23), as shown in figure 26. All set screws having these contours exemplified herein meet the requirements provided here to a sufficiently high extent. Besides the heat flow clamp terminal (7), the heat-controlled functional unit (8) is also a characterizing feature of the present invention.

Figure 27, as a representative embodiment, provides a schematic top view of the principle structure of a full mechanical heat-controlled functional unit (8) for controlling the tripping device (3) of the temperature-controlled circuit breaker. A circular carrier plate (32) made of a good heat-conducting material such as copper has a swelling portion in the form of a fixation dome (33) at the middle. A through hole (34) is provided at the center. The swelling in the form of a fixation dome (33) is formed approximately so wide that a bimetallic spiral (36) fixed in a notch in the fixation dome (33) in a mechanically and thermally-conducting manner can be mounted in a free-floating fashion without any further contact to the carrier plate (32). The bimetallic spiral (36) has at its freely-movable end a switch lug (37) as a mechanical coupling point for transmitting the activation signal (13). An adjustment screw (31 ) is provided for the fine adjustment of the activation signal (13), said screw having an outer thread engaging the corresponding thread pitches of the carrier plate (32), which, on the lateral outer edge, similarly has at least one outer thread (35) over a region of about one quarter of the circumference of the carrier plate (32). The two outer threads form a kind of self-locking worm gear, such that the adjustment screw (31 ) is to be set only once when necessary. The operation mode of the heat-controlled functional unit can be seen more clearly when viewed from the side. For clarity, the mechanical bearings of the adjustment screw is not illustrated. The details of the bearing and the screw guide correspond to the prior art, thus follow the known rules of construction in a known way and therefore do not include any characterizing subject- matter of this invention. Similarly, the bimetallic spiral (36), for instance, used in the exemplary embodiment shown here may be formed differently in principle. Basically, the bimetallic spiral can be modified in shape so that it is formed as compatible as possible to the structure of the tripping device (3). The spiral form was chosen for the structure of the first prototype, since this way the entire length of the bimetal is increased in a relatively small space to such an extent that even small temperature increases due to the heat flow (10) conducted to the fixation dome (33) in the bimetallic spiral (36) by means of the fastening points leads to relatively large changes in the location of the switch lug (37), so that significant activation signals (13) can be derived even at relatively low temperatures of the electric lines (12) to be protected.

Figure 28, as a representative embodiment, provides a schematic lateral view of the principle structure of a full mechanical heat-controlled functional unit (8) for controlling the tripping device (3) of the temperature-controlled circuit breaker.

In order to couple the heat-controlled functional unit (8) to the heat flow clamp terminal (7) mechanically and thermally, the shape of the main body (22) of the heat flow clamp terminal (7) discussed so far must first be adapted to this task.

Figure 29, as a representative embodiment, schematically illustrates the principle structure of a modified main body (22) of a heat flow clamp terminal (7) for using a full mechanical heat-controlled functional unit (8) for controlling the tripping device (3). This is essentially an expansion in the form of a support lug (39). The specially formed opening (24) in the main body (22) of the heat flow clamp terminal (7) in the embodiment shown here is closed at its rear end and has a support lug (39) with the height and the width of the main body (22) of the heat flow clamp terminal (7). A bolt (38) brought into the support lug (39) serves as a fixing pivot point for the heat-controlled functional unit (8). The heat- controlled functional unit (8) described in figures 27 and 28 is thermally and mechanically connected to the modified main body (22) of the heat flow clamp terminal (7) by the bolt (38) which is slid from below through the hole (34) of the carrier plate (32) with the fixation dome (33). For an improved thermal coupling, the carrier plate (32) is provided with a heat-conductive paste (41 ) prior to assembly. Figure 30, as a representative embodiment, is a schematic top view of the principle structure of a modified main body (22) of a heat flow clamp terminal (7) with an assembled full mechanical heat-controlled functional unit (8) for controlling the tripping device (3). It can be clearly seen that the adjustment screw (31) can be operated from the same direction from which the protected electric line (12) is introduced into the specially formed opening (24) of the heat flow clamp terminal (7). A small hole in an appropriate position in the housing of the temperature-controlled circuit breaker which is not shown here allows access to the adjustment screw (31 ). As a result of rotating the adjustment screw (31), the carrier plate (32) can be rotated around the bolt (38) as a pivot point. Thus, the temperature-dependent position of the switch lug (37) of the bimetallic spiral (36) changes. This allows setting the respective temperature very accurately at which the activation signal (13) is generated. When the protected electric line (12) is inserted into the specially formed opening (24) and is clamped by means of the set screw (23), it becomes connected to the bimetallic spiral with very good thermal conductivity thanks to this configuration. The temperature of the protected electric line (12) thus determines the temperature-dependent position of the switch lug (37). A temperature-related change in the position then forms the activation signal (13), which activates the tripping device (3) of the latch with trip-free mechanism (1).ln practice, the release of the pretensioned latch with trip-free mechanism (1 ) takes place when a small lever which is movably connected to the switch lug (37) abruptly actuates the tripping mechanism after a positional threshold is exceeded, as is the case with a trigger of a hunting riffle equipped with a hair-trigger.

Figure 31 , as a representative embodiment, is a schematic lateral view of the principle structure of a modified main body (22) of a heat flow clamp terminal (7) with an assembled full mechanical heat-controlled functional unit (8) for controlling the tripping device (3).This schematic illustration shows once again the proportions of the respective functional units. In addition, the position of the thermally-conductive paste (41 ) between the carrier plate (32) and the support lug (39) of the main body (22) of the heat flow clamp terminal (7) can be seen clearly in this view only.

Thus, when combined, the heat flow clamp terminal (7) and the heat-controlled functional unit (8) form together a combination which behaves as intended for generating an activation signal (13); For this purpose, the heat flow clamp terminal (7) is provided with a support lug (39) and a bolt (38), and the heat-controlled functional unit (8) has an adjustment screw (31 ), a carrier plate (32), a fixation dome (33) and a bimetallic spiral (36). The center of the circular carrier plate (32) is provided with a likewise circular fixation dome (33) as a circular-cylindrical embossment, as well as a central hole (34) for receiving the bolt (38) as an axis of rotation, whereas the periphery thereof is provided with an outer thread (35) in the form a screw thread, wherein rotational positioning is carried out by means of an adjustment screw (31) similarly provided with a screw thread in the form of a self-locking worm gear.

A bimetallic spiral (36) through which no line current (9) flows and which has a switch lug (37) at its end is mechanically and thermally connected to the fixation dome (33) and is so configured that, depending on the temperature of the carrier plate (32), the location of the switch lug (37) is shifted reversibly and explicitly and thus serves as a mechanical activation signal (13) for the tripping device (3) of the latch with trip-free mechanism (1).

As already described, the main body (22) of the heat flow clamp terminal (7) has a bulge in the form of a support lug (39), in which a bolt (38) is provided as a rotation axis for the carrier plate (32). After a thermally-conductive paste (41) is applied between the carrier plate (32) and the support lug, the carrier plate (32) is so slid on the bolt (38) that, on the one hand, a thermal coupling to the heat flow clamp terminal (7) is produced and, on the other hand, the position is adjusted by turning the fixation screw (31).

Electronic implementations of the functional units are also conceivable in principle. An exemplary embodiment for an electronic version of a heat-controlled functional unit would be to mount a semiconductor device for detecting the temperature of the heat flow clamp terminal (7), which in turn would be electrically connected to a suitable electronic interpreting device. For the sake of completeness, figure 32, as a representative embodiment, provides a schematic lateral view of the principle structure of a modified main body (22) of a heat flow clamp terminal (7) with an assembled alternative electronic heat-controlled functional unit (8) for controlling an electronic tripping device (3).

It was already pointed out in connection with the description of figures 2 and 3 that the delayed thermal trip for overload protection provided in conventional circuit breakers is completely the same in temperature-controlled circuit breakers for all conductor cross- sections referred to in the proximity table given at the beginning, since not the amperage, but the respective line heating is used as a criterion for switching-off.

Thus, temperature-controlled circuit breakers which are structured completely similar can be used for all rated currents, for example, of 13 A to 80 A as an additional safety measure. However, the electromagnetic tripping in the event of a short circuit depends on the respective rated current. There is also a classification according to the so-called switching characteristics. It can be shown that a single temperature-controlled circuit breaker can equally replace up to four conventional circuit breakers according to the switching characteristics, if the short- circuit detector can be produced with a sufficient precision and with low tolerance only and trips as precisely as possible at a predetermined value of 130 A in our example. This problematic will be elaborated now in the following. Since not the thermal overload protection, but the different conditions in the event of a short circuit restrict the universal use of the temperature-controlled circuit breakers, the problematic of different values for the respective short-circuit amperages is solved to that effect that a selective clamp terminal (42) on the one hand, and a selective short-circuit detector (43) electrically connected to the former on the other hand can be connected to the temperature- controlled circuit breaker as additional functional units according to the present invention, whereby one and the same type of temperature-controlled circuit breaker can equally replace a large plurality of conventional circuit breakers.

Figure 33, as a representative embodiment, provides a schematic front view of a selective clamp terminal (42) with exemplary illustrated three selection options and the respective clamp screw (45).

Using this selective clamp terminal (42), it is possible to select the respective amperage by which the latch with trip-free mechanism (1 ) shall interrupt the current flow in the event of a short circuit. The clamp screw (45) comprises an external thread (46) and is inserted into the threaded hole (49) of the clamp housing (47). It serves to fix a main electric line inserted into the respective opening. The clamp housing (47) is composed of a durable tough material such as steel. It holds together the individual components of the selective clamp terminal and absorbs the forces which occur as a main electric line is screwed down. Three openings, i.e. option 1 (54), option 2 (52) 3 and option 3 (50), are given in this exemplary embodiment. The lower part of the respective openings is provided with a terminal bar made of copper or a similar good conductive material. The terminal bars comprise a rounded contour in the region of the respective openings to increase the contact area for each inserted main electric line and are separated from each other by means of an insulator (48) which is composed of a ceramic-like solid material and fills the entire remaining selective clamp terminal. The terminal bars are arranged so that when a main electric line is inserted into the opening of option 1 (54), it can be pressed on the terminal bar 1 (55) by means of the clamp screw (45), and when a main electric line is inserted into the opening of option 2 (52), it can be pressed on the terminal bar 2 (53) by means of the clamp screw (45), and when a main electric line is inserted into the opening of option 3 (50), it can be pressed on the terminal bar 3 (51 ) by means of the clamp screw (45). In order to let the clamp screw (45) reach all levels, the terminal bar 2 (53) and the terminal bar 3 (51 ) are each provided with a bore having diameters which are significantly larger than the diameter of the clamp screw (45), such that the screw cannot reach the boundary of the terminal bar, and thus no electrically-conductive connection can be produced between the clamp screw (45) and the respective terminal bar 2 (53) or the terminal bar 3 (50).

In order to let the clamp screw (45) reach all levels, the insulating material (48) also has three holes, namely one between the opening of option 1 (54) and the terminal bar 2 (53), then between the opening of option 2 (52) and the terminal bar 3 (51 ), and finally between the opening of option 3 (50) and the threaded hole (49) in the clamp housing (47). The diameter of these holes is only slightly larger than the diameter of the clamp screw (45). Thus, the respective holes act as guide sleeves and provide an effective prevention of the tilting of the clamp screw (45) even when it is turned very forcefully.

Figure 34, as a representative embodiment, provides a schematic front view of a selective clamp terminal (42) with three selection options and a respective clamp screw (45), which presses an inserted wire (56) against the terminal bar 2 (53), for instance. When the inserted wire (56) is screwed down, the clamp screw (45), the clamp housing (47) and the terminal bar 2 (53) are arranged at the same potential as the inserted wire (53). Therefore, the clamp housing must be mounted in the housing of the temperature-controlled circuit breaker in an insulated manner. If the wire (56) would be inserted into another optional opening, it would then be connected to another respective terminal bar in an electrically- conductive manner. Therefore, as the wire (56) is inserted, it can be determined by the professional who carries out the assembly with which terminal bar the wire (56) is to be electrically connected by choosing the respective optional opening.

Thus, by choosing the optional opening, the range of the short circuit amperage causing the tripping of the latch with trip-free mechanism (1 ) can be determined in the temperature-controlled circuit breaker with the selective clamp terminal (42).

Now, for further explanation, first the functional structure of the selective short-circuit detector is to be considered. Figure 35 schematically illustrates, as a representative embodiment, the multi-tapped coil for the electromagnetic selective short-circuit detector (43) with an exemplary designed movable ferromagnetic core (61 ) with partially different radii for generating a selective short-circuit signal (44). The coil to generate the magnetic field, which moves the ferromagnetic core (61 ) in the case of short circuit also in conventional circuit breakers so that it lets the latch with trip- free mechanism (1 ) open the switch contact (4), comprises multiple tapping points in the selective short-circuit detector (43).

A few spiral turns are adequate in a very high short-circuit current in order to generate a magnetic field with a sufficiently high flux density so that the ferromagnetic core (61) is moved with sufficient force, whereas more spiral turns are required in a less high short- circuit current in order to generate a magnetic field with a sufficiently high flux density so that the ferromagnetic core (61 ) is moved with sufficient force and still more spiral turns are required in a low short-circuit current in order to generate a magnetic field with a sufficiently high flux density so that the ferromagnetic core (61 ) is moved with sufficient force.

Now, if the coil terminal 1 (62) is connected to the terminal bar 1 (55) in an electrically- conductive manner, then even a low short-circuit current flowing from this terminal to the tie point (65) is sufficient to generate a selective short-circuit signal (44) in the form of a self-moving ferromagnetic core (61 ).

Now, if the coil terminal 2 (63) is connected to the terminal bar 2 (53) in an electrically- conductive manner, then a higher short-circuit current must flow from this terminal to the tie point (65) to generate a selective short-circuit signal (44) in the form of a self-moving ferromagnetic core (61 ). Now, if the coil terminal 3 (64) is connected to the terminal bar 3 (51 ) in an electrically- conductive manner, then still a higher short-circuit current must flow from this terminal to the tie point (65) to generate a selective short-circuit signal (44) in the form of a self- moving ferromagnetic core (61 ).

In this way, the magnitude of the short circuit current can be initially determined relatively roughly by the choice of an optional opening. However, since the taps cannot be implemented at any arbitrary point in terms of construction, the short-circuit current cannot be determined in the first instance with sufficient accuracy in terms of production technology.

This problem can be solved with good approximation by a specific selection of the respective diameter of the ferromagnetic core in the partially different field ranges of the magnetic flux density.

Three local field ranges are defined by the tapped coil. The coil field range 1 (66) is located between the coil terminal 1 (62) and the coil terminal 2 (63).

The coil field range 2 (67) is between the coil terminal 2 (63) and the coil terminal 3 (64) and the coil field range 3 (68) is between the coil terminal 3 (64) and the tie point (65).

The interaction of a ferromagnetic core (61 ) with the magnetic field depends also on the diameter thereof in terms of the emerging action of the force, i.e. on the amount of the magnetizable material in the region of the magnetic flux density. A ferromagnetic core having a small radius encounters a lower force action at the same magnetic flux density as compared to a ferromagnetic core with a larger radius. This provides a further degree of freedom to determine the respective amperage required for tripping the latch with trip- free mechanism (1) in the event of a short circuit.

Thus, the switching-off behavior in the event of a short circuit can be better determined in advance, which significantly expands the applicability of the temperature-controlled circuit breaker. The application of the selective clamp terminal (42) in combination with the selective short-circuit detector (43) results in a further improved temperature-controlled circuit breaker.

Figure 36 schematically illustrates the typical configuration of a representative embodiment according to the present invention for a temperature-controlled circuit breaker with the respective functional units, as a complete replacement for conventional circuit breakers for a plurality of switching characteristics.

This configuration comprises, on the one hand, the functional units all shown already in figure 2 for the basic expansion step of the temperature-controlled circuit breakers introduced here. In place of the expansion shown in figure 3 by a conventional short-circuit detector (14) which generates a conventional short-circuit signal (15) and forwards it to the tripping device (3), the expansion configuration here looks now completely different.

Here, a selective clamp terminal (42) is used in place of the conventional clamp terminal (6) shown in Figure 2. The selectable different terminal bars (51 ), (53) and (55) are electrically connected to the respective coil terminals (64), (63) and (61 ) of a selective short-circuit detector (43), which generates a selective short-circuit signal (44) when a selectively-determined amperage threshold is exceeded, which may take place in the event of a short circuit, the selective short-circuit signal acting on the tripping device (3) and forcing the latch with trip-free mechanism (1 ) to an abrupt opening of the switch contact (4).

Thus, the line current (9) is not supplied directly to the latch with trip-free mechanism (1 ) through a conventional clamp terminal (6), which was the case of the exemplary embodiments discussed and explained in connection with figures 2 to 6 (included). Rather, the current path for the line current (9) is first determined and fixed by means of the selective clamp terminal (42) so that the line current (9) flows through only a very specific portion of the magnet coil of the electromagnet in the selective short-circuit detector (43), before it is further conducted to the latch with trip-free mechanism (1).

Then, the line current (9) from the latch with trip-free mechanism (1 ) finally reaches the protected electric line (12) through the heat flow clamp terminal (7) already known from figure 2.

As a result of the sum of the innovative measures described above, an improved temperature-controlled circuit breaker has been developed as an optimized product, which is universal and can be used for numerous applications.

List of References

[01 ] Free online encyclopedia Wikipedia:Leitungsschutzschalter, http://de.wikipedia.org/wiki/Leitungsschutzschalter, (entered on 19.02.2013, accessed on 05.03.2013)

[02] Free online encyclopedia Wikipedia.Elektrischer Widerstand, http://de.wikipedia.org/wiki/Elektrischer_Widerstand,

(entered on 26.02.2013, accessed on 14.03.2013)

[03] Free online encyclopedia Wikipedia:Kreis, http://de.wikipedia.org/wiki/Kreis,

(entered on 07.03.2013, accessed on 14.03.2013)

[04] Free online encyclopedia Wikipedia:Ellipse, http://de.wikipedia.org/wiki/Ellipse, (entered on 26.02.2013, accessed on 14.03.2013)