CLIAMS:1. A test circuit for a residual current circuit breaker, said test circuit comprising:
a test button;
a TRIAC; and
a test resistor, wherein said TRIAC is configured to protect the test resistor from acting as an additional current operated switch operated from outgoing supply.

2. The test circuit of claim 1, wherein phase to the test button is taken from supply line and is connect to T1 of the TRIAC through the test resistor.

3. The test circuit of claim 1, wherein GATE (G) of the TRIAC is connect to load side and T2 is connected to neutral such that when the test button is pressed, T1 and the T2 of the TRIAC get shorted and residual current flows through the CBCT to give a relay signal for tripping the circuit.

4. The test circuit of claim 1, wherein the TRIAC remains ON once outgoing supply gets disconnected such that when the test button is pressed, a small amount of forward leakage current flows to enable very limited heat to be developed in the test resister.

5. The test circuit of claim 4, wherein forward leakage current is negligible when compared with the residual current.

6. The test circuit of claim 1, wherein the TRIAC works as an additional AC switch in the test circuit and operates in both positive and negative cycles of the supply.

7. The test circuit of claim 1, wherein the TRIAC enables proper isolation between the phase and neutral.

8. The test circuit of claim 1, wherein size of the test resistor is reduced.

9. A residual current circuit breaker having a test circuit, said test circuit comprising:
a test button;
a TRIAC; and
a test resistor, wherein said TRIAC is configured to protect the test resistor from surges by creation of a high impedance path.

10. The residual current circuit breaker of claim 9, wherein GATE (G) of the TRIAC is connect to load side and T2 is connected to neutral such that when the test button is pressed, T1 and the T2 of the TRIAC get shorted and residual current flows through the CBCT to give a relay signal for tripping the circuit.
,TagSPECI:TECHNICAL FIELD
[0001] The present disclosure relates generally to protection devices such as residual circuit breakers. More particularly, the present disclosure relates to a test circuit arrangement for a circuit breaker.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Function of a typical test button is to check product functionality at regular time intervals. When the push button is pressed, current equivalent to specified residual current of the sensing device flows, and the product should trip. Test button needs supply from phase and neutral of the product. When a typical test device is connected on the incomer side, test resistor of the test device requires higher wattage as it needs to carry current continuously till the test button pressed. Higher wattage resistor needs more space in the device, and therefore, for compact devices, one may not be able to connect a high wattage test resistor due to space constraint.
[0004] FIG. 1 illustrates an exemplary conventional test circuit arrangement of a residual current device (RCD), wherein phase to the push button is given from load side and neutral is provided directly from supply. When the test button is pressed, current flows in CBCT through test resistor (RT), wherein the CBCT senses the residual current, gives mV output, and the product trips through electronics or permanent magnet relay.
[0005] When there is no possibility of taking phase to the push button from the load side in the product, and the test circuit is required to be connected on the incomer side, an alternate test circuit can be configured as shown in FIG. 2, wherein the phase to the push button is given from supply (Line) side and neutral is provided directly from supply. FIG. 2 therefore illustrates an existing alternate test circuit arrangement when test circuit is required to be connected on incomer side. FIG. 3, on the other hand, shows an existing test circuit arrangement with current direction when push button is pressed.
[0006] A drawback of above circuit is even if the load side is disconnected from supply, continuous flow of current (I1) in the test circuit is present when the push button remains pressed, leading to burning of the test resistor (RT) if wattage of RT is not adequate.
[0007] There is therefore a need in the art for a test circuit arrangement that overcomes the above-mentioned limitations.
[0008] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0009] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0010] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0011] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0012] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0013] It is an object of the present disclosure to provide a test circuit arrangement that protects test resistor from burning.
[0014] It is an object of the present disclosure to provide a test circuit arrangement that incorporates a TRIAC that act as an additional switch in series with test resistor.
[0015] It is an object of the present disclosure to provide a test circuit arrangement that incorporates a TRIAC that provides a high impedance path to minimize entry of surges in it.
[0016] It is an object of the present disclosure to provide a test circuit arrangement that incorporates a TRIAC that helps avoid unwanted nuisance tripping.
[0017] It is an object of the present disclosure to provide a test circuit arrangement that incorporates a TRIAC that enables proper isolation to be maintained between phase and neutral.
[0018] It is an object of the present disclosure to provide a test circuit arrangement that enables reduced size of the test resistor.
SUMMARY
[0019] The present disclosure relates generally to protection devices such as circuit breakers. More particularly, the present disclosure relates to a test circuit arrangement for a circuit breaker.
[0020] The present disclosure relates to a test circuit for a residual current circuit breaker (RCCB), wherein the test circuit can include a test button, a TRIAC, and a test resistor, wherein the TRIAC can be configured to protect the test resistor from continuous flow of current through it and additional protections against surges by creation of a high impedance path. In an aspect, the phase to the test button can be taken from supply line and can be connected to T1 of the TRIAC through the test resistor. In another aspect, GATE (G) of the TRIAC can be connected to the load side, and T2 can be connected to neutral such that when the test button is pressed, T1 and T2 of the TRIAC can get shorted and residual current flows through the CBCT to give a relay signal for tripping the circuit. In yet another aspect, the TRIAC remains ON once the outgoing supply gets disconnected such that when the test button is pressed, only a small amount of forward leakage current flows to enable very limited heat to be developed in the test resister.
[0021] In an aspect, the forward leakage current is negligible when compared with the residual current, enabling the TRIAC to act as an additional AC switch in the test circuit and operate in both positive and negative cycles of the supply. In an aspect, the TRIAC enables proper isolation between the phase and neutral. In yet another aspect, size of the test resistor can be reduced.
[0022] In another embodiment, the present disclosure relates to a residual current circuit breaker having a test circuit, wherein the test circuit includes a test button, a TRIAC, and a test resistor, wherein the TRIAC can be configured to protect the test resistor from continuous flow of current through it and additional protections against surges by creation of a high impedance path. In another aspect, the GATE (G) of the TRIAC can be connect to load side and T2 can be connected to neutral such that when the test button is pressed, T1 and T2 of the TRIAC can get shorted and residual current flows through the CBCT to give a relay signal for tripping the circuit.
[0023] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0025] FIG. 1 illustrates a conventional test circuit arrangement of a residual current device (RCD).
[0026] FIG. 2 illustrates an existing alternate test circuit arrangement when test circuit is required to be connected on incomer side.
[0027] FIG. 3 shows an existing test circuit arrangement with current direction when push button is pressed.
[0028] FIG. 4 illustrates the proposed test circuit arrangement in accordance with an embodiment of the present disclosure.
[0029] FIG. 5 illustrates the proposed test circuit arrangement in accordance with an embodiment of the present disclosure.
[0030] FIG. 6 illustrates the proposed test circuit arrangement in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0032] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0033] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0034] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0035] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0036] The present disclosure relates generally to protection devices such as circuit breakers. More particularly, the present disclosure relates to a test circuit arrangement for a circuit breaker.
[0037] The present disclosure relates to a test circuit for a residual current circuit breaker (RCCB), wherein the test circuit can include a test button, a TRIAC, and a test resistor, wherein the TRIAC can be configured to protect the test resistor from continuous flow of current through it and additional protections against surges by creation of a high impedance path. In an aspect, the phase to the test button can be taken from supply line and can be connected to T1 of the TRIAC through the test resistor. In another aspect, GATE (G) of the TRIAC can be connected to the load side, and T2 can be connected to neutral such that when the test button is pressed, T1 and T2 of the TRIAC can get shorted and residual current flows through the CBCT to give a relay signal for tripping the circuit. In yet another aspect, the TRIAC remains ON once the outgoing supply gets disconnected such that when the test button is pressed, only a small amount of forward leakage current flows to enable very limited heat to be developed in the test resister.
[0038] In an aspect, the forward leakage current is negligible when compared with the residual current, enabling the TRIAC to act as an additional AC switch in the test circuit and operate in both positive and negative cycles of the supply. In an aspect, the TRIAC enables proper isolation between the phase and neutral. In yet another aspect, size of the test resistor can be reduced.
[0039] In another embodiment, the present disclosure relates to a residual current circuit breaker having a test circuit, wherein the test circuit includes a test button, a TRIAC, and a test resistor, wherein the TRIAC can be configured to protect the test resistor from continuous flow of current through it and additional protections against surges by creation of a high impedance path. In another aspect, the GATE (G) of the TRIAC can be connect to load side and T2 can be connected to neutral such that when the test button is pressed, T1 and T2 of the TRIAC can get shorted and residual current flows through the CBCT to give a relay signal for tripping the circuit.
[0040] According to one embodiment, the present disclosure relates to a novel self-protected test circuit arrangement, which incorporates a TRIAC as an additional switch in series of the test circuit having test resistor and a switch, wherein the TRIAC acts as an open switch when GATE (G) pulse is taken from the other side of the switch to get disconnected. Such an arrangement can find application where test circuit is required to be connected on the incomer side in any RCD device or application where additional protection may be required.
[0041] According to another embodiment, the present disclosure uses a TRIAC whose terminal is connected on the incomer side but takes its GATE (G) supply from outgoing side of the device such that when the test circuit operates, supply to the outgoing side gets disconnect, turning OFF the TRIAC, which makes the test circuit not to carry any continuous current and remain safe when someone continuously presses the test button.
[0042] In another aspect, the present disclosure enables usage of low wattage test resistor, which can be accommodated on the electronic card itself. Also, the test resistor burning issues under continuous pressing of test button are eliminated through the proposed circuit arrangement.
[0043] According to another embodiment, the proposed design saves space due to the reduced size of test resistor. Furthermore, test resistor burning issue due to continuous supply gets eliminated and a high degree of self-protection is provided to the test circuit with TRIAC. Furthermore, life of the test resistor is increased and high transient voltages to avoid nuisance tripping are restricted.
[0044] With reference to FIGs. 4-6, the figures show the proposed test circuit arrangement. In an aspect, the proposed test circuit can include a test button, a TRAIC, and a test resistor, wherein the TRAIC can be added for the protection of the test resistor (RT). Phase to the test button can be taken from Lin and can be connected to T1 of the TRAIC through the test resistor. GATE (G) of the TRIAC can be connected to load side (Pout) and T2 can be connected to the neutral. In an implementation, as soon as the push button is pressed, T1 and T2 get shorted and residual current flows through the CBCT, giving a signal to the relay to enable the mechanism to be tripped.
[0045] FIG. 6 illustrates use of the TRIAC in the proposed circuit, wherein the TRIAC’s GATE (G) can be connected on the outgoing side and TRAIC will not remain OFF once the outgoing supply get disconnected. Whenever the push button remain in pressed condition, very small amount of forward leakage current defined in a respective TRIAC datasheet flows, which is usually very negligible when compared to the residual current, and therefore very limited heat gets developed in the test resistor (RT) and test resistor remains protected from any damage. The reason to connect the TRAIC in the present circuit is that it is a bidirectional semiconductor device and therefore works as an additional AC switch in the test circuit to operate during both positive as well as negative cycles of the supply.
[0046] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0047] The present disclosure provides a test circuit arrangement that protects resister from burning.
[0048] The present disclosure provides a test circuit arrangement that incorporates a TRIAC that protects continuous flow of current through it and additional protections against surges.
[0049] The present disclosure provides a test circuit arrangement that incorporates a TRIAC that provides a high impedance path.
[0050] The present disclosure provides a test circuit arrangement that incorporates a TRIAC that helps avoid unwanted nuisance tripping.
[0051] The present disclosure provides a test circuit arrangement that incorporates a TRIAC that enables proper isolation to be maintained between phase and neutral.
[0052] The present disclosure provides a test circuit arrangement that enables reduced size of the test transistor.