DESC:TECHNICAL FIELD
[0001] The present disclosure generally relates to field of low voltageswitchgear used in distribution of electricity. In particular,systems and methods of the present disclosure pertain to residual current circuit breakers. More specifically,the systems and methods pertain toa testing mechanism in residual currentcircuit breaker,which mechanism ensures functioning of safety features of residual current circuit breaker in both three phase and phase to neutral connection applications.

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] Residual current circuit breakers(RCCB) are low voltage switchgear normally provided in home and industrial power systems in order to detect fault current and trip the circuit to avoid danger to users and to equipment connected to the electric line. RCCB therefore comes under the category of lifesaving products. Essentially, when a residual current circuit breaker detects a fault current it disconnects the line, thereby interrupting the power supply to prevent harm/damage to men/equipment connected downstream. After the release of the residual current circuit breaker, and once the correct operating conditions of the system have been restored, theresidual current circuit breaker must be reset or gets automatically reset to resume normal operation.
[0004] RCCBs operate by measuring the current balance between two or more conductors using a differential current transformer or core balance current transformer, which detects any difference between current flowing through live conductor and that returning through neutral conductor or through three phases in three phases application. If these do not sum to zero, there is a leakage of current to somewhere else (to earth/ground, or to another circuit), and the device will open its contacts. Residual current circuit breakers (RCCB) are designed to trip when the residual current is between 50% of rated residual current and rated residual current.
[0005] In accordance with prevailing applications, RCCBs are available in either 2P or 4P configurations. A typical 2P RCCB shall have provision for two conductors- one being live and other being neutral, whereas a typical 4P RCCB provides for four conductors three live – one for each phase - and fourth for neutral.
[0006] FIG. 1 depicts internal mechanism of a typical 2P RCCB 100 with test button 102. Incoming supply and neutral conductors are connected to terminals L & N respectively. Conductors pass througha differential current transformer 106. Secondary winding 108 of differential current transformer 106 is connected to solenoid 110, which when actuated by current from secondary winding 108 of differential current transformer 106, operates circuit breaker 112.
[0007] As can be seen operation of RCCBs generally depends on functioning of the circuit breaker 112, which is a mechanical device and can become stiff when old or dirty and may not function when need arises.
[0008] Considering the severity of implications of circuit breaker failing to function during occurrence of residual current, potentially causing damage to individuals and/or equipment, it is mandatory for each circuit breaker to be provided with a built in testing facility in order to check health of circuit breaker, without waiting for an actual fault such as an earth leakage or earth fault for example to occur. This is why all national & international product standards provide that RCCBsshould have a testing facility for testing their health. For example,IS:12640 Part 1 / Part 2& IEC 1008 -1 / IEC1009-1 lay down requirements of test button in RCCB.In accordance withthese standards,RCCBsare provided with a test button such as 102, which when actuated, generates desired level of current to facilitate checking i.e. to ensure that the circuit breaker trips. For example, in FIG. 1, test circuit is provided between live and neutral conductor with test button 102.
[0009] The stated testing facility usually is a circuit connecting neutral and live conductor as shown in FIG. 1 and includes a test resistor 104 and a test button 102 connected in series, whereby operation of the test button 102 will close the test circuit, generating a simulated residual current from one conductor to another conductor past the differential current transformer/core balance current transformer. If theRCCB functions correctly, it will be triggered and tripping mechanism shall open separable contacts of the circuit breaker to interrupt current flow in a protected power system.
[0010] The test circuit should, in addition, reliably function under varying voltage conditions.For example, test circuit must function at a voltage, which is 85% of the rated voltage.
[0011] To comply with prevailing regulations, all currently available RCCBs provide the testing facility either between phase and neutral connections or between two of the phases (415V).FIG. 2 represents an exemplary built-in test button operation circuit 200 of a 4P, between R phase and neutral in accordance with first of the two prevalent configurations stated above. As depicted, test circuit is drawn between neutral 202 and phase R 204, incorporating resistance 208, and a test button 206 in series. When the test button 206 is actuated,the circuit gets closed setting it operational, and a simulated residual current is produced past the core balance current transformer 210, which is connected to the Permanent Magnet Relay (PMR) 214 by means of a secondary winding 212. The PMR 214 triggers the tripping of circuit breaker giving an indication of satisfactory and desired functioning of the RCCB.
[0012] Test circuit of this RCCBshall function satisfactorily if used in an application connected between phase and neutral, However in the event of above RCCB being used in application having phase to phase connection, for example, three phases without neutral, operation of test button 206 will not cause circuit breaker to trip and therefore will be unable to check the health ofRCCB.
[0013] FIG. 3illustrates second of the two said test button configurations in currently available RCCBs. In this configuration, test button operation circuit 300 is provided between phase B302 and phase R304. As depicted,a circuit is drawn between Phase B 302 and phase R304, with a resistance 308 and a test button 306 placed in series. When the test button306 is actuated, closing the circuit and setting it operational, a simulated residual current is produced past the core balance current transformer 310, which is connected to PMR 314 by means of a secondary winding 312. The PMR 314 triggers tripping of circuit breaker, thereby giving an indication of satisfactory functioning of the RCCB.
[0014] Test circuit of this RCCB shall function satisfactorily if used in phase-to-phase application. However, in the event of this RCCB being used in an application connected between one of the phasesand neutral, operation of the test button 306 will not cause the circuit to trip and thereby will be unable to give an indication of health of the RCCB. Such a situation may arise if acustomer uses this RCCB for domestic application and connects supply between any phase and neutral,in which case, on pressing test button, the RCCB shall not trip and hence will not be able to verify health of RCCB even though it has in build test button facility. The reason being that in built facility is provided between any two phases and not between phase and neutral.
[0015] From above, it can be seen that both the above configurations of RCCBs even though meeting the requirement set forth in the product standards, in certain conditions are not able to provide an indication of their health, defeating the very purpose for which the test button is provided. There is therefore a need for a test circuit configuration in RCCBs,which provides an option to user to choose RCCB testing based on application of RCCBin which it is being used.
[0016] Accordingly, there is a need for a user friendly RCCB in which,apart from the test button to initiate testing, a selection mechanism can be incorporated to select a phase to phase (415V) or a neutral and phase (215V) configuration depending upon the application,enabling a user to get an indication of health of RCCB irrespective of configuration in which it is used.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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
[0022] An object of present disclosure is to remove shortcomings in the currently available 4P RCCBs
[0023] Another object of present disclosure is to provide characteristics for phase to phase application as well as phase to neutral application in a single 4P RCCB
[0024] Another object of the disclosure is to provide 4P RCCB which can be used in any configuration without compromise in safety requirements
[0025] Another object of present disclosure is to a provide 4P RCCB, which gives an option to user to select the configuration in which it is used.
[0026] Yet another object is to provide a 4P RCCB, which can be used in either three-phase circuit or phase-neutral circuitdepending on user’s requirement without compromising on test button operation.
[0027] Another object is to reduce variety of 4P RCCB and help users in inventory management.

SUMMARY
[0028] Aspects of present disclosure relates to inbuilt testing mechanism of a 4P (4-phase) RCCB, wherein a user can check the health of the RCCB irrespective of the configuration in which it is used. In an aspect, the disclosed RCCB can be adapted for use in any of the possible intended configurations for use so that requirement of test button is not compromised.
[0029] As mentioned above, in existing architectures, a 4P RCCB configured for use in phase to neutral connection,if deployed by user for phase-to-phase application,would not give an indication of its health when checked using test button, thus compromising safety. Likewise, a 4P RCCB configured for use in phase-to-phase application, if deployed by user for phase-to-neutral application would fail in the essential safety requirement. The present inventive disclosure therefore provides RCCB, which shall meet mandatory test button requirement irrespective of the configuration in which it is deployed.
[0030] In another aspect of the present disclosure, along with a test button in accordance with mandatory requirement, 4P RCCB can be provided with a selection mechanism, which may have options for selecting between 415Vapplication when deployed in phase to phase application, and 240V connection when supply is connected between R phase and neutral.
[0031] In yet another aspect of the disclosure, additional optionscan be provided to connect load between phase R and neutral or between phase Y and neutral.
[0032] In another aspect, the present disclosure provides the user with an option to deploy the RCCB in any configuration and at the same time meeting the mandatory requirement of test button.
[0033] 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
[0034] 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.
[0035] FIG. 1 illustrates a prior art schematic diagram of a 2P RCCB depicting essential elements of RCCB.
[0036] FIG. 2 illustrates a prior art schematic diagram of4P RCCB configured for phase to neutral application.
[0037] FIG. 3 illustrates a prior art schematic diagram of 4P RCCB configured for phase to phase application.
[0038] FIG. 4 illustrates an exemplary schematic diagram of 4P RCCBwith selector switch giving an option to user to the RCCB either for phase-to-neutral (240V) or phase-to-phase (415 V) application in accordance with present disclosure.
[0039] FIG.5 illustrates an exemplary schematic diagram of a 4P RCCB with selector switch-1and selector switch-2giving an option to the user to use the RCCB either in phase-to-neutral (340 V) or phase-to-phase (415 V) application and additional option to select the phase in accordance with present disclosure.
[0040] FIG. 6(a) illustrates a perspective view of 4P RCCB with single selector switch in accordance with present disclosure.
[0041] FIG. 6(b) illustrates a perspective view of 4P RCCB with single selector switch in three phase applicationin accordance with present disclosure.
[0042] FIG. 6(c) illustrates a perspective view of 4P RCCB with single selector switch in phase to neutral application in accordance with present disclosure.
[0043] FIG. 7(a) illustrates a perspective view of 4P RCCB with selector switch 1 and selector switch 2 in accordance with present disclosure.
[0044] FIG. 7(b) illustrates a perspective view of 4P RCCB with selector switch 1 and selector switch 2 in phase to phase application in accordance with present disclosure.
[0045] FIG. 7(c) illustrates a perspective view of 4P RCCB with selector switch 1 and selector switch 2 and selector switch 2 in Rposition for Rto neutral application in accordance with present disclosure.
[0046] FIG. 7(d) illustrates a perspective view of 4P RCCB with selector switch 1 and selector switch 2 in Y position for Yto neutral application in accordance with present disclosure.
[0047] FIGs. 8(a) and 8(b) illustrate exemplary prototypes of the proposed system in accordance with an embodiment of the present disclosure.
[0048] FIG.9 illustratesanother exemplary prototype of the proposed system in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0049] Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.”
[0050] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0051] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.
[0052] The headings and abstract of the disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
[0053] Reference will now be made in detail to the exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
[0054] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
[0055] Embodiments ofpresent disclosure describe a testing mechanism in 4P RCCB to check its health to meet the mandatory safety requirements as laid down in product specifications.Embodiments of present disclosure also relate to and are applicable to RCCB’s incorporating/with overload protection (RCBO). Therefore, although the present disclosure has been explained with reference to RCCB, embodiments and implementations are also equally applicable to RCBO and residual current devices (RCDs) as well. In an aspect, embodiments of the present disclosure ensure that the health of RCCB can be reliably checked irrespective of configuration in which it is deployed or used. In another embodiment, the disclosed 4P RCCB can be provided with selection mechanism, which can be a switch or any such manual mechanism orsome other automated mechanism that enables user to select between at least two options such as phase to phase (415V) application/deployment or phase to neutral (240V) application/deployment.A person skilled in art can, for example, provide automatic mechanism to sense the voltage and actuate the selector. In an aspect of the embodiment, single 4P RCCB can meet the requirement of user of at least two different configurations, thus reducing his inventory.
[0056] FIG. 4 illustrates is an exemplary circuit diagram 400 of an embodiment, wherein 4P RCCB provides user with two options. In the illustration,Red (R) 408, Yellow (Y) 406, and Blue (B) 404, along with neutral 402 constitute four conductors.As an example,as illustrated in FIG. 4, test circuit can be provided between conductor R on incoming side and conductor B/neutral on load side. The circuit can incorporate a test button 416 and a selector switch 414. After the selector switch 414, the circuit can get bifurcated with one end at phase B 404, and the other end at neutral 402 conductors on load side. Selector switch 414, which for example, can have two positions, each corresponding to one of the two bifurcated circuits- connects test button side to either of the two circuits. The selector switch 414 can also have markings for each position indicating the selection such as 415Vand 240V. Each of the two bifurcated circuits can also have resistance 410 and 412. The resistances 410 and412 can be chosen such that on completion of the test circuit, current generated is within predetermined limits and is derived to meet the requirements of governing product specification laying down the requirements of test button functioning.
[0057] In an implementation, when a user wants to use above disclosed RCCB in phase-to-phase application without neutral, he/she can connect the load as desired and shift the selector switch 414 to position 415V.In this configuration, if the test button 416 is pressed to check the health of RCCB, circuit between conductor R on incoming side and conductor B on load side would be completed and a current will flow through core balance current transformer (CBCT) 418. As a result, current shall be generated in secondary winding 420 of CBCT 418, which are connected to permanent magnet relay (PMR) 422. The current from secondary winding 420 of CBCT 418 can actuate the PMR 422, which is configured to trip the RCCB 400.
[0058] In another embodiment of the application of disclosed RCCB, if a user wants to use the RCCB in phase-to-neutral application, he/she can connectthe incoming power and load between conductor R and neutral 402, and shift the selector switch to position 240V. In this configuration, when user presses test button 416 to check the health of RCCB, circuit between conductor R on incoming side and neutral 402 on the load side would be completed and a current will flow through CBCT 418. As a result, current shall be generated in secondary winding 420 of the CBCT 418, which is connected to PMR 422. Current from the secondary winding 420 of the CBCT 418 can actuate the PMR 422, which is configured to trip RCCB.
[0059] Yet another embodiment of the present disclosure is illustrated in Fig. 5, which depicts an exemplary circuit diagram 500 of RCCB and provides more than two options to user while deploying it for use. The circuit 500 incorporates two selector switches, Selector Switch-1 514, and Selector Switch-2 518on either side of the test button 516. Selector mechanism of the present disclosure does not necessarily need to include two switches, and the proposed system/architecture can also bea single switch having multiple positions or any other manual or automatic selector device meeting circuit requirement. In the present configuration,Selector Switch-1 514, as in embodiment disclosed vide circuit diagram 400 in FIG. 4, bifurcates the circuit beyond test button 516 in twoconnecting sides of test button 516 to either conductor B 504 or neutral N 502 on load side, through resistances 510 and 512respectively.Selector Switch-1 514 can also have markings for each position indicating the selection such as 415Vand 240V.Selector switch-2 518, on the other hand,can connect on the other side i.e. side 2 of test button 516 to either conductor R or conductor Y on incoming side. Two positions of Selector Switch-2 can have markings R and Y to indicate conductors to which the circuit is connected in the corresponding position. One should appreciate that any phase can be configured to be selected through any of the switches, i.e., for instance, Selector Switch-2 can be used to select one of B or N, or R and B, among other like combinations. Switches, instead of being two way-switches, can also be configured as multi-way switches to enable selection of any phase/neutral. Any other construction/configuration of the switches is completely within the scope of the present disclosure.
[0060] In an embodiment of the present application, when a user wants to use above disclosed RCCB in three phase application without neutral, he/she can connect the load as desired and shift the Selector Switch-1 514 to position 415V. Selector Switch-2 518 can be placed in any position. In this configuration, if the user presses test button 516 to check the health of RCCB, circuit between two conductors on two sides of RCCB, either R and B or Y and B, depending upon the position of Selector Switch-2 518 can get completed. As a result, a current can flow through CBCT 520 generating current in secondary winding 522 of CBCT 520, which are connected to PMR 524. Current from secondary winding 522 of CBCT 520can actuate PMR 524, which is configured to trip RCCB.
[0061] In another embodiment of application of above RCCB, if a user wants to use the RCCB in phase to neutral application, he/shehas an option to connect load between conductor R and neutral or conductor Y and neutral. He/Shecan connect the load according to his/her choice and shift Selector Switch-2 518 to accordingly i.e. either R or Y depending upon conductor of choice. Simultaneously,the user can shift the selector switch-1 514 to position240V. In this configuration, if the test button 516 is pressed to check the health of RCCB, circuit between conductors R or Y on the incoming side, and neutral on the load side would be completed and a current will flow through core balance current transformer (CBCT)520, tripping the RCCB in sequence of operations as explained before.
[0062] It will be apparent to one skilled in art that above concept can be extended to provide more options to user such as connecting the load between B and neutral N and other such varying configurations and all such configurations are well within the scope of present disclosure.
[0063] FIG. 6(a) illustrates perspective view of an exemplary RCCB 600 incorporating test circuit 400 as illustrated in Fig. 4. The RCCB 600 incorporates a selector switch 604 for selecting option for operation using 3phases without neutral (415V) or phase R to neutral (240V). 606, 608, 610, and 612 are points for connecting R, Y, B phases and neutral respectively. 614 and 602 correspond to test button and circuit breaker respectively.
[0064] FIG. 6(b) illustrates an exemplary implementation of a RCCB 600 in three phase without neutral, wherein R Y and B phases have been connected to respective points and selector switch 604 shifted to 415V position.
[0065] Fig. 6(c), on the other hand, illustrates application of RCCB 600 in phase to neutral, wherein live conductor has been connected to point R along with neutral at point N and selector switch 604shifted to 240V position.
[0066] FIG. 7(a) illustrates a perspective view of an exemplary RCCB 700 incorporating test circuit 500 of FIG. 5. It incorporates a Selector Switch-1 704 for selecting option for operation using 3phases without neutral (415V) or a phase to neutral (240V). A second switch Selector Switch-2 706 provides an option to user to choose either R or Y for use withneutral.708, 710, 712 and 714 are points for connecting R, Y, B phases and neutral respectively. 716 and 702 correspond to test button and circuit breaker respectively.
[0067] FIG.7(b) illustrates application of RCCB 700 in three phase without neutral wherein R, Y, and B phases have been connected to respective points and Selector Switch-1704 shifted to 415V position. Selector Switch-2 can be in any of the two positions i. e. R or Y. FIG. 7(c), on the other hand, illustrates application of RCCB 700 in phase to neutral, wherein live conductor has been connected to point R along with neutral at point N and Selector Switch-1 704 shifted to 240V position and Selector Switch-2 shifted to position R in accordance with connection. In addition, Fig. 7(d) illustrates application of RCCB 700 in phase to neutral, wherein live conductor has been connected to point Y along with neutral at point N, and selector Switch-1 704 shifted to 240V position, and Selector Switch-2 shifted to position Y in accordance with connection.
[0068] FIGs. 8(a) and 8(b) show two exemplary prototypes 800 and 850, with FIG. 8(a) being configured for RCCB testing and having a selector switch 802, which can be moved left for selecting 240V (phase-to-neutral connection) and can be moved right for selecting 415V (phase-to-phase connection). Similarly, FIG. 8(b) is being configured for residual-current circuit breaker with overload protection (RCBO) testing and has a selector switch 852, which can be moved up for selecting 240V (phase-to-neutral connection) and can be moved down for selecting 415V (phase-to-phase connection).
[0069] FIG. 9 illustrates another exemplary prototype of an exemplary RCCB 900 incorporating test circuit 500 of FIG. 5. It incorporates a Selector Switch-1 902 for selecting option for operation using 3phases without neutral (415V) or a phase to neutral (240V). A second switch Selector Switch-2 904 provides an option to user to choose either R or Y for use with neutral.
[0070] The above description represents merely an exemplary embodiment of the present invention, without any intention to limit the scope of the present invention thereto. Various equivalent changes, alterations or modification based on the present invention are all consequently viewed as being embraced by the scope of the present invention.
[0071] As used herein, and unless the context dictates otherwise, the term "coupled to" is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms "coupled to" and "coupled with" are used synonymously. Within the context of this document terms "coupled to" and "coupled with" are also used euphemistically to mean “communicatively coupled with” over a network, where two or more devices are able to exchange data with each other over the network, possibly via one or more intermediary device.
[0072] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C …. and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

ADVANTAGES OF THE INVENTION
[0073] The present disclosure removes short comings in the currently available 4P RCCBs.
[0074] The present disclosure provides characteristics of phase to phase application as well as phase to neutral application in a single 4P RCCB.
[0075] The present disclosure provides 4P RCCB which can be used in any configuration without compromising safety requirements.
[0076] The present disclosure provides 4P RCCB which gives an option to user to select the configuration in which it is used.
[0077] The present disclosure reduces variety of 4P RCCB thereby helps users in better inventory management.
,CLAIMS:1. A test apparatus for testing a circuit for residual current comprising:
a selector mechanism configured to allow a user to select any of a phase-to-neutral connection or a phase-to-phase connection for testing, enabling said user to use same said test apparatus for both connections.
2. The apparatus of claim 1, wherein said circuit comprises any or a combination of RCCB, RCD, and RCBO.
3. The apparatus of claim 1, wherein said phase-to-neutral application configures a phase incoming conductor to be connected with a neutral load conductor.
4. The apparatus of claim 1, wherein said phase-to-phase application configures a phase incoming conductor to be connected with a phase load conductor.
5. The apparatus of claim 1, wherein saidselector mechanism is configured to enable selection of 415V option for testing of phase-to-phase connection and selection of 240V option for testing of phase-to-neutral connection.
6. The apparatus of claim 1, wherein saidselector mechanism is a switch.
7. The apparatus of claim 1, wherein saidselector mechanism creates a two-way bifurcation, each of said two-way bifurcation comprising a resistance, wherein one of said two-way bifurcation is selected by said user to enable one of said phase-to-neutral connection or said phase-to-phase connection for testing.
8. A test apparatus for testing a circuit for residual current comprising:
a first selector mechanism configured to allow a user to select any of a phase-to-neutral connection or a phase-to-phase connection for testing, enabling said user to use same said test apparatus for both connections; and
a second selector mechanism configured to allow said user to select an incoming phase for any of said phase-to-neutral connection or said phase-to-phase connection.
9. The apparatus of claim 8, wherein said selected incoming phase is one of a Red conductor, a Yellow conductor, and a Blue conductor.
10. The apparatus of claim 8, wherein said circuit comprises any or a combination of RCCB, RCD, and RCBO.