Claims:1. A residual current device comprising:
at least one flexible flag indicator component positioned into a housing of said device by using a flag indicator holder;
at least one moving contact;
at least one fixed contact, wherein said moving contact and said fixed contact is in closed condition during normal ON condition;
a solenoid plunger mechanically coupled to said flag indicator component and actuated to trigger an actuator to trip along with said flag indicator component and a knob profile, to provide an indication of trip signal and enabling said moving contact and said fixed contact to open.

2. The device as claimed in claim 1, wherein said flexible flag indicator component comprises:
a flexible curve profile operably coupled to said knob profile; and
a spring type structure which fits into a slot of said housing.

3. The device as claimed in claim 1, wherein said solenoid plunger retains its initial position due to at least one reset spring means.

4. The device as claimed in claim 2, wherein said spring type structure of said flexible flag indicator component is originally placed in a first position of said slot, during said normal ON condition.

5. The device as claimed in claims 4, wherein said spring type structure of said flexible flag indicator component displaces and gets locked in a second position of said slot, during tripped condition.

6. The device as claimed in claim 5, wherein said spring type structure of said flag indicator component flexes without moving out of said second position when said knob profile is rotated to OFF condition from said tripped condition.

7. The device as claimed in claim 6, wherein said knob profile overrides said flag indicator component for resetting said flag indicator component during OFF condition to ON condition.

8. A flexible flag indicator component for residual leakage in residual current device as claimed in claims 1-7, wherein said flexible flag indicator component includes a curve profile and operably couple to a solenoid plunger of said residual current device, for capturing of residual fault signal and provide trip flag indication.
, Description:TECHNICAL FIELD OF THE INVENTION

[0001] The present subject matter described herein, in general, relates to the field of fault indicator of residual current device, and more particularly, to the mechanical capturing of residual fault signal by a fault indicator housed within a residual current device.

BACKGROUND OF THE INVENTION

[0002] A residual-current device (RCD), or residual-current circuit breaker (RCCB), is a device that instantly breaks an electric circuit to prevent serious harm from an ongoing electric shock. Currently, all residual current devices are either passive or active. The passive residual current devices are those which trips in case of an earth leakage and does not trip when supply goes off. It remains in ON condition. The active residual current devices are those which trips in case of an earth leakage and also trips when supply goes off.

[0003] In typical voltage dependent residual breakers, tripping signal is given by only solenoid coil and magnetic plunger. In all residual current devices, the difference in the currents is detected by the core balanced current transformer (CBCT), where both phase and neutral are passed through the CBCT. Existing CBCT, solenoid and knob mechanism are used to achieve RCD performance.

[0004] Presently, only knob ON/OFF indication is only indication for fault in the residual-current devices and there is no compact trip flag indication for leakage fault. Therefore, due to malfunctioning of mechanism of ON/OFF knob, fault indication is not proper and then customers may get shock.

[0005] Thus, there exists a need to provide an additional true indication of fault to customer irrespective of mechanism knob ON/OFF position, which is independent of the breaker mechanism.

SUMMARY OF THE INVENTION

[0006] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

[0007] An object of the present invention is to provide the compact mechanical capturing of residual fault signal and giving trip flag indication through only one component of residual current device.

[0008] Another object of the present invention is to provide additional true leakage trip signal flag indication for leakage fault, which is independent of breaker mechanism.

[0009] Accordingly, in one aspect, the present invention provides a residual current device comprising:
at least one flexible flag indicator component positioned into a housing of said device by using a flag indicator holder;
at least one moving contact;
at least one fixed contact, wherein said moving contact and said fixed contact is in closed condition during normal ON condition;
a solenoid plunger mechanically coupled to said flag indicator component and actuated to trigger an actuator to trip along with said flag indicator component and a knob profile, to provide an indication of trip signal and enabling said moving contact and said fixed contact to open.

[0010] In another aspect of the present invention, there is provided a flexible flag indicator component for residual leakage in a residual current device, wherein said flexible flag indicator component includes a curve profile and operably couple to a solenoid plunger of said residual current device, for capturing of residual fault signal and provide trip flag indication
[0011] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0012] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:

[0013] Figure 1 illustrates flag indicator components and its features, in accordance with the subject matter of the present invention.

[0014] Figure 2 illustrates the assembly of flag indicator inside housing of residual current devices, in accordance with an embodiment of the present invention.

[0015] Figure 3 illustrates an arrangement of flag indicator, knob mechanism and contact system in normal ON condition, in accordance with an embodiment of the present invention.

[0016] Figure 4 illustrates an arrangement of flag indicator, knob mechanism and contact system in tripped condition, in accordance with an embodiment of the present invention.

[0017] Figure 5 shows an arrangement of flag indicator, knob mechanism and contact system in Trip to OFF condition, in accordance with an embodiment of the present invention.

[0018] Figure 6 illustrates an arrangement of flag indicator, knob mechanism and contact system in OFF to ON position, in accordance with an embodiment of the present invention present invention.

[0019] Figure 7 illustrates reset condition of flag indicator, in accordance with the indicator present invention.

[0020] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0021] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

[0022] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0023] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

[0024] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0025] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0026] Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

[0027] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0028] The present invention provides a compact mechanical arrangement for capturing of residual fault signal and giving trip flag indication through only one component of residual current devices. This single flag indication component is independent of breaker mechanism which takes signal from solenoid to show trip indication and reset through knob of product to show ON indication.

[0029] In one implementation, figure 1 shows the flag indicator components (1) and its features that may include spring action, ON-OFF and trip indication. The flexible flag indicator component includes a flexible curve profile operably coupled to the knob profile of the RCD, and a spring type structure which fits into a slot of the housing of the RCD.

[0030] In one implementation, figure 2 shows an assembly of the flag indicator (1) into a separate housing of residual current device product (2) .The flag indicator can be fixed into the housing (2) by a flag indicator holder (4). During normal ON condition, moving contact (6) and fixed contact (7) will be in a closed condition and a solenoid plunger (8) will be at the initial position and the flag component (1) is fixed in its original position (first position) as shown in figure 3. The position of reset spring (10) and solenoid reset spring holder (11) during and after tripping is as shown in figure 4.

[0031] In all residual current devices, the difference in the currents is detected by the core balanced current transformer (CBCT), where both phase and neutral are passed through the CBCT. In normal case, the currents values in phase and neutral are same hence there is no difference in currents. In case of an earth leakage, the difference in current is detected by the CBCT and current starts appearing at the CBCT secondary (S) which gives to solenoid to actuate.

[0032] In one implementation, as shown in figure 4, wherein the solenoid plunger travels to a position and starts to give signal to the actuator (9) of mechanism to trip along with the flag indicator (1) and knob (5) of the breaker mechanism will reach the trip position, thereby giving true indication of trip signal and thus moving contact (6) and fixed contact (7) will open from a closed position. The forward motion of the flag restricts at spring action feature of the flag indicator as shown in figure 4 into slot of housing (3). The flag indicator component (1) gets locked in new position (second position) as shown in figure 4. The solenoid plunger (8) will come back to its initial position due to the reset spring (10) in its assembly as shown in figure 5.

[0033] In one implementation, during said normal ON condition, the spring action type structure of the flexible flag indicator component (1) is originally placed in a first position of the slot of the housing, as shown in figure 3. During tripped condition, the spring type structure of the flexible flag indicator component displaces and gets locked in a second position of the slot, as shown in figure 4.

[0034] In one implementation, as shown in figure 5, wherein the knob profile (5) of breaker mechanism will be turned to OFF position from trip condition. The flag indicator component (1) flexes without moving out of its second position, when the knob profile (5) is further rotated to OFF position. The knob(5) will overcome the flag indicator (1) due to flexibility of the curve portion of the flag indicator(1) and corresponding reaction force acting on it creating counter clockwise rotation to flag indicator (1). The knob will reach the OFF position and in this condition too the flag indicator component will indicate trip signal.

[0035] In one implementation, as shown in figure 6, to reset the flag indicator, the knob profile (5) will be rotated from OFF to ON condition. The knob profile overrides the flag indicator component to reset it during OFF to ON. The knob (5) will create pressure on the flag indicator curve (1) portion and it will start showing that the residual current device is ON. The flag indicator (1) will reach to its original position (first position) as shown in figure 7.

[0036] Some of the important features of the present invention, considered to be noteworthy are mentioned below:
• The compact mechanical capturing of residual fault signal and giving trip flag indication through only one component of residual current device.
• A single flag indication component is independent of knob mechanism which takes signal from solenoid to show Trip indication and reset through knob.
• The single flag indication component will give true leakage fault indication which is independent of mechanism. Single component is taking trip signal directly from solenoid to give trip signal through flag. Knob of mechanism helps to reset this component to its original position during next ON operation.

[0037] Some of the non-limiting advantages of the present invention are mentioned below:
1. A combined arrangement for trip signal pick up and flag indication.
2. Ease of assembly inside housing
3. Trip signal is taken from solenoid
4. Reset of flag indication done by knob of mechanism
5. Ture leakage trip indication.
6. Leakage trip indication is independent of mechanism ON/OFF.
7. No additional reset spring is required

[0038] Although an arrangement of flag indicators within residual current devices and circuit breakers have been described in language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of the fault indicator arrangement of the residual current devices for providing true leakage fault indication which is independent of the breaker mechanism.