A leakage current and overcurrent protection device with leakage current fault indicator

Abstract

Leakage current and overcurrent protection device (100) comprises a main mechanism (14) configured to connect and disconnect a power supply in the device (100), a handle (9) connected with the main mechanism (14), a leakage current fault detection circuit (13) including a solenoid, a plunger (7), a leakage fault indicator (5) to indicate leakage current faults; an indicator latch (6) holding the leakage fault indicator (5); and a trip link (4) coupled with plunger (7). In operation, upon detection of a leakage current fault, the leakage current fault detection circuit (13) is configured to trigger electromagnetic force in the solenoid (16) and actuate the plunger (7). Then, the plunger (7) is configured to move the trip link (4) to release a trip lever (18) from the main mechanism (14) to disconnect the electrical power supply, and simultaneously push the indicator latch (6) to flag the leakage current fault indicator (5).

Description

A LEAKAGE CURRENT AND OVERCURRENT PROTECTION DEVICE WITH LEAKAGE CURRENT FAULT INDICATORFIELD OF THE INVENTION

[0001] Embodiments of the present invention generally relate to technologies for protection against faults in electrical power systems. Particularly, present disclosure relates to a leakage current and overcurrent protection device with leakage current fault indicator and test button.BACKGROUND OF THE INVENTION

[0002] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of it being mentioned in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.

[0003] Appliances installed in an electrical system or circuits require protection devices to ensure the safety of personnel and equipment. There are various types of protection devices available for this purpose. Among them, miniature circuit breakers or MCBs and residual current circuit breakers or RCCBs are widely used. Circuit breakers protect electrical circuits from damage caused by current surges by interrupting or breaking the current path between the input terminals and output terminals. A conventional miniature circuit breaker comprises a pair of contacts located in a main current path between a line terminal for connecting to a power supply and a load terminal for connecting to a load to be powered by the power supply.

[0004] Some of these protection devices have an indicator like components to show the supply is disconnected or is in ON state. But these protection devices do not have any provision to indicate that the cut off by a particular type of fault like leakage current fault. Besides, overcurrent protection and leakage current protection may also require two separate / independent devices.

[0005] Hence, there exists a need for a protection device that can provide protection for both overcurrent and leakage current with provision for indicating the associated fault. Such device should be able to address the limitations of MCBs and RCCBs by protecting against both the overcurrent and current leakage conditions with maximum electrical safety.

[0006] This background information is provided to make known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.SUMMARY OF THE INVENTION

[0007] The present invention relates to leakage current and overcurrent protection devices within the field of electrical safety. These devices may be commonly known as Miniature Circuit Breakers (MCBs) or Residual Current Circuit Breakers (RCCBs), or a combination thereof, which are designed to protect electrical circuits from damage caused by excess current from an overload or short circuit as well as to prevent electric shock from current leakage. It builds upon the applicant’s previous design as detailed in patent WO2023038556, titled "Improved and simplified multifunction 2-lever mechanism and improved miniature circuit breaker." The present invention extends the technological advancements of the WO2023038556. It incorporates a selection of the established components such as a handle for operational command, a contact support lever for managing the position of electrical contacts, magnetic coil, bimetallic strips, and the tripping mechanism, which are the elements that are utilized in circuit interruption devices for their proven reliability and effectiveness. While these components form a part of the present patent application, it is important to note that the inventiveness of the present invention lies in completely different aspects, focusing on distinctive attributes and functionalities that are not contemplated in the earlier patent, particularly in the domain of leakage current detection and indication.

[0008] According to a first aspect of the present invention, there is provided a leakage current and overcurrent protection device with leakage current fault indicator. The device comprises, but not limited to, a main mechanism configured to connect and disconnect a power supply in the device; a handle connected with the main mechanism, the handle being movable between an ON condition and an OFF condition to operate the main mechanism; a leakage current fault detection circuit including a solenoid; a plunger connected with the solenoid; a leakage fault indicator to indicate leakage current faults; an indicator latch holding the leakage fault indicator; and a trip link coupled with plunger. During operation, in the event of leakage current fault detection, the leakage current fault detection circuit is configured to trigger an electromagnetic force in the solenoid and actuate the plunger. Thereafter, the plunger is configured to move the trip link to release a trip lever from the main mechanism to disconnect the electrical power supply, and simultaneously push the indicator latch to flag the leakage fault indicator.

[0009] In accordance with an embodiment of the present invention, the device further comprises a test button assembly. The test button assembly includes, but not limited to, a test button, a pair of testing plates connected to the leakage current fault detection circuit and a compression spring configured between the test button and the pair of testing plates. Herein, upon pressing of the test button, the compression spring is configured to short the pair of testing plates to trip the device, thereby simulating a leakage current fault condition for verifying the working condition of the device.

[0010] In accordance with an embodiment of the present invention, the compression spring is configured to keep the test button in position during normal condition, and during testing, is configured to short the phase and neutral terminals of the electrical power supply to simulate fault condition.[Oil] In accordance with an embodiment of the present invention, the device further comprises a device housing made of a material selected from plastic polymers, poly amide or its derivates to make a robust and thermally stable structure.

[0012] In accordance with an embodiment of the present invention, in the event of the leakage current fault, the leakage current fault indicator rotates and is exposed outside through a window (31) provided in the device housing.

[0013] In accordance with an embodiment of the present invention, wherein the handle is rotated upward or downward manually to turn ON and turn OFF the device.

[0014] In accordance with an embodiment of the present invention, the trip lever operates in conjunction with the main mechanism and the handle, enabling precise and reliable tripping mechanism in response to leakage current, thereby enhancing electrical safety and operational integrity within the device.

[0015] In accordance with an embodiment of the present invention, further comprising one or more input and output ports for an electrical power supply configured to receive an electrical power supply with one input phase one input neutral and one output phase one output neutral.

[0016] According to another aspect of the invention, there is provided a test button assembly for a leakage current and overcurrent protection device. The test button assembly comprises a test button; a pair of parallel testing plates connected to the leakage current fault detection circuit; and a compression spring assembled with the test button at one end and is grounded on an upper testing plate of the pair of parallel testing plates. Herein, the compression spring has an extended armsuspended between the pair of parallel testing plates. In that sense, upon pressing of the test button, the extended arm of the compression spring is configured to move and contact a lower testing plate of the pair of parallel testing plates, thereby shorting the pair of testing plates to simulate a leakage current fault condition for verifying the working condition of the device.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular to the description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, the invention may admit to other equally effective embodiments. These and other features, benefits and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

[0018] Fig. 1 A illustrates a leakage current and overcurrent protection device (hereinafter referred to as ‘the device’), in accordance with an embodiment of the present invention;

[0019] Fig. IB illustrates a side view of the device of Fig. 1A without a cover to show the internal components of the device, in accordance with an embodiment of the present invention;

[0020] Fig. 2A illustrates a detailed view of the internal components of the device responsible for the leakage current detection and protection, in accordance with an embodiment of the present invention;

[0021] Fig. 2B illustrates a leakage current fault detection circuit including a solenoid-plunger assembly, in accordance with the present invention;

[0022] Fig. 2C illustrates an exploded view of the solenoid-plunger assembly, in accordance with an embodiment of the present invention.

[0023] Fig. 2D illustrates an indicator latch of the device shown in Fig. 2A, in accordance with an embodiment of the present invention;

[0024] Fig. 2E illustrates a leakage fault indicator of the device shown in Fig. 2A, in accordance with an embodiment of the present invention;

[0025] Fig. 2F illustrates a trip link of the device shown in Fig. 2A, in accordance with an embodiment of the present invention;

[0026] Fig. 2G illustrates a main mechanism of the device shown in Fig. 2A, in accordance with an embodiment of the present invention;

[0027] Fig. 2H illustrates a test button assembly of the device shown in Fig. 2A, in accordance with an embodiment of the present invention;

[0028] Fig. 3A-3B illustrate an operation of the device for leakage current protection, in accordance with an embodiment of the present invention; and

[0029] Fig. 4A-4B illustrate an operation of the test button assembly for simulating the leakage current fault in the device, in accordance with an embodiment of the present invention.DETAILED DESCRIPTION OF THE DRAWINGS

[0030] The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description.

[0031] While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims. As used throughout this description, the word "may" is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense, (i.e., meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term"comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.

[0032] This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.

[0033] Figure 1A illustrates a leakage current and overcurrent protection device (hereinafter referred to as the device (100)), in accordance with an embodiment of the present invention. Figure 1A displays a perspective view of the device (100) showing the components that are visible from outside a device housing (30). As shown in figure 1A, the device (100) comprises, but not limited to, a handle (9), a test button assembly (10), a window (31) for a leakage current fault indicator (5), one or more input and output ports (Lin, Lout, Nout) for an electrical power supply. These components are interconnected electromechanically, and their inter-dependent functioning enables the present invention to facilitate leakage current and overcurrent protection. This will be understood better with reference to figure IB that offers more insight to the arrangement of above components inside the device (100) housing by removing a side cover (11). In one embodiment, the device (100) housing and the cover (11) may be made of a material selected from, but not limited to, plastic polymers, poly amide or its derivates to make a robust and thermally stable structure.

[0034] Figure IB illustrates a side view of the device (100) of Figure 1A without the cover (11) to show the internal components of the device (100), in accordance with an embodiment of the present invention. As shown in figure IB, the device (100) further includes, but not limited to, a main mechanism (14) responsible for engaging and disengaging the power supply. This main mechanism (14) is operatively linked to the handle (9) that transitions between an ON and an OFF condition to control the power connectivity. Integrated within the device (100) is a leakage current fault detection circuit (13) that houses a solenoid. A plunger (7) is associated with this solenoid,and together, they play a role in the detection process. Additionally, there is a leakage fault indicator (5) purposed for signaling the presence of leakage currents, which is held in place by an indicator latch (6). Completing the assembly is a trip link (4), which is engaged with the plunger (7) to form the complete circuit protection mechanism. The detailing of the above-mentioned components and their interconnection of the above components will be further explained in subsequent figures.

[0035] Additionally, Figure IB illustrates the presence of a magnetic coil (12) and bimetallic strips (15) . These components are typically associated with overcurrent and short circuit protection. As generally known in the art, the magnetic coil (12) , when energized by an overcurrent or a short circuit condition, generates a magnetic field strong enough to actuate the trip mechanism, albeit this function remains secondary to the leakage detection feature. Complementing the magnetic coil (12) are bimetallic strips (15) , typically employed in thermal overload protection. These strips are constructed from two metals with different coefficients of thermal expansion, bonded together. As the current exceeds normal levels, the resultant heating causes the bimetallic strip to bend, initiating the tripping action. The bending movement is mechanically linked to the trip mechanism, which disconnects the power supply to prevent damage from sustained overcurrent. Both the magnetic coil (12) and the bimetallic strips (15) are connected in series with the power circuit, poised to respond to their respective fault conditions.

[0036] While they are included in the overall schematic and contribute to the device (100)'s protective functions, they do not directly relate to the core feature of leakage current fault detection and indication, which is the primary focus of this invention. Their inclusion, however, ensures a comprehensive protection system, addressing a variety of electrical safety concerns.

[0037] Figure 2A illustrates a detailed view of the internal components of the device (100) responsible for the leakage current detection and protection, in accordance with an embodiment of the present invention. As shown in Figure 2A, a main mechanism (14) tasked with the regulation of the power supply within the device (100). This main mechanism (14) is operationally connected to a handle (9), which is manually adjustable to an ON or an OFF position, thereby controlling the activation or deactivation of the power flow. The handle's design and its operational connectivity to the main mechanism (14) are detailed, ensuring clarity in manual operation.

[0038] Within this configuration, the invention incorporates the leakage current fault detection circuit (13) that encompasses a solenoid. The leakage current fault detection circuit (13) has been shown in detail in figure 2B. As shown in figure 2B, the leakage current fault detection circuit (13) may be typically embodied as a printed circuit board (PCB) outfitted with various electroniccomponents configured to monitor electrical flow anomalies suggestive of leakage currents including Earth fault conditions. The leakage current fault detection circuit (13) is likely to include sensors, Current Transformer (CT) etc. capable of detecting imbalances between the live and neutral wires, operational amplifiers to enhance the signal quality of the detected imbalances, and a control logic to interpret these signals and determine the presence of a fault condition. The CT's secondary winding may function as a sensing coil, integral in monitoring the balance of currents flowing through the conductors.

[0039] Accompanying this setup, is a sensitive solenoid (16), that may be connected electrically to the secondary winding of the CT. This solenoid (16) plays a pivotal role in the mechanism, being primed to react to any current induced in the CT's secondary winding due to an imbalance in the line and neutral currents. Although the PCB may also house additional components like sensors, amplifiers, a solenoid (16) control circuit, control logic etc., but the CT and solenoid (16) are key in detecting the leakage current fault, including the Earth fault conditions. The precise nature of these components and their interconnections are tailored to ensure sensitivity to leakage currents, enabling the device (100) to respond promptly and reliably to protect the electrical system it monitors.

[0040] Further as show in figures 2A and 2B, the solenoid (16) is further assembled with the plunger (7), and this solenoid-plunger assembly (17) forms an integral part of the protection process. Figure 2C illustrates an exploded view of the solenoid-plunger assembly (17), in accordance with an embodiment of the present invention. As shown in figure 2C, the solenoid (16) is depicted as a cylindrical coil housing, designed to generate a magnetic field upon electrical activation. The solenoid (16) generally comprises a coil of wire wound around a cylindrical core. The core is typically made of a ferromagnetic material, such as iron or steel, which enhances the magnetic properties. When the current flows through its coil, the magnetic field magnetizes the core, causing it to become magnetic as well. If there is a movable ferromagnetic component, such as a plunger (7) or a slug inside the core, it will be attracted towards the magnetic field in the core. The attractive force between the coil's magnetic field and the ferromagnetic component causes the movable part to move. This motion can be linear or rotational, depending on the solenoid (16) design and application. The strength of the magnetic field and the characteristics of the core material determine the force exerted by the solenoid (16) and its overall performance.

[0041] Continuing from figure 2B, there may be two mounting brackets with through-holes, to provide a means for secure attachment to the leakage current fault detection circuit (13) (or the PCB). These brackets ensure that the solenoid (16) remains stationary during normal operation.Extending from the coil housing are terminal ends, likely for electrical connection to the activation circuit.

[0042] The depicted plunger (7) in the figure 2C is a rod-like element, designed to slide into the coil housing. It features an extended arm that terminates in a T-shaped end, which may serve as an interface for mechanical linkage to other components, such as the trip link (4) and the indicator latch (6). When the solenoid (16) is energized, the plunger (7) is drawn into the coil, creating linear motion that can be harnessed to perform a variety of functions, such as triggering a tripping mechanism (solenoid-plunger- trip link) in the device (100). This interconnection between the solenoid (16) and plunger (7) is fundamental to converting electrical signals into mechanical actions within the device (100).

[0043] The device (100) then include the leakage fault indicator (5), designed to alert users to leakage current faults, which is secured by an indicator latch (6). The indicator latch (6) and the leakage fault indicator (5) have been individually illustrated in Figures 2D-2E, respectively, in accordance with an embodiment of the present invention.

[0044] As shown in Figure 2D, the indicator latch (6) may have a distinct inverted T-shaped profile. It starts with a flat, horizontal upper segment transitioning into a vertical descending segment through an approximately right-angled bend. The descending segment maintains a uniform width but features a complex profile with two distinct contours: an outward flange near the top, likely serving as a catch or guide, and an inward curve towards the bottom, ending in a pointed tip which may function as a precise engagement or alignment feature. A concave indentation on one side of the vertical segment enables the design for mechanical compliance or intercomponent interaction. The lower part of the latch extends outward at an obtuse angle, culminating in a bifurcated end with chamfered inner edges, indicative of a mechanism to ensure guided and secure engagement with the plunger (7) as well as the leakage fault indicator (5).

[0045] Moving on to Figure 2E, the leakage fault indicator (5) is connected in between the indicator latch (6) of Figure 2D as well as the handle (9). It features a cylindrical base with a central, circular aperture, presumably to allow rotational movement around an axis. Extending radially from this base are several protrusions with specialized contours, each exhibiting a beveled edge, which may facilitate a snap-fit or a lock-and-release mechanism with the indicator latch (6). Above this base, a curved, elongated arm extends diagonally, terminating in a flat, widened end that likely serves as the visual indicator flag. The arm's upper surface is smooth and slopes gently upward, creating an ergonomic profile for actuation. Grooves and ridges on the cylindrical basesuggest points of contact for the indicator latch (6) and the handle (9), designed to ensure precise engagement and release during operation, allowing the indicator to rotate visibly when the latch is actuated. The overall design integrates functional geometry with the mechanical requirements for consistent and reliable movement within the device (100).

[0046] In accordance with an embodiment of the present invention, it is often a colored flag, provides a visual indication of the device’s status. It can show whether the device (100) is functioning correctly, or has been tripped due to a fault. This visual confirmation helps users quickly identify the state of the device (100) and take appropriate actions accordingly. The presence of a visible leakage current fault indicator (5) assists user or maintenance personnel or a skilled addressee in quickly identifying a tripped device. Instead of having to rely solely on electrical measurements, they can visually confirm the fault indication and take appropriate measures to resolve the issue promptly. A user or a skilled addressee can verify its response and working condition by simple visual inspection, ensuring that it is in compliance with the required standards and regulations in the electrical system in which it is installed.

[0047] Furthermore, Figure 2F illustrates a trip link (4) of the device (100), in accordance with an embodiment of the present invention. A trip link (4) is mechanically engaged with the plunger (7), forming a part of the sequence that responds to leakage current faults. As shown in figure 2F, it exhibits an asymmetric profile consisting of two main portions: an upper section with an aperture and a lower circular segment. The upper part is elongated, with an oblong opening through which the plunger (7) is intended to be inserted, suggesting that the trip link (4) is mounted at an angle relative to the plunger (7).

[0048] The lower section of the trip link (4) embodies a circular form with a central void, indicative of its role as a pivot point. This circular element is connected to the upper section via a short, angled bridge that provides the necessary offset, ensuring the trip link (4) rotates upon the actuation of the plunger (7). The overall geometry of the trip link (4), with its combination of angular and rounded elements, is engineered to establish a specific mechanical relationship with the plunger (7), ensuring secure engagement and precise movement.

[0049] Returning to Figure 2A, the trip link (4) is further connectable with the main mechanism (14) provided proximal to the trip link (4). The main mechanism (14) is an assembly of a number of components inter-connected within the device (100). The main mechanism (14) has been separately shown in figure 2G, in accordance with an embodiment of the present invention.

[0050] As shown in figure 2G, the main mechanism (14) includes a trip lever (18) that is connected with a support (19) at one end, and a moving contact (22) at the other end. The trip lever (18) is proximal to the trip link (4). In between, there is a central circular portion (21) that acts as a pivot point of the main mechanism (14) , about which it rotates. One or more torsion springs (20) are also included in the mechanism to facilitate rotation as well as to ensure that the components return to their normal position. The main mechanism (14) is also connected with the handle (9) via a connecting rod (23) disposed between the support (19) and the handle (9).

[0051] Furthermore, Figure 2H illustrates another important component of the present invention i.e., the test button assembly (10) and its constituent components i.e., the test button (1), the compression spring (2) and a pair of parallel testing plates (3). The test button (1) may be provided just below the handle (9) of the device (100) or anywhere else outside the casing (30) where it is easily accessible from outside the device casing (30). As shown in Figure 2H, the test button assembly (10) is centered around the test button (1), which is a rectangular push-button that is the user interface for initiating the test function. This test button (1) interacts with a compression spring (2), which is configured to provide resistance and return the button to its original position after being pressed.

[0052] The compression spring (2) is unique in design, featuring an extended arm. The compression spring (2) is assembled with the test button (1) at one end and is grounded on an upper testing plate of the pair of parallel testing plates (3). The pair of parallel testing plates are electrically connected to the leakage current fault detection circuit (13) and are integral to the testing process. The extended arm of the compression spring (2) is suspended between the pair of parallel testing plates (3).

[0053] The construction of this test button assembly (10) allows for a direct and simple method to manually verify the functionality of the leakage current fault detection circuit (13). When the test button (1) is pressed, the compressions spring's (2) extended arm moves within the confines of the testing plates (touching the lower testing plate), momentarily altering the circuit's condition to simulate a fault, which in turn should trigger the tripping mechanism if the device (100) is functioning correctly.

[0054] The method of operation:

[0055] Before, getting into the operation or working of the device (100), it is important to understand that the leakage current mentioned herein, refers to the current flowing through unintended paths in a circuit. In some cases, the leakage current can flow from the supply to theneutral termed as earth leakage current. Therefore, they can be used interchangeably. The leakage current that flow occur due to insulation degradation, electronic component defects, or other factors. Leakage current is typically measured between the electrical power supply in the conductors and the neutral conductor connected in an electrical circuit.

[0056] The fault condition may also be understood in the following exemplary scenario. When the load is connected to the supply through the device (100), the line and neutral conductors passes through CT (Current Transformer). In this arrangement, the secondary winding of CT is used as a sensing coil and is electrically connected to the sensitive solenoid, the operation of which triggers the tripping mechanism. When the line and neutral currents are balanced, as in a healthy circuit, they produce equal and opposite magnetic fluxes in the CT core with the result that there is no current generated in the secondary winding. However, when the line and neutral currents are not balanced, they create an out-of-balance flux. This will induce a current in the secondary winding which is used to actuate the tripping mechanism.

[0057] Figures 3A-3B illustrate an operation of the device (100) for leakage current protection, in accordance with an embodiment of the present invention.

[0058] Herein, Figure 3A illustrates a normal operation of the device (100) the indicator latch (6) holds the leakage current fault indicator (5) in place, keeping the trip lever (18) connected with the trip link (4) and the moving contact (22) of the main mechanism (14) in electrical contact with the fixed contact (24) of the device (100). This allows electrical current to flow through the device (100) without interruption.

[0059] However, when a fault condition occurs, the leakage fault detection circuit (13) in the device (100) senses the fault. Accordingly, whenever a fault condition arises, the leakage current fault detection circuit (13) is configured to trigger an electromagnetic force in the solenoid (16) and actuates the plunger (7).

[0060] Now referring to the figure 3B, force generated in the solenoid pulls the plunger (7). Since the trip link (4) is coupled with plunger (7), so when the trip link (4) is pulled by plunger (7), it rotates with respect to center and causes the trip lever (18) to open the circuit breaker by disconnecting the fixed contact (24) and the moving contact (22). As can be observed from the drawing, there is a visible gap between the trip lever (18) and the trip link (4); as well as between the fixed contact (24) and the moving contact (22). The movement of trip lever (18) also causes the connecting rod (23) to rotate the handle (9) to an OFF condition.

[0061] Simultaneously, the plunger (7) is configured to simultaneously push the indicator latch (6) to release the leakage current fault indicator (5). The leakage current fault indicator (5) rotates and is exposed outside through the window (31) provided on the front side in the device (100) housing. The leakage current fault indicator (5) is responsible for signaling a leakage current fault, regardless of the position of the handle (9). The leakage current fault indicator (5) allows a user to monitor the status of the device (100) through a hole or a window (31) without opening the device (100) housing.

[0062] Now, for re-configuring the device (100) for normal operation, the trip lever (18), the handle (9), and the leakage current fault indicator (5) are returned to their original position to reset the device (100). This way, the device (100) would be configured effectively detect and respond to the leakage current faults once again.

[0063] Method of operation of test buton assembly (10):Figure 4A-4B illustrate an operation of the test button assembly (10) for simulating the leakage current fault in the device (100), in accordance with an embodiment of the present invention. The function of test button (1) arrangement is to simulate the fault condition to check the function of the device (100) in case of residual or leakage current fault. As shown in figure 4A, the test button (1) is held in position by a compression spring (2) between the pair of parallel testing plates (3). The pair of parallel testing plates (3) are connected to the leakage current fault detection circuit (13) by a pair of conductors or wires. The arrangement of test button (1) with the compression spring (2) is configured in such a way that one end of it rests on the upper testing plate and the extended arm hangs in an initial position above the lower testing plate.

[0064] Now the testing process has been illustrated in figure 4B, in accordance with an embodiment of the present invention. As shown in figure 4B, when the test button (1) is pressed, the extended arm of the compression spring (2) makes contact with the lower testing plate, which causes shorting of the pair of parallel testing plates (3), thereby simulating the fault condition. This causes the solenoid-plunger assembly (17) to pull the trip link from the trip lever (18) to open the circuit breaker by disconnecting the fixed contact (24) and the moving contact (22). As can be observed from the drawing, there is a visible gap (illustrated by arrows) between the trip lever (18) and the trip link (4); as well as between the fixed contact (24) and the moving contact (22). The movement of trip lever (18) also causes the connecting rod (23) to rotate the handle (9) to an OFF condition. Simultaneously, the leakage fault current indicator is also flagged to indicate the detection of leakage current fault. This is similar to the method of operation explained in figures 3A-3B, expect that the leakage current fault is simulated by the test button assembly.

[0065] Herein, it will be appreciated by a skilled addressee that the compression spring (2) is configured to serve two purposes; one is keeping the test button (1) in position and second is shorting a pair of parallel testing plates (3). The loaded test button (1) with the compression spring (2) allows users to easily test the functionality of the device (100). When the test button (1) is pressed, it simulates a fault condition and verifies whether the device (100) trips, as expected. The compression spring (2) mechanism ensures that the test button (1) returns to its original position after being pressed, ready for future testing.

[0066] In this manner, the test button (1) and leakage current fault indicator (5) can also play a crucial role in compliance verification during electrical inspections or safety audits. The device (100) can be easily tested for functionality by pressing the test button (1).

[0067] The present invention offers a number of advantages. Firstly, the present invention provides an effective alternative to traditional protection devices like Miniature Circuit breakers and Residual Current Circuit breakers as it offers a common device for both leakage current and overcurrent current protection. Additionally, the introduction of the unique tripping mechanism, the leakage current fault indicator, and test button with the spring mechanism in the device provides convenience, visual confirmation, enhanced safety, ease of maintenance, and compliance verification. This contributes to the overall effectiveness and reliability of the device in protecting against electrical faults and residual currents. Such an arrangement offers another advantage that it requires minimum tripping force, and smaller sized components, therefore, it is able to offer a compact design as compared to prior art.

[0068] Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and the appended claims.

Claims

Claims:

1. A leakage current and overcurrent protection device (100) with leakage current fault indicator (5), the device (100) comprising: a main mechanism (14) configured to connect and disconnect a power supply in the device (100); a handle (9) connected with the main mechanism (14), the handle (9) being movable between an ON condition and an OFF condition to operate the main mechanism (14) ; a leakage current fault detection circuit (13) including a solenoid (16); a plunger (7) connected with the solenoid; a leakage fault indicator (5) to indicate leakage current faults; an indicator latch (6) holding the leakage fault indicator (5); and a trip link (4) coupled with plunger (7); wherein, in the event of leakage current fault detection, the leakage current fault detection circuit (13) is configured to trigger an electromagnetic force in the solenoid (16) and actuate the plunger (7); wherein the plunger (7) is configured to move the trip link (4) to release a trip lever (18) from the main mechanism (14) to disconnect the electrical power supply, and simultaneously push the indicator latch (6) to flag the leakage fault indicator (5).

2. The device (100) as claimed in claim 1, further comprising a test button assembly (10), including a test button (1), a pair of parallel testing plates (3) connected to the leakage current fault detection circuit (13) and a compression spring (2) configured between the test button (1) and the pair of parallel testing plates (3); wherein upon pressing of the test button (1), the compression spring (2) is configured to short the pair of parallel testing plates (3) to trip the device (100), thereby simulating a leakage current fault condition for verifying the working condition of the device (100).

3. The device (100) as claimed in claim 2, wherein the compression spring (2) is configured to keep the test button (1) in position during normal condition, and during testing, is configured to short the phase and neutral terminals of the electrical power supply to simulate fault condition.

4. The device (100) as claimed in claim 1, further comprising a device housing (30) made of a material selected from plastic polymers, poly amide or its derivates to make a robust and thermally stable structure.

5. The device (100) as claimed in claim 1, wherein in the event of the leakage current fault, the leakage current fault indicator (5) rotates and is exposed outside through a window (31) provided in the device (100) housing.

6. The device (100) as claimed in claim 1, wherein the handle (9) is rotated upward or downward manually to turn ON and turn OFF the device (100).

7. The device (100) as claimed in claim 1, wherein the trip lever (18) operates in conjunction with the main mechanism (14) and the handle (9), enabling precise and reliable tripping mechanism in response to leakage current, thereby enhancing electrical safety and operational integrity within the device (100).

8. The device (100) as claimed in claim 1, further comprising one or more input and output ports for an electrical power supply configured to receive an electrical power supply with one input phase one input neutral and one output phase one output neutral.

9. A test button assembly (10) for a leakage current and overcurrent protection device, comprising: a test button (1); a pair of parallel testing plates (3) connected to the leakage current fault detection circuit (13); and a compression spring (2) assembled with the test button (1) at one end and is grounded on an upper testing plate of the pair of parallel testing plates (3); wherein the compression spring (2) has an extended arm suspended between the pair of parallel testing plates (3); wherein upon pressing of the test button (1), the extended arm of the compression spring (2) is configured to move and contact a lower testing plate of the pair of parallel testing plates (3), thereby shorting the pair of parallel testing plates (3) to simulate a leakage current fault condition for verifying the working condition of the device (100).

10. The device (100) as claimed in claim 9, wherein the compression spring (2) is configured to keep the test button (1) in position during normal condition, and during testing, is configured to short the phase and neutral terminals of the electrical power supply to simulate fault condition.

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