Claims:1. A modular earth leakage module (3, 4) comprising:
A CBCT housing module (5) configured to house a core balanced current transformer assembly (8);
A card housing module (6) configured to house a microprocessor card (11);and
An isolation-box module (7) configured to house an isolation box (15) that comprises a first set of contacts having power tappings from line conductors(9) of a circuit breaker required to power up the microprocessor card (11) and a second set of contacts having tapping connection to the microprocessor card(11), wherein the CBCT housing module (5), the isolation-box module (7), and the card housing module (6) are configured such that the modular earth leakage module(3,4) is configured for both three pole (1)as well as four pole circuit breaker(2).

2. The modular earth leakage module (3, 4) of claim 1, wherein the earth leakage module(3, 4) is a L-shaped three pole earth leakage module (3).

3. The modular earth leakage module (3, 4) of claim 1, wherein the earth leakage module(3, 4) is a L-shaped four pole earth leakage module (4).

4. The modular earth leakage module(3, 4) of claim 1, wherein the CBCT housing module (5) further comprises a voltage tapping means (10) from the line conductors (9) for powering up of the microprocessor card (11), wherein voltage is tapped from the line conductors (9) of the circuit breaker on line side of the modular earth leakage module (3, 4).

5. The modular earth leakage module(3, 4) of claim 1, wherein the microprocessor card (11) comprises settings comprising one or a combination of current settings (12), time settings (13), and trip indication(14).

6. The modular earth leakage module (3, 4) of claim 1, wherein the isolation box (15) comprises a mechanism that isolates the first and second contacts in case of dielectric test so that high voltage does not appear at the terminals on the microprocessor card (11).

7. The modular earth leakage module(3, 4) of claim 1, wherein, for the four pole circuit breaker(2), the CBCT housing module (5), the card housing module (6), and the isolation-box module (7) are integrated by means of slide fit and screw joining, and wherein, for the three pole circuit breaker(1), CBCT housing module (5),and the card housing module (6) are integrated by means of slide fit & screw joining and the isolation-box module (7) is not required.

8. The modular earth leakage module(3, 4) of claim 1, wherein the CBCT housing module (5) has provision of voltage tapping (10) from the line conductors (9) of the circuit breaker (1, 2) on the line side of earth leakage module (3, 4) in mounted condition.

9. The modular earth leakage module(3, 4) of claim 1, wherein the CBCT housing module (5) has an elongated feature (5b) along its depth so as to engage with the circuit breaker, wherein the elongated feature (5b) serves as mechanical joining between the earth leakage module (3, 4) as well as the circuit breaker (1, 2) respectively.

10. The modular earth leakage module(3, 4) of claim 1, wherein the elongated feature (5b) has T-provision (5c) on its upper end that locks the earth leakage module (3, 4) in position and prevents its translational motion along height direction of a circuit breaker (1, 2).

11. The modular earth leakage module(3, 4) of claim 1, wherein the CBCT housing module (5) has a hexagonal feature (5d) that engages with the slot in the circuit breaker (1, 2) to prevent translational motion along height direction of a circuit breaker (1, 2).

12. The modular earth leakage module(3, 4) of claim 1, wherein the CBCT housing module (5) has provision (5e) of keeping the voltage tapping wires (10) intact and shielded by means of plastic casing (16), wherein the plastic casing (16) ensures that customer termination does not interfere with the voltage tapping wires (10).

13. The modular earth leakage module (3, 4) of claim 1, wherein the CBCT housing module (5) has slot (5f) to accommodate the core balanced current transformer (8).

14. The modular earth leakage module (3, 4) of claim 1, wherein the core balanced current transformer (8) is designed considering termination required for a four pole circuit breaker (2) or a three pole circuit breaker (1).

15. The modular earth leakage module(3, 4) of claim 1, wherein the CBCT housing module (5) has a knockout feature (5g), wherein, in case of modular four pole earth leakage module (4), the feature (5g) is knocked out before the assembly so as to integrate internal elements in the CBCT housing module (5), the card housing module (6), and the isolation-box module (7), and wherein in case of modular three pole earth leakage module (3), the CBCT housing module (5) is used as is with the feature (5g) intact.

16. The modular earth leakage module (3, 4) of claim 1, wherein when modular three pole earth leakage module (3) is configured for a three pole circuit breaker (1), the voltage tapping means (10) for the fourth pole is not assembled in the CBCT housing module (5).

17. The modular earth leakage module(3, 4) of claim 1, wherein the microprocessor card (11) has a slot (11a) and is placed vertically in the card housing module (6) and is constrained in the breaker’s (1, 2) width-height direction at the bottom side by means of locking feature (6a) given in the card housing module (6), and wherein the microprocessor card (11), on the top side, has a slot (11b) that gets locked by means of feature (17a) given in the card cover (17).

18. The modular earth leakage module(3, 4) of claim 1, wherein the card housing module (6) has features (6b) & (6c), wherein the feature (6b) of card housing module (6) slides through feature (7a) of the isolation-box module (7) and gets locked by T-shaped feature given in feature (6c) of the card housing module (6), wherein upon sliding the isolation-box module (7) over the card housing module (6), feature (6d) of card housing module (6) comes under feature (7b) given in the isolation-box module (7).

19. The modular earth leakage module(3, 4) of claim 1, wherein the isolation-box module (7)houses the isolation box (15) only in case of modular four pole earth leakage module (4) for a four pole circuit breaker (2), and wherein the isolation-box module (15) is not connected in case of a modular three pole earth leakage module (3).

20. The modular earth leakage module (3, 4) of claim 1, wherein a top cover (19, 20) is configured for earth leakage modules (3, 4) for both three pole (1) and four pole circuit breaker (2), wherein the top cover (20) comprises a window (20a) that has a flapper (22) to enable better view while terminating cables at customer end, wherein the isolation box (15) is accessible through window (20b).
, Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to circuit breakers. In particular, the present disclosure relates to a modular earth leakage add-on module for circuit breakers.

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] Circuit breakers are widely used in domestic, commercial, and light industrial installations. Circuit breakers provide protection for electrical systems from electrical fault conditions such as overload, short circuits and under voltage conditions. A circuit breaker is an automatically operated electric switch designed to detect fault condition and immediately interrupt the current flow, either instantaneously or with time-delay, usually of few milliseconds. Unlike a fuse, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers come in various sizes ranging from small ones that are used to protect individual house-hold appliance up to large switchgear designed to protect high voltage circuits feeding an entire city. In addition to fault conditions as mentioned above, there can also be stray voltages on metal enclosures of electrical equipment causing leakage currents to flow through parts which are actually not meant to be live, which can be fatal to human life, commonly called as electrical shock and even result in electrocution.
[0004] Earth leakage modules are designed to disconnect the circuit if there is any leakage current. Earth leakage modules can detect leakage current typically from setting as low as 30 milliamperes to several amperes. There are earth leakage modules which can detect leakage currents typically 5-30 milliamperes & disconnect quickly in time much lesser than 25-40 milliseconds, and thus preventing electrocution. There are earth leakage modules with low sensitivities and intentionally slower responses designed to protect equipment or avoid risk of electric fires, but not disconnect unnecessarily the equipment with greater leakage currents in normal operation.
[0005] An earth leakage module basically consists of a core balanced current transformer. The earth leakage module is connected such that all the phase conductors of the circuit breaker will pass through core balanced current transformer. In case of fault free system, flux induced by each of the phase conductor will cancel each other, and the net resultant magnetic flux induced will be nil. As such, there will no secondary voltage induced across the secondary of the CBCT. In case of any residual current flowing through the conductor, residual flux present in the CBCT will induce a secondary voltage across its secondary.
[0006] The earth leakage modules are currently available as integrated as well as add-on modules. The integrated earth leakage modules have the detection, evaluation and actuating means of interruption means integrated inside the circuit breaker module. The circuit breaker with integrated earth leakage protection thus will provide basic circuit breaker functions like protection against overloads, short circuit and under voltage in addition to earth leakage protection. These modules will be compact in size as compared to add-on module, but will provide lesser features.
[0007] The add-on modules are separate modules housing the detection, evaluation and some parts of actuating means of interruption which are mounted in conjunction with the circuit breaker. Add-on earth leakage modules are available in different configurations. The bottom mounted configuration is the one which is mounted just below the circuit breaker in vertically mounted condition. The bottom mounted configuration has the best advantage of catering to all the termination types as that of the basic circuit breaker.
[0008] The side mounted configuration will have the earth leakage add-on module mounted next to the associated circuit breaker along its height in mounted condition. The side mounted will also have advantage of catering to maximum of the termination types as that of the basic circuit breaker. Also, the setting will be visible when mounted in distribution boards.
[0009] The L-shaped add-on configuration will typically have L-shape and when mounted in conjunction with the circuit breaker will have one limb along the height of the breaker and the other limb below the breaker in vertically mounted condition. This module has the best advantage of setting visibility when mounted in distribution boards and better than side mounted configuration. There will be similar configurations separately for a three pole breaker as well as four pole breaker.
[0010] All the configurations like bottom mounted, side mounted as well as conventional L-shaped earth leakage module are currently available in both three pole as well as four pole versions, which increases the inventory at the assembly site, which in turn increases complexity as well as cost involved.
[0011] There is therefore a need in the art for a modular construction of L-shaped earth leakage module for three pole as well as for four pole circuit breaker, which ensures common components being used for both three pole as well as for pole circuit breakers, which helps in minimizing inventory.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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
[0017] It is an object of the present disclosure to provide a modular construction of L-shaped earth leakage module for three pole as well as for four pole circuit breaker, which ensures common components being used for both three pole as well as for pole circuit breakers, which helps in minimizing inventory.

SUMMARY
[0018] The present disclosure relates generally to circuit breakers. In particular, the present disclosure relates to a modular earth leakage add-on module for circuit breakers.
[0019] In an aspect, the proposed disclosure relates to a modular earth leakage module comprising a CBCT housing module configured to house a core balanced current transformer assembly; a card housing module configured to house a microprocessor card; and an isolation-box module configured to house an isolation box that comprises a first set of contacts having power tappings from line conductors of a circuit breaker required to power up the microprocessor card and a second set of contacts having tapping connection to the microprocessor card, wherein the CBCT housing module, the isolation-box module, and the card housing module are configured such that the modular earth leakage module is configured for both three pole as well as four pole circuit breaker.
[0020] In an aspect, the earth leakage module is a L-shaped three pole earth leakage module. In another aspect, the earth leakage module is a L-shaped four pole earth leakage module.
[0021] In another aspect, the CBCT housing module can further include a voltage tapping means from the line conductors for powering up of the microprocessor card, wherein voltage is tapped from the line conductors of the circuit breaker on line side of the modular earth leakage module.
[0022] In another aspect, the isolation box can include a mechanism that isolates the first and second contacts in case of dielectric test so that high voltage does not appear at the terminals on the microprocessor card.
[0023] In an aspect, for the four pole circuit breaker, the CBCT housing module, the card housing module, and the isolation-box module can be integrated by means of slide fit and screw joining. On the other hand, for the three pole circuit breaker, CBCT housing module, and the card housing module can be integrated by means of slide fit & screw joining and the isolation-box module is not required.
[0024] In an aspect, the CBCT housing module has provision of voltage tapping from the line conductors of the circuit breaker on the line side of earth leakage module in mounted condition.
[0025] 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
[0026] 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.
[0027] FIG. 1 shows a modular L-shaped three pole earth leakage module and a modular L-shaped four pole earth leakage module in accordance with one or more embodiments of the present disclosure.
[0028] FIG. 2 shows exploded view of a modular L-shaped four pole earth leakage module in accordance with one or more embodiments of the present disclosure.
[0029] FIG. 3 shows exploded view of a modular L-shaped three pole earth leakage module in accordance with one or more embodiments of the present disclosure.
[0030] FIGs. 4-7 show details of the CBCT housing module in accordance with one or more embodiments of the present disclosure.
[0031] FIG. 8 shows microprocessor card in accordance with one or more embodiments of the present disclosure.
[0032] FIG. 9 shows card housing module in accordance with one or more embodiments of the present disclosure.
[0033] FIG. 10 shows card cover in accordance with one or more embodiments of the present disclosure.
[0034] FIG. 11 shows isolation-box module in accordance with one or more embodiments of the present disclosure.
[0035] FIG. 12 shows another view of the isolation-box module in accordance with one or more embodiments of the present disclosure.
[0036] FIG. 13 shows top cover in accordance with one or more embodiments of the present disclosure.

DETAILED DESCRIPTION
[0037] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0038] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0039] 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.
[0040] 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.
[0041] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0042] The present disclosure relates generally to circuit breakers. In particular, the present disclosure relates to a modular earth leakage add-on module for circuit breakers.
[0043] In an aspect, the proposed disclosure relates to a modular earth leakage module comprising a CBCT housing module configured to house a core balanced current transformer assembly;a card housing module configured to house a microprocessor card; and an isolation-box module configured to house an isolation box that comprises a first set of contacts having power tappings from line conductors of a circuit breaker required to power up the microprocessor card and a second set of contacts having tapping connection to the microprocessor card, wherein the CBCT housing module, the isolation-box module, and the card housing module are configured such that the modular earth leakage module is configured for both three pole as well as four pole circuit breaker.
[0044] In an aspect, the earth leakage module (3, 4) is a L-shaped three pole earth leakage module (3). In another aspect, the earth leakage module (3, 4) is a L-shaped four pole earth leakage module (4).
[0045] In another aspect, the CBCT housing module (5) can further include a voltage tapping means (10) from the line conductors (9) for powering up of the microprocessor card (11), wherein voltage is tapped from the line conductors (9) of the circuit breaker on line side of the modular earth leakage module (3, 4).
[0046] In another aspect, the isolation box (15) can include a mechanism that isolates the first and second contacts in case of dielectric test so that high voltage does not appear at the terminals on the microprocessor card (11).
[0047] In an aspect, for the four pole circuit breaker (2), the CBCT housing module (5), the card housing module (6), and the isolation-box module (7) can be integrated by means of slide fit and screw joining. On the other hand, for the three pole circuit breaker (1), CBCT housing module (5), and the card housing module (6) can be integrated by means of slide fit & screw joining and the isolation-box module (7) is not required.
[0048] In an aspect, the CBCT housing module has provision of voltage tapping from the line conductors of the circuit breakeron the line side of earth leakage module in mounted condition.
[0049] With reference to the figures, following is the numbering for each component of the different figures:
1- A three pole circuit breaker
2- A four pole circuit breaker (of the same frame size as that of the three pole circuit breaker)
3- Modular L-shaped three pole earth leakage module
4- Modular L-shaped four pole earth leakage module
5- CBCT Housing module
6- Card Housing module
7- Isolation-box module
8- Core balanced current transformer assembly
9- Line conductors of a three/four pole circuit breaker
10- Voltage tapping means
11- Microprocessor card
12- Current settings & Time settings
13- Trip indication
14- Setting flapper
15- Isolation box
16- Plastic casing
17- Card cover
18- Self-tapping mechanical joining screw
19- Top cover for Modular L-shaped three pole earth leakage module
20- Top cover for Modular L-shaped four pole earth leakage module
21- Flapper for Modular L-shaped three pole earth leakage module
22- Flapper for Modular L-shaped four pole earth leakage module
23- Sub assembly of (6) card housing module & (7) isolation-box module
24- Sub-assembly of (6) card housing module, (7) isolation-box module & CBCT housing module (5)
25- Sub assembly of (6) card housing module & (7) CBCT housing module (5).
[0050] With references to figures, FIG. 1 shows a modular L-shaped three pole earth leakage module (3), and a modular L-shaped four pole earth leakage module (4).
[0051] The present disclosure makes use of modular construction of Modular L-shaped four pole earth leakage module (4). The modular construction of Modular L-shaped four pole earth leakage module (4) configuration can include three main modules, namely CBCT housing module (5), card housing module (6), and isolation-box module (7).
[0052] FIG. 2 shows exploded view of a modular L-shaped four pole earth leakage module (4). FIG. 3 shows exploded view of a modular L-shaped three pole earth leakage module (3). In an aspect, the CBCT housing module (5) can be configured to house the core balanced current transformer assembly (8). In addition, the CBCT housing module (5) also encloses the voltage tapping means (10) from line conductors (9) for powering up of microprocessor card (11). The voltage is tapped from line conductors (9) of the circuit breaker on the line side of the L-shaped earth leakage module (3, 4).
[0053] In an aspect, a card housing module (6) can be configured to house the microprocessor card (11), which includes settings such as current settings (12), time settings (13), trip indication(14) etc.
[0054] In an aspect, an isolation-box module (7) can be configured to house isolation box (15) that can include two sets of contacts: one set having power tappings from the line conductors(9) of the circuit breaker required to power up the microprocessor card (11), and the other set having tapping connection to the microprocessor card(11). The isolation box (15) can include a mechanism that does not just disconnect but also isolates the two set of contacts in case of dielectric test so that the high voltage does not appear at the terminals on the microprocessor card (11).
[0055] In the present disclosure, CBCT housing module (5), isolation-box module (7), and card housing module (6) can be designed in such a manner that using the same modules, the earth leakage module(3,4) can be configured for both three pole (1)as well as four pole circuit breaker(2). In case of Modular L-shaped four pole earth leakage module (4) for a four pole circuit breaker(2), the CBCT housing module (5), the card housing module (6) and the isolation-box module (7) can be integrated by means of slide fit and screw joining. In case of Modular L-shaped three pole earth leakage module (3) for a three pole circuit breaker(1), CBCT housing module (5) and the card housing module (6) can be integrated by means of slide fit & screw joining, and isolation-box module (7) will/may not be included.
[0056] FIGs. 4-7 show details of the CBCT housing module (5). As seen in FIG. 4, the CBCT housing module (5) has provision of voltage tapping (10) from the line conductors (9) of the circuit breaker (1, 2) on the line side of earth leakage module (3, 4) in mounted condition. The voltage tapping means (10) can be provided in the feature (5a). The module (5) has an elongated feature (5b) along its depth so as to engage with the circuit breaker. This serves as mechanical joining between the earth leakage module (3, 4) as well as the circuit breaker (1, 2) respectively. Also, it helps in meeting the necessary clearance & creepage requirements as per the standards. This elongated feature also has T-provision (5c) on its upper end, which locks the earth leakage module (3, 4) in position & prevents its translational motion along height direction of a circuit breaker (1, 2). In addition to this, the module (5) also has a hexagonal feature (5d) as seen in FIG. 5, which engages with the slot in the circuit breaker (1, 2). This again helps in preventing the translational motion along height direction of a circuit breaker (1, 2).
[0057] In an aspect, the CBCT housing module (5) also has provision (5e) of keeping the voltage tapping wires (10) or conductors or strips whichever used, intact and shielded by means of plastic casing (16). This plastic casing (16) also ensures that the customer termination does not interfere with the voltage tapping wires (10). The CBCT housing module (5) has slot (5f) as seen in Figure 6 to accommodate the core balanced current transformer (8).
[0058] In an aspect, the core balanced current transformer (8) can be designed considering termination required for a four pole circuit breaker (2). The same core balanced current transformer (8) can be used in Modular L-shaped three pole earth leakage module (3) for a three pole circuit breaker (1) as shown in FIGs. 2 and 3.
[0059] The CBCT housing module (5) can have a knockout feature (5g) as shown in the FIG. 5. In case of Modular L-shaped four pole earth leakage module (4) for a four pole circuit breaker (2), the feature (5g) will be knocked out before the assembly, as shown in FIG. 7 so as to integrate the internal elements in the CBCT housing module (5), card housing module (6) as well as isolation-box module (7). In case of an Modular L-shaped three pole earth leakage module (3) for a three pole circuit breaker (1), the CBCT housing module (5) will be used as it is, with the feature (5g) intact and secured by some means, say like factory seal, label, sticker etc. as this will be the part of the outside facia of Modular L-shaped three pole earth leakage module (3).
[0060] In an aspect, whenever Modular L-shaped three pole earth leakage module (3) is configured for a three pole circuit breaker (1), the voltage tapping means (10) for the fourth pole will not be assembled in the CBCT housing module (5). Also, the hexagonal feature (5d) given in the fourth pole of CBCT housing module (5) will be accommodated inside the card housing module (6).
[0061] The card housing module (6) houses the microprocessor card (11). The microprocessor card (11) as seen in FIG. 8 has a slot (11a) and is placed vertically in the card housing module (6) and is constrained in the breaker’s (1, 2) width-height direction at the bottom side by means of locking feature (6a) given in the card housing module (6) as seen in FIG. 9. On the top side too, the microprocessor card (11) has a slot (11b), which gets locked by means of feature (17a) given in the card cover (17) as seen in FIG. 10. This constrains the microprocessor card (11) along the depth of the breaker (1, 2).
[0062] In an aspect, card housing module (6) has features (6b) & (6c) as shown in detailed view in FIG. 9. Now, in case of Modular L-shaped four pole earth leakage module (4),the feature (6b) of card housing module (6) slides through the feature (7a) of the isolation-box module (7) and gets locked by T-shaped feature given in the feature (6c) of the card housing module (6). On sliding the isolation-box module (7) over the card housing module (6), the feature (6d) of card housing module (6) will come under the feature (7b) given in the isolation-box module (7). Then the hole-feature (6d) in card housing module (6) will lie in the same axis as that of the hole-feature (7c) of the isolation-box module (7). Now, a sub-assembly (23) of card housing module (6) and isolation-box module (7) will be formed.
[0063] Then the inverted L-shaped feature (7d) & (7d’) of the isolation-box module as seen in FIG. 12 will be clamped over the walls of the CBCT housing module (5) and the subassembly (24) consisting of (6) card housing module, (7) isolation-box module & CBCT housing module (5) will be formed. Now, the card cover (17) will be assembled over the card housing module (6) with the feature (17c) lying axially with (6d) of card housing module and (7c) of isolation-box module (7). Self-tapping mechanical joining screw (18) is provided through features (17b) & (6e) to engage respectively the card cover (17) &card housing module (6).
[0064] In an aspect, isolation-box module (7), as seen in FIG. 11 houses the isolation box (15) only in case of Modular L-shaped four pole earth leakage module (4) for a four pole circuit breaker (2) which was described previously. The isolation-box module (15) is cot connected in case of a Modular L-shaped three pole earth leakage module (3) for a three pole circuit breaker (1).
[0065] In case of Modular L-shaped three pole earth leakage module (3) forthree pole circuit breaker (1), the features (7a) as shown by in isolation-box module (7) will be given by (5h) in the CBCT housing module (5) as shown by in Figure. Similarly, features (7b) & (7c) of isolation-box module (7) will be provided by (5j) & (5k) of the CBCT housing module (5) as seen in Figure 6.
[0066] The features (5h), (5j) & (5k) however will not serve any purpose only in case of Modular L-shaped four pole earth leakage module (4) for four pole circuit breaker (2) as shown in Fig.
[0067] Now, the feature (6b) of card housing module (6) slides through the feature (5h) of the CBCT housing module (5) and gets locked by T-shaped feature given in the feature (6c) of the card housing module (6).
[0068] On sliding the CBCT housing module (5) over the card housing module (6), the feature (6d) of card housing module (6) will come under the feature (5j) given in CBCT housing module (5) .Then the hole-feature (6d) in card housing module (6) will lie in the same axis as that of the hole-feature (5k) of the CBCT housing module (5) .Now, a sub-assembly (25) of card housing module (6) and CBCT housing module (5) will be formed.
[0069] Now, the card cover (17) will be assembled over the card housing module (6) with the feature (17c) lying axially with (6d) of card housing module and (5k) of CBCT housing module (5).Self-tapping mechanical joining screw (18) is provided through features (17b) & (6e) to engage respectively the card cover (17) &card housing module (6).Top cover for Modular L-shaped three pole earth leakage module (19) can then be assembled over the above assembly. A self-tapping mechanical joining screw (18) can be provided to engage the top cover (20), card housing module (6), card cover (17) and CBCT housing module (5). The card cover (17) can be same for earth leakage modules (3, 4) for both three pole (1) as well as four pole circuit breaker (2).
[0070] FIG. 13 shows the top cover (19, 20) which are different for earth leakage modules (3, 4) for both three pole (1) as well as four pole circuit breaker (2).The top cover (20), as one can see has window (20a) which has a flapper (22) as shown .The purpose of the window (20a) given in top cover (20) is to have better view while terminating cables at customer end. The isolation box (15) will be accessed through the window (20b). Similarly, top cover (19), as one can see has window (19a), which has a flapper (21) as shown. The purpose of the window (19a) given in top cover (19) is to have better view while terminating cables at customer end. The isolation box (15) will be accessed through the window (19b).
[0071] The proposed disclosure enables optimization of the inventory for configuring earth leakage modules for a three pole as well as four pole circuit breaker. Therefore, the proposed disclosure minimizes tooling cost, which could have been incurred separately for earth leakage module for a three pole as well as four pole circuit breaker. In addition, inventory management will be easier in the assembly line.
[0072] In an aspect, the proposed modular L-shaped earth leakage (3,4) module can include a CBCT Housing module (5), a Card housing module (6), an Isolation-box module (7), a Core balanced current transformer (8), a Sub assembly (23) of card housing module (6) and of isolation-box module(7), a Sub-assembly of card housing module(6) and isolation-box module (7) and CBCT housing module (5), and a Sub assembly of card housing module (6) and of CBCT housing module (5).
[0073] In an aspect, the three pole Modular L-shaped earth leakage module (7) can be assembled by assembling CBCT Housing module (5), Card housing module (6), Core balanced current transformer (8), Sub assembly of card housing module (6) and CBCT housing module (5). Here, the isolation-box module (7) can be assembled inside the CBCT hosing module (5).
[0074] In another aspect, the four pole Modular L-shaped earth leakage module (8) can be assembled by assembling CBCT Housing module (5), Card housing module (6), Isolation-box module (7), Core balanced current transformer (8), sub assembly (23) of card housing module (6) and isolation-box module (7), sub-assembly of card housing module(6) and isolation-box module (7) and CBCT housing module (5), and Sub assembly of card housing module (6) and CBCT housing module (5).
[0075] In an aspect, the elongated protrusion features given in the card-housing module (6) can be used to slide through similar groove cut feature given in the CBCT housing module (5) in case of assembly of three pole Modular L-shaped earth leakage module (7). The elongated protrusion features given in the card-housing module (6) can be used to slide through similar groove cut feature given in the Isolation-box module (7) in case of assembly of four pole Modular L-shaped earth leakage module (8).
[0076] In an aspect, an interlocking feature can be configured in the elongated protrusions of the card housing module (6), which ensures that the CBCT housing module (5) in case of assembly of three pole Modular L-shaped earth leakage module (7) remains secured in its final assembled position and prevents the CBCT housing module (5) from falling apart.
[0077] In another aspect, the interlocking feature configured in the elongated protrusions of the card housing module (6) ensures that the Isolation-box module (7) in case of assembly of four pole Modular L-shaped earth leakage module (8) remains secured in its final assembled position and prevents the Isolation-box module (7) from falling apart.
[0078] In an aspect, wedge feature given in the Isolation-box module (7) can be used to clamp on the walls of the CBCT housing module (5) in case of assembly of four pole Modular L-shaped earth leakage module (8).
[0079] In another aspect, CBCT housing (5) has a knock out feature that can be knocked out in case four pole Modular L-shaped earth leakage module (8) is being assembled so as to integrate the internal elements in the CBCT housing module (5), card housing module (6) as well as isolation-box module (7).
[0080] The CBCT housing (5) can also have a knock out feature that remains secure and intact by some means such as factory seal, label, sticker, etc. when the three pole Modular L-shaped earth leakage module (7) is being assembled as this will be the part of the outside face of Modular L-shaped three pole earth leakage module (3).
[0081] The card housing module (6) can also have features on its bottom surface to secure the microprocessor card (11) at the bottom.
[0082] In an aspect, a card cover (17) can have features to secure the microprocessor card (11) at the top.
[0083] In another aspect, top cover (19, 20) for three pole and four pole Modular L-shaped earth leakage module (7), (8) respectively has window which has a flapper, wherein purpose of the window given in top cover is to have better view while terminating cables at customer end. The isolation box can be accessed through the window given in top cover (19, 20) for three pole and four pole Modular L-shaped earth leakage module (7), (8) respectively.
[0084] In another aspect, modular construction of L-shaped module configuration gives advantage over conventional L-shaped module with respect to the fact that the same modules can be configured differently to form earth leakage modules for a three pole circuit breaker as well as four pole circuit breaker. Connecting modules in the sequence as explained in the description & images, earth leakage modules for three & four pole can be assembled. The assembly being modular, it is easy to replace the defective module on line, instead of entire module. Minimal tooling cost required for development of earth leakage modules for three pole as well as four pole circuit breaker. The proposed construction offers easy inventory management on the assembly line.
[0085] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0086] It is an object of the present disclosure to provide a modular construction of L-shaped earth leakage module for three pole as well as for four pole circuit breaker, which ensures common components being used for both three pole as well as for pole circuit breakers, which helps in minimizing inventory.