Claims:1. A system for post trip fault indication in earth leakage module (EL) of circuit breaker, said system comprising:
an IR transmitter means configured within the earth leakage module to emit light signal;
an IR receiver means configured within the earth leakage module for detecting incoming light signal from the IR transmitter through the ETU of circuit breaker;
a ray blocking means configured to block the transmission of IR light signal from the said transmitter to the said receiver;
a plunger placed on the flux shift device (FSD) of earth leakage module; and
a controller means configured to actuate a latching relay so as to enable at least one indicator means to indicate trip fault;
wherein said earth leakage module initiates a trip command upon detecting a fault and pops out the flux shift device (FSD) which moves the plunger in upward direction thereby blocking the passage of IR light by the said ray block means from the transmitter to the said receiver, resulting in high input to the controller means which actuates the latching relay to indicate the user that the EL module has tripped.

2. The system as claimed in claim 1 optionally comprising a battery for true indication of FSD popping even if the breaker is turned on when the main power is out.

3. The system as claimed in claim 1, wherein the latching relay is actuated by a switching means.

4. The system as claimed in claim 3, wherein the said switching means is a transistor.

5. The system as claimed in claim 1, wherein the controller means is a microcontroller or a microprocessor.

6. The system as claimed in claim 1, wherein IR light rays are passed from the transmitter to the receiver by an opening through the ETU when the breaker is in closed position.

7. The system as claimed in claim 1, wherein the IR transmitter means is IR LED.

8. The system as claimed in claim 1, wherein the IR receiver means is IR transistor.
, Description:TECHNICAL FIELD OF THE INVENTION

The present subject matter described herein, in general, relates earth leakage (ground fault) detection devices. More specifically, the present invention relates to a system for trip indication, used in earth leakage module of circuit breaker.

BACKGROUND OF THE INVENTION

Earth leakage devices are used to protect the people and appliances from residual currents. Many times it is used in conjunction with the circuit breaker. Circuit breaker(s) is/are used to protect the device from overload and short circuit current. The circuit breaker has its own Electronic trip unit (ETU) to sense the current and accordingly trip the device either in overload or short circuit using a Flux shift device (FSD).

Earth leakage devices do not have a breaking mechanism as with the circuit breaker. So to trip the breaker they need to somehow send the signal to the trip plate which acts upon the breaking mechanism thereby separating the contacts. It can be done using a shunt trip or using another FSD.

Once the trip command is given by Earth leakage (EL) module, the FSD or Shunt trip operates and the breaker is open. But when the user comes to check for maintenance or to evaluate the fault condition it becomes troublesome for him/her to evaluate which unit or module has been tripped i.e Electronic trip unit or the EL module.

In prior art documents, US6784770B2 patent teaches a separate mechanism which is used for giving a trip command and it is linked through the trip plate of the circuit breaker mechanically. The trip mechanism inside the EL module has an auxiliary switch which is actuated when the trip command is initiated and then it activates a mechanical indicator that is used as a visual indication to user that the earth leakage module has tripped.

In prior art documents, US7710694B2 patent teaches a micro switch which is placed inside the circuit breaker and it is used to give mechanical indication to user when the earth leakage protection function has crossed its threshold.

Most of the devices use a micro switch which is actuated when the FSD or shunt trip operates which then gives a pop out indication to the user indicating that the EL module has tripped and not the ETU. Normally for having post fault indication micro switch or an auxiliary switch inside a separate mechanism is used. If a micro switch is used with the FSD then it consumes space inside the breaker and if a separate mechanism is used then it takes a large amount of space in the EL module. Thus, use of a micro switch or any separate mechanism takes more space, cost and also requires that the EL module must be powered up to reset the trip position of the breaker or reset the mechanism until the breaker is turn on.

Thus, there is a particular need to provide a system for post trip fault indication of EL module that takes less space, involves less cost and also provides true sensing or indication of the FSD in the existing circuit breakers.

SUMMARY OF THE INVENTION

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.

Accordingly, the object of the present invention is to provide a system for post trip fault indication of EL module in the existing circuit breakers.

It is another object of the present invention is to provide a system that takes less space and involves less cost.

It is yet another object of the present invention is to provide system that provides true indication of the FSD popping in the circuit breakers.

It is still another object of the present invention to provide a system for post trip fault indication with no mechanical linkages.

According to the present invention, the foregoing and other objects and advantages are attained by providing a system for post trip fault indication in earth leakage module (EL) of circuit breaker, said system comprising:
an IR transmitter means configured within the earth leakage module to emit light signal;
an IR receiver means configured within the earth leakage module for detecting incoming light signal from the IR transmitter through the ETU of circuit breaker;
a ray blocking means configured to block the transmission of IR light signal from the said transmitter to the said receiver;
a plunger placed on the flux shift device (FSD) of earth leakage module; and
a controller means configured to actuate a latching relay so as to enable at least one indicator means to indicate trip fault;
wherein said earth leakage module initiates a trip command upon detecting a fault and pops out the flux shift device (FSD) which moves the plunger in upward direction thereby blocking the passage of IR light by the said ray block means from the transmitter to the said receiver, resulting in high input to the controller means which actuates the latching relay to indicate the user that the EL module has tripped.

Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of instrumentalities and combinations particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

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:

Figure 1 illustrates a block diagram of Earth leakage module in conjunction with circuit breaker in closed position, in accordance with an embodiment of the present subject matter.

Figure 2 illustrates a block diagram of Earth leakage module in conjunction with circuit breaker in open position, in accordance with an embodiment of the present subject matter.

Figure 3 illustrates the circuit diagram of IR circuit used in EL module, in accordance with an embodiment of the present subject matter.

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

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

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 and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

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.

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

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.

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.

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.

The present invention relates to a system post trip fault indication in earth leakage module (EL) of circuit breaker, which takes less space and is cost effective. It also relates to true indication of the FSD popping.

The present invention provides a system for post trip fault indication in earth leakage module (EL) of circuit breaker by an IR transmitter (IR Tx) and IR receiver (IR Rx) placed in the EL module. The system comprising: an IR transmitter means to emit light signal; an IR receiver means for detecting incoming light signal from the IR transmitter through the ETU of circuit breaker; a ray blocking means configured to block the transmission of IR light; a plunger placed on the flux shift device (FSD) of earth leakage module; and a controller means configured to actuate a latching relay, wherein said latching relay is actuated to enable at least one indicator means to indicate trip fault.

In an embodiment, when the breaker is in the closed position then the infrared light is passed through the (electronic trip unit) ETU to the EL module. When the earth leakage module finds a fault then it initiates a trip command on which the FSD pops out which makes the plunger move in the upward direction thereby no infrared light reaches the IR Rx and the output of the transistor is high. The controller means receives an input and turn on a relay which displays the user that the EL module has tripped.

In an embodiment, the invention provides true indication of FSD popping as the device is battery powered, so even if the breaker is turned on when the main power is not there then also the IR circuit is always powered using battery. Hence is it possible to have true sensing of FSD in the circuit breaker.

Referring now to figure 1, which provides a block diagram of Earth leakage module in conjunction with circuit breaker in closed position. When the breaker is in closed position, the IR Tx is in contact with the IR Rx through the narrow opening. The infrared light rays are passed from the transmitter to the receiver through the ETU. Since the receiver is turned on, the input to the microcontroller is low.

Referring now to figure 2, which provides a block diagram of Earth leakage module in conjunction with circuit breaker in open position. When the EL module senses the fault, it gives a trip command to the FSD. FSD pops out and the plunger is moved in the upward direction. So no infrared light is passed to the receiver as it is blocked using a Ray block as shown in the figure. Since the receiver is turned OFF, the input to the microcontroller is high.

Referring now to figure 3, which provides a circuit diagram of IR circuit used in EL module, in accordance to the present invention. When the EL module is powered up the IR TX is continuously turned on and the infrared light is passed to the IR receiver. As the IR Rx receives infrared light, the input pin of P1.1 to the microcontroller is low. When the FSD pops out, the IR Rx is turned off as the rays from the IR Tx is block using a Ray block and the input to the microcontroller is turned high. As the microcontroller receives this input it gives an output high command on port pin P1.2 thereby turning on the transistor Q1 which turns On the latching relay and the display is latched to Trip position indicating that the breaker is tripped using EL module. The display may be a simple mechanical indicator which may be latched using action of the latching relay. R1 is the resistor used to limit the current through the IR Tx. R2 is the pull up resistor for the IR Rx. R3 is the current limiting resistor for Q1. IR Tx may be a simple IR led and IR Rx can be a simple IR transistor. The main power supply is the line power supply taken directly from mains and the battery is used only when the main power is not present. And D1 and D2 are used for O-ring both of them.

Accordingly, a system for post trip fault indication in earth leakage module (EL) of circuit breaker, said system comprising: an IR transmitter means configured within the earth leakage module to emit light signal; an IR receiver means configured within the earth leakage module for detecting incoming light signal from the IR transmitter through the ETU of circuit breaker; a ray blocking means configured to block the transmission of IR light signal from the said transmitter to the said receiver; a plunger placed on the flux shift device (FSD) of earth leakage module; and a controller means configured to actuate a latching relay, wherein said latching relay is actuated to enable at least one indicator means to indicate trip fault.

Apart from the advantages and benefits mentioned above, other advantages and benefits are mentioned below:
• The present invention is Cost effective.
• The present invention is requires no mechanical linkage.
• The present invention provides true indication of FSD popping.
• The present invention is requires small space.

The illustrations of arrangements described herein are intended to provide a general understanding of the structure of various embodiments, and they are not intended to serve as a complete description of all the elements and features of apparatus and systems that might make use of the structures described herein. Many other arrangements will be apparent to those of skill in the art upon reviewing the above description. Other arrangements may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Figures are also merely representational and may not be drawn to scale. Certain proportions thereof may be exaggerated, while others may be minimized. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

Thus, although specific arrangements have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific arrangement shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments and arrangements of the invention. Combinations of the above arrangements, and other arrangements not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.