Claims:
1. A circuit breaker for protecting electrical systems against fault current conditions, the circuit breaker comprising:
a molded housing having a fixed conductor;
a moving conductor assembly movable with respect to said fixed conductor assembly;
an arc extinguishing housing assembly formed by a stack of deionizing splitter plates; and
an arc runner cum shield flanked to said fixed conductor wherein arc runner cum shield acts as bottom most deionizing splitter plate and electrically connected to said fixed conductor and configured such that it adds magnetic forces and resistance on arc during arc quenching.
2. The circuit breaker of claim 1, wherein the circuit breaker further comprises separable contacts and an arc chute to extinguish an electric arc formed when opening of said contacts takes place.
3. The circuit breaker of claim 1, wherein the arc runner cum shield comprises of slopped bend such that when arc current flows through it during arcing, a magnetic field is generated that pushes the arc into deionizing splitter plates.
4. The circuit breaker claim 1, wherein the arc runner cum shield further comprises of bend profile wherein said profile is bent such that the fixed conductor and the moving conductor are placed exactly at center.
5. The circuit breaker of claim 1, wherein the arc runner cum shield is a magnetic stimulator shield with a cut in the middle and the moving conductor moves exactly in center.
6. The circuit breaker of claim 1, wherein during arcing, current equally or unequally divides in strap and creates a balanced field across said moving conductor.
7. The circuit breaker of claim 1, wherein said deionizing splitter plates are rectangular in shape with a U-shaped cut in the middle.
8. The circuit breaker of claim 1, wherein said arc runner cum shield has a specific arc guided path made by two rectangular slots.
9. The circuit breaker of claim 1, wherein said arc runner cum shield is attached to said fixed conductor.
10. The circuit breaker of claims 8, characterized thereby, that additional blow-out loop is formed in rectangular shape by angled portions of rearward prolongation of arc runner, wherein side parallel to the arc runner forms hypotenuse while both components are arranged in edge regions of free space behind the arc runner.
, Description:
TECHNICAL FIELD
[0001] The present disclosure relates generally to the field of protection devices for protecting electrical systems against fault current conditions. In particular, the present invention relates to circuit breakers and MCCBs for arc quenching system using arc runner cum MS shield.

BACKGROUND
[0002] Circuit Breakers are electro-mechanical switching devices capable of making, carrying and breaking currents and are also known as over current protective devices. Under normal circuit conditions, it closes the circuit, carries current for a specified time and breaks the circuit under specified abnormal circuit conditions. These protection devices are also employed for current interruption. More particularly MCCBs are utilized to protect instruments from damage during adverse conditions that prevails during the operation of the circuit in which molded case circuit breakers are employed. During adverse conditions like short circuit, current rises to an alarmingly high level. This high level current may cause damage to parts of electrical system. Hence during these conditions, the circuit has to be opened to protect the parts of the electrical system.
[0003] Generally a circuit breaker has two electrical conductors located inside a molded case housing. The first electrical conductor is stationary, and may be connected to either the line or the load. The second electrical conductor is movable with respect to the first electrical conductor, such that when the circuit breaker is in “OFF” condition, or tripped position, a gap exists between the first and second electrical conductor, but most dangerous thing happens during circuit interruption is arc which can damage the breaker and contact system.
[0004] Evidently, there have been many devices that can quench an arc. For instance, a device with a sealed arc chamber wherein inside of the sealed arc chamber is a gas designed to quench the arc that is formed when the circuit breaker trips. Another instance is an arc chute which consists of stack of deionizing splitter plates made up of ferromagnetic material to attract, split-up & cool the arcs. These deionizing splitter plates are stacked in between two electrically insulating material plates known as lining or stacked inside a chamber. The function of deionizing plates is to split the arc in several series arcs of approximately equal length which will result in higher arc voltage and distinctly greater dielectric strength after current zero. However, these devices are accompanied with high erosion level of conductors and higher let through energy during formation of arcs.
[0005] Thus there is a need of a shield cum arc runner assembly electrically connected to a fixed conductor that limits current and achieves faster arc quenching through increased upward repulsion force acting on the moving conductor, arc lengthening and increase in arc resistance.

OBJECTS OF THE INVENTION
[0006] A general object of the present disclosure is to provide an integrated arc runner cum MS shield for an improved arc quenching in circuit breakers.
[0007] Another object of the present disclosure is to provide an integrated arc runner cum MS shield that increases circuit breaker life.
[0008] Another object of the present disclosure is to provide an integrated arc runner cum MS shield that incorporates lower let through energy and lower erosion of conductors.
[0009] Another object of the present disclosure is to provide an integrated arc runner cum MS shield that provides high breaking capacity.
[0010] Another object of the present disclosure is to provide an integrated arc runner cum MS shield that provides faster contact opening during fault condition.
[0011] Another object of the present disclosure is to provide an integrated arc runner cum MS shield that reduces material usage due to less contact erosion.

SUMMARY
[0012] The present disclosure relates generally to the field of protection devices for protecting electrical systems against fault current conditions. In particular, the present invention relates to circuit breakers and MCCBs for arc quenching system using arc runner cum MS shield. The present invention discloses a circuit breaker for protecting electrical systems against fault current conditions wherein the circuit breaker consists of a molded housing having a fixed conductor, a moving conductor assembly movable with respect to said fixed conductor assembly, an arc extinguishing housing assembly formed by a stack of deionizing splitter plates, and an arc runner cum shield flanked to said fixed conductor wherein arc runner cum shield acts as bottom most deionizing splitter plate and electrically connected to said fixed conductor and configured such that it adds magnetic forces and resistance on arc during arc quenching. In an aspect, the circuit breaker further includes separable contacts and an arc chute to extinguish an electric arc formed when opening of said contacts takes place.
[0013] In an aspect, arc runner cum shield includes slopped bend such that when arc current flows through it during arcing, a magnetic field is generated that pushes the arc into deionizing splitter plates. Further, the arc runner cum shield consists of bend profile wherein said profile is bent such that the fixed conductor and the moving conductor are placed exactly at center and arc runner cum shield acts a magnetic stimulator shield with a cut in the middle and the moving conductor moves exactly in center. Additionally, arc runner cum shield has a specific arc guided path made by two rectangular slots and arc runner cum shield is attached to said fixed conductor.
[0014] In an aspect, during arcing, current equally or unequally divides in strap and creates a balanced field across said moving conductor. Further, deionizing splitter plates are rectangular in shape with a U-shaped cut in the middle.
[0015] In an aspect, an additional blow-out loop is formed in rectangular shape by angled portions of rearward prolongation of arc runner, wherein side parallel to the arc runner forms hypotenuse while both components are arranged in edge regions of free space behind the arc runner.

BRIEF DESCRIPTION OF THE DRAWINGS
[0016] 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.
[0017] Fig. 1A illustrates an exemplary top view of a circuit breaker assembly with arc runner cum shield and fixed conductor assembly in accordance with embodiments of the present disclosure.
[0018] Fig. 1B illustrates an exemplary side view of a circuit breaker assembly with arc runner cum shield and fixed conductor assembly in accordance with embodiments of the present disclosure.
[0019] Fig. 2 illustrates an exemplary view of fixed conductor assembly and arc chute assembly in accordance with embodiments of the present disclosure.
[0020] Fig. 3 illustrates an exemplary view of fixed conductor assembly in accordance with embodiments of the present disclosure.
[0021] Fig. 4 illustrates an exemplary view an arc runner cum shield in accordance with embodiments of the present disclosure.
[0022] Fig. 5A illustrates an exemplary side view of a circuit breaker during initial arcing condition in accordance with embodiments of the present disclosure.
[0023] Fig. 5B illustrates an exemplary side view of a circuit breaker during finial arcing condition in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION
[0024] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details 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.
[0025] Embodiments explained herein relate to the field of protection devices for protecting electrical systems against fault current conditions. In particular, the present invention relates to circuit breakers and MCCBs for arc quenching system using arc runner cum MS shield. The present invention discloses a circuit breaker for protecting electrical systems against fault current conditions wherein the circuit breaker consists of a molded housing having a fixed conductor, a moving conductor assembly movable with respect to said fixed conductor assembly, an arc extinguishing housing assembly formed by a stack of deionizing splitter plates, and an arc runner cum shield flanked to said fixed conductor wherein arc runner cum shield acts as bottom most deionizing splitter plate and electrically connected to said fixed conductor and configured such that it adds magnetic forces and resistance on arc during arc quenching. In an aspect, the circuit breaker further includes separable contacts and an arc chute to extinguish an electric arc formed when opening of said contacts takes place.
[0026] In an aspect, arc runner cum shield includes slopped bend such that when arc current flows through it during arcing, a magnetic field is generated that pushes the arc into deionizing splitter plates. Further, the arc runner cum shield consists of bend profile wherein said profile is bent such that the fixed conductor and the moving conductor are placed exactly at center and arc runner cum shield acts a magnetic stimulator shield with a cut in the middle and the moving conductor moves exactly in center. Additionally, arc runner cum shield has a specific arc guided path made by two rectangular slots and arc runner cum shield is attached to said fixed conductor.
[0027] In an aspect, during arcing, current equally or unequally divides in strap and creates a balanced field across said moving conductor. Further, deionizing splitter plates are rectangular in shape with a U-shaped cut in the middle.
[0028] In an aspect, an additional blow-out loop is formed in rectangular shape by angled portions of rearward prolongation of arc runner, wherein side parallel to the arc runner forms hypotenuse while both components are arranged in edge regions of free space behind the arc runner.
[0029] Fig. 1A and Fig. 1B illustrate exemplary top and side views of a circuit breaker assembly with arc runner cum shield and fixed conductor assembly wherein a circuit breaker 100, having a fixed conductor assembly 102 that can be mounted directly to a housing 104 or may be mounted inside the housing 104 along with arc chute assembly 106, generally connected to line (incoming supply). However, this electrical conductor can also be connected to the load (output from the circuit breaker). Further, circuit breaker 100 has a moving conductor assembly 108 movable with respect to the fixed conductor assembly 102 that is generally is connected to the load. However, this electrical conductor can also be connected to the load (output from the circuit breaker). Additionally, circuit breaker 100 consists of an arc chute assembly 106 with a stack of deionizing splitter plates 110 each having a U-shaped cut at center and mounted on fixed conductor assembly 102 which consist of an arc runner cum MS shield 112 and a fixed conductor 114 wherein arc runner cum MS shield 112 is attached to the fixed conductor 114. Further, circuit breaker 100 is designed to quickly cool and quench an arc.
[0030] Fig. 2 and FIG. 3 illustrate an exemplary view of fixed conductor assembly 102 and arc chute assembly 106 wherein arc chute assembly 106 consists of a stack of deionizing splitter plates 110 and an arc liner 202 and a fixed conductor assembly 102 best seen in Fig 3, which can be directly mounted to the housing 104. The arc runner cum shield 112 includes a bend profile 302 same as that of fixed conductor 114, and a sloped bend 304. The arc runner cum MS shield 112 can be divided into MS shield 306 part and arc runner 308 part. The moving conductor 310 moves radially between the arc chute assembly 106. This arrangement reduces arc concentration around moving conductor 310, and guides electric arc into deionizing splitter plates 110.
[0031] Fig. 4 illustrates an exemplary view an arc runner cum shield wherein arc runner cum magnetic stimulator shield 112 is made of ferromagnetic material. Arc runner cum shield 112 has bend profile 302 same as that of fixed conductor 114 and provides an additional upward force on the conductor during high current short circuit condition and has a slopped bend 304 which acts as arc runner 308 and MS shield 306. The MS shield part 306 helps in magnetic field shielding which will enhance the blow force on the electric arc 402 during short circuit interruption. Arc runner 308 part guides the electric arc 402 into deionizing splitter plates 110 and helps in saving the contact material and also provides additional blow force on electric arc 402 for faster quenching. Further, arc runner 308 acts as an extra deionizing splitter plate 110 and also provide additional resistance to the arc which subsequently increase the arc voltage for faster and smoother arc quenching.
[0032] Fig. 5A and FIG. 5B illustrate exemplary side views of a circuit breaker during initial arcing condition and final arcing condition respectively wherein FIG. 5A depicts direction of flow of conventional current during initial phase of arcing during high current breaking. During initial arcing phase, moving conductor 310 has separated from fixed conductor 114 but electricity is still conducted by the breaker assembly in the form of an arc and high current still flows from fixed conductor 114 to moving conductor 310. Electric arc 402 is capable of jumping between electrical conductors, through air which follows a low reluctance path and can cause damage to both electrical conductors. In a worst case scenario, a single arc 402 can damage the conductors so severely that in normal operation the breaker is impossible. Electrical arc 402 can reduce lifespan of the electrical conductors, which in turn shorten lifespan of circuit breaker. This would lead to frequent replacement of circuit breaker, which can be both costly and difficult depending on the location of the circuit breaker.
[0033] In an aspect, electric arc 402 must be squelched as quickly as possible to protect current conducting path and circuit breaker. This can be done by speeding up the process of electric arc 402 entering into deionizing splitter plates 110. Arc Chute assembly 106 may be a stack of spaced apart deionizing splitter plates 110 arranged by means of arc liners 202 which cools and quenches the arc. Quicker cooling and quenching of arc mainly depends upon total magnetic forces acting on the arc in forward direction, arc lengthening and increase in arc resistance. Hence, it is beneficial to provide additional magnetic forces for pushing or pulling arc into arc chute assembly 106. In this case, to provide additional magnetic forces, arc runner cum MS shield 112 is used that commutes electric arc 402 into deionizing splitter plates 110 and increases arc length with increased arc voltage, and also provides quick arc quenching.
[0034] In an aspect, during high current breaking condition, as the moving conductor 310 tries to separate from fixed conductor 114, an arc is generated between the conductors. This arc tries to follow low reluctance path and forms arc roots. As the moving conductor 310 opens arc forms, an initial arc root 502 on the arc runner part 308 leaves the fixed conductor 114, and as arc root moves forward with the help of arc runner part 308, the arc enters deionizing splitter plate 110 and quenches. As the arc moves forward the arc stretches 502 with contact opening, this contact opening depends on magnetic field forces acting on the conductor, enhanced magnetic field around the conductor means higher upward force on the conductor. This MS shield part 112 reduces downward force acting on the moving conductor 310 and increases the contact opening speed that results in faster arc quenching.
[0035] 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
[0036] The present disclosure provides provide an integrated arc runner cum MS shield for an improved arc quenching in circuit breakers.
[0037] The present disclosure provides an integrated arc runner cum MS shield that increases circuit breaker life.
[0038] The present disclosure provides an integrated arc runner cum MS shield that incorporates lower let through energy and lower erosion of conductors.
[0039] The present disclosure provides an integrated arc runner cum MS shield that provides high breaking capacity.
[0040] The present disclosure provides an integrated arc runner cum MS shield that provides faster contact opening during fault condition.
[0041] The present disclosure provides an integrated arc runner cum MS shield that reduces material usage due to less contact erosion.