Claims:1. An apparatus (100) for protection of an electrical circuit, said apparatus comprising:
a magnetic core (102) configured in the electrical circuit, the magnetic core comprising:
a primary coil (104);
a secondary coil (106); and
a tertiary coil (108), wherein current flows from supply to a load; and
a voltage limiting component (110) electrically coupled between the supply side of the primary coil (104) and the load side of the secondary coil (106), the voltage limiting component (110) that provides protection against a high voltage spike,
wherein, when the applied voltage is greater than a threshold voltage, the voltage limiting component (110) starts to conduct current that passes through the secondary coil (106), and restrict the passage of current in the primary coil (104) to produce differential current in the tertiary coil (108), and
wherein, the differential current in the tertiary coil (108) actuates to isolate the supply from the load.
2. The apparatus as claimed in claim 1, wherein the primary coil (104) that contains phase current.
3. The apparatus as claimed in claim 1, wherein the secondary coil (106) that contains neutral current.
4. The apparatus as claimed in claim 1, wherein the difference between the current in phase and neutral breaks the electrical circuit.
5. The apparatus as claimed in claim 1, wherein the tertiary coil (108) electrically coupled to a relay.
6. The apparatus as claimed in claim 1, wherein the voltage limiting component (110) is a metal-oxide varistor (MOV).
7. The apparatus as claimed in claim 1, wherein a test switch (112) configured in the electrical circuit, the test switch is being configured to test the electrical circuit.
8. The apparatus as claimed in claim 1, wherein the voltage limiting component (110) provides protection of electrical appliances from a combination of high voltage spike.
9. The apparatus as claimed in claim 1, wherein the magnetic core (102) is a toroidal transformer.

Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to electrical protection systems, and more specifically, relates to a residual current circuit breaker with overvoltage protector.

BACKGROUND
[0002] Residual current circuit breakers (RCCB) employed as safety devices, the electrical wiring in the RCCB can disconnect the electrical circuit whenever it detects that the electric current is not balanced between the line conductor and the neutral conductor. The RCCB is designed to protect people and appliances from electric shock/earth leakage, for example, from the risk of electrocution, protection against the risk of an electrical fire and overcurrent protection of equipment and cables.
[0003] Currently, voltage protector device is being used separately to prevent overvoltage spikes. The device can shut down the supply, or clamps the output when the voltage exceeds a present level. Both the RCCB and the voltage protector device have a circuit-breaking mechanism. Existing RCCB can, however, limit the levels of performance, for example, the existing RCCB can limit the performance due to the requirement of separate voltage protector device installed to prevent from an overvoltage condition.
[0004] Therefore, there is a need in the art to provide a means that can be constructed in a simple, cost-effective manner to exhibit protection against electric shock and overvoltage conditions by solving the aforementioned problems.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] An object of the present disclosure relates, in general, to electrical protection systems, and more specifically, relates to a residual current circuit breaker with overvoltage protector.
[0006] Another object of the present disclosure is to provide an apparatus that can ensure protection against electric shock.
[0007] Another object of the present disclosure is to provide an apparatus that can be enhanced as overvoltage protector.
[0008] Another object of the present disclosure is to provide an apparatus that can protect electrical appliances from overvoltage or high voltage conditions.
[0009] Another object of the present disclosure is to provide an apparatus that can provide better protection against electrical accidents, thereby can lead to increased safety of user.
[0010] Another object of the present disclosure is to provide an apparatus that may require small number of electronic components.
[0011] Yet another object of the present disclosure is to provide an apparatus that can be constructed in a simple, cost-effective and resource-conserving manner.

SUMMARY
[0012] The present disclosure relates, in general, to electrical protection systems, and more specifically, relates to a residual current circuit breaker with overvoltage protector.
[0013] In an aspect, the present disclosure provides an apparatus for protection of an electrical circuit, the apparatus including a magnetic core configured in the electrical circuit of a circuit breaker, the magnetic core including a primary coil, a secondary coil, and a tertiary coil, wherein current flows from supply to load, and a voltage limiting component electrically coupled between supply side of the primary coil and the load side of the secondary coil, the voltage limiting component adapted to provide protection against a high voltage spike, wherein, when the applied voltage is greater than a threshold voltage, the voltage limiting component starts to conduct current that passes through the secondary coil and restrict the passage of current in the primary coil to produce the differential current in the tertiary coil, and wherein, the differential current in the tertiary coil actuates to isolate the supply from the load.
[0014] In an embodiment, the primary coil may be adapted to carry phase current.
[0015] In another embodiment, the secondary coil may be adapted to carry neutral current.
[0016] In another embodiment, the difference between the phase current and neutral current may break the electrical circuit.
[0017] In another embodiment, the tertiary coil may be electrically coupled to a relay.
[0018] In another embodiment, the voltage limiting component may be a metal-oxide varistor (MOV).
[0019] In another embodiment, a test switch coupled in the electrical circuit, the test switch adapted to test the electrical circuit.
[0020] In another embodiment, the voltage limiting component may be adapted for protection of electrical appliances from a combination of high voltage spike.
[0021] In another embodiment, the magnetic core may be a toroidal transformer.
[0022] 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
[0023] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0024] FIG. 1 illustrates an exemplary representation of a residual current circuit breaker with over voltage protector, in accordance with an embodiment of the present disclosure.
[0025] FIG. 2 illustrates an exemplary view of voltage limiting device, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0026] 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. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0027] 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.
[0028] The present disclosure relates, in general, to electrical protection systems, and more specifically, relates to a residual current circuit breaker with overvoltage protector. The apparatus configured for protection against certain potentially dangerous situations arising in electrical supply installations. The present disclosure may include toroidal transformer containing three coils as discussed below, where the three coils are primary coil, secondary coil and tertiary coil. The primary coil contains line/phase current and the secondary coil contains neutral current, which produces equal and opposite fluxes if both currents are equal. Whenever in the case there is leakage towards earth, phase current and neutral current are not equal, it creates out of balance flux, which in turn produces the differential current, which flows through the tertiary coil, which is connected to relay.
[0029] Additionally, voltage limiting component, for example, metal-oxide varistor (MOV) may be connected between supply side of phase coil and load side of neutral coil. MOV is being used with cross-connection i.e., supply side phase and load side neutral. MOV may be appropriately selected to conduct current above voltage protection threshold. When the voltage goes above the protection threshold, MOV starts conducting, where the MOV current may flow through the neutral coil but not in the phase coil. This may produce the differential current in the tertiary coil, therefore by adding MOV, the RCCB can be enhanced as overvoltage protector. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0030] FIG. 1 illustrates an exemplary representation of a residual current circuit breaker with over voltage protector, in accordance with an embodiment of the present disclosure.
[0031] Referring to FIG.1, residual current circuit breaker (RCCB) 100 (also referred to as an apparatus 100, herein) may be configured to detect fault condition in an electrical circuit to ensure protection against electric shock and from high voltage spikes. The apparatus 100 may require a small number of electronic components to perform the required operation, where the apparatus 100 can include a transformer comprising a magnetic/iron core 102, which may be constructed, for example, as a toroidal iron core. The magnetic core 102 may include three coils (104, 106, 108), where the three coils may be primary coil 104, secondary coil 106 and tertiary coil 108. Further, the apparatus 100 may also include a voltage limiting component 110 to protect the electrical circuit from high voltage spikes.
[0032] In an embodiment, electrical supply installation may have a live conductor and neutral conductor, that is connected to supply and fed to load. The primary coil 104, the secondary coil 106 and the tertiary coil 108 wound around the magnetic core 102, where the primary coil 104 may be adapted to carry phase/line current, and the secondary coil 106 may be adapted to carry neutral current. The primary coil 104, and the secondary coil 106 are adapted to carry current to and from the load, where the load may include ring main to which electrical/electronic appliances may be connected. The primary coil 104 and the secondary coil 106 may produce equal and opposite fluxes if both currents are equal. If there is a small change in the current between the live and the neutral carrying coils, it may trigger to trip the electrical circuit.
[0033] In another embodiment, the tertiary coil 108 interchangeably referred to as a trip coil, the tertiary coil 108 may wound around the magnetic core 102, where the tertiary coil 108 can be electrically coupled to a relay. Any imbalance caused in the current flowing in the primary coil 104 and the secondary coil 106 produces the differential current, which can flow through the tertiary coil 108. For example, whenever in the case there is leakage towards earth, the phase current and the neutral current are not equal, it creates out of balance flux, which in turn produces the differential current, which flows through the tertiary coil 108. The tertiary coil, upon detecting the differential current, adapted to actuate the relay to isolate the supply from the load, thus sensing the difference between the current in phase and neutral can break the electrical circuit. Therefore, the apparatus 100 protect the electrical circuit from electric shock/electric leakage.
[0034] In another embodiment, the voltage limiting component 110 may be configured in the electrical circuit of the apparatus 100. In an exemplary embodiment, the voltage limiting component as presented in the example may be metal-oxide varistor (MOV), where the MOV protect the circuit from high voltage spikes by varying its resistance. As can be appreciated, the present disclosure may not be limited to this configuration but may be extended to other configurations. As shown in FIG. 1, the MOV is electrically coupled between the supply side of primary coil 104 (interchangeably referred to as a phase coil) and load side of the secondary coil 106 (interchangeably referred to as a neutral coil). In the existing known art, the MOV is connected directly between the phase and neutral in any existing circuit, whereas in the present disclosure, the MOV is being used with cross-connection i.e., the supply side of the phase and the load side of the neutral.
[0035] MOV adapted to protect the electrical/electronic appliances from voltage surges, the voltage surge is generally an undesired increase in voltage that typically lasts for a relatively brief length of time, generally of a few microseconds. However, voltage surges can last for longer periods of time, ranging from tens of milliseconds to a few seconds. If the voltage across it increases the resistance decreases and vice versa. This property is useful in protecting the circuits from high voltage spikes.
[0036] In another embodiment, when an applied voltage is greater than the threshold voltage, i.e., voltage protection threshold, the MOV appropriately selected to conduct current above the voltage protection threshold and the MOV current may flow through the secondary coil 106. For example, when voltage goes above protection threshold, MOV starts conducting, and the MOV current may flow through the secondary coil 106 i.e., neutral coil, however, the current may not flow in the primary coil 104 i.e., the phase coil. The imbalance of current between the primary coil 104 and the secondary coil 106 may produce the differential current in the tertiary coil 108.
[0037] The tertiary coil 108, upon detecting the differential current, adapted to actuate the relay to isolate the supply from the load. Therefore, by adding MOV in the electrical circuit of the circuit breaker, the apparatus 100 can be enhanced as overvoltage protector. In another embodiment, a test switch 112 may be included in the electrical circuit to test the electrical circuit, the test switch 112 can ensure that the reliability of RCCB.
[0038] In an implementation, the apparatus 100 may be configured to enable protection of the electrical circuit, where the apparatus may include the magnetic core 102 configured in the electrical circuit, the magnetic core 102 may include the primary coil 104, the secondary coil 106, and the tertiary coil 108, where the current flows from the supply to the load. The voltage limiting component 110 electrically coupled between supply side of the primary coil 104 and the load side of the secondary coil 106, the voltage limiting component 110 may provide protection against high voltage spike, where, when the applied voltage is greater than the threshold voltage, the voltage limiting component 110 starts to conduct current that passes through the secondary coil 106, and restrict the passage of current in the primary coil to produce the differential current in tertiary coil 108, and where, the differential current in the tertiary coil 108 actuates to isolate the supply from the load.
[0039] For example, when the voltage is within the rated limits the resistance of the MOV may be high, hence all the current flows through the electrical circuit. However, when the voltage spike occurs, the current flow through the MOV, where the MOV starts conducting, and the MOV current may flow through the neutral coil that may produce the differential current in the trip coil, thereby, protecting from high/overvoltage conditions.
[0040] Thus, the apparatus 100 can be enhanced as overvoltage protector, where the apparatus 100 may require a small number of electronic components and can be constructed in a simple, cost-effective and resource-conserving manner. The differential current can be detected effectively, whether they operate from an alternating current (AC) or direct current (DC) supply. The apparatus 100 can provide better protection against electrical accidents, thereby can lead to increased safety of the user. The apparatus 100 of the present disclosure can achieve earth leakage and overvoltage protection, and the addition of MOV may not impact characteristic of RCCB of tripping while earth leakage.
[0041] FIG. 2 illustrates an exemplary view of voltage limiting device, in accordance with an embodiment of the present disclosure.
[0042] Referring to FIG. 2, the apparatus 100 can include the transformer comprising the magnetic/iron core 102, which may be constructed, for example, as the toroidal iron core. The magnetic core 102 may include three coils, where the three coils may be primary coil 104, secondary coil 106 and tertiary coil 108. Further, the apparatus 100 may also include the voltage limiting component 110 to provide protection from overvoltage spikes.
[0043] The voltage limiting component 110 as presented in the example may be MOV that can be configured in the apparatus 100 to protect from voltage surges so that the electrical/ electronic appliances are not damaged when voltage surges occur. The MOV starts conduction of current at a specific voltage which is greater than the threshold voltage and can stop conduction when the voltage falls below the threshold voltage. The MOV can be widely used for protection of electrical appliances from overvoltage or high voltage conditions caused by electrical surges, lightning, high voltage line contact and the like. Therefore, by adding MOV in the electrical circuit of the circuit breaker, the apparatus 100 can be enhanced as overvoltage protector.
[0044] It will be apparent to those skilled in the art that the apparatus 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0045] The present disclosure provides an apparatus that can ensure protection against electric shock.
[0046] The present disclosure provides an apparatus that can be enhanced as overvoltage protector.
[0047] The present disclosure provides an apparatus that can protect electrical appliances from overvoltage or high voltage conditions.
[0048] The present disclosure provides an apparatus that can provide better protection against electrical accidents, thereby can lead to increased safety of the user.
[0049] The present disclosure provides an apparatus that may require small number of electronic components.
[0050] The present disclosure provides an apparatus that can be constructed in a simple, cost-effective and resource-conserving manner.