Residual current circuit breakers (RCCBs), also known as ground fault circuit interrupters (GFCIs), detect ground faults and disconnect power to prevent electric shock. RCCBs use a core balance transformer and relay to sense minor differences in current between live and neutral wires, indicating a ground fault. They provide protection against direct and indirect contact with live parts. RCCBs must disconnect power within 40 milliseconds of detecting a ground fault of 30mA or more, as required by safety regulations. Types are available for domestic, industrial, and commercial applications to protect against electric shocks.
Unit I: Introduction to Protection System:
Introduction to protection system and its elements, functions of protective relaying, protective zones, primary and backup protection, desirable qualities of protective relaying, basic terminology.
Relays:
Electromagnetic, attracted and induction type relays, thermal relay, gas actuated relay, design considerations of electromagnetic relay.
Unit-II: Relay Application and Characteristics:
Amplitude and phase comparators, over current relays, directional relays, distance relays, differential relay.
Static Relays: Comparison with electromagnetic relay, classification and their description, over current relays, directional relay, distance relays, differential relay.
Unit-III Protection of Transmission Line:
Over current protection, distance protection, pilot wire protection, carrier current protection, protection of bus, auto re-closing,
Unit-IV: Circuit Breaking:
Properties of arc, arc extinction theories, re-striking voltage transient, current chopping, resistance switching, capacitive current interruption, short line interruption, circuit breaker ratings.
Testing Of Circuit Breaker: Classification, testing station and equipments, testing procedure, direct and indirect testing.
Unit-V Apparatus Protection:
Protection of Transformer, generator and motor.
Circuit Breaker: Operating modes, selection of circuit breakers, constructional features and operation of Bulk Oil, Minimum Oil, Air Blast, SF6, Vacuum and d. c. circuit breakers.
Protection of transmission lines(encrypted)Rohini Haridas
This document discusses protection methods for transmission lines. It describes:
1. Transmission lines require more protective schemes than other equipment due to their long lengths and exposure, making faults more common.
2. Key methods of transmission line protection include time-graded overcurrent protection, differential protection, current-graded overcurrent protection, and distance protection.
3. Distance protection uses impedance relays that can discriminate between faults along the line and those near the end, providing more selective operation than overcurrent protection alone. It describes implementations using simple impedance, reactance, and mho relays.
In-Country Training
On
Operation, Maintenance, Protection & Control of 33/11 kV Substation
Project Name: Design, Supply, Installation, Testing & Commissioning of 33/11 kV sub-stations with source end feeder bays.
Contract No: BREB/UREDS/W-01A-001/02/2016-2017
BREB/UREDS/W-01A-002/03/2016-2017
BREB/UREDS/W-01A-004/04/2016-2017
This document provides an overview of the electrical equipment found in a switchyard at an NTPC power plant, including transformers, conductors, insulators, isolators, busbars, lightning arresters, circuit breakers, relays, and capacitor banks. It describes the purpose and basic functioning of each type of equipment, such as how transformers change voltage levels, current transformers reduce current readings, conductors transmit power, and relays and circuit breakers disconnect faulty circuits. The document also notes that new technologies like SCADA allow remote control and monitoring of substations.
The document discusses the theory of circuit interruption in power systems. It begins by introducing circuit breakers, which can manually or automatically open a circuit under normal or fault conditions. When contacts within a circuit breaker open under a fault, an arc is produced that must be extinguished to interrupt current flow. There are two main methods for extinguishing arcs: the high resistance method, which lengthens and cools the arc to increase its resistance over time; and the low resistance or current zero method, used for AC circuits, which maintains a low resistance arc until current reaches zero to naturally extinguish the arc.
The document discusses different types of circuit breakers, including air blast, vacuum, oil, and SF6 circuit breakers. It explains that a circuit breaker can make, carry, and break currents under normal and abnormal circuit conditions. The operating mechanism involves using stored energy to move a moving contact to open or close the circuit. When contacts separate during a fault, an arc is formed that must be quickly quenched for circuit interruption. Each breaker type uses a different medium, such as air, vacuum, oil or SF6 gas, to rapidly cool and extinguish the arc. Modern systems commonly use vacuum or SF6 breakers for their fast, reliable performance.
A switchgear or electrical switchgear is a generic term which includes all the switching devices associated with mainly power system protection. It also includes all devices associated with control, metering and regulating of electrical power system. Assembly of such devices in a logical manner forms a switchgear. This is the very basic definition of switchgear.
⋗To get more with details
https://www.youtube.com/channel/UC2SvKI7eepP241VLoui1D5A
Unit I: Introduction to Protection System:
Introduction to protection system and its elements, functions of protective relaying, protective zones, primary and backup protection, desirable qualities of protective relaying, basic terminology.
Relays:
Electromagnetic, attracted and induction type relays, thermal relay, gas actuated relay, design considerations of electromagnetic relay.
Unit-II: Relay Application and Characteristics:
Amplitude and phase comparators, over current relays, directional relays, distance relays, differential relay.
Static Relays: Comparison with electromagnetic relay, classification and their description, over current relays, directional relay, distance relays, differential relay.
Unit-III Protection of Transmission Line:
Over current protection, distance protection, pilot wire protection, carrier current protection, protection of bus, auto re-closing,
Unit-IV: Circuit Breaking:
Properties of arc, arc extinction theories, re-striking voltage transient, current chopping, resistance switching, capacitive current interruption, short line interruption, circuit breaker ratings.
Testing Of Circuit Breaker: Classification, testing station and equipments, testing procedure, direct and indirect testing.
Unit-V Apparatus Protection:
Protection of Transformer, generator and motor.
Circuit Breaker: Operating modes, selection of circuit breakers, constructional features and operation of Bulk Oil, Minimum Oil, Air Blast, SF6, Vacuum and d. c. circuit breakers.
Protection of transmission lines(encrypted)Rohini Haridas
This document discusses protection methods for transmission lines. It describes:
1. Transmission lines require more protective schemes than other equipment due to their long lengths and exposure, making faults more common.
2. Key methods of transmission line protection include time-graded overcurrent protection, differential protection, current-graded overcurrent protection, and distance protection.
3. Distance protection uses impedance relays that can discriminate between faults along the line and those near the end, providing more selective operation than overcurrent protection alone. It describes implementations using simple impedance, reactance, and mho relays.
In-Country Training
On
Operation, Maintenance, Protection & Control of 33/11 kV Substation
Project Name: Design, Supply, Installation, Testing & Commissioning of 33/11 kV sub-stations with source end feeder bays.
Contract No: BREB/UREDS/W-01A-001/02/2016-2017
BREB/UREDS/W-01A-002/03/2016-2017
BREB/UREDS/W-01A-004/04/2016-2017
This document provides an overview of the electrical equipment found in a switchyard at an NTPC power plant, including transformers, conductors, insulators, isolators, busbars, lightning arresters, circuit breakers, relays, and capacitor banks. It describes the purpose and basic functioning of each type of equipment, such as how transformers change voltage levels, current transformers reduce current readings, conductors transmit power, and relays and circuit breakers disconnect faulty circuits. The document also notes that new technologies like SCADA allow remote control and monitoring of substations.
The document discusses the theory of circuit interruption in power systems. It begins by introducing circuit breakers, which can manually or automatically open a circuit under normal or fault conditions. When contacts within a circuit breaker open under a fault, an arc is produced that must be extinguished to interrupt current flow. There are two main methods for extinguishing arcs: the high resistance method, which lengthens and cools the arc to increase its resistance over time; and the low resistance or current zero method, used for AC circuits, which maintains a low resistance arc until current reaches zero to naturally extinguish the arc.
The document discusses different types of circuit breakers, including air blast, vacuum, oil, and SF6 circuit breakers. It explains that a circuit breaker can make, carry, and break currents under normal and abnormal circuit conditions. The operating mechanism involves using stored energy to move a moving contact to open or close the circuit. When contacts separate during a fault, an arc is formed that must be quickly quenched for circuit interruption. Each breaker type uses a different medium, such as air, vacuum, oil or SF6 gas, to rapidly cool and extinguish the arc. Modern systems commonly use vacuum or SF6 breakers for their fast, reliable performance.
A switchgear or electrical switchgear is a generic term which includes all the switching devices associated with mainly power system protection. It also includes all devices associated with control, metering and regulating of electrical power system. Assembly of such devices in a logical manner forms a switchgear. This is the very basic definition of switchgear.
⋗To get more with details
https://www.youtube.com/channel/UC2SvKI7eepP241VLoui1D5A
A protective relay is a device that detects abnormal conditions in an electrical circuit, such as a fault, and triggers a circuit breaker to disconnect the faulty part of the circuit. There are several types of relays including definite time, differential, solid state, electromechanical, backup, current, voltage, and frequency relays. A differential relay compares currents on both sides of a power transformer to detect faults. Solid state relays have no moving parts, allowing for high-speed operation. Electromechanical relays use a spring, armature, electromagnet and contacts to close the circuit when energized. Protection schemes use primary and backup relays, with primary relays clearing faults fastest and backup relays removing more of
This document discusses procedures for operation and maintenance of electrical equipment. It outlines steps to monitor voltages, check breaker trip circuits, observe battery performance, ensure communication equipment is working, monitor transformer loading and temperatures, check diesel generators, inspect the substation yard, test gas pressures in SF6 breakers, and check additional equipment. Precautions are provided for testing procedures and limits are given for acceptable pole discrepancies when measuring circuit breaker operation times.
This document explains the key differences between various types of circuit protection devices:
- MCB (Miniature Circuit Breaker) is rated up to 100A and has non-adjustable thermal or magnetothermal operation.
- MCCB (Molded Case Circuit Breaker) is rated up to 1000A and has adjustable trigger characteristics and thermal or magnetothermal operation.
- Air and vacuum circuit breakers are for larger industrial systems, rated up to 10,000A and 3000A respectively, with fully adjustable settings.
- RCD/RCCB (Residual Current Device/Circuit Breaker) detects imbalance between phase and neutral currents to quickly trip if current flows to ground. It provides
This document provides information on underground cables, including their construction, classification, insulating materials, and types. It discusses how underground cables consist of conductors covered with insulating material and a protective covering to reduce interference from external disturbances. The general construction of a 3-conductor cable is described, including its cores or conductors, insulation, metallic sheath, bedding, armouring, and serving. Various types of cables are classified based on voltage levels. Key properties and examples of insulating materials used in cables are also outlined, along with the advantages and disadvantages of underground cables compared to overhead systems.
Miniature Circuit Breakers (MCB) and Molded Case Circuit Breakers (MCCB) protect electrical circuits from overcurrent. MCBs are for circuits rated under 100 amps, while MCCBs are for circuits rated over 100 amps. MCBs use a bimetallic strip or electromagnet to open contacts when overcurrent is detected, while MCCBs have thermal and magnetic elements to operate for overloads and instantly for short circuits. MCBs and MCCBs differ in their current ratings and interrupting capacities.
This document summarizes a 220kV substation in Kanpur, India. It has three main sections: a panel section containing control panels and relay panels, a switchyard containing components like circuit breakers and transformers, and a battery room. The substation receives 220kV power from two incoming lines and steps it down to 132kV and 33kV for outgoing distribution lines. It uses transformers to convert between voltages and buses to distribute power. Key terms like tripping, shutdown, and breakdown are also defined relating to power disruptions and maintenance.
The document discusses different types of electrical insulators used in power transmission and distribution systems. It describes pin insulators, which are used for voltages up to 33kV and secure the conductor to cross-arms on poles. For higher voltages, suspension insulators are used, consisting of multiple porcelain discs connected in series. Strain insulators are used where there are sharp turns or high tension, using assemblies of suspension insulators or shackle insulators for lower voltages. Each type of insulator is designed to support and isolate electrical conductors without allowing current flow.
Power system-protection-presentation-dated-03-10-2013-integrated-protection-c...jbpatel7290
The document discusses numerical relays and their advantages over electromagnetic relays. It describes the functions and features of microprocessor-based numerical relays used for protection of transmission lines, transformers, busbars, distribution feeders, generators and motors. Numerical relays offer benefits like low cost, mathematical processing capabilities, self-checking, low burden on CTs/PTs, metering, fault recording, fault location, event logging and oscillography. Digital relays also provide standard hardware, flexibility in operation, multi-functionality, communication capabilities, adaptive relaying, and connectivity with SCADA systems. Block diagrams of generic digital relays and their hardware components are also presented.
Pin, Suspension, and Strain insulators are used in medium to high voltage systems. While Stay and Shackle Insulators are mainly used in low voltage applications.
Voltages and currents present at the generator's rated voltage and current are provided as examples. Sample relay setting calculations are shown for generator protection elements including 59N neutral overvoltage, 27TN third harmonic undervoltage, 46 negative sequence overcurrent, and coordination between protective devices. Formulas for calculating voltage and current settings from generator nameplate data are demonstrated.
This document provides information on underground power cables. It discusses the construction of underground cables including conductors, insulation materials like rubber, paper and PVC. It classifies cables based on voltage level and describes common cable types used for different voltages like screened and pressure cables. It also discusses cable insulation materials, laying of cables, types of cable faults and compares underground and overhead power systems.
This document summarizes types of lightning arresters, their classification, identification, standard ratings, and service conditions. There are three main types of arresters: expulsion, valve, and gapless metal-oxide. Arresters are classified into four classes based on their nominal discharge current and use: station, intermediate, distribution, and secondary. Arresters must be properly identified and can operate under normal conditions of temperature, radiation, altitude, and frequency, but may require special consideration under abnormal conditions.
Air circuit breaker (ACB) Low-Voltage Miduim-Voltage High VoltageRathana Lan
Air Circuit Breaker, is the application use full in low voltage for the main switch gear. easy to quench the arc and long life varrenty. but for high voltage is completly replace by oil circuit breaker. It mainly 2 types of ACB are Plain Aircircuit Breaker and Air-blash Air Circuit Breaker. Plain Aircircuit Breaker mostly use in Low and Miduim Voltage and Air-Blash Air Circuit Breaker is mostly use in high voltage.
Thanks.
This document describes various protection schemes for transformers, including differential, restricted earth fault, overcurrent, and thermal protection.
1) Differential protection compares currents entering and leaving the transformer zone to detect internal faults. It provides the best protection for internal faults.
2) Restricted earth fault protection is used to detect high-resistance winding-to-core faults not detectable by differential relays. It uses a neutral current transformer and is sensitive to internal earth faults.
3) Overcurrent protection uses relays with current coils to detect overloads and faults above a pickup threshold. It also includes ground-fault protection.
This document provides details on substation layout and busbar arrangements. Part A discusses substation layout, including a single line diagram and descriptions of common switchyard accessories like lightning arrestors, CVTs, isolators, circuit breakers, transformers, and other equipment. It also covers PLCC and SCADA systems. Part B covers various busbar arrangements like the single bus system, double bus system, one and a half breaker system, and ring main bus system. It discusses the advantages and disadvantages of each configuration. In summary, the document is a technical report that outlines and compares different substation and busbar designs.
Circuit breakers are used to protect electrical circuits from damage caused by overloads or short circuits. They operate automatically to detect faults and interrupt current flow. Modern high power AC circuit breakers use either sulfur hexafluoride gas or a vacuum as insulating mediums to rapidly extinguish arcs when contacts open through cooling and rapidly increasing dielectric strength between contacts. Vacuum circuit breakers provide the fastest interruption and are most compact and reliable due to the superior arc quenching properties of a vacuum.
SF6 and vacuum circuit breakers are described. SF6 breakers use sulfur hexafluoride gas to rapidly absorb electrons in an electric arc, restoring insulation. Vacuum breakers extinguish arcs quickly due to the fast recovery of dielectric strength in a vacuum. Both breaker types have advantages like compact size, reliability, and lack of maintenance requirements, making them suitable for outdoor applications. Circuit breaker ratings include breaking capacity, making capacity, and short-time capacity to safely interrupt faults.
Over Head Line Insulators : Presentation Topic in Electrical Engineering SeminarSandip Kumar Sahoo
Over Head Line Insulators a Presentation Topic in Electrical Engineering for Seminars was prepared by me with comprehensive research and phenomenal guidance. You just need a little research on the mentioned points and you are ready to go. I hope this PPT will help you immensely.
Every power supply depends upon a reliable infeed of electricity. Air circuit breakers reliably protect electrical installations against damage or fire as a result of short circuits, ground faults, or overload faults.
Bus bars are the nerve center of a power system where various circuits are connected. Differential protection is suitable for bus bars since terminals are near each other, allowing comparison of current entering and leaving via CTs. Any difference signals an internal fault and causes the relay coil to trip circuit breakers on both sides, isolating the bus. CT ratios for bus differential schemes equal the maximum feeder current divided by 1 or 5 amps. External faults may cause maloperation if a CT saturates, but a stabilizing resistance can restrain the relay. Dot convention defines the direction of current flow in CT secondaries. Only class PS CTs should be used to avoid undesired difference currents. Differential protection is important to protect bus bars
MPFIM4, Residual Current Devices for earth leakage detection. It is to be used in association with miniature circuit breakers, its function is to detect earth leakage current and open the connected circuit to protect people and equipment, major used in industrial application. These devices are designed to meet the Earth Leakage Protection Standards of the IEC: IEC/EN 61008.
MCB stands for Miniature Circuit Breaker. It is a manually or automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. It detects fault conditions and interrupts current flow, unlike a fuse which must be replaced after operating. MCBs protect individual appliances up to large high voltage circuits for cities. They automatically switch off circuits during abnormal network conditions like overloads or faults. MCBs are more sensitive to overcurrent than fuses but can be reset to resume operation, while an advantage of fuses is they are less costly than MCB systems.
A protective relay is a device that detects abnormal conditions in an electrical circuit, such as a fault, and triggers a circuit breaker to disconnect the faulty part of the circuit. There are several types of relays including definite time, differential, solid state, electromechanical, backup, current, voltage, and frequency relays. A differential relay compares currents on both sides of a power transformer to detect faults. Solid state relays have no moving parts, allowing for high-speed operation. Electromechanical relays use a spring, armature, electromagnet and contacts to close the circuit when energized. Protection schemes use primary and backup relays, with primary relays clearing faults fastest and backup relays removing more of
This document discusses procedures for operation and maintenance of electrical equipment. It outlines steps to monitor voltages, check breaker trip circuits, observe battery performance, ensure communication equipment is working, monitor transformer loading and temperatures, check diesel generators, inspect the substation yard, test gas pressures in SF6 breakers, and check additional equipment. Precautions are provided for testing procedures and limits are given for acceptable pole discrepancies when measuring circuit breaker operation times.
This document explains the key differences between various types of circuit protection devices:
- MCB (Miniature Circuit Breaker) is rated up to 100A and has non-adjustable thermal or magnetothermal operation.
- MCCB (Molded Case Circuit Breaker) is rated up to 1000A and has adjustable trigger characteristics and thermal or magnetothermal operation.
- Air and vacuum circuit breakers are for larger industrial systems, rated up to 10,000A and 3000A respectively, with fully adjustable settings.
- RCD/RCCB (Residual Current Device/Circuit Breaker) detects imbalance between phase and neutral currents to quickly trip if current flows to ground. It provides
This document provides information on underground cables, including their construction, classification, insulating materials, and types. It discusses how underground cables consist of conductors covered with insulating material and a protective covering to reduce interference from external disturbances. The general construction of a 3-conductor cable is described, including its cores or conductors, insulation, metallic sheath, bedding, armouring, and serving. Various types of cables are classified based on voltage levels. Key properties and examples of insulating materials used in cables are also outlined, along with the advantages and disadvantages of underground cables compared to overhead systems.
Miniature Circuit Breakers (MCB) and Molded Case Circuit Breakers (MCCB) protect electrical circuits from overcurrent. MCBs are for circuits rated under 100 amps, while MCCBs are for circuits rated over 100 amps. MCBs use a bimetallic strip or electromagnet to open contacts when overcurrent is detected, while MCCBs have thermal and magnetic elements to operate for overloads and instantly for short circuits. MCBs and MCCBs differ in their current ratings and interrupting capacities.
This document summarizes a 220kV substation in Kanpur, India. It has three main sections: a panel section containing control panels and relay panels, a switchyard containing components like circuit breakers and transformers, and a battery room. The substation receives 220kV power from two incoming lines and steps it down to 132kV and 33kV for outgoing distribution lines. It uses transformers to convert between voltages and buses to distribute power. Key terms like tripping, shutdown, and breakdown are also defined relating to power disruptions and maintenance.
The document discusses different types of electrical insulators used in power transmission and distribution systems. It describes pin insulators, which are used for voltages up to 33kV and secure the conductor to cross-arms on poles. For higher voltages, suspension insulators are used, consisting of multiple porcelain discs connected in series. Strain insulators are used where there are sharp turns or high tension, using assemblies of suspension insulators or shackle insulators for lower voltages. Each type of insulator is designed to support and isolate electrical conductors without allowing current flow.
Power system-protection-presentation-dated-03-10-2013-integrated-protection-c...jbpatel7290
The document discusses numerical relays and their advantages over electromagnetic relays. It describes the functions and features of microprocessor-based numerical relays used for protection of transmission lines, transformers, busbars, distribution feeders, generators and motors. Numerical relays offer benefits like low cost, mathematical processing capabilities, self-checking, low burden on CTs/PTs, metering, fault recording, fault location, event logging and oscillography. Digital relays also provide standard hardware, flexibility in operation, multi-functionality, communication capabilities, adaptive relaying, and connectivity with SCADA systems. Block diagrams of generic digital relays and their hardware components are also presented.
Pin, Suspension, and Strain insulators are used in medium to high voltage systems. While Stay and Shackle Insulators are mainly used in low voltage applications.
Voltages and currents present at the generator's rated voltage and current are provided as examples. Sample relay setting calculations are shown for generator protection elements including 59N neutral overvoltage, 27TN third harmonic undervoltage, 46 negative sequence overcurrent, and coordination between protective devices. Formulas for calculating voltage and current settings from generator nameplate data are demonstrated.
This document provides information on underground power cables. It discusses the construction of underground cables including conductors, insulation materials like rubber, paper and PVC. It classifies cables based on voltage level and describes common cable types used for different voltages like screened and pressure cables. It also discusses cable insulation materials, laying of cables, types of cable faults and compares underground and overhead power systems.
This document summarizes types of lightning arresters, their classification, identification, standard ratings, and service conditions. There are three main types of arresters: expulsion, valve, and gapless metal-oxide. Arresters are classified into four classes based on their nominal discharge current and use: station, intermediate, distribution, and secondary. Arresters must be properly identified and can operate under normal conditions of temperature, radiation, altitude, and frequency, but may require special consideration under abnormal conditions.
Air circuit breaker (ACB) Low-Voltage Miduim-Voltage High VoltageRathana Lan
Air Circuit Breaker, is the application use full in low voltage for the main switch gear. easy to quench the arc and long life varrenty. but for high voltage is completly replace by oil circuit breaker. It mainly 2 types of ACB are Plain Aircircuit Breaker and Air-blash Air Circuit Breaker. Plain Aircircuit Breaker mostly use in Low and Miduim Voltage and Air-Blash Air Circuit Breaker is mostly use in high voltage.
Thanks.
This document describes various protection schemes for transformers, including differential, restricted earth fault, overcurrent, and thermal protection.
1) Differential protection compares currents entering and leaving the transformer zone to detect internal faults. It provides the best protection for internal faults.
2) Restricted earth fault protection is used to detect high-resistance winding-to-core faults not detectable by differential relays. It uses a neutral current transformer and is sensitive to internal earth faults.
3) Overcurrent protection uses relays with current coils to detect overloads and faults above a pickup threshold. It also includes ground-fault protection.
This document provides details on substation layout and busbar arrangements. Part A discusses substation layout, including a single line diagram and descriptions of common switchyard accessories like lightning arrestors, CVTs, isolators, circuit breakers, transformers, and other equipment. It also covers PLCC and SCADA systems. Part B covers various busbar arrangements like the single bus system, double bus system, one and a half breaker system, and ring main bus system. It discusses the advantages and disadvantages of each configuration. In summary, the document is a technical report that outlines and compares different substation and busbar designs.
Circuit breakers are used to protect electrical circuits from damage caused by overloads or short circuits. They operate automatically to detect faults and interrupt current flow. Modern high power AC circuit breakers use either sulfur hexafluoride gas or a vacuum as insulating mediums to rapidly extinguish arcs when contacts open through cooling and rapidly increasing dielectric strength between contacts. Vacuum circuit breakers provide the fastest interruption and are most compact and reliable due to the superior arc quenching properties of a vacuum.
SF6 and vacuum circuit breakers are described. SF6 breakers use sulfur hexafluoride gas to rapidly absorb electrons in an electric arc, restoring insulation. Vacuum breakers extinguish arcs quickly due to the fast recovery of dielectric strength in a vacuum. Both breaker types have advantages like compact size, reliability, and lack of maintenance requirements, making them suitable for outdoor applications. Circuit breaker ratings include breaking capacity, making capacity, and short-time capacity to safely interrupt faults.
Over Head Line Insulators : Presentation Topic in Electrical Engineering SeminarSandip Kumar Sahoo
Over Head Line Insulators a Presentation Topic in Electrical Engineering for Seminars was prepared by me with comprehensive research and phenomenal guidance. You just need a little research on the mentioned points and you are ready to go. I hope this PPT will help you immensely.
Every power supply depends upon a reliable infeed of electricity. Air circuit breakers reliably protect electrical installations against damage or fire as a result of short circuits, ground faults, or overload faults.
Bus bars are the nerve center of a power system where various circuits are connected. Differential protection is suitable for bus bars since terminals are near each other, allowing comparison of current entering and leaving via CTs. Any difference signals an internal fault and causes the relay coil to trip circuit breakers on both sides, isolating the bus. CT ratios for bus differential schemes equal the maximum feeder current divided by 1 or 5 amps. External faults may cause maloperation if a CT saturates, but a stabilizing resistance can restrain the relay. Dot convention defines the direction of current flow in CT secondaries. Only class PS CTs should be used to avoid undesired difference currents. Differential protection is important to protect bus bars
MPFIM4, Residual Current Devices for earth leakage detection. It is to be used in association with miniature circuit breakers, its function is to detect earth leakage current and open the connected circuit to protect people and equipment, major used in industrial application. These devices are designed to meet the Earth Leakage Protection Standards of the IEC: IEC/EN 61008.
MCB stands for Miniature Circuit Breaker. It is a manually or automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. It detects fault conditions and interrupts current flow, unlike a fuse which must be replaced after operating. MCBs protect individual appliances up to large high voltage circuits for cities. They automatically switch off circuits during abnormal network conditions like overloads or faults. MCBs are more sensitive to overcurrent than fuses but can be reset to resume operation, while an advantage of fuses is they are less costly than MCB systems.
This document discusses the basics of earthing systems. It begins by defining important terminology related to earthing. It then discusses the disadvantages of unearthed systems and the different types of earthing including system, equipment, and reference earthing. The document outlines the basic principles and methods of system earthing, including how fault currents flow. It provides details on the earthing schemes adopted in process plants, including the voltage levels and earthing methods used. Finally, it includes an earthing conductors schedule with requirements for equipment body and instrument earthing connections.
An electric shock occurs when a person comes into contact with an electric current. This can cause injuries ranging from minor burns to death, depending on several factors like the type and amount of current. Some common ways to receive electric shocks include through poorly insulated wires, ungrounded equipment, or lightning strikes. Electric shocks should be taken seriously and medical attention sought depending on the severity of symptoms. Proper safety precautions around electricity can help prevent shocks.
Nobody is save against potential electricity failures. It does not take much for a current that serves us well to bring extreme danger to our everyday life. The most reasonable way to reduce the risk is to use a protection equipment RCCB (residual current device).
Protections:
1. kWh meter adalah alat pengukur energi listrik yang mengukur secara langsung hasil kali tegangan, arus, faktor kerja dan waktu.
2. Terdiri dari kumparan tegangan, kumparan arus, dan piringan penggerak yang memutar register sesuai dengan besarnya daya yang dilewatinya.
3. Prinsip kerjanya didasarkan pada interaksi fluks tegangan dan fluks arus di dalam kumparan yang menimbulkan momen putar
This document discusses different types of earthing used in electrical engineering. Earthing refers to connecting non-current carrying parts of electrical systems to the earth to provide an alternative path for fault currents. The purposes of earthing are to protect human life, buildings and equipment from faults, provide lightning protection, and maintain voltage stability. Good earthing has low impedance to ensure faults are quickly disconnected. Common earthing methods discussed are strip, water main, rod, pipe and plate earthing. Each method involves burying a conductor like copper wire or pipes in the ground to dissipate currents. Proper earthing is important for safety and performance in various electrical applications.
Circuit breakers are devices designed to automatically open an electrical circuit under abnormal current conditions without being damaged. They can be reset to resume normal operation, unlike fuses which must be replaced. There are different types of circuit breakers including oil, air, SF6, and vacuum. Circuit breakers can sense overcurrent through either thermal or magnetic methods and operate on either a time delay or instantaneous basis. Common circuit breakers used in buildings include miniature circuit breakers and molded case circuit breakers.
This document discusses different types of earthing systems used in electrical installations. It defines earthing as connecting electrical equipment to the earth to provide a safe path for electric current. The main purposes of earthing are to protect humans and equipment from electric shocks. The document describes maintenance free earthing and conventional earthing methods. It also explains different earthing electrodes like plates, pipes, rods and strips that are buried underground to reduce earth resistance.
Electric shock occurs when a person comes into contact with a source of electricity, causing an electric current to pass through their body. Adolescents and adults are often injured by high voltage sources through mischievous or occupational exposure. The severity of injuries from electric shock depends on factors like voltage, current, and the pathway through the body. Treatment involves addressing burns, broken bones, or other injuries according to their severity through cleaning, dressing, grafting, or other procedures. Prevention emphasizes safe electrical practices, especially for children, and caution during thunderstorms.
ELCB Fuji: thiết bị đóng cắt Fuji
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Unified power quality conditioner for compensating power quality problem adIAEME Publication
This document describes a proposed Adaptive Neuro-Fuzzy Inference System (ANFIS) based Unified Power Quality Conditioner (UPQC) to improve power quality compensation performance. A UPQC uses two voltage source inverters to compensate for both voltage and current disturbances but has high DC link capacitor discharge times. The proposed system adds an ANFIS device to generate a bias voltage that maintains the DC link voltage at a lower level. ANFIS combines neural networks and fuzzy logic to approximate nonlinear functions from numerical and linguistic data. The generated fuzzy rules are trained using a neural network to produce the desired output. Analysis shows the proposed ANFIS-based UPQC provides better power quality compensation than controllers using neural networks,
Edf R&D Xemard Coupling Between Transmission Underground Cables And Pipelinescorinne rocherieux
This document discusses the coupling between underground transmission cables and pipelines. It notes that induced voltage from transmission systems can disturb cathodic protection of pipelines and potentially lead to corrosion. It evaluates inductive coupling using line theory and EMTP-RV modeling software. As an example, it shows the induced voltages on bitumen and polyethylene coated pipelines from a 225kV underground cable 10m away were 1.1V and 2.1V respectively. Safety standards generally limit induced voltages to less than 10Vrms or 4Vrms depending on soil conditions. A toolbox called CRINOLINE has been developed to facilitate calculations of induced voltages on pipelines and cables.
Unified power quality conditioner: protection and performance enh(1)Nagaraj Madival
This document summarizes a PhD thesis submitted to the Dublin Institute of Technology. The thesis, authored by Iurie Axente, examines the unified power quality conditioner (UPQC) and its ability to provide protection and performance enhancement. The thesis presents the results of testing a UPQC configuration in both laboratory and field prototypes. It also includes publications and appendices describing the hardware designs and control approaches developed as part of the research.
A relay is an electrically operated switch that uses a small current to control a larger current. Relays were invented in 1835 and use electromagnetic attraction to change switch contacts. A relay has a coil that creates a magnetic field when powered, attracting a lever to change the switch position. Relays can switch AC or DC and higher voltages or currents than simple switches.
This document discusses underground cables for electrical power distribution. It covers the construction of cables including conductors, insulation, metallic sheathing, bedding, armouring and serving. Common insulating materials like XLPE are described. Cables are classified based on voltage level. Methods of laying cables underground include direct laying, draw-in systems and solid systems. Potential cable faults include open circuits, short circuits and earth faults. Underground cables have advantages over overhead systems like better appearance, lower maintenance needs and fewer faults, but the installation costs are higher.
This document discusses various electrical safety topics such as grounding, overcurrent protection, GFCIs, proper power strip usage, bonding and grounding, and an example of electrocution due to improper equipment usage. Grounding reduces shock risk by providing an alternative current path back to the source in case of a fault. Fuses and circuit breakers protect against overheating from too much current, while GFCIs quickly shut off power if any current leaves the circuit. Power strips should only be used for electronics and not overloaded or combined with extension cords. Proper bonding and grounding of all surfaces protects against static electricity dangers. The example incident describes a fatal electrocution that occurred due to a combination of unsafe factors including using
Superconductor fault current limiters (SFCLs) provide an effective way to limit fault current in power systems. SFCLs use the properties of superconductors, which have virtually zero resistance below a critical temperature, current, and magnetic field. During a fault, the superconductor transitions to a normal resistive state, limiting the fault current. The two main types are resistive and inductive SFCLs. SFCLs offer benefits over traditional fault current limiting methods like faster response, shorter recovery times, and the ability to protect equipment without upgrades. They can be applied in the main transformer, feeder, or bus-tie positions in a power system.
This document contains diagrams and explanations of different wiring configurations for light switches, including:
1) One-way switching with a common wire connecting the light and single switch.
2) Two-way switching with two switches controlling the light using two wires.
3) Two-way switching with an intermediate switch also controlling the light using two wires.
4) Alternate two-way switching configurations using three wires to connect the switches and light.
TONGOU Electrical is a leading Chinese manufacturer and exporter of modular electric terminal devices for household, commercial, industrial, and similar installations. It produces a wide range of products including miniature circuit breakers, residual current circuit breakers, moulded case circuit breakers, air circuit breakers, contactors, and more. TONGOU prides itself on innovative design, excellent craftsmanship, and high reliability. It has obtained certifications from international organizations and supplies products globally.
TONGOU Electrical is a leading Chinese manufacturer and exporter of modular electric terminal devices for household, commercial, industrial, and similar installations. It produces a wide range of products including miniature circuit breakers, residual current circuit breakers, moulded case circuit breakers, air circuit breakers, contactors, and more. TONGOU prides itself on innovative design, excellent craftsmanship, and high reliability. It has obtained certifications from international organizations and supplies products globally.
This document discusses circuit breakers, including their purpose, types, and working principles. It begins by defining a circuit breaker as a switching device that can manually and automatically control and protect an electrical power system by interrupting faults. It then describes the main types of circuit breakers used in low, medium, and high voltage applications. Specific types like MCBs, MCCBs, RCCBs, and ELCBs are also defined and their differences explained. The document concludes by summarizing the critical role of circuit breakers in protecting electrical networks and devices.
This document provides information about various electrical components including MCCB, air circuit breaker, control gear, capacitor, load bank, and testing procedures. It discusses MCCBs, including types (G-frame, A-frame, etc.), testing procedures for thermal, magnetic, trip/not trip, and mechanical endurance testing. Information is also given on air circuit breakers, contactors, thermal overload relays, capacitors, load banks, APFC panels, busbar chambers, and MCCB enclosures.
Miniature circuit breakers (MCBs) and residual current circuit breakers (RCCBs) provide overcurrent protection for electrical circuits. MCBs are thermal and magnetic switches that automatically break circuits during short circuits or overloads to protect wiring and devices. RCCBs detect residual current leakage to ground and disconnect power to prevent electric shock. There are different types of each for various applications based on trip characteristics and number of poles. Both provide important safety functions and find widespread use in homes, businesses, and industry.
This document provides technical data on LV switchgear products from Alfanar including:
- Circuit breakers from Teraski for applications up to 6300A with short circuit ratings of 100kA/1s or 50kA/3s.
- MCCBs and MCBs from Teraski for applications up to 1600A and 125A respectively.
- Switchboards can be designed to IEC 61439-2 standards with IP65 protection, internal arc testing up to 65kA, and seismic withstand of 8 on the Richter scale.
The document discusses various components of low voltage switchgear including switch fuse units (SFU), miniature circuit breakers (MCB), earth leakage circuit breakers (ELCB), and molded case circuit breakers (MCCB). It describes the components, working principles, advantages, and applications of each type of switchgear. Safety precautions for electrical work and first aid for electric shocks are also briefly mentioned.
DIGITAL TESTING OF HIGH VOLTAGE CIRCUIT BREAKERRitesh Kumawat
1. The document discusses the testing of high voltage circuit breakers. Digital testing employs software to simulate circuit breaker performance based on characteristic measurements from standard tests.
2. High resolution current and voltage measurements are made around current zero crossing to characterize breaker behavior. An empirical arc model is validated and used to predict test outcomes.
3. The software can be used to study the influence of system components on breaker performance and determine critical line lengths for short line faults by simulating different test circuits digitally.
The 220kV power substation in Muradnagar has a capacity of 2*160MVA and 1*100MVA. It receives power from three 220kV transmission lines and two 400kV lines, which it steps down to lower voltages of 132kV, 66kV, 33kV and 11kV. The substation contains various equipment like circuit breakers, isolators, transformers, lightning arrestors, current and potential transformers, and wave traps to distribute, monitor and protect the flow of electricity. It utilizes equipment like oil and air-blast circuit breakers, vacuum and SF6 gas circuit breakers, and oil and air-cooled power transformers in its operations.
The document provides an overview of a power substation (switchyard) including:
- Typical components including busbars, circuit breakers, current transformers, and surge arrestors.
- Explanations of switchyard equipment such as circuit breakers, isolators, earth switches, and their functions.
- Descriptions of different types of substations based on voltage levels and mounting structures.
- Brief explanations of additional equipment such as capacitive voltage transformers, wave traps, and post insulators.
The document discusses vacuum circuit breakers (VCBs). It describes that VCBs use vacuum as an interrupting medium inside vacuum interrupters to extinguish arcs. This provides superior arc quenching over other mediums. The document discusses various components and functions of VCBs like auxiliary switches, anti-pumping relays, contact resistance testing, short circuit ratings, and accessories. It compares features of shunt and undervoltage releases and lists advantages of VCBs like being maintenance-free and having rapid arc interruption.
1. Dynamic Elecpower Private Limited is a well-established company in Jaipur, Rajasthan, India that manufactures and supplies electrical panels and components.
2. The company has a 2000 square meter facility for panel manufacturing with in-house fabrication, powder coating, and chemical pre-treatment.
3. Dynamic Elecpower offers customized control relay panels, motor control centers, variable frequency drives, soft starter panels and other products for industrial applications.
The document discusses residual current circuit breakers (RCCBs) that provide protection against earth faults and leakage currents. It lists various RCCB models that comply with IEC 61008 standards and have ratings up to 125A and 630A breaking capacity. The document provides details on RCCB construction, features, technical specifications, wiring diagrams, and dimensions for installation. It describes how RCCBs automatically disconnect circuits when earth faults exceed their rated sensitivity levels.
This document provides information about various types of circuit breakers. It begins with listing the group members and then discusses the introduction, definition, working principle, components, and types of circuit breakers. The main types discussed are oil circuit breakers, vacuum circuit breakers, air blast circuit breakers, SF6 circuit breakers, miniature circuit breakers, and earth leakage circuit breakers. It provides details on the working, advantages, and disadvantages of each type.
Here are the key points about multimeters:
- A multimeter is an instrument used to measure multiple electrical properties such as voltage, current, resistance.
- It combines the functionality of a voltmeter, ammeter, and ohmmeter into a single device.
- Basic multimeters can measure voltage, current and resistance. More advanced ones can also measure temperature, frequency and other properties.
- Analog multimeters have a needle dial display while digital multimeters have a digital screen display.
- To measure voltage, the multimeter is connected in parallel across a circuit. For current, it is connected in series. And for resistance, it provides a small current and measures the voltage drop.
- Mult
The present-day electrical power system is A.C. i.e. electric power is generated, transmitted and distributed in the form of alternating current. The electric power is produced at the power stations which are located at favourable places, generally quite away from the consumers. It is delivered to the consumers through a large network of transmission and distribution
The document provides information about ABB's medium voltage V-Contact VSC contactors. It describes the contactors' permanent magnet drive system and vacuum interrupter breaking mechanism. It lists the available contactor versions and their technical specifications, including voltage ratings, short circuit ratings, switching times, and environmental compliance standards. Installation and application information is also provided.
This document discusses power system protection devices. It covers the objectives of power system protection which is to isolate faulty sections from the rest of the system. It describes components that need protection like generators, transformers, busbars and transmission lines. The main protective system elements are fuses, protective relays, circuit breakers, and instrument transformers. It discusses different types of relays like electromechanical, static, numerical and thermal relays. It also covers different types of circuit breakers based on voltage level and arc quenching media. Other devices discussed are reclosers, polyswitches, earth leakage and residual current circuit breakers.
The document discusses substations and their components. It defines a substation as an assembly of apparatus that transforms electrical energy from one form to another, such as changing voltage levels. Substations contain step-up transformers to increase voltage for transmission and step-down transformers to decrease voltage for distribution to consumers. The document describes various types of substations and explains their functions. It also provides details about components within substations such as circuit breakers, transformers, buses, isolators and instrument transformers.
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1 residual current circuit breaker (rccb) ( elcb)
1. Residual Current Circuit Breaker
www.saraswateng.com
Introduction – Residual Current Circuit Breaker / ELCB
The Fault current overloads and short circuits
can be detected by circuit breakers like MCB’s
MCCB’s & HRC Fuses etc. But, Circuit
breakers don’t detect leakage currents, which
are dangerous for humans and livestock and if
not detected can lead to fire hazards. We need
a solution that detects such leakages currents
and disconnects the circuits from the power
supply. Here comes the solution in the form of
RCCB (Residual Current Circuit Breaker) also
known as ELCB (Earth Leakage Circuit
Breaker) which provides protection against
direct and indirect contact of personnel or
livestock and against probable fires.
Product
Stop Shock RCCB’s.
Classification
Domestic and Industrial use Residual Current
Circuit Breaker.
Range
Available in 2 Pole and 4 Pole.
Application
Prevents shocks caused by earth leakage
which could be fatal.
As per the Rule 61A of the Indian Electricity
Rules 1956, the supply of energy of following
installations shall be controlled by the earth
leakage protective devices so as to disconnect
the supply instantly on the occurrence of earth
fault or leakage current.
• Installations having load above 5KW.
• Luminous Tube Installations.
• X – Ray Machines.
2 Pole
Used for three phase electrical connections, for
industrial and commercial purposes.
As per Government of India Gadget notice, the
RCCB’s must have ISI mark in India.
Selling of non ISI RCCB’s in India is prohibited.
6, Vanrai Complex, W E Highway, Goregaon (E), Mumbai – 400065. E-mail: response@saraswateng.com
2. Residual Current Circuit Breaker
www.saraswateng.com
Salient Features
• Use of special magnetic materials for the toroidal core balance transformer and a specially
developed highly sensitive miniature relay ensure positive detection of earth leakage currents
as low as 30mA in less than 40 milli seconds thereby acting as a life saver. All the RCCB's are
protected from nuisance tripping against transit voltages (lighting, line disturbances...) and
transient currents (from high capacitive circuits).
• STOP SHOCK RCCB's are housed in high quality thermoplastic insulating material. The
materials used are fire retardant, anti tracking, non-hygroscopic, impact resistant and can
withstand high temperatures.
• The moving contacts of the phases are put on a moving arm, actuated by a rugged toggle
mechanism. Hence the closing and opening of all the phases occur simultaneously. This also
ensures simultaneous opening of all the contact under automatic tripping conditions.
• STOP SHOCK RCCB's incorporate advanced neutral i.e. neutral makes ahead of phases and
breaks after phases, which ensures complete discharge of line inductance and capacitance. (It
also has safe interrupting clearances as per IS: 13947-1. These two provisions make STOP
SHOCK RCCB an ideal selection as main switch.)
• ON & OFF Positions is clearly visible with the help of window provided at the top of housing.
The green colour indicates the OFF position and red colour indicates the ON Position.
• Mechanism components are made of plastic which are of high-quality, high-strength, low
inertia and self lubricating properties. This results in a very fast opening action of the device
under fault conditions. Though the moving components of the mechanism are made of plastic
for friction free and smooth operation, load bearing parts of mechanism are made of high-
strength steel thus the combination resulting in making the mechanism more sturdy.
• RCCB’s relay draws the energy from the residual current which it needs to trip the RCCB
that’s why it can still operate normally if the mains voltage drops or if the neutral wire is
interrupted, even a relatively long period of over voltage resulting from a fault current in the
mains can’t destroy RCCB or interfere with its normal operations.
• The ever increasing use of rectifies, particularly in the mining industry, requires safety
measures against fault current which will also safety detect and respond to AC residual
currents with a frequency of 50Hz to smooth DC residual currents. This so-called universal
sensitivity which can only be achieved with auxiliary voltage-dependents circuit breakers, i.e
‘DI’ devices.
Equipments likely to emit smooth DC residual currents may only be used outside house
instillations and it may not be operated downstream of ‘normal’ RCCB’s to which other circuits
are connected. In the events of a residual DC current arising, the RCCB’s operation could be
impaired and it might not even trip if a residual current occurs simultaneously at another
electrical equipments. In order to be able to ensure selective protection against direct and
indirect contact, professional bodies are increasingly demanding that AC-DC sensitive devices
be employed. Our devices are designed and constructed to IEC 1008 / IS: 12640 – 2000.
They will respond to residual currents from smooth DC currents to 400Hz AC and pulsating
currents and provide extremely high operational reliability. These RCCB’s are available in
selected rating only.
6, Vanrai Complex, W E Highway, Goregaon (E), Mumbai – 400065. E-mail: response@saraswateng.com
3. Residual Current Circuit Breaker
www.saraswateng.com
• RCCB’s are provided with an ARC chamber consisting of arc-chute. They arc-chute quenches
the arc faster, which further increases electrical contacts life.
• STOP SHOCK RCCB’s are life saving devices and hence, incorporate a lest button ‘T’ for
periodic checking of the mechanism and function of the RCCB.
• Apart from suitability to copper cables the terminals are suitable for aluminum cables from 1 to
25 Sq.mm.
• STOP SHOCK RCCB can be easily mounted on a standard DIN rail of 35mm. Furthermore,
operation of the RCCB is independents of mounting position. Supply connections can be
terminated can be terminated either from top or bottom.
• STOP SHOCK RCCB’s have been completely type tested at CPRI / ERDA in accordance with
IS: 12640-1-2000 and is ISI Marked.
Principal of Operation
Residual current protection in the event of indirect contact
RCCB works on the principle that in an electrical circuit the incoming current is the same as out
going current as shown in the Diagram. RCCB incorporates a core balance transformer having
primary and secondary windings and a sensitive relay for instantaneous detection of fault signal.
The primary winding lies in series with the supply mains and load. Secondary winding is
Connected to a very sensitive relay. In a faultless situation, the magnetizing effects of the current
carrying conductors cancel each other out. There is no residual magnetic field that could Induce a
voltage in the secondary. During flow of leakage current in the circuit an imbalance is created in
the circuit which gives Rise to leakage flux in the core. This leakage flux generates an electrical
signal that is sensed by the relay and it trips the Mechanism thereby disconnecting the supply.
When pressing the TEST button 'T', a fault is simulated via the Test resistance & RCCB trips.
To ensure that the RCCB switches off the protected circuit Immediately. If there is an insulation
fault causing a short-circuit to an exposed part (frame etc.) of machinery and equipment
(protection against indirect contact), the maximum permissible touch voltage U must occur at a
residual current greater than or equal to the rated residual operating current I that triggers the ?n
RCCB. This condition is met by earthing the exposed part with a Sufficiently low resistance to
earth RE.
Earth Resistance RE < Touch Voltage U E T
Rated Residual operating current – I
The maximum values of R for touch voltages of 25V, 50V & 65V E
are given in the specification tables.
cal effects
Fire Protection
To provide extra protection in the event of direct contact with an (unearthed) live part, extremely
sensitive RCCB's with a rated residual operating current of 30 mA or less (I = 30 mA) are used
instead of more conventional RCCB's with higher residual operating fault currents.
This extra protection is necessary if:
1) The insulation of totally insulated devices or their loads are damaged.
2) The earth wire is interrupted
3) The earth wire and live wire are transposed (accidentally thus rendering line the body of a
protection class I device).
4) A component which is live in normal operation is touched during repair work.
In view of this increased range of protection, an RCCB or RCCB/MCB with
6, Vanrai Complex, W E Highway, Goregaon (E), Mumbai – 400065. E-mail: response@saraswateng.com
4. Residual Current Circuit Breaker
www.saraswateng.com
I = 30 mA is must - by law in some European countries - to be used when? Installing machinery of
equipment in areas with particularly high accident risk.
l Socket-outlet power circuits in rooms with bath or shower.
l Caravans, boats and yachts and their power supply on camping or berthing
Sites
l Electrical appliances in rooms used for medical purposes.
The drawn-in switch-off characteristics of residual current devices with a rated fault current of 10
and 30 mA make it clear that these residual current devices are able to prevent the occurrence of
the dangerous heart chamber fibrillation. For this reason, residual current circuit breakers with
rated fault currents of 10 mA are used for the protection of particularly exposed individual
equipment. Residual current circuit breakers with 30 mA rated fault current are already specified
today for many areas (bath, medically utilized rooms, outside areas, agriculture, etc.) in order to
ensure the protection of persons.
• Usually no reaction effects.
• Usually no harmful physiological effects.
• Usually no organic damage to be expected. Likelihood of muscular contraction and difficulty of
breathing reversible disturbance of formation and conduction of impulses in the heart and
transient cardiac arrest without ventricular fibrillation increase with current magnitude and
time.
• In addition to the effects of zone 3, increasing with magnitude and time pathy physiological
effects such as cardiac arrest, breathing arrest and heavy burns may occur.
Even relatively insensitive RCCB's (I = 300 mA) can be used to provide effective protection
against fire caused by earth-Ieakage faults. With a residual current = 300 mA, the electrical
energy released at the location of the earth fault is not sufficient to ignite normal building
materials. With larger residual currents, the RCCB switches off the circuit in less than 200
milliseconds, thus limiting the amount of energy released to a harmless level.hysiological
effects
Fire Protection
Additional Protection Against Pulsating Fault Currents.
t finding when RCCB trips
While the tripping of residual current circuit breakers with pure alternating fault currents was usual and
adequate in the past, these can only be used conditionally in modern electrical installations. With light
controls, speed controls etc. pulsating forms of current increasingly occur also as fault currents as a result of
the use of electronic components. In order to tackle such pulsating direct fault currents which tend to zero or
almost zero within every period of the mains frequency at least for half a period, 'A' type of RCCB's are
suitable. Type A is more sensitive than AC type. It covers all requirements of AC type plus it is pulse current
sensitive.
Precaution for Installations
Wiring should be done by a trained & qualified electrician as per the wiring diagram.
All wiring necessary for operation shall be passed through the RCCB.
The neutral conductor must be insulated against earth to the same extent as the live conductors.
All equipments used must be properly earthed.
To ensure correct functioning care must be taken that the neutral conductor on the load side of the RCCB
must not be Connected to earth, otherwise nuisance tripping may occur or tripping may be impaired.
Suitable device either MCB or HRC fuses shall be used for short circuit and overload protection of the
circuit under installation.
6, Vanrai Complex, W E Highway, Goregaon (E), Mumbai – 400065. E-mail: response@saraswateng.com
5. Residual Current Circuit Breaker
www.saraswateng.com
Don't expose the circuit breaker to direct sunlight, rough weather and keep it away from the influence of
magnetic field.
Fault finding when RCCB Trips
Switch OFF all the switches/MCB connected in the circuit downstream the RCCB. Switch ON RCCB and
switch ON the Switches one by one. You will find that during switching ON of a particular appliance/switch
RCCB trips again and again
Which shows that this is the faulty circuit/appliance. Isolate the faulty circuit, rectify the fault and switch ON
the RCCB.
Permissible Earth Resistance (R ) With Max. Permissible Touch Voltage (U )
Therefore the following earth resistance must be guaranteed with 300mA rated fault current of the selective
switches :
U = 25V R = 83 Ohm U = 50V R = 166 Ohm U = 65V R = 216 Ohm
Touch Earth Resistance R (?) Sensitivity I (mA)
Voltage (U) (V) 30 100 300
25 833 250 83
50 1666 500 166
65 2160 650 216
Sensitivity Application
30mA Tripping current designed for additional protection against direct contact, or where
specially required b y
the Indian wiring regulations, the 30 mA RCCB protects against leakage currents and
indirect
contact with earth loop impedance up to 1667 Ohms; for use as additional protection
against direct
contact, residual tripping current must not exceed 30 mA.
100mA Tripping current is suitable for protection against indirect contact and leakage currents for
larger
installations; the 100 mA RCCB's operate within 30 ms, but do not provide the same
level of
personal protection as the 30 mA units; the 100 mA RCCB protects against leakage
currents and
indirect contact with earth loop impedance up to 500 ohms.
300mA A less sensitive protection suitable for large installations having high levels of leakage
current;
300 mA RCCB's protect against leakage current and indirect contact up to 167 ohms
earth loop
impedance.
6, Vanrai Complex, W E Highway, Goregaon (E), Mumbai – 400065. E-mail: response@saraswateng.com
6. Residual Current Circuit Breaker
www.saraswateng.com
Dimensional Drawing
Wiring Diagram
6, Vanrai Complex, W E Highway, Goregaon (E), Mumbai – 400065. E-mail: response@saraswateng.com