Pdf basics of electrical engineering a text book for. Although electricity supply companies will often provide an earth terminal, they are under no legal obligation to do so. Important formulas for designing a substation grid earthing system. In any discussion of the grounding of electrical systems, particularly as it applies to power systems. Basic principles of electrical grounding for electricians and technicians photo credit. The checklists are in pdf format and can be completed electronically or printed and used as hard copy. Pdf most engineers view earthing mainly as a method to protect equipment from damage or malfunction. We have already given an introduction to substation earthing system in an article published earlier. This is a preliminary, rough cut, of a onetake training video. Using the basic electrical floor plan and the symbol chart on the following pages, explain the electrical symbols to the students. Electrical grounding is a basic principle of electrical engineering and home circuitry wiring, but it is also used to protect people and property from a lightning strike. It protects them from electrical shocks when a piece of electric equipment has an insulation failure to ground. This kind of poles has a longer life, and the maintenance cost is negligible. It is also the main element for avoiding rf intrusion in communication.
The concept of earthing system as per bnbc bangladesh national building code. This pdf contains 77 electrical inspection checklists taken from the 2014 electrical inspection manual with checklists. Grounding, or earthing, is a fundamental topic for the correct operation of electrical systems and devices. Concept of earthing systems all the people living or working in residential, commercial and industrial installations, particularly the operators and personnel who are in close operation and contact with electrical systems and machineries, should essentially be protected against possible electrification. These beds basically have conductive systems that transfer the earths electrons from the ground into the body. Uncategorized 2 comments as a part of the safety and standard sweep in the textile factories in bangladesh, as an auditor i have visited more than dozens of facilities. Most modern homes in europe have a tncs earthing system. Pdf power continuity and electrical safety are essential for all. The cross section of the buried cable should calculated in accordance with the value of the phaseto earth short. The basics of grounding electrical systems technical. Electrical earthing is one of the most essential parts of electrical engineering. The conductor wire, which is connected among different electrical devices and appliances like, distribution board, different plugs and appliances etc. Theses parameters must be considered in earthing system design. Its is a short, instructional video about electrical grounding, aimed at nabcep pv entry lev.
Give students a standard photocopy of a floor plan see the end of this activity plan that. Principles of electrical grounding john pfeiffer, p. When designing an electrical installation, one of the first things to determine is the type of earthing system. Circuit drawings and wiring diagrams open school bc. Grey matters offers electrical earthing training and grounding training courses. Basics of electrical grounding earthing and bonding power. Before 1960s the design criterion of substation earthing system was low earth resistance. A fundamental aspect of electrical engineering, electrical grounding is the manner in which an electrical circuit is attached to the earth or the ground. When people are tripped up by the requirements for grounding, its often because they dont realize art. That part of the earthing system which interconnects the overall metallic parts of electrical installation e. Earth wells for a specific building or installation are actually the location, where the pure zero potential is provided and practically act as drain pits for any rush current which accidentally appears in the earthing system grid in the event of an earth fault connection of electrical live parts to the earthing system.
But having an earthing system is not enough you have to calculate your overall load and individual earthing for each electrical equipment and machine. Just like the sun constantly provides us with important energy, nutrients and vitamins, the earth too is a source of subtle energy that provides important elements that contribute to optimum health. This arrangement covers installations not provided with an earth terminal by the. Earthing refers to a physical connection that takes place between the electrical frequencies of the human body and those of the earth. All exposedconductiveparts of an installation are connected to an earth electrode. You can understand grounding by overcoming common reasons for confusion. The largest collection of symbols in the network in pdf format. National electrical code and canadian electrical code forbid the use of systems that combine the grounding conductor and neutral beyond the customers disconnecting switch.
This type of poles is costlier than a wooden pole but cheaper than a steel pole. The checklists are intended to help inspectors keep track of the numerous aspects of an electrical installation. There are two methods to accomplish this system of grounding, namely the low resistance grounding and high resistance grounding. You may deal will different types of electrical equipment and if there is no earthing system then you are at high risk. Most of the electrical, electronic, or civil engineers view electrical earthing for protecting the buildings, equipment from some breakdowns or damages, but the safety of an operator is the most essential element. In argentina and france the customer must provide its own ground connection tt. Basic principles of electrical grounding for electricians. Commonly called a lightning rod, it is really a grounding rod. Substation earthing system design underground horizontal earth mesh matgrid the mesh is formed by placing mild steel bars placed in x and y directions in mesh formation in the soil at a depth of about 0. Earthing department of electrical engineering, iit bombay. Either rigid or flexible, conduit protects the wires and is used in exposed locations, such as along the exterior surface of a wall. Control panel technical guide how to protect a machine from malfunctions due to electromagnetic disturbance 10 layout of equipment in a panel 1 importance of the layout if highpower and lowpower devices are juxtaposed without taking precautions and if cables of different kinds are routed in the same raceways, serious malfunctions are. Today we are going to discuss the design of substation earthing system. Grounding is a huge topic full of standards, practical rules, misconceptions, surprises, and some magic.
Lp consultants international pvt ltd 208,647 views 5. While it is easy to understand the definition of earthing, the topic of earthing and its application in practice is often the most misunderstood of all. It is also used in unfinished areas, like basements, crawlspaces, and attics, and for surfacemounted installations outdoors. There are two methods to accomplish this system of grounding, namely the low resistance. System earthing is primarily required to ensure that the potential of each conductor of the system restricts to its desired value for which the insulation is provided. The international standard iec60364, part 4, and reference 10 uses a set of diagrams to explain the five basic methods of earthing and providing the neutral of an electrical installation where it is required. Scribd is the worlds largest social reading and publishing site. Today i will explain steps of earthing systems design process as follows. Fundamentals of earthing for power systems may 2019. Concept of earthing systems all the people living or working in residential, commercial and industrial installations, particularly the operators and personnel who are in close operation and contact with electrical systems and. Oct 28, 2009 electrical earthing system a grid of hard drawn high conductivity copper tapes of crosssectional area not less than 150 sq. Basic electrical engineering pdf notes bee pdf notes.
Earthing system is made of a mesh of buried bare copper cable, with additional earth rods, and shall be calculated, being recommended to use ieee std. Hence, the emphasis of the course is on the main principles for high voltage system earthing v ac and higher. May 17, 2016 lightning protection design, earthing system design lightning protection for buildings design duration. Bus protection l overcurrent l differential l backup l under voltage. The system earthing is so designed that it should facilitate the efficient and quick operation of protective relays in case of any earth. Download fulltext pdf basics of electrical engineering a text book for first year b tech students of engineering all specializations book july 2016 with 125,432 reads. The distributor will be able to provide this information. Earthing also known as grounding, is simply connecting your body directly to the subtle, natural electrical energy that exists on the surface of the earth. Electricity safety, quality and continuity regulations.
Home download center electrical engineering books and technical guides power substation guides power system earthing guide hazard scenarios consideration of appropriate safety criteria usually an allowable shock voltage is required for all electrical assets that form part of the network. The electrical earthing is done by connecting the noncurrent carrying part of the equipment or neutral of supply system to the ground. The basic understanding of an earthing protection system diagram and definitions earthing of the supply in a house or building serves as a protection for the users. Nov 27, 2011 the main reason for doing earthing in electrical network is for the safety.
The earthing or grounding of an electrical system plays a very important role for the stability and safety operation of the system. Earthing of electrical equipment and power systems in. Probably one of the most important safety aspects of an electrical system is correct earthing or grounding throughout the installation. The concept of earthing system as per bnbc bangladesh. Electrical earthing grounding systems a technical report and a short course. However, few people understand this matter or the reason it is used. In modern home wiring systems, each circuit has its own ground wire that leads back to the service panel. Johnston neca executive director, standards and safety 1 welcome to a neca webinar based on the national electrical code.
This is a discussion of the basic principles behind electrical grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers basic principles of electrical grounding for electricians and technicians photo credit. This is a discussion of the basic principles behind grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers. It will therefore be worthwhile to explore some points about the basics of earthing. If the live wire touches the grounded case then the circuit is effectively shorted and fuse. As fault current can be coupled to nonpower system plant, so it is required to also consider the safety requirements at those locations outside the substations and easements the specific locations will represent a different risk profile by virtue of the fact that there will be different coincident probabilities of system events and human contacts and different series impedance for example. The connection made with the earth is vital, for it uses the ground as a conductor. Earthing resistance, configuration of the earth electrode and favourable earth surface potential distribution, adequate current carrying capacity, long durability. This seminar is the first in a short series of electrical grounding and bonding webinars presented by neca. Electrical basics ohms law ohms law is a mathematical equation that shows the relationship between voltage, current and resistance in an electrical circuit. The electrical equipment has two noncurrent carrying parts such as neutral of the system and frame of the equipment. What is electricity the definition of electricity is the flow of charge. Basic principles of electrical grounding for electricians and. An unfamiliarity with the fundamental differences between the terms bonded, grounded, and effectively grounded makes the situation even worse.
Electrical earthing definition, types of electrical. The earth is so comparatively large, any excess current traveling through a circuit is absorbed by dirt, water, rocks, and everything else that comprises it. Jun 26, 2018 the earthing or grounding of an electrical system plays a very important role for the stability and safety operation of the system. V i x r r v i i v r where v voltage i current r resistance. Electrician circuit drawings and wiring diagrams youth explore trades skills 5 activity 1. Electrical conduit is metal or plastic pipe through which electrical wires are run.
Earthing system components part one electrical knowhow. Components of electrical earthing system earth continuity conductor or earth wire. Basics of electrical grounding earthing and bonding free download as powerpoint presentation. Differential protection i 1p i 1s ct1 20005 a i 2p i 2s bus ct2 20005 a h1 x y i i 1s i 2s i i 1s i 2s i i1p i2p i 2s i 1s. Basics, maintenance, and diagnostics xi contents continued page 9. Types of earthing systems used in electrical installations.
For consultation and interpretation of components, devices and electrical and electronic circuit. Design of earthing grounding system in a substation grid. You can do this by walking barefoot outside or by using barefoot substitutes like the ones we teach you about on our site. Basics of electrical grounding earthing and bonding. Earthing systems design steps part one electrical knowhow.
Dec 24, 2018 an electrical ground is a safety system that provides a safe path for electricity to follow in the event of a short circuit, electrical surge, or other safety or fire hazard. Therefore, flexibly tailored from halfday courses to fullday or longer seminars. In high and medium voltage air insulated substations ais the electromagnetic field, which causes are the static charges of bare cable and conductors and by the atmospheric conditions surges, induce voltages at nolive parts of the installation that create potential differences between metallic parts and ground and also between different points of. Jul 27, 2018 system earthing is primarily required to ensure that the potential of each conductor of the system restricts to its desired value for which the insulation is provided. Resistance grounding in an electrical system is defined as the use of a resistor as a grounding path between the neutral point of transformer or generator and the earth ground. Electrical earthing or grounding concept engineering basic. The process of connecting neutral of the system to the earth through a gi wire is known as neutral earthing or system earthing. Just like the sun constantly provides us with important energy, nutrients and vitamins, the earth too is a source of subtle energy that provides important elements that contribute to. This device channels the charge from a lightning strike away from areas of the house that would otherwise absorb. Jun 19, 2016 this is a preliminary, rough cut, of a onetake training video. The system earthing is so designed that it should facilitate the efficient and quick operation of protective relays in.
A type of electricallycharged bed has been created that features silver wires that are connected to the electrical charge of the earth once plugged into an earthing port. Electrical earthing fully explained fletcher electric. The process of transferring the immediate discharge of the electrical energy directly to the earth by the help of the low resistance wire is known as the electrical earthing. This is a discussion of the basic principles behind electrical grounding systems and how grounding is related to safety and the effective operation of circuit protection devices such as fuses and circuit breakers. One can distinguish several types of earth electrodes including. Pdf electrical earthing grounding systems a technical report. Ppt earthing system powerpoint presentation free to. Basics of electrical before getting into electrical circuit its important to understand electrical terms. When all metallic parts in electrical equipments are grounded then if the insulation inside the equipments fails there are no dangerous voltages present in the equipment case.
Principles of electrical grounding pfeiffer engineering. The first letter denotes the source of power from a starconnected winding. Earthing grounding quiz questions electrician exams. You have to calculate your overall load and individual earthing for each electrical equipment and. Power system earthing guide electrical engineering portal. Electrical earthing grounding systems a technical report and a short course technical report pdf available february 2018 with 15,911 reads how we measure reads.