VIRGINIA DEPARTMENT OF MINES, MINERALS & ENERGY DIVISION OF MINES ELECTRICAL REPAIRMAN MAINTENANCE FOREMAN & CHIEF ELECTRICIAN CERTIFICATION STUDY GUIDE 2011 Copyright 1997 Commonwealth of Virginia Commonwealth of Virginia Department of Mines, Minerals, and Energy Division of Mines P.O. Drawer 900 Big Stone Gap, VA 24219 (276) 523-8100 Repairman, Maintenance Foreman, and Chief Electrician Certification Study Guide INTRODUCTION The purpose of the Electrical Repairman, Maintenance Foreman and Chief Electrician Certification Study Guide is to assist a qualified applicant in obtaining the Underground Electrical Repairman, Maintenance Foreman and/or Chief Electrician certification(s). The Board of Coal Mining Examiners (BCME) may require certification of persons who work in coal mines and persons whose duties and responsibilities in relation to coal mining require competency, skill or knowledge in order to perform consistently with the health and safety of persons and property. The purpose of the electrical repairman’s section is to assist an applicant who possesses one-year electrical experience in underground coal mining in obtaining an Underground Electrical Repairman certification in accordance with the regulations for the BCME’s certification requirements. Applicants may be given six months credit for electrical educational training from a college, technical school, or vocational school. In addition, each applicant shall pass examinations in first aid and gas detection. The purpose of the maintenance foreman’s section is to assist the electrical repairman who possesses three years of electrical experience in underground coal mining in obtaining a Maintenance Foreman certification. Knowledge of the material in the repairman’s and maintenance foreman’s sections is needed to prepare for the examination. The Maintenance Foreman applicant shall hold a valid electrical repairman’s certification and shall meet the continuing education requirements prior to being eligible to take the Maintenance Foreman examination. An applicant shall possess three years electrical experience as applied to underground mining. An applicant may be given one-year credit for an electrical engineering degree or six months credit for electrical education training from a technical or vocational school. In addition, each applicant shall pass an examination in first aid. The purpose of the chief electrician’s section is to assist the Maintenance Foreman who possesses 5 years of electrical experience in underground coal mining in obtaining the Chief Electrician certification. Knowledge of the material in the repairman’s, electrical maintenance foreman’s and the chief electrician’s sections is needed to prepare for the examination. The Chief Electrician applicant shall hold a valid Electrical Repairman and Maintenance Foreman certification prior to being eligible to take the Chief Electrician examination. An applicant shall possess five years electrical experience as applied to underground mining or appropriately related work experience approved by the Chief of the Division of Mines and shall meet continuing education requirements. In addition, each applicant shall pass a first aid examination. DEPARTMENT OF MINES MINERALS AND ENERGY DIVISION OF MINES DISCLAIMER Article 3 of the Coal Mine Safety Laws of Virginia establishes requirements for certification of coal mine workers. The certification requirements are included in §45.1- 161.24 through §45.1-161.41 in which the Board of Coal Mining Examiners is established for the purpose of administering the certification program. The Board has promulgated certification regulations 4 VAC 25-20, which set the minimum standards and procedures required for Virginia coal miner examinations and certifications. The Virginia Department of Mines Minerals and Energy, Division of Mines developed this study guide to better train coal miners throughout the mining industry. The study guide material should be used to assist with the knowledge necessary for coal mining certifications. The material is not all-inclusive and should be used only as an aid in obtaining knowledge of the mining practices, conditions, laws and regulations. This material is based upon the Coal Mining Safety Laws of Virginia, Safety and Health Regulations for Coal Mines in Virginia, Title 30 Code of Federal Regulations (30 CFR), State and Federal Program Policy Manuals and other available publications. Nothing herein should be construed as recommending any manufacturer’s products. The study guide and materials are available at the Department of Mines, Minerals and Energy. Any questions concerning the study guide should be addressed to the Regulatory Boards Administrator at the Big Stone Gap Office. Electrical Repairman, Maintenance Foreman, and Chief Electrician Certification Study Guide TABLE OF CONTENTS Section I Electrical Repairman Section Chapter 1 Introduction to Electricity, Direct Current 1 Chapter 2 Alternating Current 48 Chapter 3 Electrical Circuits and Equipment 91 Chapter 4 Cable Splicing 162 Chapter 5 High Voltage 191 Chapter 6 Legal Requirements 214 Chapter 7 Permissibility 246 Chapter 8 Diesel Equipment 306 Chapter 9 Electrical Practical Stations 312 Chapter 10 Electrical System Review 331 Section II Maintenance Foreman Section Chapter 1 Electrical Inspection, Testing, Examination and Diesel 368 Equipment Chapter 2 Electrical Theory Review 374 Chapter 3 Power Sources: Batteries, Rectifiers and Transformers 377 Chapter 4 Grounding and Ground Monitoring 384 Chapter 5 Electrical Motors 394 Chapter 6 Inductance, Capacitance and Impedance 397 Section III Chief Electrician Section Chapter 1 Electrical Inspection, Testing, and Examination 412 Chapter 2 Circuits, Equipment and High Voltage 438 Chapter 1 Introduction to Electricity Direct Current A. Electron Theory 2 B. Electrical Units 5 C. Electromagnetism 8 D. Types and Sources of Electricity 13 E. Ohm’s Law and Basic Electrical Circuits 16 F. Batteries 26 G. Direct Current Motors and Generators 31 H. Electrical Meters 32 I. Direct Current (DC) Review 36 (Questions and Answers) J. Glossary of Terms 46 Introduction to Electricity CHAPTER 1 INTRODUCTION TO ELECTRICITY DIRECT CURRENT Electricity was first introduced into coal mines before the beginning of the 20th century in the form of direct current for rail haulage. Direct Current (DC) generators provided power for most electrical power systems. Batteries served as the first power source for rail haulage. Keeping the batteries charged was impossible, so trolley wires were soon introduced. The first electrically driven coal mining equipment installed in the 1920's was the coal-cutting machine. Shuttle cars were introduced in the late 1930's. Electrically powered continuous mining machines were introduced in the late 1940's. From the 1950's and extending to present day mining, alternating current (AC) systems have replaced the vast majority of DC systems. Most present day equipment operates in a wide range of voltages from 440 volts to 4,160 volts. The AC systems are more complicated but are more efficient than DC systems. This brief review of the development of electrical systems in coal mines has shown that mines have gone from DC (trolley wire systems) rail haulage to very complicated AC systems. 1 Introduction to Electricity A. ELECTRON THEORY Everything around us, even the air we breathe, occupies space and has weight. Anything that meets this description is called matter. It is impossible to name a physical substance or object that is not matter. Coal, water, wood, and gas all are examples of matter. What does matter consist of? Matter is made of very small units called molecules. The molecules are made of atoms. The atoms, in turn, are made of minute particles called protons, neutrons, and electrons. Elements Not only does matter consists of the minute particles mentioned in the preceding paragraph, but also all matter is composed of elements. Elements are the so called "building blocks of nature.” Elements cannot be divided or reduced to a simpler substance by chemical means. Examples of elements are pure iron, gold, silver, copper, hydrogen, and oxygen. There are some 90 naturally occurring elements known to man. Elements may be combined in two different ways, in either compounds or mixtures. A compound is a combination of elements that can be separated only by chemical means. Examples of familiar compounds are pure water (which is composed of the elements hydrogen and oxygen) and salt (which is composed of the elements sodium and chlorine). Molecules A drop of water can be divided into many small parts. In fact, it can be divided until the parts are no longer visible, yet each part retains the characteristics of the original drop. The smallest part of a substance that has all the characteristics of that substance is called a molecule. A single drop of water is made up of many millions of molecules, as are all other substances. A molecule of water is expressed chemically as H20, meaning that each molecule is composed of two distinct elements. H20 stands for the combination of two parts of the element hydrogen (H) and one part of the element oxygen (0). The water molecule has a very simple structure, consisting of only two common elements. Molecules of other substances may be more complex, sometimes consisting of several elements. Atoms The individual elements that combine to form molecules are made up of atoms. For a long time it was thought that, the atom was the smallest subdivision of matter. However, in recent years, the electron theory