Book excerpt: The Oregon 2020 Master study guide will help you prepare for the exam by providing 12 practice open book exams and 2 Final Closed Book Exams. Includes Oregon License Forms and Sample Applications. This book also covers most topics that are included on all Master Electricians exams such as conductor sizing and protection, motors, transformers, voltage drop, over-current protection and residential and commercial load calculations. The text contains the most widely used electrical calculations and formulas the reader needs to pass the Master electrical competency exam.About the AuthorRay Holder has worked in the electrical industry for more than 40 years as an apprentice, journeyman, master, field engineer, estimator, business manager, contractor, inspector, and instructor. He is a graduate of Texas State University and holds a Bachelor of Science Degree in Occupational Education. A certified instructor of electrical trades, he has been awarded a lifetime teaching certificate from the Texas Education Agency in the field of Vocational Education. Mr. Holder has taught thousands of students at Austin Community College; Austin Texas Odessa College at Odessa, Texas; Technical-Vocational Institute of Albuquerque, New Mexico; Howard College at San Angelo, Texas, and in the public school systems in Fort Worth and San Antonio, Texas. He is currently Director of Education for Electrical Seminars, Inc. of San Marcos, Texas. Mr. Holder is an active member of the National Fire Protection Association, International Association of Electrical Inspectors, and the International Brotherhood of Electrical Workers.