Product reliability is one of the important aspects of product quality. It's dependent on the reliability of every component used in the system. In Reliability Basic Theories and Applications in Electrical Apparatus, authors Lu Jianguo, Wang Jingqin, Luo Yanyan, and Su Xiuping, colleagues at Hebei University of Technology, present a guidebook to help manufacturers ensure the soundness of their electrical products. Providing information about how to design, test, and interpret the results, Reliability Basic Theories and Applications in Electrical Apparatus; gives an introduction to the history of electrical apparatus development and the content of reliability work; expounds on the fundamental knowledge of reliability; discusses the basic theory of reliability sampling, inspection, and design; details the reliability indices, reliability test method, reliability verification test sampling plan, test procedure 'shows reliability tests for relays, contactors, miniature circuit breakers, residual current operated circuit breakers, low-voltage circuit breakers, and overload relays. Summarizing achievements from the last thirty years, Reliability Basic Theories and Applications in Electrical Apparatus offers a collection of the many standards used in the certification of electrical apparatus, such as relays, contactors, molded case circuit breakers, and miniature circuit breakers.

Reliability Basic Theories and Applications in Electrical Apparatus

By Lu Jianguo Wang Jingqin Luo Yanyan Su Xiuping

iUniverse, Inc.

Copyright © 2012 Lu Jianguo, Wang Jingqin, Luo Yanyan, Su Xiuping
All right reserved.
ISBN: 978-1-4759-5240-7

Contents

Preface..........................................................................................iiiChapter 1 Overview...............................................................................11 Survey of Electrical Apparatus Reliability.....................................................22 Definition of Reliability......................................................................183 Relation between Product Reliability and Quality...............................................194 Inherent Reliability and Use Reliability.......................................................195 Failure Laws...................................................................................206 Significance of Improving Electrical Apparatus Reliability.....................................217 Basic Content of Reliability Work..............................................................22Chapter 2 Basic Knowledge of Reliability.........................................................251 Basic Knowledge of Boolean Algebra.............................................................252 Failure Density Function and Cumulative Failure Distribution Function..........................263 Reliability Characteristic Parameters of Electrical Apparatus..................................294 Failure Distribution Types.....................................................................385 Estimation of Reliability Characteristic Parameters............................................71Chapter 3 Basic Theories for Electrical Apparatus Reliability....................................931 Theory and Methods of Sampling for Electrical Apparatus Reliability............................932 Reliability Design Theory of Electrical Apparatus..............................................111Chapter 4 Reliability of Relay...................................................................1731 Reliability Index..............................................................................1732 Test Requirements..............................................................................1743 Test Method....................................................................................1764 Reliability Test of Relay with Contact Load cc1................................................1805 Reliability Test of Relay with Contact Load cc2................................................1856 Reliability Test Device........................................................................186Chapter 5 Reliability of Contactor...............................................................1951 Reliability Index..............................................................................1952 Test Requirements..............................................................................1953 Test Method....................................................................................1974 Reliability Grade..............................................................................1985 Determined Method of Contactor Reliability in Practical Load Condition.........................2026 Reliability Test Device........................................................................203Chapter 6 Reliability of Miniature Circuit Breaker...............................................2091 Reliability Index..............................................................................2092 Test Requirements..............................................................................2133 Test Method....................................................................................2154 Sampling Plan and Test Procedures of Reliability Verification Test.............................2185 Reliability Test Device........................................................................223Chapter 7 Reliability of Miniature Residual Current Operated Circuit Breaker.....................2291 Reliability Index..............................................................................2292 Test Requirements..............................................................................2323 Test Method....................................................................................2364 Sampling Plan and Test Procedures of Reliability Verification Test.............................2385 Reliability Test Device........................................................................242Chapter 8 Reliability of Low-Voltage Circuit Breaker.............................................2531 Reliability Index..............................................................................2532 Test Requirements..............................................................................2543 Test Method....................................................................................2574 Sampling Plan and Test Procedures for the Reliability Verification Test........................2575 Reliability Test Device........................................................................260Chapter 9 Reliability of Overload Relay..........................................................2931 Reliability Index..............................................................................2932 Test Requirements..............................................................................2943 Test Method....................................................................................2954 Test Plan and Procedure of Reliability Verification Test.......................................2975 Reliability Test Device........................................................................298Reference........................................................................................303Appendix.........................................................................................307

Chapter One

OVERVIEW

The reliability of an electrical product refers to the ability of this product to perform its required functions under stated conditions for a specified period of time. In modern day reliability studies, the advancement of manufacturing must be accompanied by better understanding of the science and technology (S&T) of reliability to solve practical reliability problems.

Reliability technology refers to the engineering methods related to product reliability and has been in continuous development for decades. During the World War II, electronic devices were widely used in military equipment. However, it frequently occurred that various electronic devices were unreliable and could not be effectively put into service. In a battle in the early 1950s, this problem was so remarkable that the radar equipments of the U.S. were frequently incapable of normal operation and idle in repair-waiting state. The high repair and maintenance cost caused by low reliability of electronic devices lead the U.S. industry to start to attach importance to the reliability problems. This embarked the investigation, research and test works that raised the curtain of reliability research in the field of electronic devices. The early researches were focused on the electron tubes and their performance. This focus was not only on its electrical properties, but also attached importance to its resistance to shock and impact and other environmental adaptability.

The period from the 1950s to 1960s was the decades of rapid development of reliability technology during which the U.S. Defense Department established various reliability...