Electrical Contacts Principles and Applications, Second Edition

Covering the theory, application, and testing of contact materials, Electrical Contacts: Principles and Applications, Second Edition introduces a thorough discussion on making electric contact and contact interface conduction; presents a general outline of, and measurement techniques for, important corrosion mechanisms; considers the results of contact wear when plug-in connections are made and broken; investigates the effect of thin noble metal plating on electronic connections; and relates crucial considerations for making high- and low-power contact joints. It examines contact use in switching devices, including the interruption of AC and DC circuits with currents in the range 10mA to 100kA and circuits up to 1000V, and describes arc formation between open contacts and between opening contacts. Arcing effects on contacts such as erosion, welding, and contamination are also addressed. Containing nearly 3,000 references, tables, equations, figures, drawings, and photographs, the book provides practical examples encompassing everything from electronic circuits to high power circuits, or microamperes to mega amperes. The new edition: Reflects the latest advances in electrical contact science and technology Examines current research on contact corrosion, materials, and switching Includes updates and revisions in each chapter, as well as up-to-date references and new figures and examples throughout Delivers three new chapters on the effects of dust contamination, electronic sensing for switching systems, and contact phenomena for micro-electronic systems (MEMS) applications With contributions from recognized experts in the field, Electrical Contacts: Principles and Applications, Second Edition assists practicing scientists and engineers in the prevention of costly system failures, as well as offers a comprehensive introduction to the subject for technology graduate students, by expanding their knowledge of electrical contact phenomena.

Preface to the Second EditionPreface to the First EditionIntroductionEditorContributorsContact Interface ConductionElectrical Contact Resistance: Fundamental PrinciplesRoland S. TimsitIntroductionElectrical Constriction ResistanceEffect of Surface Films on Constriction and Contact ResistanceTemperature of an Electrically Heated a-SpotMechanics of a-Spot FormationBreakdown of Classical Electrical Contact Theory in Small Contact SpotsConstriction Resistance at High FrequenciesSummaryAcknowledgementsReferencesIntroduction to Contact Tarnishing and CorrosionPaul G. SladeIntroductionCorrosion RatesCorrosion GasesTypes of CorrosionGas Concentrations in the AtmosphereMeasurementsMixed Flow Gas Laboratory TestingElectronic ConnectorsPower ConnectorsOther ConsiderationsAcknowledgementsReferencesGas CorrosionWilliam H. Abbott and Paul G. SladeIntroductionThe Field Environments for Electrical ContactsLaboratory Accelerated TestingLubrication and Inhibition of CorrosionAcknowledgementReferencesEffect of Dust Contamination on Electrical ContactsJi Gao ZhangIntroductionDusty Environment and Dust CompositionThe Characteristics of Dust ParticlesApplication Conditions in Dusty EnvironmentTheoretical Analysis of Connector Contact Failure due to the DustFuture WorkReferencesNonarcing ContactsPower ConnectorsMilenko BraunovicIntroductionTypes of Power ConnectorsProperties of Conductor and Connector MaterialsParameters Affecting Performance of Power ConnectionsPalliative MeasuresConnector DegradationPrognostic ModelsShape-Memory Alloys (SMA)Metal Foam MaterialsInstallation of Power ConnectionsAccelerated Current-Cycling Tests (Standards)ReferencesLow-Power Commercial, Automotive, and Appliance ConnectionsAnthony Lee and George DrewIntroductionConnectorsContact TerminalsDegradation of Connector ContactAutomotive Connector ContactsSummaryReferencesTribology of Electronic Connectors: Contact Sliding Wear, Fretting, and LubricationRoland S. Timsit and Morton AntlerIntroductionSliding WearFrettingLubricationReferencesMaterials, Coatings, and PlatingsMorton Antler and Paul G. SladeIntroductionMetallic FinishesProperties Related to PorosityMetallurgical and Structural PropertiesPhysical and Mechanical PropertiesAcknowledgementReferencesThe Electric Arc and Switching Device TechnologyThe Arc and InterruptionPaul G. SladeIntroductionThe Fourth State of MatterEstablishing an ArcThe Formation of the Electric ArcThe Arc in Air at Atmospheric PressureThe Arc in VacuumArc InterruptionAcknowledgementsReferencesThe Consequences of ArcingPaul G. SladeIntroductionArcing TimeArc Erosion of Electrical ContactsBlow-Off ForceContact WeldingChanges in the Contact Surface as a Result of ArcingAcknowledgementsReferencesReed SwitchesKunio HinoharaPrinciples and Design of the Reed SwitchRecommended Contact PlatingContact Surface Degradation and CountermeasuresApplications of Reed SwitchesReferencesLow Current and High Frequency Miniature Switches: Microelectromechanical Systems (MEMS) Metal Contact SwitchesBenjamin F. Toler, Ronald A. Coutu, Jr., and John W. McBrideIntroductionMicro-Contact Resistance ModelingContact Materials for Performance and ReliabilityFailure Modes and ReliabilityConclusionReferencesLow Current SwitchingJohn W. McBrideIntroduction and Device ClassificationDevice TypesDesign Parameters for Static Switching ContactsMechanical Design ParametersThe Measurement of Contact Wear and Contact DynamicsElectrical Characteristics of Low-Current Switching Devices at OpeningElectrical Characteristics of Low-Current Switching Devices at ClosureSummaryAcknowledgementsReferencesMedium to High Current Switching: Low Voltage Contractors and Circuit Breakers, and Vacuum InterruptersManfred LindmayerGeneral Aspects of Switching in AirContacts for Switching in AirLow-Voltage ContactorsLow-Voltage Circuit-Breakers and Miniature Circuit-BreakersSimulations of Low-Voltage Switching DevicesVacuum InterruptersReferencesArc Faults and Electrical SafetyJohn J. SheaIntroductionArc Fault Circuit Interrupters (AFCIs)Arcing FaultsGlowing ConnectionsArcing Fault PropertiesOther Types of Arcing FaultsConclusionsReferencesArcing Contact MaterialsArcing Contact MaterialsGerald J. WitterIntroductionSilver Metal OxidesSilver Refractory MetalsVacuum Interrupter MaterialsTungsten ContactsNon-Noble Silver AlloysSilver-Nickel Contact MaterialsSilver Alloys and Noble MetalsSilver-Graphite Contact MaterialsConclusionAcknowledgementsReferencesContact Design and AttachmentGerald J. Witter and Guenther HornIntroductionStaked Contact Assembly DesignsWelded Contact Assembly DesignsBrazed Contact Assembly DesignsClad Metals, Inlay, and Edge LayContact Alloys for Non-Arcing Separable ContactsAcknowledgementsReferencesElectrical Contact Material Testing Design and MeasurementGerald J. Witter and Werner RiederObjectivesDevice Testing and Model Switch TestingElectrical Contact Testing VariablesElectrical Testing Result Types and Measurement MethodsReferencesArc Interactions with ContaminantsGerald J. Witter and Werner RiederIntroductionOrganic Contamination and ActivationMineral Particulate Contamination of Arcing ContactsSilicone Contamination of Arcing ContactsLubricants with Refractory FillersOxidation of Contact MaterialsResistance Effects from Long ArcsAcknowledgementsReferencesSliding Electrical ContactsSliding Electrical Contacts (Graphitic Type Lubrication)Kiochiro Sawa and Erle I. Shobert IIIntroductionMechanical AspectsChemical AspectsElectrical EffectsThermal EffectsBrush WearBrush Materials and AbrasionSummaryReferencesIllustrative Modern Brush ApplicationsWilferd E. Yohe and William A. NystromIntroductionBrush MaterialsBrush ApplicationsSliding Contacts for Instrumentation and ControlGlenn Dorsey and Jax GlossbrennerIntroductionSliding Contact—The Micro PerspectiveElectrical PerformanceMicro-Environment of Contact RegionMacro Sliding ContactMaterials for Sliding ContactsFriction and Wear CharacteristicsContact Parameters and Sliding-Contact AssembliesFutureSummaryAcknowledgementsReferencesMetal Fiber BrushesGlenn Dorsey and Doris Kuhlmann-WilsdorfIntroductionSliding Wear of Multi-Fiber BrushesSurface Films, Friction, and Materials PropertiesElectrical ContactBrush DynamicsFutureSummaryAcknowledgementsReferencesContact DataUseful Electric Contact InformationPaul G. SladeIntroductionNotes to the TablesReferencesAuthor IndexSubject Index

Paul G. Slade began his studies in the fascinating world of electrical contacts as a graduate student at the University of Wales, Cardiff, UK in the mid-1960s. Since that time, he has been involved with electrical contacts both as a research scientist and as a developer of switching components. Currently retired, he ended his five decades of experience in electrical contact research first at the Westinghouse R &D Center, Pittsburgh, Pennsylvania, USA, and then at the Eaton Corporation’s Vacuum Interrupter Factory, Horseheads, New York, USA.