Electric Fuses: Fundamentals and new applications

Description

Fuses are designed to operate when over-currents, large and small, occur within electrical equipment; they thus interrupt the flow of current, preventing damage. They are needed for various power electric systems, for stationary and automotive applications, as well as power grid components like PV systems and distribution lines. Different types of equipment and voltages require special fuses, and their behaviour must be understood to guarantee correct choice and safe operation. For the 3rd edition in 2004, Wright and Newbery's classic had been revised to include pre-arcing and arcing behaviour, retrofitting of fuses, chip and automotive fuses, and insulated gate bipolar transistor (IGBT) protection. Edition 4 includes updates on standards and new applications. Data, standards descriptions and many illustrations have been revised and updated. Chapters cover pre-arcing and arcing behaviour of cartridge fuselinks, constructions and types of low-and high-voltage fuses as well as miniature, plug and other small fuses, various applications, standards, manufacture, quality assurance and inspection. This reference is indispensable for researchers involved with power electric equipment, grids and motors, and experts engaged in fuse development, design and production. Cover Contents About the authors Preface Acknowledgements Obituries List of principal symbols 1 Introduction 1.1 History of fuse development 1.2 Basic requirements 1.3 Fuse types and constructions 1.3.1 Classifications 1.3.2 Basic constructions 1.3.3 ‘Resettable fuses’ and fault limiters 1.3.4 The antifuse 1.4 World production 2 Pre-arcing behaviour of cartridge fuselinks 2.1 General behaviour 2.1.1 Clearance of very high currents 2.1.2 Clearance of high currents 2.1.3 Behaviour at intermediate current levels 2.1.4 Behaviour at currents near the minimum fusing level 2.1.5 Mathematical and experimental studies 2.2 Control of time/current characteristics 2.3 M-effect 2.3.1 Oxidation 2.4 Skin and proximity effects 2.5 Advances in modelling 3 Arcing behaviour of cartridge fuselinks 3.1 Basic conditions during the arcing period 3.2 Arc model 3.2.1 Cathode-fall region 3.2.2 Anode-fall region 3.3 Positive column 3.3.1 Length of a positive column 3.3.2 Cross-sectional area of a positive column 3.3.3 Electrical conductivity of a positive column 3.4 Complete mathematical model 4 Constructions and types of low-voltage fuses 4.1 Cartridge fuses 4.1.1 Fuselink elements 4.1.2 Further details on selection of element materials 4.1.3 Fuselink bodies 4.1.4 Filling material 4.1.5 Industrial fuses 4.1.6 Domestic fuses 4.1.7 Fuses for the protection of circuits containing semiconductor devices 4.1.8 Other types 4.2 Semi-enclosed fuses 4.3 Continental European fuses 4.3.1 Blade-contact-type fuses 4.3.2 End-contact or screw-type fuses 4.3.3 Cylindrical-cap-contact fuses 4.3.4 Semiconductor fuses 4.4 North American fuses 4.4.1 Industrial fuses 4.4.2 Domestic fuses 4.4.3 Semiconductor fuses 4.5 Fuses for telecommunication power systems 4.6 Fuses for railway applications 4.7 Fuse for photovoltaic (solar power) systems 4.8 Fuses for battery energy storage systems 5 Constructions and types of high-voltage fuses 5.1 Non-current-limiting fuselinks 5.1.1 Expulsion fuses 5.1.2 Liquid fuses 5.2 Current-limiting fuselinks 5.2.1 Constructions of Back Up or partial-range fuselinks 5.2.2 Current-interrupting abilities and categories of fuselinks 5.2.3 Full-Range fuselinks 5.3 Continental European practice 5.4 North American practice 5.4.1 Current-limiting fuses 5.4.2 Non-current-limiting fuses 6 Constructions of miniature, plug and other small fuses 6.1 Miniature fuses 6.1.1 Cartridge fuselinks 6.1.2 Subminiature fuses 6.1.3 Universal modular fuselinks 6.2 Domestic plug fuses 6.3 Automotive fuses 7 Application of fuses 7.1 General aims and considerations 7.1.1 Time/current relationships 7.1.2 I2t 7.1.3 Virtual time 7.1.4 Published time/current characteristics 7.1.5 Cut-off characteristics 7.1.6 Operating frequency 7.1.7 Application of fuses to DC circuits 7.2 Discrimination and co-ordination 7.2.1 Networks protected by fuses 7.2.2 Networks protected by fuses and devices of other types 7.2.3 Co-ordination between a current-limiting fuse and a directly associated device of lower breaking capacity 7.3 Protection of cables 7.4 Protection of motors 7.4.1 Protection of soft starters 7.5 Protection of power transformers 7.6 Protection of voltage transformers 7.7 Protection of capacitors 7.8 Protection of semiconductor devices 7.8.1 Protection requirements 7.8.2 Basic protective arrangements 7.8.3 Co-ordination of fuselinks and semiconductor devices 7.8.4 Cyclic loading of semiconductor fuselinks 7.8.5 Application of fuselinks to equipment incorporating semiconductor devices 7.8.6 Protection of DC thyristor drives 7.8.7 Protection of inverters 7.8.8 Protection of power transistors 7.8.9 Combination of rectifier and inverter 7.8.10 Situations where there are high surge currents of short duration 7.8.11 Special applications 7.9 Protection against electric shock 7.9.1 Protection against direct contact 7.9.2 Protection against indirect contact 7.10 Arc flash 7.11 Power quality 7.12 Protection of photovoltaic (PV) systems 7.13 Protection of battery energy storage systems 8 International and national standards 8.1 Contents of standards 8.1.1 Scope 8.1.2 Normative references 8.1.3 Definitions 8.1.4 Standard conditions of operation 8.1.5 Ratings and characteristics 8.1.6 Markings 8.1.7 Type tests 8.1.8 Dimensions 8.1.9 Application guides 8.2 IEC fuse standards 8.2.1 Low-voltage fuses 8.2.2 High-voltage fuses 8.2.3 Miniature fuses 8.2.4 Temperature rise 8.3 European standards 8.3.1 British standards 8.3.2 Other national standards 8.4 North American standards 8.4.1 Low-voltage and miniature fuses 8.4.2 High-voltage fuses 8.5 Approvals procedure 9 Manufacture, quality assurance and inspection 9.1 Quality assurance 9.2 Design and manufacturing control 9.3 Purchased material and components 9.3.1 Bodies 9.3.2 End caps 9.3.3 Element material 9.3.4 Granular filling material 9.3.5 Machined parts for striker assemblies 9.3.6 Components and other materials 9.3.7 Calibration 9.4 In-process inspection 9.4.1 Production of fuselink elements 9.4.2 Winding of high-voltage-fuselink elements 9.4.3 Fuselink assembly 9.4.4 Striker assemblies 9.4.5 In-process final inspection 9.4.6 Dimensional check 9.4.7 X-ray examination 9.4.8 Resistance measurement 9.5 Other fuse parts 10 Fuse recycling – even after operation fuses are still useful References Glossary of terms Bibliography Index Back Cover