Guia tecnica: Guia de aplicacion de fusibles rapidos Bussmann (Ingles)

OPERATION OF THE FUSE-LINK 5 PROTECTION REQUIREMENTS FOR HIGH SPEED FUSES ? 6 HOW HIGH SPEED FUSE-LINKS ARE DIFFERENT TO OTHER FUSE TYPES. 6 Characteristics required / provided 6 Ambient Temperatures 7 Forced Cooling 7 Mean, Peak and RMS Currents 7 Time / Current Characteristics 7 Surges 8 CO-ORDINATION WITH SEMICONDUCTOR CHARACTERISTICS 9 Short Circuit Performance 9 I2t Ratings 9 Peak Fuse Currents 9 Arc Voltage 9 Conductor Size 9 Package protection 9 THE DATA SHEET OF THE HIGH SPEED FUSE 10 The Time Current Curve 10 The AA-curve 11 Clearing integral information 11 The I2t Curve 11 Cut Off Current Curve 12 The Arc Voltage Curve 12 Watt loss correction Curve 12 Temperature conditions 12 RATED VOLTAGE DIMENSIONING 13 Voltage Rating 13 International Voltage Ratings 13 IEC Voltage Ratings 13 North American Voltage Rating 13 Simple Rated Voltage Dimensioning 13 Frequency dependency 13 Extended Rated Voltage Dimensioning 13 Possible AC/ DC combinations 13 AC Fuses in DC Circuits 14 Fuses under oscillating DC 14 Fuse-Links in Series 14 RATED CURRENT DIMENSIONING 15 Part 1. Basic selection 15 Control of the fuse amperage 16 Part 2. Influence of overloads 16 Part 3. Cyclic Loading 17 Fuse-Links in Parallel 18 APPLICATION AREAS - GENERAL 19 RMS currents in common bridges 19 TYPICAL RECTIFIER CIRCUITS 20 PROTECTION BY FUSE-LINKS 21 Internal and External Faults 21 Protection from an internal Fault 21 Protection from an External Fault 21 Service Interruption upon Device Failure 21 Non-Interrupted Service upon Device Failure 22 FUSES UNDER DC CONDITIONS 23 DC fed systems 23 Battery as a load. 23 Battery as only source 24 DC APPLICATION OF BUSSMANN AC FUSES 25 Calculation example 26 SELECTION OF FUSES FOR THE PROTECTION OF REGENERATIVE DC-DRIVES. 27 Internal fault 27 Cross-over fault 27 External fault 27 Conclusion on the rectifier mode 27 Commutation fault 27 Loss of AC-power 27 DC shoot-through 28 Conclusion on the regenerative mode 28 Summery of voltage selection for regenerative drives 28 PROTECTION OF INVERTERS 29 Voltage selection. 29 Current selection. 29 I2 t selection 29 Protection of drive circuits. 30 Bi-polar Power transistors and darlingtons 30 WORKED EXAMPLES 31 Example 1. DC Thyristor Drive 31 Example 2. DC supply with redundant diodes 31 Example 3. Regenerative Drive Application 33 APPENDIX 1. INTERNATIONAL STANDARDS AND BUSSMANN PRODUCT RANGE 34 BUSSMANN PRODUCT RANGES 35 European Standard 35 Blade type fuses 35 Flush-end contact type 35 British Standard - BS 88 36 US Style - North American blade and flush-end style 36 Cylindrical Fuses 36 APPENDIX 2. FUSE-LINK REFERENCE SYSTEM 37 Reference system for European High Speed Fuses 37 Reference system for BS88 High Speed Fuses 39 Reference system for US High Speed Fuses 40 Standard Programme - type FW 40 Special Programme - types SF and XL 41 APPENDIX 3. INSTALLATION ISSUES 42 Tightening torque and contact pressure. 42 Fuses with flush end contacts. 42 Special flush-end types. 42 Fuses with contact knives 42 DIN 43653 - on busbars 43 DIN 43653 - in fuse bases. 43 DIN 43620 43 Press Pack fuses. 43 Mounting Alignment 43 Surface material 44 Tin plated contacts 44 Resistance to vibration and shock. 44 SERVICE AND MAINTENANCE 44 Check points during routine maintenance of electrical cabinets and switchgear. 44 ENVIRONMENTAL ISSUES 44 Basic materials 44 STORAGE 44