Page 3 - Application Guide Semiconductor Fuse Link
P. 3
Contents
Pages
Introduction .................................................................................................................. 4
Continuous current rating In ......................................................................................... 5
Protection against overcurrents - basic concepts ............................................................. 6
The time-current characteristic ....................................................................................... 7
Adjusting the fuse rated current to allow for real-world working conditions ................... 8
Estimation of fuse life under cyclic overloads................................................................. 12
Occasional (non-repetitive) overload coeffi cient Cf3 ...................................................... 14
Short-circuit currents..................................................................................................... 15
Current-limiting operation............................................................................................. 16
Interruption of d.c. fault currents .................................................................................. 20
Surge withstand of semiconductor devices ................................................................... 21
3-phase controlled bridge rectifi er ................................................................................. 23
Converters with multiple parallel devices ...................................................................... 26
Regenerative loads....................................................................................................... 28
AC controllers (soft-starters, static switches) ................................................................... 31
Forced commutated inverters ....................................................................................... 32
Fuse selection examples ............................................................................................... 35
Select-A-Fuse for Power Electronics (SAF/PE) ................................................................. 39
Problem solved using SAF/PE ........................................................................................ 41
Appendix .....................................................................................................................45
Ferraz Shawmut Technical Services - contact information .............................................. 49
