Virtual time for current limiting fuses
Virtual time for current limiting fuses
(OP)
I have no clear the definition of virtual time for current limiting fuses. Is it the time provided by the I-t characteristic of the fuse? Is it the prearcing time or the total operation time?
Thanks in advance
Thanks in advance






RE: Virtual time for current limiting fuses
RE: Virtual time for current limiting fuses
4ms is being typicaly taken as a fuse operating time if the fuse is exposed to fault current above the total clearing time at the bottom of time-current characteristic (0.01 seconds). This is the amount of time it takes to melt fuse element before the elements starts arcing and clearing the fault. In arc flash analysis, if the arcing fault current is above the total clearing time at the bottom of the curve (0.01 seconds), IEEE 1584 uses 10 miliseconds for the arc duration (clearing) time.
RE: Virtual time for current limiting fuses
Perhaps IEC standard 60269 “Low Voltage Fuses” may help to clarify this issue.
See also the enclose glossary from Bussmann:
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