Fuse Impedance
Fuse Impedance
(OP)
How uniform is fuse impedance? I am performing an arc flash mitigation study for a facility, and have come across a scenario in which two identical fuses (208V 400A... I don't recall the type off the top but can get it if it makes a difference) are in parallel.
Can I assume that the total available fault current at the high side divides evenly between each fuse? If not, how have any of you dealt with this situation?
Can I assume that the total available fault current at the high side divides evenly between each fuse? If not, how have any of you dealt with this situation?






RE: Fuse Impedance
RE: Fuse Impedance
The current in any parallel protective device obey the physical law and are not perfectly distributed even if you find a manufacturer that could provide this parallel device. At best, the average performance may be provided in range of time fusing fashion.
Beware that arc flash calculation is also an approximation since there is many random variables including the protective devices clearing the fault in a wide range of accuracy usually conservatively if compare with actual test values.
RE: Fuse Impedance