Just Another Sparky
- Joined Dec 8, 2019
- 244
For perspective, the largest interrupting rating you'll probably ever see in a fuse is somewhere around 300kA. That sort of available fault current at the voltages you're talking about is typically only found directly off the secondary lugs of a 6~20 MVA transformer. If my math skills hold up, with a voltage of 1kV you're going to need a total circuit impedance of not over 200uΩ to achieve 5MA. For 5 feet of wire (2 wire circuit), that translates to 700KCMIL conductors - and this is without accounting for any sort of inductive reactance or the load/line characteristics. Pushing it to 10 feet would require 1250 or 1500KCMIL conductors - wire bigger in cross-section than a half-dollar coin! And the I^2R losses even at that would be near 100%.
Not only that, the magnetic forces alone from 5MA of current would rip your circuit apart in an instant!
And on the odd chance you really are working with currents above 5-10kA at 500 volts, you should probably be wearing a 40 cal flash suit! Arc flash is a shitty way to go.
Something doesn't add up.
Not only that, the magnetic forces alone from 5MA of current would rip your circuit apart in an instant!
And on the odd chance you really are working with currents above 5-10kA at 500 volts, you should probably be wearing a 40 cal flash suit! Arc flash is a shitty way to go.
Something doesn't add up.
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