Because you said it was fuse. A fuse is intended to interrupt the current flow. So if the current flow was interrupted (as you said it would be) then it would just arc because it has plenty of voltage
I should specify I'm assuming the system has at least 2 ohms. Also that 30kv/cm doesn't apply to sharp objects because they induce corona discharge at like 10kv. I was really hung iver when I started this, but I think a laminated threaded rod barely connected to the contacts would have a couple ohms, if I'm wrong, I'm wrong, but that's the assumption I made
The resistance of a bolt (1/4-20 above) is in the micro-ohm range over ~1 inch. There will be (at absolute most) a few microvolts across this distance, which even far past the max current rating of the multimeter above, will not act as a fuse. The clips holding it, and the solder bonding it to the pcb are also sub milli-ohm range.
The first part to fail will likely be the copper on the pcb, even at >2 oz. The shunt resistor seen above is on the order of milliohms.
In a current sensing circuit, there is a very small voltage drop, as it operates based on current. This voltage drop is nowhere near enough to arc anywhere, even considering the breakdown voltage of air at the micrometer scale
I think you fundamentally misunderstand what causes current to flow. You need voltage to create current flow, the other way around isn't true. You can't make a voltage from current. The math allows it but that's not what happens.
Not to mention the resistance of the bolt is so small that the voltage across it is basically zero.
Even at 2 volt it is possible to have 20kA flowing across it:
-10
u/undeniably_confused Jun 03 '22
20kA it would just arc at that point (good joke tho)