Safety when experimenting with large currents
If we consider this model of a high energy switching circuit we can simulate the induced voltage on a nearby conductor. This provides a simple simulation of the type of electromagnetic interference that would be coupled into nearby conductors or electronic devices.







simulate this circuit &ndash; Schematic created using CircuitLab

As any switch opens, or you simply tap wires together to briefly conduct that 1,000 amps, when you have 1u (1 micron, 10,000 Angstroms, or 1/25th of a mil) separation of the wires, the 3 volt potential causes an arc.

The 100pF across 1micron separation (3mm by 4mm ---- heavy wire --- contact) will resonant with the 1uH (~~ 1 meter) wire in your high-current path. Fring will be 15MHz. What is the dI/dT of 1,000 amps ringing at 15Mhz? 

100,000 MegaAmps/second.

Place a wire 4" from the high current, that wire formed into 4" by 4" loop; expect 2,000 volts across the ends of that 4" loop.