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but you still have ESD issues with boards, not just chips, I still have to wear my wrist band and stand on the mat...

With a million volts flowing through the air, i find it hard to believe that much of an over voltage of electrons is NOT going to cause heat inside chips and fry them, each circuit is closed to some extent from their power source to their ground, it may be small and short distance, but it is still a path for flow...

“but you still have ESD issues with boards, not just chips”

True. So boards are more sensitive to EMP damage - especially if they are connected to other boards with ribbon cables and power supplies. Definitely vulnerable in that case.

The spectrum of an EMP is up to 1000MHz, but the majority of the energy is concentrated towards the lower end of the spectrum. This is the unclassified version of a “reference pulse”.

This means that longer wavelength energy will not readily couple to short wavelength conductors in the board. there are also polarization issues, and orientation issues. For electrically small devices the field strength (not the same as ESD voltage) even at 50,000 V/m the energy coupled into a stand alone system will be relatively small - perhaps within system tolerances. Damage is certainly possible, but not as likely for systems with electrically long conductors connected to it (power cords, conductive data cables, even ground wires, etc.)

The other thing to keep in mind - to differentiate from ESD - a “ground” in ESD is not necessarily a “ground” for RF/EMP. You can still get an RF shock (and arc across a semiconductor junction) without being specifically grounded. A ground wire can act as an antenna and direct energy INTO a system. This again seems counterintuitive, but it’s one of the joys of EMP/RF assessment.

Most Generators are generally well protected from extreme voltage spikes. This is probably due to the fact that the relays are analog and are site specific.

I have seen some massive voltage spikes, lighting hitting a 345kv line. These will take a unit out in 1/2 a cycle.

The real problem is the conversion of units to electronic control systems. Made life a lot easier but aux power is drawn off of secondary sources that is not as well protected and possess the potential to cause a few problems.