How can these non-wire equipment grounding paths get checked/verified for for current carrying capacity? Is that possible? Sure, a test for conductivity can be performed but say the conductive path relied on one last bit of metal thread in a buried conduit acting as an EGC.
Only way I know how is via a loop impedance tester:
232 amps / 20 amps = 11.6x the handle rating is enough to trip the breaker in under 0.8 seconds.
However, this assume that there are no parallel paths in relation to the conduit itself.
In my world view, the wire type EGC is the only acceptable fault current path unless demonstrated otherwise.
Until chapter 9 can list the impedances for each conduit size, and that research is done to verify stable restive values with age I personally (in my humble world view) can not acknowledged metal raceways as a reliable fault current path.
Lucky to be working in a time when the rules made more sense. A few tweaks and we would have had a legitimate modern code.
