It is my understand that the pulse travels through the ground so to protect it, it would have to be disconnected.
I have seen arguments that a Faraday cage would sheild electronics. I have seen arguments that it would not. The more sensitive the electronics, the more damage. CMOS chips, etc. toast.
I don’t know who is right.
Most of the equipment on the ranch other than new vehicles have no electronics to speak of and have a few vehicles I’ve kept for nostalgia purposes that have no electronic’s either. Point’s plug’s and condenser.
Never heard about EMP traveling thru the ground. It will travel down the long power lines. It will invade anything not shielded (as in a Faraday cage).
Even if it is unplugged.
Seems I recall a TV show, maybe Myth-Busters, they built a Faraday cage and it protected the gear inside. . .or maybe it was a different show.