That’s interesting mnem
Dunno what was going on there ?
In the nearly forty years of using mains powered units the one thing I’ve never scrimped on is the fence earth so to get down deep to the water table.
Even though it might be an earth connection it should still be insulated all the way to the earth peg/s as when there’s a big short somewhere the peg can obtain an elevated voltage that if nothing else can be a bloody nuisance for all. Especially so if the installation is nearby a milking shed or some animal yard or barn.
Normally elevated earth peg voltages are dealt with by adding more pegs but in the last few decades I’ve used a single full 20ft length of galv pipe to get down deep and be sure to be in the water table.
IIRC I got ~3.5kV on that fence wire when I checked it, piss ant earth and you get nutthing like that 2km from the unit.
When I was in elementary school we converted from 110V to 220V. The electrician showed me how to install a ground rod.
1: Get a bucket of water and wet the immediate area.
2: Attach Vice-Grips to the top of the rod.
3: Pump the rod like churning butter.
4: Add water
5: Keep pumping. The rod will soon be sucked down to the Vice-Grips.
Takes me about 10 minutes in good clay soil. The hydraulic action will displace small rocks, larger ones may require moving 6" to several feet and restarting. NO HAMMER needed.