I'm looking to install a couple of vertical grounding rods for a friend's property in the middle of nowhere (very country - The earth is mostly clay, rocks and sandstone)
From the limited research I've done I believe the grounding rods should be about 2.5 metres deep and 5 metres laterally separated.
My questions are:
Have I got the depths and spacing correct?
How far from the building/foundation should the rods be?
If I'm to hire an auger that can exhume 2.5m depth, what diameter should the auger be? I intend to use a slurry of ground enhancement material <- still not quite sure what this stuff is but I guess it's a good conductor? How many KG's for a 2.5m deep hole of "x" diamater
How can I test the efficacy of the finished job? Looking at ground resistance testers (clamp style) they run in to the hundreds of dollars. Also, do you need two grounding rods driven and connected in order to use these clamp style testers? Do you clamp it on the connecting wire or individual rods? Can the connecting wire be buried or is a that a big no-no?
Is something like this a complete waste of money? https://www.ebay.com.au/itm/192390605919 It seems a lot cheaper than the AUD$500 alternatives, probably for a reason.
Any hot tips for what I assume will be an incredibly laborious task? I'm guessing an auger is a better choice than a jackhammer with a macgyver attachment to drive the rods, only because I'm using the ground enhancement material, otherwise a tighter drive from a jackhammer would yield better conductivity I guess.
I know if I'm asking these questions it means I'm probably ill-equipped to be doing the job but I'm making the best of a bad/dangerous situation. I'm installing CB's, RCD's and grounding on an installation that is effectively just hardwired, online and unprotected from ground faults. I figure it's a step in the right direction that simply won't happen if I don't step in. It's a case of a friend thinking his electrical "just works" but he doesn't understand the need for further protection. I hope you guys (and gals) understand where I'm coming from. Many thanks.