Ground rod alternatives?

 My cabin, and soon to be installed pole mounted PV panels are
surrounded by good old Maine ledge.....what options do I have if I
can't get an 8' ground rod in the ground?

The odds are against me getting any deeper than maybe 2 feet.

 

    This is a case where local knowledge will trump any opinion that you receive
from strangers on the Internet.  Talk to some of your local electricians and ask
what they do.

  If you have any topsoil at all, ask if a ground halo might be a good starting
place.  That is simply a loop of heavy bare wire trenched around your building
and connected to your ground terminal.  Normally you install ground rods at (at
minimum) all four corners, but if driving a ground rod is impossible, at least
you have provided some conductivity to ground.

Do you have any buried metal water pipes?  A well casing?

Vaughn

 

That is such a good point.  What do others in your general area do for
grounding?  

Time to meet the neighbours!

 In article


Have you put in the poles? Are they steel set into drilled holes in the
ledge? Could help. If there's concrete to be poured (if it's already
been, too late) look up "Ufer ground" - basically welding or otherwise
electrically connecting together all the steel reinforcement in the
concrete to help make a ground connection. A steel well casing should be
tied into the ground system if you have one of those - though I wonder
what the proper course to take is WRT electrolytic corrosion (steel
connected to copper) in that case and the Ufer ground case.

I suspect for a pole mount on ledge a well driller might be the ideal
"pole" contractor - drill a hole 10-20 feet deep and drop a 20-40 foot
stick of steel well casing in the hole, checking with an engineer that
that's adequate (or what size will be adequate) for the load, of course.

If using wooden poles, drop the ground rod in with them - I'd imagine
that whatever pole you use will have to be in a drilled hole if you only
have 2 feet of soil.

--
Cats, coffee, chocolate...vices to live by

 Home Depot sells grounding plates. In my area they have to be buried flat 2
feet from the surface on virgin soil.

Grounding rods take two units mre than 10 feet apart.

YMMV