On Fri, 17 Apr 2020 09:27:54 -0700, Bob F wrote:

On 4/17/2020 1:42 AM, micky wrote:
Do copper or copper-clad steel ground rods disappear with time?

After 37 years, does mine need replacing?

When I put in my first burglar alarm, 37 years ago, I put in a ground
rod to ground the system, and iiuc reduce the chance of lightening
damage. (Nonetheless, after about 20 years, when I was leaving for
work, there were wisps of smoke coming from the keypad/control usit, and
it never worked again. ;-) I have a new alarm now, grounded to the same
rod, but something told me the rod was gone. The top of it is still
there so maybe I dreamed it, but is it likely that the part above ground
is there but most of it below ground is gone, and needs replacing?



You could measure the resistance to ground of the rod installation.
A galvanized ground rod should be good for 15 or more years. A copper
bonded steel rod should be good for 40 or more years. Stainless steel
will last 75 years or more. Depends on soil type and
alkalinity/acidity or salt content