Ground Rod Install Location Query

[mistaphix]

Firstly, thank you everybody for the wealth of information on playing with 'fire' in Thailand.
Am getting ready to install a new Consumer Unit to coexist in a older property which has no earth anywhere (except the street, every third pole)

To comply and make available properly grounded circuits for some delicate equipment, the task of bashing a 2m+ copper clad rod into either the garden outside by the soi, not far from the incoming meter (on the street pole) and close to the incoming knife switch, only 60amp (but more on that in a moment)
OR
into the sand on the beach, which is very close proximity to the new consumer unit location (installed inside)
My primary question after reading all the material (thanks Crossy) is:
The beach location suitable (short run approx 5m)
or the garden option which is obvious. (additional 14metres of 16mm cable required) 

[RichCor]

Question:

 

If you dig down in either location do you encounter salt water intrusion?   Are their 'salts' in the soil?

 

...some interesting data on soil types buried in this FLUKE data sheet:

support.fluke.com_Earth_Ground_Resistance.PDF

[Crossy]

The shorter cable run is the "correct" location.

 

My worry would be salt in the sand, salty water will quickly eat away the mild-steel core of the regular copper-clad rods.

 

The solution would be either a solid copper rod ($$$) or a stainless steel rod.  Your local metal shop should be able to supply a length of 10-15mm SS round bar, they should also be able to sharpen one end if you don't have the facilities.

 

Generally the rule with ground rods is longer is better, but over 3m is a wrestle to handle and drive. I would cut a 2.5m length and bash it in as far is it will go then cut it off to 15cm above ground level to put on your clamp connection.

 

[RichCor]

Many articles will say a good earth-ground location, besides being the shortest distance, usually is one consisting of black or brown dirt, or soils with higher moisture levels and higher electrolyte levels.

 

Beach Sand can be an issue as an earth-ground. The sand itself is a poor electrical conductor, water drains through is rather quickly taking both the moisture and any electrically beneficial electrolytes (salts) along with it.

 

As Crossy mentioned, Salts tend to corrode the steel core, but can also interact with the copper.

 

 

Achieving an Acceptable Ground in Poor Soil
Keith Switzer, ERICO, Inc.

 

This EC&M article, covers some of the issues. If your current earth-ground environment is insufficient to the task, the lower part of article also provides some possible alternatives via "ground enhancement materials", referring to filler material mixed into or replacing the soil area the ground stake is placed in.

[mistaphix]

Thank you for the input which I took onboard and dug deeper (not literally and found the solution the kind team at PEA had left for me hiding in the garden whilst pruning the trees before starting the whole job (see other related post)
used THW 16mm, heavy duty copper cable to cable bolted connector, some hi-voltage tape then a mass of insulation tape.