"the earth electrode should be installed at a depth sufficient to reach the water tableof the soil to remain effective." (my emphasis) seems a bit over-zealous. Around here two or three feet down remains damp enough even during summer droughts, but as we're on a hillside the actual water table is likely to be much much deeper - probably several tens of metres - really not a practical depth.
I might take slight issue with Fig 1 too - to my mind the consumer's electrode is part of the consumer's installation, not the supply system (e.g. isn't included in the oft quoted 21 Ohms Ze for TT systems) - so really it should be to the right of the dotted line.
"the earth electrode should be installed at a depth sufficient to reach the water tableof the soil to remain effective." (my emphasis) seems a bit over-zealous. Around here two or three feet down remains damp enough even during summer droughts, but as we're on a hillside the actual water table is likely to be much much deeper - probably several tens of metres - really not a practical depth.
I might take slight issue with Fig 1 too - to my mind the consumer's electrode is part of the consumer's installation, not the supply system (e.g. isn't included in the oft quoted 21 Ohms Ze for TT systems) - so really it should be to the right of the dotted line.
