I have been working at a property that is TT earthed. Normally around here the loop impedance readings are between 100 to 200 Ohms for TT systems.
Today I had a reading of just 8.5 Ohms at a distant socket in the property's garage about 30 metres from the main fuse and first earth rod. There is a second earth rod nearby as well.
The reason for the low reading is that the property is next to a staithe with a canal nearby. The water table is only about half a meter under the garden soil. I saw this as ground work is being undertaken. Amazing. The lowest rod resistance I have ever seen.
Z.
