This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Low Loop Impedance Reading.

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.

Parents

0 Sparkingchip over 4 years ago

Kelly Marie Angel:

Zoomup I think you should just be releived you gota nice low earth loop enjoy not having to worry about will the fault current be enough cos clearly it will and then some.

It not unusual to get readings of less than one ohm in a TT earthed installation, which to me is an issue because the gas and/or water pipe is serving as the main earth conductor.

I actually feel more comfortable with readings around 35 ohms than 0.35 ohms in a TT installation when I know the rod is more than 100 ohms.
Cancel
Vote Up 0 Vote Down

Cancel

Reply

0 Sparkingchip over 4 years ago

Kelly Marie Angel:

Zoomup I think you should just be releived you gota nice low earth loop enjoy not having to worry about will the fault current be enough cos clearly it will and then some.

It not unusual to get readings of less than one ohm in a TT earthed installation, which to me is an issue because the gas and/or water pipe is serving as the main earth conductor.

I actually feel more comfortable with readings around 35 ohms than 0.35 ohms in a TT installation when I know the rod is more than 100 ohms.
Cancel
Vote Up 0 Vote Down

Cancel

Children

No Data

Low Loop Impedance Reading.

Community Rules & Guidelines