UK Earth Electrode Test - what can it tell you that EFLI test cannot?

[John-]

Hi

Please feel free to shoot me down in flames. I have a TT system that I need to do some work on soon, one of which is to move the Earth rod (put in new one). I have never had to an Earth Electrode test before. I have looked at some videos on line and the GN3. But i cannot derive what useful information i will get out of doing the test that i cannot get from doing a ZE test at the board? Can the Electrode test distinguish between dry ground / poor ground verses a corroded electrode? If not why bother?

Cheers

John

 

[DPG]

The full earth electrode test uses more than one test spike, and so takes into account ground conditions. A web search should give more details.

 

[John-]

Thanks for the reply. Point is if you are getting a good EFLI reading, would yo need to bother with an electrode test?

 

[stevethesparks]

One reason is because it isn't influenced by any possible nearby extraneous items

 

[John-]

But then neither would a test from the board with only the earth connected to it, isolated from any other conducted parts in the premises (while I test it). There may metallic items buried near the rod, but neither test would expose these. Or i suppose, i would get low readings as i move about? But then that could just be a scrap metal, not connected to the house. Would i then have to do a test between metal work in the house and the ets spike that picked up the reading?

 

[stevethesparks]

Your rod could be in close proximity to Water/Gas pipes, rebar, the incomer itself etc

 

[John-]

Your rod could be in close proximity to Water/Gas pipes, rebar, the incomer itself etc

Thanks again for coming back. I appreciate that , but how would that show up on the testing? How would i be able to distinguish between wet and dry areas of a lawn or frontage, lumps of scrap metal in the soil and metal work linked in some way to the house and back through the PME?

Article here is okay, but fails to say what is a good verses a bad readings are: -

https://professional-electrician.com/technical/earth-electrode-testing/

About to read this one: -

https://www.weschler.com/wp-content/uploads/2020/01/gettingdowntoearth.pdf

Cheers

John

 

[Midwest]

Have you watched John Ward's vids on the subject?

 

[sinewove]

Have you watched John Ward's vids on the subject?

Thought the loop tester method was quite acceptable on a tt install according to gn3.
S.

 

[LastManOnline]

But then neither would a test from the board with only the earth connected to it, isolated from any other conducted parts in the premises (while I test it). There may metallic items buried near the rod, but neither test would expose these. Or i suppose, i would get low readings as i move about? But then that could just be a scrap metal, not connected to the house. Would i then have to do a test between metal work in the house and the ets spike that picked up the reading?

An EFLI test on the earth rod after having isolated the protective conductor from the CU is usually deemed to be perfectly acceptable.

 

[Midwest]

Thought the loop tester method was quite acceptable on a tt install according to gn3.
S.

If I recall JW demonstrates both methods.