TT system testing

[Timmydoc10]

Hi everyone. A recent install I've done on a tt system is giving me a reading of 93.3ohms as a Ze reading. When I then test from my circuits inside I'm getting readings like 106.3 for a socket circuit supplied from 32 amp type b mcb (which should be no higher than 1.10 ohms in bs7671) anyone help me out as to why my meter is giving me these readings ?

 

[buzzlightyear]

Definitely not a water pipe or anything like that. I did the Ze with the earth disconnected yes.

possible the earth rod is either not deep or lose connection .

 

[Timmydoc10]

possible the earth rod is either not deep or lose connection .

I would think that if my earth reading wasnt 93.3 ohms. I personally think that's good for a tt system. Just wondering why the Zs readings jump to 107.3 ohms and they are all in and around that

 

[buzzlightyear]

I honestly cant see anything wrong as it's a simple install

did you install the rod or was it still present .

 

[pc1966]

It is probably something simple like a bad connection, wobbly rod being kicked by someone, or similar.

Do a few dead tests using a wander lead to confirm the R2 for rod-MET-CU and CU-socket, same for phase to socket L. Poke thing (not while live!) to see if loose or something changes.

 

[Timmydoc10]

did you install the rod or was it still present .

I installed 3 new rods to get the reading to that

 

[Mike Johnson]

Did you take the rod reading at the DB or at the rod, assuming you did it at the rod, have you checked the reading of the connecting cable disconnected from the rod at the DB?
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I installed 3 new rods to get the reading to that

Hope that's in one continuous rod or each outside the zone of influence of the other.

 

[Timmydoc10]

Did you take the rod reading at the DB or at the rod, assuming you did it at the rod, have you checked the reading of the connecting cable disconnected from the rod at the DB?
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Hope that's in one continuous rod or each outside the zone of influence of the other.

That's with all rods connected

 

[Mike Johnson]

Sorry don't quite understand your response.

From your reply I assume three separate rods connected together, can you tell us the length of the rods, the distance between them, readings from each rod, readings from the rod to the DB and the reading of the cable to the DB disconnected at both ends?

Bed calls.

 

[Timmydoc10]

Sorry don't quite understand your response.

From your reply I assume three separate rods connected together, can you tell us the length of the rods, the distance between them, readings from each rod, readings from the rod to the DB and the reading of the cable to the DB disconnected at both ends?

Sorry Mike dont have the readings on hand. But spike 1 is below the pirelli box. Spike 2 is about 15 meters away and then spike 3 is 10 meters away from spike 2. All spikes are 1m in length

 

[buzzlightyear]

Why did you put 3 in?

 

[Timmydoc10]

Why did you put 3 in?

Couldn't get the readings down

 

[buzzlightyear]

Couldn't get the readings

What type of soil? Clay

 

[Timmydoc10]

What type of soil?

Bit of everything. Mostly gravel

 

[buzzlightyear]

Bit of everything. Mostly gravel

I would have put another rod in with the first one and see what results are.

 

[Timmydoc10]

I would have put another rod in the first one and see what results are.

What do you mean by another rod in first one