Earthing

[JustStartingOut]

Hello

I went to look at a job and this is the earthing arrangement....I think it was originally supposed to be TNS however the earth from the supply sheath seems to be floating in mid-air.

I think someone has converted it to a TT, as there may be an earth cable going from the CU to a rod elsewhere, however I couldn't confirm this because the rod wasn't accessible.

I am waiting for my first multifunction tester to arrive so that I can take a Ze reading.

Any thoughts or comments?

http://www.flickr.com/photos/35250598@N04/3266853973/

 

[Robojin]

HelloI went to look at a job and this is the earthing arrangement....I think it was originally supposed to be TNS however the earth from the supply sheath seems to be floating in mid-air.

I think someone has converted it to a TT, as there may be an earth cable going from the CU to a rod elsewhere, however I couldn't confirm this because the rod wasn't accessible.

I am waiting for my first multifunction tester to arrive so that I can take a Ze reading.

Any thoughts or comments?

http://www.flickr.com/photos/35250598@N04/3266853973/

So did you find an earth running from the CU to somewhere or not, from the picture I can't tell

 

[Robojin]

I am waiting for my first multifunction tester to arrive so that I can take a Ze reading.

Until you have discovered an earth you will not be able to take a Ze

Also remember you can make an enquiry I'd recommend you try this route if you have some doubt as to what has been done to the supply

 

[extension15]

That is a TN-S supply..

 

[extension15]

From the picture ,it looks like the earth is going nowhere.. (to the left)

; \

 

[Robojin]

From the picture ,it looks like the earth is going nowhere.. (to the left) ; \

Or could it be an old Lightning conductor, very similar to something still in my loft

I'd have expected a breaded flat earth cable looking at this

 

[extension15]

Or could it be an old Lightning conductor, very similar to something still in my loftI'd have expected a breaded flat earth cable looking at this

Not always my friend...

 

[extension15]

Anyway, a lightening conductor is connected to the ground, not the sheath of an incoming supply..

 

[JustStartingOut]

An earth cable did appear to be going to the outside through the wall in to what would be the garden.... the CU is in the cellar. I wasn't able to find the end of it, hence assume earth rod has been buried by the person that did the electrical work.

I contacted DNO they said they couldn't tell me the earthing arrangement at the property.... (helpfull!!)

The CU has light circuits on Type 2 breakers only and the rings covered by a 30mA RCD......therefore I dont think that this was meant to be a TT (as I thought all circuits should be covered by RCD?)

If this is supposed to be TNS, do I need to get the DNO to come out and reconnect an earth to the supply sheath, or can I add another earthing rod in a location that is accessible to ensure it is TT?

 

[Robojin]

Anyway, a lightening conductor is connected to the ground, not the sheath of an incoming supply..

Very true, or perhaps this is 1930's DIY

 

[extension15]

An earth cable did appear to be going to the outside through the wall in to what would be the garden.... the CU is in the cellar. I wasn't able to find the end of it, hence assume earth rod has been buried by the person that did the electrical work.I contacted DNO they said they couldn't tell me the earthing arrangement at the property.... (helpfull!!)

The CU has light circuits on Type 2 breakers only and the rings covered by a 30mA RCD......therefore I dont think that this was meant to be a TT (as I thought all circuits should be covered by RCD?)

If this is supposed to be TNS, do I need to get the DNO to come out and reconnect an earth to the supply sheath, or can I add another earthing rod in a location that is accessible to ensure it is TT?

My friend, this is a TN-S suppy, to confirm connect your meter accross L, N (incoming) and what can be clearly seen as as a clamp (E) across the the top of the sheath...

Then come back to us with the reading...

regards

Kev

 

[JustStartingOut]

Thanks for your responses.

My meter should have been delivered on Friday last week but Im still waiting for it. As soon as it arrives I'll get to customers and make the measurements.

 

[extension15]

Your meter is everything, that is important................

Applaud Smiley

 

[NozSpark]

As that's not a sweated earth then if your DNO are anything like mine they will claim it is an illegal DIY connection and that your earth should be TT

 

[Andy™]

As that's not a sweated earth then if your DNO are anything like mine they will claim it is an illegal DIY connection and that your earth should be TT

just about every TN-s supply i come accross is a clamp - normally a proper DNO clamp, not a 951. rarely come accross sweated or spring

 

[extension15]