apparently no earth?

[markymark2406]

My mate invited me round to see if his fuse board was earthed, i opened it up and didn't find any earth wire to a stake (TT) we looked around the house and there wasn't one.
The board isn't on a TN system as there is no wire from the fuse board to the service cut out (N)

We took a random socket and put a meter between live and the earth terminals and got 230volt?

A bit mystified?

 

[Spark123]

It could be grounded via a neighbouring property or similar, one thing for sure it needs rectified properly by an electrician!

 

[oharaf]

The board isn't on a TN system as there is no wire from the fuse board to the service cut out (N)

Does not neccessarily mean it is not a TN system, someone may have removed it!!!!!!!!!!

Call the DNO, ask them what type of earthing supply there is (supposed to be) They may just tell you to p.o.

What age is the property and what sort of location is it? Rural, suburban?

He certainly needs some earthing arrangement put in place asap.

 

[Lectrician]

A digital volt meter measures voltage through a high impedance.

If the earth had a resistance of thousands of ohms you would still read 240 odd volts. Try putting the meter between live and the wall and you will see a similar reading.

You need to carry out a loop impedance test to verify the actual resistance of the earth loop, but this is pointless if you don't physically have an earth in the form of TN-S, TN-C-S or TT present, as even if you get a reading you cannot deem this to be satisfactory.

Did that make sence? It seemed garbled!

 

[markymark2406]

well an earth loop test would be good i suppose, what reading should i get at a socket if earth or no earth?

 

[Spark123]

Don't know - you need to start by doing a Ze (external earth fault loop impedance) test.
If you can't do that then you can't ensure that the earthing will be reliable.