Earthing system quiz

[Zerax]

What sort of earthing system would you say this is ?

 

[Mike Johnson]

Same as this?

 

[buzzlightyear]

PME to you T.N.C.S .lol

 

[Julie.]

T.......

That's it, just T

 

[buzzlightyear]

That's it, just T

oh ,forgot the kettle ,teapot and cup.lol.

 

[HappyHippyDad]

View attachment 62306What sort of earthing system would you say this is ?

Is this something you know the answer to Zerax or something you are unsure of?
Are we all falling into the trap of saying TNCS (if it's a trick question).
I will say it's anything but TNCS just to be different.

 

[7029 dave]

TN

 

[telectrix]

WTFTE...... where the f*cks the earth

 

[Julie.]

WTFTE...... where the f*cks the earth

Hence T

Not TT, or TNx - just T

 

[Mike Johnson]

? I seem to see an earth cable on the left of the picture, perhaps my eyes are playing tricks on me, it is at least five hours past the yard arm.

 

[Simon47]

Is it one of those new ideas - TNN, where the N derived earth just loops back to the N ? I can see there's an earth cable, but it disappears out of sight, so it might go anywhere, but might be stuck into the bottom of the cutout.

 

[Pretty Mouth]

TN-C-S.

The earth conductor disappears behind the bottom of the cutout, then reappears above it. You can just about make out the green/yellow between the live conductors.

 

[Zerax]

I came across it the other day... was interested if it was just me who guessed wrong... I assumed that it was PME, then the Ze came back as 77 Ohms ! Then realised that the earth block on the left is not actually connected to the neutral internally.

I called out the DNO who tried to tell me that I should either install my own rod and connect that to their cut-out, or just rewire the earth into the neutral block. After a few words of bemusement they 'converted' it to PME for me.

 

[Zerax]

TN-C-S.

The earth conductor disappears behind the bottom of the cutout, then reappears above it. You can just about make out the green/yellow between the live conductors.

The earth conductor just goes from the cut-out to the CU.

 

[David Prosser]

Is the link between the neutral and earth terminal in the cut out still in place ?

 

[buzzlightyear]

If there was a problem with the Earth then that new smart meter should not been
Put in.

 

[Julie.]

If there was a problem with the Earth then that new smart meter should not been
Put in.

I think you are assuming too much competence on behalf of the meter fitter!

Most will just take out the old and fit the new without actually trying to understand what's going on.

I thought it was quite obvious that the earth was unconnected, as it isn't a main cable entering the head, just two cores, line and neutral - is it fed from overhead lines, or is there a proper intake head somewhere?

 

[Zerax]

Is the link between the neutral and earth terminal in the cut out still in place ?

No... they're separate. No connection between them at all.

 

[Zerax]

If there was a problem with the Earth then that new smart meter should not been
Put in.

Agreed. The seals on the cut-out and meter covers were identical and looked correct to me... so I'm guessing it was the same person.

 

[Julie.]

No... they're separate. No connection between them at all.

Is it ohl, or is the a proper head somewhere?

 

[Simon47]

Is the link between the neutral and earth terminal in the cut out still in place ?

Must admit, I was wondering if it was fitted, or had ever been fitted.

I think you are assuming too much competence on behalf of the meter fitter!

Probably
As I recall, when I had an isolator fitted, the guy didn't take any measurements at all - only a quick check of polarity.

I thought it was quite obvious that the earth was unconnected, as it isn't a main cable entering the head, just two cores, line and neutral - is it fed from overhead lines, or is there a proper intake head somewhere?

TN-C-S is like that. Just two cores in which may be separate cables overhead, or concentric (buried or overhead). Inside the service head (a.k.a. main fuse unit) the earth terminal is linked to the neutral conductor. Out in the street, there will be multiple points where the neutral is earthed - hence the name "PME" (protective multiple earthing).
As long as the neutral conductor doesn't get broken, this does give a very good earth.

 

[Burtones]

After a few words of bemusement they 'converted' it to PME for me.

So what did they do, just link the earth terminal to neutral in the cut out?

 

[Julie.]

Must admit, I was wondering if it was fitted, or had ever been fitted.

Probably
As I recall, when I had an isolator fitted, the guy didn't take any measurements at all - only a quick check of polarity.

TN-C-S is like that. Just two cores in which may be separate cables overhead, or concentric (buried or overhead). Inside the service head (a.k.a. main fuse unit) the earth terminal is linked to the neutral conductor. Out in the street, there will be multiple points where the neutral is earthed - hence the name "PME" (protective multiple earthing).
As long as the neutral conductor doesn't get broken, this does give a very good earth.

But that isn't configured as as a main intake head aka service head, there would naturally be no connection between the neutral and earth connection.

That could be configured for TT, or TN-C-S, but it isn't configured for anything!

So T at best!

Even if it does end up being interconnected for TN-C-S, given the age of the cable it isn't necessarily PME

 

[Zerax]

So what did they do, just link the earth terminal to neutral in the cut out?

Exactly !

 

[Zerax]

Is it ohl, or is the a proper head somewhere?

That is the proper head... it's a very normal terraced house with nothing else weird or whacky.