this is odd!

[esc]

Hi guys, would you like to have a look at this and tell me what you think, i'm a bit confused. Only had time to have a quick look at this as im away for a couple of weeks as of tomorrow, so couldn't delve deeper.

There's a lable stating PME, a 4mm earthing conductor that runs from the CU to the outside where it joins more conductor via a MET hanging from the wall and then dissapears along the row of terraced houses. As you can see there's a CPC with the incoming suppy and a terminal block with the DNO' fuse thats empty. CU's CPC's unsleaved, Terrible it is!
I can get a Zs at a SO near by (0.44 ohms), but when i try take a Ze, instrument throws a big question mark up before i can test and wont allow it. It's giving odd values of PD between L & N and L & E. Thought maybe leads have thrown a wobbly, but they check out at home.
Any ideas appreciated.
Sorry theres not more info at the moment.

 

[telectrix]

before doing anything, i'd get DNO to sort the supply end first. if there's a PME sticker, it should be PME ( if it don't do in the tin what it says on the tin).

 

[esc]

I also tried to test at the earth terminal on the DNO's service fuse (assuming the lable was correct and it had been promoted to PME) but the meter didn't like that either. It gave the same PD values as above

 

[Kamikaze]

Did you get any voltage between neutral and what you assume to be the earth?

 

[esc]

Think thats a good idea telectrix. Not been in this position before. The house im refering to has just been moved into by a close friend of mine, it's being rented. Ive already told them to get onto the landlord to have the earthing (especially the bonding) rectified. Can i approach the DNO, can the tennant, or is this something that has to go through the landlord?

 

[esc]

Hi kamikazi, no mate, with the main earthing conductor in the MET LE LN LE checked out. When i pulled it out to do loop, the crazy voltages appeared on screen. Have just done another Ze at home, meter ok.

 

[Kamikaze]

Personally, I think there is no earth continuity. A test between neutral and earth would confirm that. You would get a random voltage.

 

[esc]

I have plenty of doubt of the earths continuity kamikazi. Im trying to get my head round what you say, but its been a long day, am off for a bath. If you've time could you expand on that some more regarding the voltage and maybe explain why i might get a low Zs reading with poor earth continuity.
Many thanks

 

[Kamikaze]

Basically, it does not matter what voltage readings you get between live and earth or live and neutral, there could be countless reasons for that. However, the neutral and earth should be at the same potential, so you should not be able to get a reading. If you do, it will be due to a high resistance.

 

[GLENNSPARK]

Like tel mate and get the DNO in.....

 

[esc]

Thanks for that kamikazi. I'm a bit wiser on that. Still od that if i do a Zs at a SO those odd voltages dissapear and allow me to test.

 

[esc]

Cheers glennspark and tel. Like tel says, it's not what it says on the tin, and if it is, it's broke, so they can have a look and tell me what it is/isn't.

 

[esc]

Was thinking today guys. You see that earth coming in with the supply (top of picture) Could the DNO of linked that inside with neutral to give PME. Ive never seen inside one of these boxes so dont know how the external earth connection (where we put our main earth conductor) and neutral inside the box connect. or wether its permanent, can be made up or taken out or what?
Cheers

 

[Spudnik]

Nearly all overhead supplies were TT back in the day.

I am guessing this is still the case with yours.

Although the sticker says "PME", your first port of call would be to the DNO.

It is THEIR responsibility.

 

[Engineer54]

Nearly all overhead supplies were TT back in the day.

I am guessing this is still the case with yours.

Although the sticker says "PME", your first port of call would be to the DNO.

It is THEIR responsibility.

That was one of the major reasons for bringing PME to rural areas, to get rid of the multitude of TT installations. I know in Essex vast area's of overhead supplies were converted to PME supplies. Now we have all the numbties converting out buildings and garages back to TT systems. ..lol!! Not sure about elsewhere in the UK, but according to my DNO friend, they have an obligation to convert X amount of unearthed overhead lines per annum. Not sure if it's based on properties or network strings...