Main Earth Terminal

[Adrian80]

The DNO keep on telling me that this is not a PME supply. So it seems bloody strange for them to advise me to connect into the neutral.

I think i am only left with the option of banging in an earthrod, and having that as my main earth.

I apologise if i am being a bit thick, it seems like the DNO are somewhat contradicting themselves.

A

 

[ban-all-sheds]

The thing is the guy said it aint proper PME its plastic sheathed cable,

Don't see what difference that would make - as long as you have a neutral you can have a TN-C-S supply.

and the ze from the neutral to live is kind of indicating that its only just good enough....

It is only just under the max allowed.

It all sounds a bit s**t to me, and it sounds like i need to bang in an earth rod somewhere??

Simple question - do you have a sticker or notice anywhere to say that you have a PME supply, or anything in writing from them?

 

[Adrian80]

hi BAS,

Nothing in writing saying it is PME, they keep on telling me its not PME because its on a loop.

Yet they are trying to get me to earth into the neutral ????

I dont get it, are they sending me mixed messages?
A

really thankful for all your advice.

 

[ban-all-sheds]

Nothing in writing saying it is PME,

Then it isn't. Or at least you may not treat it as such.

they keep on telling me its not PME because its on a loop.

OTTOMH I can't see why that should be relevant, but I've not thought about it.

Yet they are trying to get me to earth into the neutral ????

I dont get it, are they sending me mixed messages?

Write to the head of engineering at the DNO, tell him what's happened, if possible quote names of people telling you to connect to it as if it were TN-C-S, ask him to get it properly resolved.

In the meantime get an earth rod installed somewhere suitable and make it TT.

 

[Adrian80]

Cheers BAS,

Good firm advice.
god knows why the DNO just didnt say.. we cannot guarantee PME, therefore you must treat it as a TT...

Surely that is the clearer message.

BAS, Sparky123, and sparkyspike much appreciated.

Adrian

 

[sparkyspike]

You say that they have already offered to provide you with an earth terminal. If this is true, then ask them to do it. At the moment they are been unclear as to what kind of supply you have, which is stupid, but once you get your PME terminal, you'll know. Connect the earth cables to the terminal they give you and you will be sorted. It's up to the DNO to worry about the PME side of things.

Don't worry about your Ze. Even though it's relatively high, it's still within limits which is absolutely fine.

 

[JohnD]

You say that they have already offered to provide you with an earth terminal. If this is true, then ask them to do it.

Hear hear!

It will also become their responsibility to maintain it.

So I would not stir them up until after they've provided it.

You are not allowed to connect your own earth wire to their neutral anyway - only to any earth terminal they provde, which may be PME.

 

[Adrian80]

Hi guys, the DNO want a £120 quid to change the service head which will then give me the earth terminal, this seems somewhat more expensive than trying to get an earth rod in.

What do you, is it really worth spending the extra money???

A

 

[JohnD]

yes

 

[17thman]

If it is a plastic sheathed cable it won't be a pme earth. pme earth uses the neutral not the sheath as the earth path. send a pic please.

 

[RF Lighting]

Do you actually understand what a PME earth is?

There are pictures in the wiki.

 

[ricicle]

tested the supply by putting the meter between the live and the neutral, they ended up with a reading of 0.34

the ze from the neutral to live is kind of indicating that its only just good enough....

 

[Spark123]

2 core concentric can be TN-CS (PME)
3 core split concentric is generally TN-S

 

[17thman]

promise never t come home from pub and log on

 

[securespark]

tested the supply by putting the meter between the live and the neutral, they ended up with a reading of 0.34

the ze from the neutral to live is kind of indicating that its only just good enough....

Suppose on a PME supply, LN EFLI reading is same as LE.