PME Earth & DP Isolator

[Cartboy52]

Here are 2 photos of my meter / fuse boxes arrangement

I have a some concerns over this, but was wondering -

1 - Why has the installer taken the earth from the DP isolator and not the earth terminal on the big black box to the left?

2 - The main fuse is 100A, but the isolator is only rated 60A. Should I get the DP isolator updated?

3 - Links to 2 - Who owns what? What belongs to the supplier and what belongs to me?


Thanks in advance!

 

[Lectrician]

You have a TT earthing arrangement protected by a Voltage Operated ELCB.

The ELCB is no longer recognised in the regs, and should be removed asap and the earthing system either changed to PME/TN-S (from the service head), or a main RCD fitted and a rod installed if not present.

You rbest bet is to get a sparky in to sort this, and he will know what he can do and what he has to get the DNO to do.

 

[Lectrician]

Voltage operated ELCBs do not function well due to parallel paths etc, and where only in use for a very short period of time.

ALSO - The off peak circuit you have has no protection what so ever - It doesn't pass through an RCD or ELCB.

This all needs sorting.

 

[JohnD]

1) don't know. Looks like the service head was changed many years after the isolator was fitted. I see no reason why you shouldn't connect to it using 16mm G&Y. is there a PME label on or near the suppliers cutout? (sometimes the earth terminal is not connected inside by accident or otherwise If PME is available, it's best to make use of it.
My preference would be to add an 8-way earth block to the board as your main earth terminal, and connect everything else to that

(2) You don't know what size fuse is in the cutout. It might be 60A. edited: i did not notice it ws a Voltage ELCB Inspect the tails from cutout to meter and if you see any damage or perishing, ask for those to be replaced too. It would be better to have an isolator off each meter. It looks to me as if you have one meter to each flat, is that right?

(3) As a rule of thumb, everything fixed to the meter board belongs to the supplier, and everything else belongs to the householder. Henley blocks isolators and earth blocks may be supplied by the householder's electricain but the suppliers generally don't object to them being fixed to the meter board. they do object to anything else being fixed to it (they are entitled to remove or replace the meter board and meters at whim).

OOI, your installation looks a bit of a muddle. Are you planning to have it renovated? Do you have main bonding?

 

[Taylortwocities]

You have an off peak arrangement with an old voltage earth leakage breaker. I do not see an earth cable coming out of the supply head. What sort of supply do you have? Is it overhead? Do you have an earth rod with an earth lead connected to it in the ground outside??

1 - Why has the installer taken the earth from the DP isolator and not the earth terminal on the big black box to the left?

This is an old type of ELCB and is now obsolete. These are no longer used and not effective. It will operate as a means of siconnecting the supply but will not provide any form of safety protection. The reason for the earth arrangement is probably because the supplier doesnt provide one. See my Q above.

2 - The main fuse is 100A, but the isolator is only rated 60A. Should I get the DP isolator updated?
As stated above. It needs removing and updating. As far as i can see, your installation is quite a mess and uses the old type rewireable fuses, I would recommend that the update includes a new consumer unit (fusebox)
3 - Links to 2 - Who owns what? What belongs to the supplier and what belongs to me?

Everything up to and including the red and black meter tails going into the old ELCB belongs to the electricity company. the rest is yours.

edit: damn you Pitmans touch typers!!!

 

[Cartboy52]

is there a PME label on or near the suppliers cutout?

There is a green label just inder the earth connections on the black box on the left (I don't know what it's called!) that reads "Earthing Terminal P.M.E. System"

Does this not indicate it has already been converted to PME?

There is evidence of old earth rods outside, but they have long since corroded and wires removed. I presumed this was an old arrangement that is no longer used?

It's a house, not flats. There is only one meter and one radio switch. The cheap rate fuse board is liked to a storage heater in the loft that I don't use.

There is currently no earth bonding. I was thinking of taking a 16mm earth from the labeled PME earth terminal to a earth block and then toeach fuse board, and 10mm to the water / gas pipe etc

 

[JohnD]

There is a green label just inder the earth connections on the black box on the left (I don't know what it's called!) that reads "Earthing Terminal P.M.E. System"

Does this not indicate it has already been converted to PME? Yes, that's great

There is evidence of old earth rods outside, but they have long since corroded and wires removed. I presumed this was an old arrangement that is no longer used? No need now you have PME

It's a house, not flats. There is only one meter and one radio switch. The cheap rate fuse board is linked to a storage heater in the loft that I don't use. Can you make any use of it for imersionheter, tumble drier etc? as it is cheap night-time elecricity. f not, convert to single-rate tariff as the Economy setup has to be paid for (by you)

There is currently no earth bonding. I was thinking of taking a 16mm earth from the labeled PME earth terminal to a earth block and then toeach fuse board, and 10mm to the water / gas pipe etc Yes that's great. And 16mm to all of your Consumer Units, of course.

 

[Cartboy52]

The plan was to get the meter changed for a single rate meter, since I don't use much of the cheap rate stuff anyway. I'm in the East Mids and here you pay a higher day rate if you have economy 7. I don't use enough night electricity to cover the increased day fee.

If I got the meter changed, would the supplier then also update the rest up to a new isolator?

 

[JohnD]

If I got the meter changed, would the supplier then also update the rest up to a new isolator?

No. If the job is "replace meter" thats what they'll do. (it will almost certainly be subcontracted out to another firm on a fixed, and rather low, price and the engineer will have been allowed X minutes to do it).

However if you ply the fitter with tea, biscuits and dancing girls, he might do the rest. your chances will be improved if you buy in advance a 100A DP isolator (preferably a MEM with the removable load-side hatch on the enclosure; a couple of metres of 25mm tails, and some new Henley Blocks to replace those wrinkled old ones.

 

[kai]

There appears to be a nice shiny earth terminal labelled PME earth, at the side of the rather modern looking Service Fuse Block, why on earth didn't the electrician connect the main earthing to that I wonder?

This is unusual, as it's rare to see the Service Fuse Block, and the main service feed cable to be in such good condition, whilst the rest of the install is so outdated! - Its usually the other way round!

 

[ricicle]

Those earth wires are a disgrace

 

[Adam_151]

Central networks should do you an isolator FOC, but its probably not central networks you'll have to swap the meter.

I'd just have a 100A DP isolator mounted on the wall with a couple of 25mm² tails in the supply side and just tell the metering bod that they are the outgoing tails he is to connect to the new meter (obviously make him a coffee etc)

I'd sort the earthing before he came, tidy it up and put 16mm² from that PME terminal and make sure your bonding is up to scratch and make so no earths go through the ELCB when you connected to the PME terminal.

Then when the metering guy has finsihed (or even before he comes if you don't mind beig without power for a bit) just drop the outgoing tails out the bottom of the the ELCB and into the outgoing side of the new isolator

 

[Cartboy52]

I'd just have a 100A DP isolator mounted on the wall with a couple of 25mm² tails in the supply side and just tell the metering bod that they are the outgoing tails he is to connect to the new meter (obviously make him a coffee etc)

That sounds good to me!

I've emailed my supplier (ecotricity) to ask if they will put an isolator in. I doubt they will, but you don't get if you don't ask!

If I get a new consumer unit fitted at some point in the future, is the 100A isolator in that the same sort of thing that I need to get now?

 

[Deleted member 54734]

Talk to your supplier and ask them to raise a job to fit an isolator at the same time as changing the meter.

As long as I get 2 jobs raised (one for meter change and one for fitting isolator) then not only do I have the time allowed to fit the isolator, but I also get two jobs for the price of one.
Which makes my figures look good and increases my chances of a pay rise at the end of the year

Not much that coffee and biscuits will make me do lately as I've been rushed off my feet. sorry

 

[JohnD]

it is the same sort of thing, and often the same part no. You just need an enclosure to go with it. Here is one in another oldish installation (the white rectagular box).