upgrade to PME - but REC is asking for EIC ?

[joepublic]

I recently moved house. I have TNS supplied to my property via the outer sheath of the supply cable. I checked with EDF and they said PME is available to the property and that the electricity co (Seeboard) should arrange my earth connection to be upgraded to PME (not sure what exactly this involves - perhaps replacing the service cut-out..?)

When I contacted Seeboard, they said I must have an EIC by my own electrician to have this done. This is as they quote " for the safety of their engineer".

Is this normal practice?

 

[dingbat]

It's not normal, but it should be.

RECs used to ask for a cert before they would reconnect a supply, but I've never been asked for one - for most of them everything after the cutout is your problem.

 

[ban-all-sheds]

You'll struggle to get an EIC for an existing installation.

PIR, yes.

 

[supersparky]

why the hell are you swapping a TN-S for pme!!!!!!??

tn-s is far far better! keep it

i actuly told them not to PME mine when they changed my service head!

 

[joepublic]

Thanks for replying.
BAS,
I also thought PIR would have been the appropriate certificate to ask for.
Perhaps the call-centre operator mis-quoted..?

Supersparky,
Perhaps I misunderstood, but I thought PME was an upgrade to all other earthing methods. But if TN-S is good enough then I'll certainly not bother with arranging a EIC/ PIR done for this.

Adice on whether to keep TN-S or switch to PME would be greatly appreciated
JP

 

[Adam_151]

TNS, where in good condition is the best earthing system, the other two TNC-S and TT are just work arounds sometimes employed to save money for the REC (they only need to use a 2 core cable).

The problems with TT are mainly that the ELFI is not low enough to trip any overcurrent device and you have to have everything rcd protected, and with TNC-S there is the whole issue of what happens if the neutral drops, and the issue of circulating ground currents.

TNC-S (PME) is an improvement over TT (in most cases), but to swap TN-S for it seems daft

 

[Qedelec]

Echo Adams comments, have you ever seen the effect of a dropped Neutral? Current usually finds a way back to the transformer using the shortest earth path, Alarm panels are a favourite, I have been told.

 

[lookinn]

I agree with the previous comments. PME is normally used when the property is fed overhead. Where no cable sheath is availible as a last resort. If the earth is a high RCD's can be used. Have you done earth loop impedance check.

 

[joepublic]

Thanks for all the advice. Much appreciated.
I will make no further queries to EDF / Seeboard on this. It's a nightmare trying to deal with them anyway.

BTW, I also asked them to fit a "load side isolator" but they refused outright. So I'll have my spark to fit one & avoid paying REC for pulling the service fuse for all future maintenance.

Lookinn; I will have my CU replaced soon and all circuits will be tested then. I'll make sure that Earth Loop Impedance is also checked then.

cheers
joepublic

 

[Stoday]

It's a nightmare unless you understand who does what.

EDF is the Distribution Network Operator. They provide a service connection, but don't connect it. They give you an MPAN number as a reference that you give to your supplier.

Your supplier connects your supply to the service connection. You can choose a supplier but not your DNO. So if your supplier asks for imposssible paperwork, like an EIC for an existing connection, you can go to a different supplier. Alternatively, you can start quoting the legislation à la BAS at them (it'll be more fun). You'll find helpful words in paragraph 25 & on from Statutory Instrument 2665, 2002 - The Electricity Safety, Quality and Continuity Regulations 2002.

For all this complication, blame M Thatcher.

 

[ban-all-sheds]

On another "M Thatcher woz here" note, I read a letter in the paper a couple of years ago about the railway fiasco, and in it the guy said "even the toy companies know that when you buy a train set you get the track and the station and the train all in the same box". Brilliant.

 

[Adam_151]

its not in the spirit of things, but if the DNO demands an EIC before connection, and the installation is existing, then fit an isolator switch and after that a shower CU with 30ma RCD and 16A MCB feeding a DSO, give them an EIC for that, then as soon as he is gone, isolator off, and swap the tails over

(of course you'll have to get Ze and PSCC by enquiry for your EIC, and test your RCD off site)