New board and TT to PME Change

[slicedbread]

I need a new consumer board and I've had a few quotes for the work but I'm getting really confused.

The local elec co. did one of those free inspections. The guy was around for some time and condemed the existing consumer board and also found no bonding and couldn't even locate the earth rod (reckon it's under the floor boards myself).

Local elec co. then gave me a quote for the work and phoned back a few days later to say he'd cheked and PME was available for my house so knock £200 off the quote. So far so good.

Now the confusing bit. I get a quote from a local electrician who says yup can do all the work (new board, bonding etc) and swap me onto PME as it's availableand issue me the relevent part P certs.

Then another local elec. has given me a quote for twice the price but says I can't go PME and have to stay TT as elec board would need to do the swap to me to PME and I wouldn't be earthed in between the new board going in and the actual switch to PME He also says the price need to be higher as the house needs a coplmete elec check when the new board goes in.

Both the local sparks are NICEIC

Not sure what to think they can't both be right can they?

 

[Spark123]

Only the electricity company are allowed to install an earthing terminal on their equipment.

 

[RF Lighting]

No decent electrician who likes to be able to sleep at night would ever even consider leaving you with no earth, however temporary it might be.

The earth is there for the sole purpose of preventing you being electrocuted should a fault occour. No earth, No protection*

 

[julioarca]

If u are supplied by TT (overhead network) then its probably easier for you to install and earth stake and get the CU changed over.

The electrician who said he would have to leave u without an earth sounds a John Wayne (cowboy), NO ONE should do anything that would leave your house etc unearthed but they are correct in saying that the full house would need a Part P if u change the CU.

 

[JohnD]

but whoever does the work (and even if you don't have it done) it would be a good idea to have the PME conversion done. It might cost you £60 to £100 or it might be free.

You can arrange it by writing to your electricity supplier* requesting that they arrange to provide you with a PME earth. Keep the letter short and say nothing more.

If you can post a pic showing your incoming supply, meter, consumer unit and the cables around them we may have further suggestions.

*it may not actually be them who does the work, but they are responsible or knowing who to pass the request on to - you don't have to work it out yourself

p.s. I don't like the sound of the second contractor.

 

[RF Lighting]

It may well be easier to keep the TT supply, but it is much much much much much much better to get the upgrade to PME.

Not to mention the cost savings of not having to purchase a CU with a 100mA TD main RCD, and complexity of the other associated special precautions.

 

[slicedbread]

If I got the image thing right

Here is the supply

And here is the Consumer unit

I think I gave the wrong impression about what one spark said.

1st spark says yes to bonding and changing to PME will provide part P

2nd spark says needs to keep to TT as elec board will need to change to PME so therefore he's got to put in new board with 100Ma RCD and then part P house. As to not put in 100Ma RCD would leave house unprotected whist wait for elec co to put change to PME and elec co won't put in PME unless wiring is up to speed for Part P with PME before they switch supply to PME in any case (if I understood what he was telling me)

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Links Fixed, Mod9

 

[Lectrician]

If it was me, with my DNO, I would fit a split load CU and leave an earth tail hanging ready for connection the service head.

I would take the RCD that is there already off the wall and leave it loose, and use it to join the new 25mm tails from the new CU to the old tails - Leaving the tails long enough to go into the meter.

The DNO would connect the new tails and earth, and leave the RCD on site ready for the bin, or for me to collect if it was one of mine.

I would then fax in a connection cert for tails and earthing - At a cost of £25 from my DNO.

 

[securespark]

OR:

Get your bonding fitted first. This is no longer notifiable so if you are confident, you could do this bit.

Then get your intake converted to PME by DNO.

Then a board change by local spark.

 

[JohnD]

best.

 

[securespark]

george?

 

[JohnD]

solution.

 

[Lectrician]

Naa - Thats too bity.

If you are having a spark in to do a board change, he should be relied on to do bonding and organise the PME. It is a service you are paying for with an electrician - not just a skill.

 

[slicedbread]

Thanks for all the advice guys.

So what I'm taking away here is PME is better than TT.
The cheapest guy who's said he'll change to PME will have to part P the whole house in any case.

I guess I can trust him as he's NICEIC (?)

The only bit I don't understand is his written quote says "existing TT system to be changed to PME" PME terminal installed. But I've asked him if I need to ask the elec board for anything and he says no.

 

[Adam_151]

The cheapest guy who's said he'll change to PME will have to part P the whole house in any case.

Sometimes, just sometimes I get the feeling that people who really should know better don't undertstand the building regulations at all.... otherwise they wouldn't be making comments that don't really make sense to prosprective customers...

Guessing at what he is trying to say, I'll tell you that:....

1) A board change is changing charteristics of every circuit, so every circuit will need to be tested and an EIC issued for the board change

2) A board change is notifiable to the local authority building control dept., this can either be done through a building notice, or through a self scheme cert such as the run run by the NICEIC, BSI, BRE(ECA), BSI, or NAPIT

3) Unfortunatly NICEIC is no garentee of a good job and there are some very good people who aren't registered with NICEIC, its a good starting point, but don't set too much in store by it (do however pick one who is part of a 'self-cert scheme' it makes LABC issues easier!)

4) Unless there already is an accessible TNCS earthing terminal on the service head, then you'll need the DNO to install one (and check that its available), just bashing it into the neutral on the service head is a rather poor idea