Circuit Protection Conductor (CPC)

[Tom W]

Hi,

I recently had an electrical survey conducted on a house we intend to buy. One of the main issues that arose was that 'there is no main CPC (Circuit Protection Conductor) from the suppliers side. Can anyone explain what a CPC is, whose responsibility it would be to install one (us or the supplier?) and how much this might cost?

thanks in advance

Tom

[usenet]

The CPC conductor is what you and I call the earth wire.

It's rather a glaring omission if there really is "no main CPC (Circuit Protection Conductor) from the suppliers side". Is this a rather old installation? If it's old it *might* be that the only earth connection is one to the incoming water main but this is definitely not a good idea nowadays with the proliferation of plastic water mains.

It's the supplier's responsibility to tell you what sort of earth they are providing and where you should connect to it but I think that's all. They *might* (I suppose) tell you that they are not providing an earth in which case you need to provide your own earth rod and use RCDs. Is this in the country with an overhead supply?

It's impossible to guess costs without more information. Presumably this is from a survey/check, does your mortgage depend on it or is it just something you want to fix?

[tom w]

Thanks for your response -

The installation is quite old - I can't be sure when it was last updated but the previous occupants of the house were there for 40 years and judging by the decor didn't do much in the way of home improvements since the 70s so we could be looking at a system thats not been touched for more than 30 years. The location is in a residential area of Leeds so I doubt there's anything unusual about the supply. Since posting the last message I've spoken to the electricity supplier who says that they reckon the installation is something that should be done by an electrician at our expense and then they will come and check that the connection meets the required standards. Didn't explain what a CPC was though! Our mortgage offer states that we must get the work done, but personally I'm more interested in making the electrics safe rather than fulfilling my mortgage companies legal requirements!

cheers

Tom

[ARWadsworth]

I agree, I would call it the earth wire if it was part of the house wiring. I have never heard of the incoming earth being called anything other than an earth.

It certainly is against the regs

It could be something as simple as a lack of an earth cable from the armoured cable supply to your fuse box/CU. Have a look at

to try and identify your type of supply. If you are really unsure post a photo of the supply somewhere on the web and give the address so that we can have a look at it.

-- Adam

adamwadsworth@(REMOVETHIS)blueyonder.co.uk

[Andrew Gabriel]

The supplier is under no obligation to provide you with a main earth connection, and even if they do, you do not have to use it.

Of course, there does have to be a main earth connection, but it can be via your own earth rod/tapes/plate/... but not via any of the other services such as water pipe, although if metallic, they must be bonded to it.

[usenet]

The OP has now told us that this is an oldish house in Leeds so it seems likely to me that the supply will be either TN-S or TN-C-S, so there *should* be an earth from the incoming supply I would have thought. Thus it may be that all that is needed is a piece of (thick) wire in the right place.

I agree that the supplier isn't obliged to provide an earth but in a town I would have thought it likely that there is one.

[N. Thornton]

earth. yours.

This isnt a problem, since earth rod installs are common and perfectly acceptable. I would be starting to wonder if about the survey by now. I'm not saying its wrong, but something isnt squared yet here.

Regards, NT