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Topic Title: Copper-clad cables
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Created On: 09 July 2013 04:55 PM
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 09 July 2013 04:55 PM
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leckie

Posts: 2014
Joined: 21 November 2008

Hi all

Just come across a house with copper-clad cables.
They look like 10sq.mm for the cooker,
4.00mm stranded ring, 1.5mm solid for lights.

They want a board change. I normally do an EICR prior to a board change but I'm not really sure what to comment regarding the cable type. I know it's not compliant with BS7671 as the minimum size for aluminium is 16sq.mm. I haven't got an old enough regs book to see if details of the cable were ever listed. Although I am ancient I never fitted any and can't remember much about it. I am aware there are problems with terminations, corrosion, brittle cores, etc.

I'm thinking, providing test results are OK and the inspection results are OK, that a comment and a code 3 would be in order.

Your thoughts, as always, much appreciated.
 09 July 2013 05:03 PM
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perspicacious

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"They want a board change"

Shirley if they are informed enough to make that decision, they can make one about the cable as well?

Regards

BOD
 09 July 2013 05:13 PM
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leckie

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Please don't call me Shirley BOD

Well they might be, but I was simply seeking a bit of debate so that I can give a bit more considered opinion. I do know that in my area the local council had all this type of wiring replaced many years ago so they must have considered it a potential problem. Probably after one of the houses caught fire as I recall.
 09 July 2013 05:18 PM
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perspicacious

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Would this then be an ex council house that the tenant bought at a discount ahead of the council's rewiring program?

Regards

BOD
 09 July 2013 05:43 PM
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leckie

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No it's a private house built in the late sixties or very early seventies. The whole estate is probably the same.
 10 July 2013 03:05 PM
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leckie

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Has anyone got some input on this one please?

I have read some previous post on this so am aware that copper clad cables are not covered under the present regs, however if the test results and inspection are ok I don't feel I can suggest to a single mum that the place needs rewiring. So as previously suggested I'm thinking code 3 and observations made.
 10 July 2013 03:21 PM
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OMS

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If it helps, you can go back to the IEC documents rather than BS 7671 and the minimum conductor size there for aluminium is 2.5mm2 rather than 16mm2.

The UK doesn't like it based on the experiences of the Amercians who used aluminium before we did (but curiously couldn't spell it properly )

It's a disaster really, for all sorts of reasons - some of which you mention.

But if it isn't being altered, and it looks OK and tests out OK then it's just a recommendation to consider a rewire

Regards

OMS

-------------------------
Failure is always an option
 10 July 2013 04:13 PM
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AJJewsbury

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I'd be careful with the testing - look especially for high resistance joints (I'm not sure how effective the Cu cladding is after a terminal screw has bitten into the conductor, but I've seen several burn-outs resulting from joints with plain aluminium). I'd suggest L-N loop tests as well as the usual L-PE and check the resulting numbers carefully as otherwise poor connections on N can go unnoticed, especially on radials.
- Andy.
 10 July 2013 05:37 PM
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leckie

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Thanks very much for the replies OMS and Andy. I know this job h had a lot of previous alterations so there could be hideous joints all over (and under) the place. Good advice on the L-N impedance test as well.

I had a quick look in the existing board but didn't disconnect anything. In fact the 10mm cooker supply wasn't actually copper clad it looked like just aluminium. I know it could be the old tinned copper but I've only seen that in TRS. I think it may be aluminium hence the size, though I hope not. Aluminium direct to brass is not the best I'm thinking.

I think if all tests and inspects are ok it will be a code 3, if any issues depending what they are I may lean to a code 2. I'm on it Friday morning so I will update on my findings!
 10 July 2013 06:31 PM
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OMS

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Doesn't matter what you code it - it's going to need a rewire shortly anyway - single mum or no single mum.

I'd just make that plain on your report - you can refer to endless publications regarding the matter.

As a minimum I'd get one or more 30mA RCD's in place TBH, and put a dead line of say 3 years on it.

Regards

OMS

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Failure is always an option
 10 July 2013 09:33 PM
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leckie

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Well I agree with you OMS but I do have to code it because that is the format of the form. But you have alerted me to the seriousness of the situation. Many thanks.
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