I've just come across, for the first time, copper covered aluminium twin & earth dating from the seventies.

I'd heard about this stuff, from during the copper crisis but never actually seen it until now. The piece I have is made by BICC. It looks alot bigger than 'normal' 2.5 & feels alight lighter. Its stranded & rather brittle - the strands break off easily when tightening the screws of junction boxes etc.

What is the wisdom with this cable? Does it need special accessories & termination methods? Should it be replaced when found?

Thanks Guys

Adrian

It's bloody rubbish, why do you think BS 7671 puts a minimum conductor size of 16mm2 on Aluminium conductors. (524 and Table 52.3).

Left totally undisturbed, it's probably OK, but given it dates to the 1970's this is a case where the phrase, "Technically, economically and functionally time expired" is true.

Europe does allow smaller sizes of aluminium to be used - down to 2.5mm2 from memory - but the problems it causes are manifest. I did a study on this quite recently as our experience is that contractors in parts of europe are opting for aluminium on a cost basis - the disadvantages however based on installation, proper termination, etc coupled with the american experience of aluminium cabling makes it very difficult to show any real benefit - it's usually all negative other than cost.

I wouldn't use it full stop, other than for big distribution where all the relevant issues can be addressed properly - and only then under protest.

Leave it well alone and recommend to the client they consider replacement

Regards

OMS

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Failure is always an option

I'll go along with that.
Only MK made power accessories specially for small size 'copperclad' and stopped producing them in the mid 80's, but the light switches and roses only had rounded terminal screws rather than the cheaper squared off ones..
Mind you, it was light although 1.5mm lighting cable was a real pain, and getting 2 * 4mm power cable into the 'new' shallow sockets a bit of a challenge, it was nice to get back to using 'proper' cable.

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Norman

Dident the 14th edition stipulate a minimum size for copper clad cables, I think 4mm from memory

oh how crap it was, always snapped off as you tightened the screws


Any of you guys remember the aluminum pyro? now that was a treat to work with

Wasn't it just - and now we have just aluminium foil and we think that's OK to protect from penetration where we don't want RCD protection

Ahh well

OMS

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Failure is always an option

Well why did we use 1.5mm2 copperclad aluminium for lighting cct's then?

My parents 1970's built bungalow had what I believe was aluminium cable, full stop. There was no visible suggestion that it was copper coated aluminium. Oh the fun of finding arcing terminals on the switches of lighting circuits.

I still cannot get over how fortunate my wife and I were in that our 1973 built house was wired in copper. Also that the builder's electrician was of the old school. His workmanship was immaculate and the cable dressing inside the Wylex consumer unit a work of art.

Cheers!

Clive

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Clive S Carver GCGI IEng MIET

Slightly off topic, but for someone thats never seen CCA can anyone provide photos of installations? CCA specific fittings? Not getting a lot on google and while its a little off topic, something ive yet to come across.

I'll have a rummage in the loft, but the cable is light in weight, bends very easy and 1.5mm for lighting and 4mm for power. From memory, the insulation generally had BICC on the oversheath and I always thought it felt thick.
The terminals (sockets generally) had a flat plate to squash the cable rather than a terminal screw. MK sockets were round edged, stuck out about 3/8" and had a wider switch than ordinary ones and not recessed.

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Norman

I was only familiar with the final metric edition of the 14th, perhaps the smaller sizes of CCA were discontinued due to problems with the terminations