Solid Aluminium conductor twin and earth tabulated Zs values?

[flyingsparc]

Hello,

Board change today (domestic), cable is aluminium twin and earth - socket ring = 4mm/1.5mm, lighting = 1mm/1mm, oven 10mm/4mm

IR all good, continuity & Zs are within values set for copper equivalents.

This is not tinned copper.

I have managed to find out that this cable was used briefly in approx. 1971 due to a copper shortage (flat built in 1971 also). Apparently MK produced accessories specifically for use with this cable, although if ever fitted they are no present now.

Anyway, does anyone here know what the CCP and EFLI for cables sizes mentioned above please?

Obviously departures will be noted on cert.

Thanks.

 

[AndyL]

maximum EFLI is related to protective device not the cable type. You may end up with a higher resistance for R1 + R2, but as long as Zs is correct can't see a departure here

 

[flyingsparc]

Thanks, very good point (blushing).....what about current carrying capacities then?

 

[ChrisElectrical88]

If they are within the copper values i cant see a problem.

 

[Pete999]

Not doubting your observations flyingsparc, but you said the lighting was 1mm/1mm cpc could it be that your RFC is wired in the old 7/029 twecc, when Al cable was used lighting was 2.5mm/1.5mm cpc
Just saying thats all

 

[itselectric]

In response your post re cable size Pete999 I recall using aluminium cable in the seventies and we used 1.5 t&e for lighting.

 

[Guest55]

If they are within the copper values i cant see a problem.

i can see a massive problem.

the regs prohibit using solid aluminium cables smaller than 16mm for any circuit.
and thats not just the 17th , but 16 , 15 editions also.

so its a big fail now and it was a big fail back in the 60's / 70's when it may have been originally installed.

 

[KAS1]

Would it of been a fail to the 14th as I recall 60's / 70's was the 14th edition ? I'll check I've got the old book somewhere from 1972 lol

 

[7029 dave]

Pound to a penny it's stranded cable, not solid core, never seen 1044. 3029, 7029etc solid core.

 

[flyingsparc]

Thanks for replies so far,-

Lighting is solid aluminium 1mm csa, (too small or ali I know) I can be sure its 1mm because I fitted 1mm ferrules (snug) to help terminating in board.

Would be interested to see what 14th said if anything?

 

[Pete999]

Thanks for replies so far,-

Lighting is solid aluminium 1mm csa, (too small or ali I know) I can be sure its 1mm because I fitted 1mm ferrules (snug) to help terminating in board.

Would be interested to see what 14th said if anything?

Could be 1/044 that was a solid core lighting cable, the other was probably 3/029 stranded

 

[Engineer54]

That stuff was called copper clad aluminium, and the lighting cable size was 1.5mm not 1mm and although i may be wrong, but as i recall all cables were stranded!! The copper cladding to these cables, was to make them suitable for existing accessories, so as far as i know, there wasn't any specifically made accessories... This stuff only lasted a very short time it wasn't very successful.


I know of at least 2 large private housing estates that were all wired in that copper clad cable. I did hear many of them were rewired by the owners a few years down the line!! ...Horrible stuff!!

 

[ian.settle1]

Pound to a penny it's stranded cable, not solid core, never seen 1044. 3029, 7029etc solid core.

And you wouldn't as the first number is the amount of individual strands making up the core

 

[Guest111]

That stuff was called copper clad aluminium, and the lighting cable size was 1.5mm not 1mm and although i may be wrong, but as i recall all cables were stranded!! The copper cladding to these cables, was to make them suitable for existing accessories, so as far as i know, there wasn't any specifically made accessories... This stuff only lasted a very short time it wasn't very successful.


I know of at least 2 large private housing estates that were all wired in that copper clad cable. I did hear many of them were rewired by the owners a few years down the line!! ...Horrible stuff!!

Aye there's a lot of CCA data and telecoms cable kicking about lately,and its horrible,Had to pull in 100mtrs cat 5 at the farm,connected up tested and faulty,a break in a core somewhere,only when I looked at the box later did I realise it was CCA,otherwise I would have sent it back straight away,seems as brittle as hell.

 

[varilite]

They used aluminium in the early 70's when the price of copper went through the roof

 

[flyingsparc]

Thanks again for the responses.

I don't have a copy of 14th edition, (I was only 3 years old in 1971).

If any one still has a copy, would you mind having a look in it for me, for current carrying capacity please?

Or any publshed data?

Many thanks.

 

[KFH]

14th Ed has aluminium PVC covered from 16mm only. It lists copper clad aluminium from 1.5 (1/1.38) clipped direct 12A. 2.5 (1/1.78) 17A. 4mm ((7/0.85) 22A.

I have a customer with aluminium cable throughout the house. It is aluminium; I cannot see any copper coating on it. It is slightly larger than the normal metric cable so I am assuming it has similar rating to the equivalent copper cable. All the accessories I touch are loose. Look up aluminium cable on Google, there is a lot of it in America and they have done a lot of work on the problems and methods of rectification.