Cable Question

[Andy T]

I have just moved into a house which appears to have been rewired aroun

10 years ago, however there aren't enough sockets and there in the wron place etc. so I doing a spot of rewiring. All the cable is PVC 2.5m T&E, however there is one length of cable which is marked "Ashathene It has the same colours as normal PVC (ie red and black with gre covering) however the wires inside are stranded and silver in colou and the earth is solid but appears a little thinner than normal and i is also silver.

Sod's law of course comes into play with this cable being very awkwar to replace, which is probably why it wasn't replaced as part of th rewire.

Does anyone know anything about this type of cable? (lifespan, curren rating etc) It appears to be in good condition, but I'd like mor info.

And

-- Andy T

[Andy T]

I have just moved into a house which appears to have been rewired aroun

10 years ago, however there aren't enough sockets and there in the wron place etc. so I doing a spot of rewiring. All the cable is PVC 2.5m T&E, however there is one length of cable which is marked "Ashathene It has the same colours as normal PVC (ie red and black with gre covering) however the wires inside are stranded and silver in colou and the earth is solid but appears a little thinner than normal and i is also silver.

Sod's law of course comes into play with this cable being very awkwar to replace, which is probably why it wasn't replaced as part of th rewire.

Does anyone know anything about this type of cable? (lifespan, curren rating etc) It appears to be in good condition, but I'd like mor info.

And

-- Andy T

[Dave Plowman (News)]

Stranded 2.5mm TW&E was available once. And IIRC, the size of the earth conductor did change, since metric cable was introduced. Older 7/0.29 cable - the type used for rings before metric - would have had a 3/0.29 earth.

The silver is probably tin plating. If you look at an 'end' can you see copper?

Aluminium cable was used at one point, but I've never seen it. I'd expect the conductor size to be much bigger.

If the cable looks in good condition, simply have the earth loop impedance of the finished circuit checked. And I suspect it will be within limits.

[John_ZIZinvalid]

Sounds like some old style 2.5mm T&E, I would say mid 1960's. They were tin plated copper, possibly with a 1 mm solid CPC.

You will find the stranded wire to more troublesome when making connections with a solid core wire as used in ring circuits, so it might be easier to replace, and as for lifespan it depends on many factors, but I would say your comme to end of the life for this wire.

If the opportunity is their to replace then do so, as 2.5mm T&E is cheap enough these days, and will come with a 1.5mm CPC.

J

[bigcat]

thats the main thing. To be on the safe side I would snip the end to check its tinned copper and not aluminium. Ali wiring works but with dramatically higher incidence of fires.

NT

[Andy Wade]

AFAIK it still is.

Yes, from 1.0 to 1.5 mm^2, after someone realised that in some circumstances with a 30 A BS 3036 re-wireable fuse the CPC was not properly protected.

ITYM 7/0.029 & 3/0.029 - yes and I think this is what the OP has found. It's oversized compared to 2.5 mm^2 and won't cause any problems in itself - but make sure that the connections where 7/0.029 stranded meets

2.5 mm^2 solid are sound. Using different types/sizes of conductor in one screw terminal can easily lead to poor connections. Pull fairly hard on all the wires to ensure that they're firmly clamped by the screws. Any loose wires must be attended to immediately.

All the old imperial cables (BS 2004) had tinned conductors; the metric sizes (BS 6004) never did, AFAIK.

[Dave Plowman (News)]

Ah. I've seen stranded single 2.5mm still available, but not TW&E.

[Andy Wade]

Ah, you may have a point. The new Pirelli data sheet for 6242Y & YH, here

longer lists 2.5 stranded.

For 6491X conduit wire the 1.5 and 2.5 sizes are still available as solid or stranded:

[Martin Crossley]

cable was introduced.

I would bet that it is 7/029 with polythene insulation, but I can't find my 13th edition wiring regs. to look its rating up. (I'm reasonably sure it's OK, though.) Martin.