"urchaidh" wrote in message
oups.com...
I'm looking at reinstating a 15A spur to a socket in our kitchen for an
oven. The previous owner had an all gas cooker which (I guess) whould
just have been plugged into the ring main for any leckie it needed.

There's an existing cable with plenty slack terminated under the kithen
floor connected though to a 15A fuseway in the fusebox. The cable looks
quite old, slightly heavier than 2.5mm2 (based on my vernier
measurement) and the earth is twisted steel (?) strand rather than
solid copper.

Are the circuit conductors stranded or solid?
The old 7/029 or thicker cables often had tinned copper conductors. You may
be mistaking tinned copper for steel if you are basing your idea on colour.
Steel conductors would be very unusual and easily confirmed with a magnet.

I'm pretty sure I'm going to rip it out and run a new cable just to be
sure, but before I go to all the trouble (and it will be a lot of
trouble) is there anyway to test the integrity of the existing cable?

The conductor continuity can be checked with a low resistance tester, the
insulation value can be easily checked with a Megger. Unfortunately you
should also inspect the condition and verify there are no branches or spurs
off it and it is in good/satisfactory condition (no rodent or other damage)
This may not be possible:-(

How do I tell if it's got the old friable insulator on it?

With your eyes and try bending it to see if bits crack and falls off. If its
anything but PVC or MICC you should chuck it anyway. You can of course use
it as a pull wire to draw in a new cable

Kitchens are special locations under the fat controllers new regs and
require notification of ANY work to building control. Proper Testing and
Certification is required.