Re-routing "pyro" electical power cables

[Clive Long,UK]

Hi,

My flat has solid floors and ceilings. The flat also has "pyro" power cabling. As the flat was built in the late 60, the single power circuit for the whole flat is completely inadequate for my glut of electical devices, fridge, washing machine, micro, oven, kettle etc. etc.

Now when I use two devices in the kitchen the power breaker trips out. However, there is a supply that was for a cooker, terminating, uselessly, in a socket on a wall. I want to move this supply to the other side of the kitchen and use it dedicated to the electric cooker. This will involve lifting cork tiles which is no issue and channelling the solid floor to accept new power cable, again not a real issue. However, is it possible to "take" the pyro out of the wall, terminate it some how, then redirect a "cable extension" in the new floor channel, so that the supply terminates behind the cooker (13 amp fuse) and takes that device's load off the single power circuit that carries the rest of the devcies in the flat?

Any other things to think about before attempting this?

Thanks

Clive

[Chris Oates]

First came across Pyro about 40 years ago when fitting encoders to Veeder Root mechanical computers in petrol pumps - these fed data to Post Payment systems we made for Gilbarco. Hmmm...this stuff must be some sort of colour coded armour....aha...a loose gland....I'll just twist it to tighten it up BANG !!

[Dave Plowman]

If you can remove the MICC from the wall *without damage to it*, the existing gland and termination should be fitted to an adaptable box, or conduit box of a suitable size as a junction box. Extend the circuit using suitable TW&E. The earth to the TW&E should be made via an earth clamp on the MICC casing - don't rely on the gland to box for this.

If the existing termination is in an unsuitable place to do this - ie the junction box would be in an awkward position, and would be better moved back along the MICC, this can be done using new parts, but requires practice under ideal conditions before attempting one in a difficult situation like low down or under floor boards, etc. If you get a pro in, make sure they know what they're doing as many present day sparks will not be skilled at this either.

[Dave Plowman]

An airing cupboard will work too. Also, in future, seal the ends with gaffer tape to store. ;-)

[derek]

I worked for an electrician during my summer holidays in 1963 and we did some installations with "Pyro". He said the most difficult part of it was getting the runs straight, although I remember some spectacular cursing when the copper conductors work hardened and dropped off the end when he'd already done a 20ft run and screwed the mains switch to the wall.

IIRC he said you could hammer it flat and it would still pass an insulation (megger) test!

DG

[Dave Plowman]

At least with the old Pyro you could anneal it - not possible with the PVC covered stuff.

I remember running risers into a house which was being converted into high quality flats where the owner wanted them under the floor, and as we pulled them through it got harder and harder as they work hardened.

[Clive Long,UK]

Thanks for all the advice

Sounds like I triggered a misty-eyed trip down memory lane for some of you.

Loath though I am to admit it in a diy group, I think I am going to have to find an old pro as recommended. The thought of stuffing up the termination, then blowing the wiring which is cemented into the floor or plastered into the walls doesn't bear thinking about.

How do I assess the guy (or gal !) is up to the job? This all feels terribly pricey, but I can't tolerate the RCB tripping every week when I forget to use only one appliance at a time. Oh the wastefulness of modern life !

Clive

[Dave Plowman]

You could ask to see his special tools for MICC cable. If he's ever used it in anger, he will still have them.