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

"Clive Long,UK" wrote in message
om...
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
Ah, the joys of micc! It's at times like this a "real" sparky gets a warm
glow. Yes it's possible to "take the pyro out of the wall and terminate it
somehow" but only if you use a pyro gland. Some of our apprentices are
currently having nightmares about this stuff as we've started using it in
fire alarm circuits in place of the modern fp200 cable and they've never had
to make it off before. Be warned, it's the spawn of Satan. Stripping it back
and potting a new gland is not for the faint hearted or uninitiated. A
single "fanny hair" (technical term) of outer caught in the compound is
enough to cause a major fault and as for damp...
Hate to suggest it on a DIY group but you may be better off using an old pro
sparky.
Regards, Richard

"Frisket" wrote in message
...

Ah, the joys of micc! It's at times like this a "real" sparky gets a warm
glow. Yes it's possible to "take the pyro out of the wall and terminate it
somehow" but only if you use a pyro gland. Some of our apprentices are
currently having nightmares about this stuff.

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 !!

In article ,
Frisket wrote:
Be warned, it's the spawn of Satan. Stripping it back and potting a new
gland is not for the faint hearted or uninitiated. A single "fanny hair"
(technical term) of outer caught in the compound is enough to cause a
major fault and as for damp... Hate to suggest it on a DIY group but you
may be better off using an old pro sparky.

It's easy enough to use for a careful amateur used to plumbing - in some
ways he might be more careful than a pro in the usual rush.

As regards scrap parts of the outer causing shorts this shouldn't happen
if you use the correct tool for stripping back as it pares it off rather
like paring an apple. If you haven't got the correct tool, an ordinary
small copper tube cutter may be used and the outer stripped off to this
point using cutters - this is rather easier in the larger sizes. With
smaller sizes, examine the end carefully using a magnifying glass if
necessary to make sure a lip hasn't formed that might touch the
conductors. If this has happened it can be removed with a small scraper,
but make sure any swarf is blown away afterwards.

If there's damp in existing cable, I'd say it's scrap as either the seals
have failed or it's been penetrated somewhere. New cable shouldn't be damp
if it's been correctly stored, and if unsure cutting a couple of feet off
the end should do it. Damp insulant is in chunks, while dry is a powder,
so once getting back to powder add about a foot for safety.

The compound should be kept clean and in one of those re-seal able bags -
not left loose in the bottom of the tool box.

If you haven't got the correct tool for screwing on the seal, it can be
done carefully with slip joint pliers making sure it's kept square, or you
can make up a tool using the gland screwed into a conduit coupler with a
bush and spacer at the other end to grip the seal up to the gland - this
will keep it square as you screw it on.

Two sets of slip joint pliers can be used to force the seal cover onto the
seal and squeeze out excess compound. They can also be used to crimp over
the end to hold the cover in place.

Give the conductors a good pull in line with the cable to straighten them
before adding the cover, and afterwards.

It's super stuff to work with and looks great if you take your time, so
very satisfying for a careful amateur, but not for a pro in a hurry, which
is why it's fallen out of use. You'll have difficulty sourcing all the
bits from a normal wholesaler, and they may not even be willing to order
it in in small quantities.

I recently used it in a small conservatory, as IMHO no exposed wiring
looks as good, or is as small and neat.

--
*How do you tell when you run out of invisible ink? *

Dave Plowman London SW 12
RIP Acorn

In article ,
Clive Long,UK wrote:
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?

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.

--
*Why is the word abbreviation so long? *

Dave Plowman London SW 12
RIP Acorn

Frisket wrote:

as we've started using it in fire alarm circuits in place of the modern fp200 cable and they've never had
to make it off before.

Why the switch back to Pyro ?

Stripping it back and potting a new gland is not for the faint hearted or uninitiated.

Only a pro should attempt it without the right tools. And getting the
local scruff in the electrical disties to under stand what you want is
fun. They have to go and get "The Boss" - a grizzled tiem served sparky,
who, as you say, lights up when pyrotenax is mentioned !

A single "fanny hair" (technical term) of outer caught in the compound is enough to cause a major fault and as for damp...

We had bloody great roll of old stuff at work that we needed to use, but
its leakage current was 'orrible. So we stuffed a 12V 30 A supply up it
for about a week....Leakage dropped to 10 Meg

Steve

In article ,
Steve wrote:
We had bloody great roll of old stuff at work that we needed to use, but
its leakage current was 'orrible. So we stuffed a 12V 30 A supply up it
for about a week....Leakage dropped to 10 Meg

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

--
*If a turtle doesn't have a shell, is he homeless or naked?

Dave Plowman London SW 12
RIP Acorn

On Sat, 22 Nov 2003 11:26:51 +0000 (GMT), Dave Plowman
wrote:

With
smaller sizes, examine the end carefully using a magnifying glass if
necessary to make sure a lip hasn't formed that might touch the
conductors. If this has happened it can be removed with a small scraper,
but make sure any swarf is blown away afterwards.

If there's damp in existing cable, I'd say it's scrap as either the seals
have failed or it's been penetrated somewhere. New cable shouldn't be damp
if it's been correctly stored, and if unsure cutting a couple of feet off
the end should do it. Damp insulant is in chunks, while dry is a powder,
so once getting back to powder add about a foot for safety.

The compound should be kept clean and in one of those re-seal able bags -
not left loose in the bottom of the tool box.

If you haven't got the correct tool for screwing on the seal, it can be
done carefully with slip joint pliers making sure it's kept square, or you
can make up a tool using the gland screwed into a conduit coupler with a
bush and spacer at the other end to grip the seal up to the gland - this
will keep it square as you screw it on.

Two sets of slip joint pliers can be used to force the seal cover onto the
seal and squeeze out excess compound. They can also be used to crimp over
the end to hold the cover in place.

Give the conductors a good pull in line with the cable to straighten them
before adding the cover, and afterwards.

It's super stuff to work with and looks great if you take your time, so
very satisfying for a careful amateur, but not for a pro in a hurry, which
is why it's fallen out of use. You'll have difficulty sourcing all the
bits from a normal wholesaler, and they may not even be willing to order
it in in small quantities.

I recently used it in a small conservatory, as IMHO no exposed wiring
looks as good, or is as small and neat.

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

In article ,
derek wrote:
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.

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.

--
*Few women admit their age; fewer men act it.

Dave Plowman London SW 12
RIP Acorn

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

In article ,
Clive Long,UK wrote:
How do I assess the guy (or gal !) is up to the job?

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

--
*He's not dead - he's electroencephalographically challenged

Dave Plowman London SW 12
RIP Acorn