About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was packed full
of white powder.
I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?

On Tuesday, October 24, 2017 at 5:52:58 PM UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was packed full
of white powder.
I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?

Sounds like bog standard MICC cable.

Philip

On Tue, 24 Oct 2017 17:52:42 +0100
"Mr Pounder Esquire" wrote:

About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?



Mineral insulated cable, AKA Pyro?

https://en.wikipedia.org/wiki/Minera...per-clad_cable

On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was packed full
of white powder.
I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

In article , harry
wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house. I can't
remember why I cut into what looked like a metal pipe or conduit, but
I did. It was not flexible. Inside were 3 bare wires, no insulation but
the pipe/conduit was packed full of white powder. I'd never seen this
before, neither had the owner of the electrical shop. Has anybody any
idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

some of us would use a proper ringing tool

--
from KT24 in Surrey, England

A nasty festered rubber coated old mains supply perished to heck.

Either that or a very long bbig fuse!!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Mr Pounder Esquire" wrote in message
news
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was packed
full of white powder.
I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?

On 24/10/2017 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was packed full
of white powder.

What was the diameter of the "pipe"?

(although it sounds like MICC, that is quite narrow in most commonly
used domestic sizes).

I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 24/10/2017 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.

What was the diameter of the "pipe"?

Maybe half inch.

(although it sounds like MICC, that is quite narrow in most commonly
used domestic sizes).

I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?



/================================================== ===============\
Internode Ltd - http://www.internode.co.uk |
-----------------------------------------------------------------|
John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Steve wrote:
On Tue, 24 Oct 2017 17:52:42 +0100
"Mr Pounder Esquire" wrote:

About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?



Mineral insulated cable, AKA Pyro?

https://en.wikipedia.org/wiki/Minera...per-clad_cable

No sheath, the wires just seemed to be somehow kept apart by the powder.

harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?

On 24/10/2017 19:21, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?


I don't know how they make it either, but I suspect that, like seaside
rock, it starts off shorter and fatter, and is then drawn through a die.
Maybe hot, maybe cold? The friction between the ceramic insulator
particles will stop anything from moving about radially, and will
transmit the axial strain from the drawing process through to the wires.

Long plastic pipe, on the other hand, is extruded hot through a die. The
bore is formed by a bullet-like object located centrally by three spider
legs, the slits left by them close up as the material solidifies. You
can see the witness marks on ABS tube.

On 24/10/2017 18:55, Mr Pounder Esquire wrote:
John Rumm wrote:
On 24/10/2017 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.

What was the diameter of the "pipe"?

Maybe half inch.


That would be a fairly hefty cable - perhaps 2 x 10mm^2 (and you get
more current for your square mm in MICC since it can run hotter)

There is a table of common sizes he

http://www.remora.net/files/4d4f3a45...20Brochure.pdf




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
On 24/10/2017 18:55, Mr Pounder Esquire wrote:
John Rumm wrote:
On 24/10/2017 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.

What was the diameter of the "pipe"?

Maybe half inch.


That would be a fairly hefty cable - perhaps 2 x 10mm^2 (and you get
more current for your square mm in MICC since it can run hotter)

There is a table of common sizes he

http://www.remora.net/files/4d4f3a45...20Brochure.pdf

I think that Harry has enlightened me, thanks for your help.
What the hell was this sort of stuff doing under the floor boards of a
bungalow?

On 24/10/2017 20:48, Mr Pounder Esquire wrote:
John Rumm wrote:
On 24/10/2017 18:55, Mr Pounder Esquire wrote:
John Rumm wrote:
On 24/10/2017 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.

What was the diameter of the "pipe"?

Maybe half inch.


That would be a fairly hefty cable - perhaps 2 x 10mm^2 (and you get
more current for your square mm in MICC since it can run hotter)

There is a table of common sizes he

http://www.remora.net/files/4d4f3a45...20Brochure.pdf

I think that Harry has enlightened me, thanks for your help.
What the hell was this sort of stuff doing under the floor boards of a
bungalow?





After 30 years who knows?

Feeding a garage? It may have gone outside further down the run.

It may not have been not use. Did it go bang when you cut it? Maybe an
old feed from when it was a building site.



--
Adam

ARW wrote:
On 24/10/2017 20:48, Mr Pounder Esquire wrote:
John Rumm wrote:
On 24/10/2017 18:55, Mr Pounder Esquire wrote:
John Rumm wrote:
On 24/10/2017 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.

What was the diameter of the "pipe"?

Maybe half inch.


That would be a fairly hefty cable - perhaps 2 x 10mm^2 (and you get
more current for your square mm in MICC since it can run hotter)

There is a table of common sizes he

http://www.remora.net/files/4d4f3a45...20Brochure.pdf

I think that Harry has enlightened me, thanks for your help.
What the hell was this sort of stuff doing under the floor boards of
a bungalow?





After 30 years who knows?

Feeding a garage? It may have gone outside further down the run.

I think it may have been feeding the garage as I was putting lights in the
garage. I can't remember why I cut it, maybe to rewire the cable to the
garage, which I did.

It may not have been not use. Did it go bang when you cut it? Maybe an
old feed from when it was a building site.

I had all the power turned off.

In article ,
Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house. I can't
remember why I cut into what looked like a metal pipe or conduit, but I
did. It was not flexible. Inside were 3 bare wires, no insulation but
the pipe/conduit was packed full of white powder. I'd never seen this
before, neither had the owner of the electrical shop. Has anybody any
idea what this thing was?

Do you often cut 'pipes' without knowing what they do?

--
*If you're not part of the solution, you're part of the precipitate *

Dave Plowman London SW
To e-mail, change noise into sound.

Inside were 3 bare wires, no insulation but
the pipe/conduit was packed full of white powder. I'd never seen this
before, neither had the owner of the electrical shop. Has anybody any
idea what this thing was?

Do you often cut 'pipes' without knowing what they do?


Are shops a good source of advice? I went into Asda and the girl on the
till hadn't a clue about how to work the camera I bought from there 15
years earlier.

In article 6,
DerbyBorn wrote:
Inside were 3 bare wires, no insulation but
the pipe/conduit was packed full of white powder. I'd never seen this
before, neither had the owner of the electrical shop. Has anybody any
idea what this thing was?

Do you often cut 'pipes' without knowing what they do?


Are shops a good source of advice? I went into Asda and the girl on the
till hadn't a clue about how to work the camera I bought from there 15
years earlier.

Obviously not. Any electrician worthy of the name will have come across
MICC. I'd also wonder about the competence of anyone DIYing electrics who
hadn't heard of it either. It's covered in this newsgroup Wiki.

--
*Someday, we'll look back on this, laugh nervously and change the subject

Dave Plowman London SW
To e-mail, change noise into sound.

On 24/10/17 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was packed full
of white powder.
I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?



MICC cable aka "Mineral Insulated" or "Pyro".

The powder is Magnesium Oxide (I think) - it is packed in as part of the
drawing process - literally the "wires" star off as copper rods in a big
copper tube, add powder, draw the whole lot out to the required
thickness, rods and all.

On 25/10/2017 11:28, Tim Watts wrote:
On 24/10/17 17:52, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or conduit,
but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full
of white powder.
I'd never seen this before, neither had the owner of the electrical shop.
Has anybody any idea what this thing was?



MICC cable aka "Mineral Insulated" or "Pyro".

The powder is Magnesium Oxide (I think) - it is packed in as part of the
drawing process - literally the "wires" star off as copper rods in a big
copper tube, add powder, draw the whole lot out to the required
thickness, rods and all.

It comes in pretty long lengths. I've always wondered how it starts out,
and what sort of machinery is used to "draw" it. Wikipedia says it is
reduced using rollers which I guess makes sense.

Just for info to others who may not have come across it, thermocouples
clad in stainless steel tube are essentially the same technology. So are
the heating elements in electric ovens. I've made up "custom" heaters in
the past using nichrome clad in stainless steel. You terminate by
removing a suitable length of sheath, brazing a "nipple" to the sheath,
and sealing the exposed magnesium oxide insulation by fusing glass
powder into a cup on the nipple. If you don't do this, moisture gets
into the insulation and you lose insulation resistance.

https://en.wikipedia.org/wiki/Minera...per-clad_cable

On 24-Oct-17 7:32 PM, newshound wrote:
On 24/10/2017 19:21, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder EsquireÂ* wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?


I don't know how they make it either, but I suspect that, like seaside
rock, it starts off shorter and fatter, and is then drawn through a die...

Close, but it is rolled, rather than drawn.


--
--

Colin Bignell

Dave Plowman (News) wrote:
In article 6,
DerbyBorn wrote:
Inside were 3 bare wires, no insulation but
the pipe/conduit was packed full of white powder. I'd never seen
this before, neither had the owner of the electrical shop. Has
anybody any idea what this thing was?

Do you often cut 'pipes' without knowing what they do?


Are shops a good source of advice? I went into Asda and the girl on
the till hadn't a clue about how to work the camera I bought from
there 15 years earlier.

Obviously not. Any electrician worthy of the name will have come
across MICC. I'd also wonder about the competence of anyone DIYing
electrics who hadn't heard of it either. It's covered in this
newsgroup Wiki.

Everybody offered a sensible helpful opinion, except you.
Bravo.

DerbyBorn wrote:
Inside were 3 bare wires, no insulation but
the pipe/conduit was packed full of white powder. I'd never seen this
before, neither had the owner of the electrical shop. Has anybody any
idea what this thing was?

Do you often cut 'pipes' without knowing what they do?


Are shops a good source of advice? I went into Asda and the girl on the
till hadn't a clue about how to work the camera I bought from there 15
years earlier.


especially small copper pipes

On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and copper rods maybe 25mm diameter inside, the ends have a cap brazed over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die, heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk is very high.
Finding someone who can do it these days is very unlikely.

In article ,
newshound writes:
On 24/10/2017 19:21, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?


I don't know how they make it either, but I suspect that, like seaside
rock, it starts off shorter and fatter, and is then drawn through a die.

That's exactly how it's done.
Actually, they only make one size, and it's drawn down to make all
the smaller sizes.

Maybe hot, maybe cold?

For copper, I would guess annealed, and then cold-drawn, but
I don't know for sure.

The friction between the ceramic insulator

It's magnesium oxide powder, not ceramic.

particles will stop anything from moving about radially, and will
transmit the axial strain from the drawing process through to the wires.

Yes. Indeed one of the protection features of MICC is that if
it's hit with blunt force and compressed, the compressed shape
tranfers right through to the conductors and the insulation
integrity remains.

The weak point of MICC is that magnesium oxide is hygroscopic,
so all cable ends must be gas tight, or the magnesium oxide
will absorb moisture and destroy its insulation properties.
A well made installation lasts forever, but badly made off
cable ends would cause insulation failures after some years.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Obviously not. Any electrician worthy of the name will have come across
MICC. I'd also wonder about the competence of anyone DIYing electrics who
hadn't heard of it either. It's covered in this newsgroup Wiki.


You see it in lots of commercial premises.

harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and
copper rods maybe 25mm diameter inside, the ends have a cap brazed
over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a
blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk
is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?

On Thursday, 26 October 2017 18:26:05 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the electrical
shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them making
contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and
copper rods maybe 25mm diameter inside, the ends have a cap brazed
over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a
blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk
is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?


I expect someone half inched it from their place of work.
In days of yore when I was at work, we used only MICC and steel conduit in hospitals.
Nobody in their right mind would use it at home if they had to pay for it.

harry wrote:
On Thursday, 26 October 2017 18:26:05 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the
electrical shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them
making contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and
copper rods maybe 25mm diameter inside, the ends have a cap brazed
over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a
blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk
is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?


I expect someone half inched it from their place of work.
In days of yore when I was at work, we used only MICC and steel
conduit in hospitals. Nobody in their right mind would use it at home
if they had to pay for it.

But why half inch that sort of stuff when cable is easier to nick?

In article ,
harry wrote:
I expect someone half inched it from their place of work. In days of
yore when I was at work, we used only MICC and steel conduit in
hospitals. Nobody in their right mind would use it at home if they had
to pay for it.

In London at one time, the leccy board insisted on it if you wanted to
re-site a meter elsewhere in a house - like say when converting into flats.

It could also make sense for a feed outside the house, like say to a
garage. Although SWA is more common for this these days.

--
*If PROGRESS is for advancement, what does that make CONGRESS mean?

Dave Plowman London SW
To e-mail, change noise into sound.

On Friday, 27 October 2017 20:20:01 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Thursday, 26 October 2017 18:26:05 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the
electrical shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them
making contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and
copper rods maybe 25mm diameter inside, the ends have a cap brazed
over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a
blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk
is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?


I expect someone half inched it from their place of work.
In days of yore when I was at work, we used only MICC and steel
conduit in hospitals. Nobody in their right mind would use it at home
if they had to pay for it.

But why half inch that sort of stuff when cable is easier to nick?

A question of what won't be missed.
Probably chucked in a corner somewhere.
Only used infrequently these days.
Eg it was used for fire alarm systems at one time, (no longer so)
Mostly used in petrol pumps and similar nowadays.

On Friday, 27 October 2017 20:20:01 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Thursday, 26 October 2017 18:26:05 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the
electrical shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them
making contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and
copper rods maybe 25mm diameter inside, the ends have a cap brazed
over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a
blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk
is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?


I expect someone half inched it from their place of work.
In days of yore when I was at work, we used only MICC and steel
conduit in hospitals. Nobody in their right mind would use it at home
if they had to pay for it.

But why half inch that sort of stuff when cable is easier to nick?

When MICC first came out. it was an alternative to rubber insulated cable.(In steel conduit)
But unlike rubber, it didn't deteriorate.

On 28/10/2017 07:58, harry wrote:
On Friday, 27 October 2017 20:20:01 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Thursday, 26 October 2017 18:26:05 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire
wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house.
I can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible.
Inside were 3 bare wires, no insulation but the pipe/conduit was
packed full of white powder.
I'd never seen this before, neither had the owner of the
electrical shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand.
How the hell did they get the wires into the tube without them
making contact with each other?

I went to the factory maybe fifty years ago.
The assembly starts off as a copper tube maybe 100mm diameter and
copper rods maybe 25mm diameter inside, the ends have a cap brazed
over after it's filled with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal.
As the outer tube is squeezed, the inner rods are also squeezed.
So what started off maybe 3m long, ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.)
Water MUST be kept out, this is the purpose of the termination.
If the unprotected ends get wet,they can be dried out with a
blowlamp, starting 300mm from the end and working towards the end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install.
Used in industrial sites/other places where the fire/explosion risk
is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?


I expect someone half inched it from their place of work.
In days of yore when I was at work, we used only MICC and steel
conduit in hospitals. Nobody in their right mind would use it at home
if they had to pay for it.

But why half inch that sort of stuff when cable is easier to nick?

When MICC first came out. it was an alternative to rubber insulated cable.(In steel conduit)
But unlike rubber, it didn't deteriorate.

As long as the ends are properly potted to prevent moisture ingress and
no tiny movements break the seal.

SteveW

I used MICC in my conservatory. Where much of the wiring had to be
surface. Much smaller and neater than any other method. And great fun to
work with.

--
*I was married by a judge. I should have asked for a jury.

Dave Plowman London SW
To e-mail, change noise into sound.

On 28/10/2017 07:52, harry wrote:

Eg it was used for fire alarm systems at one time, (no longer so)

I still see it used in fire protection systems.

Also commonly used in hight combustible buildings (straw bail
construction, or close the thatched roofs).

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article , harry
wrote:
On Thursday, 26 October 2017 18:26:05 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 19:22:08 UTC+1, Mr Pounder Esquire wrote:
harry wrote:
On Tuesday, 24 October 2017 17:52:58 UTC+1, Mr Pounder Esquire
wrote:
About 30 years I was helping a mate move into his "new" house. I
can't remember why I cut into what looked like a metal pipe or
conduit, but I did. It was not flexible. Inside were 3 bare wires,
no insulation but the pipe/conduit was packed full of white
powder. I'd never seen this before, neither had the owner of the
electrical shop. Has anybody any idea what this thing was?

https://www.youtube.com/watch?v=uGj7I7uImLU

Cheers for that Harry, I now sort of understand. How the hell did
they get the wires into the tube without them making contact with
each other?

I went to the factory maybe fifty years ago. The assembly starts off
as a copper tube maybe 100mm diameter and copper rods maybe 25mm
diameter inside, the ends have a cap brazed over after it's filled
with magnesium oxide and pounded down.

It is reduced in diameter by being drawn through a circular die,
heated to red heat between to anneal. As the outer tube is squeezed,
the inner rods are also squeezed. So what started off maybe 3m long,
ends up 50 meters long.

The stuff can be run at red heat and not fail. (But not the
terminations.) Water MUST be kept out, this is the purpose of the
termination. If the unprotected ends get wet,they can be dried out
with a blowlamp, starting 300mm from the end and working towards the
end.

I think there's also a stainless steel variant these days.

It's very expensive to buy and install. Used in industrial
sites/other places where the fire/explosion risk is very high.
Finding someone who can do it these days is very unlikely.

What the hell was it doing under the floorboards of a bungalow?


I expect someone half inched it from their place of work. In days of yore
when I was at work, we used only MICC and steel conduit in hospitals.
Nobody in their right mind would use it at home if they had to pay for it.

I used it some 45 years ago, to run a supply to my garage.

--
from KT24 in Surrey, England