"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed
wrote:

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
John Rumm wrote
Lieutenant Scott wrote








A good illustration of how instincts can be misleading ;-)

With installation method 101 (which is what I described above),
its already somewhat out of spec (installed cable rated at 27A).
If it were method 103 then its significantly under rated for the
application since the cable is only rated at 23.5A
in that situation:

http://wiki.diyfaq.org.uk/index.php?...lation_Methods



That will be the saving grace if you are running it installed using
method 101 for example. (with 103, you would
probably still have a problem)

I didn't put the wire in, it was already there. I THINK it's 6mm2,
it looks like it from the outside, I've never investigated. 103-ish,
it's laying loose in some places with
insulation sometimes on top,
sometimes underneath, maybe sometimes both.

I wonder, all these people currently coming round (I've had 5 in 2
weeks) wanting to add huge amounts of loft insulation with government
grants - do they check the wires before adding
piles of insulation?
I doubt it.

Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job, so
presumably someone murdered them?

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for a
lot longer and the issue is the occupier or the owner is not aware of that
until the roof starts collapsing, especially at night, when they are
sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed
wrote:

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote























Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job, so
presumably someone murdered them?

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for a
lot longer and the issue is the occupier or the owner is not aware of that
until the roof starts collapsing, especially at night, when they are
sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

Yes, it's below the attic.


--
http://petersparrots.com
http://petersphotos.com

If I were two faced, would I be wearing this one?

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
John Rumm wrote
Lieutenant Scott wrote

A good illustration of how instincts can be misleading ;-)

With installation method 101 (which is what I described above),
its already somewhat out of spec (installed cable rated at 27A).
If it were method 103 then its significantly under rated for the
application since the cable is only rated at 23.5A in that situation:

http://wiki.diyfaq.org.uk/index.php?...lation_Methods

That will be the saving grace if you are running it installed
using method 101 for example. (with 103, you would probably
still have a problem)

I didn't put the wire in, it was already there. I THINK it's 6mm2, it looks like it from the outside, I've never
investigated.
103-ish, it's laying loose in some places with insulation sometimes on top, sometimes underneath, maybe sometimes
both.

I wonder, all these people currently coming round (I've had 5 in 2
weeks) wanting to add huge amounts of loft insulation with government grants - do they check the wires before
adding piles of insulation? I doubt it.

Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job,

They didnt die by fire.

so presumably someone murdered them?

Nope. At least one of them was electrocuted when he as actually
stupid enough to staple the foil insulation to the joists and ended up
doing that right thru the power wiring that had not been turned off.

We actually had the govt go back and test all of those for live insulation installs.

At leas one of them died of heat stroke. The temperatures in ceilings
with metal roofs and 45C outside have to be measured to be believed.

Another was actually stupid enough to let the house occupier's 7 year
old kid pass him the insulation thru a hole in the roof, with the kid walking
around on the peaked roof with bare feet. Fortunately that kid survived
fine. One of the neighbours videoed it and it was splashed across out
equivalent of your BBC evening TV news and caused one hell of a stink.

Quite a few of the installers were illegals, mostly indians.

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for a lot longer and the issue is the occupier or
the owner is not aware of that until the roof starts collapsing, especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

This isnt the attic, its the roof space. There arent
too many that put smoke detectors in there.

The govt approved insulation installers certainly didnt and there's
be a hell of a problem with the batterys even if they did anyway.

The govt just killed the scheme and the minister got sacked.

"Lieutenant Scott" wrote in message
newsp.wazd7rheytk5n5@i7-940...
On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed
wrote:

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote























Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job,
so
presumably someone murdered them?

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for
a
lot longer and the issue is the occupier or the owner is not aware of
that
until the roof starts collapsing, especially at night, when they are
sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

Yes, it's below the attic.

Then go there FFS.

"Rod Speed" wrote in message
...
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
John Rumm wrote
Lieutenant Scott wrote

A good illustration of how instincts can be misleading ;-)

With installation method 101 (which is what I described above),
its already somewhat out of spec (installed cable rated at 27A).
If it were method 103 then its significantly under rated for the
application since the cable is only rated at 23.5A in that
situation:

http://wiki.diyfaq.org.uk/index.php?...lation_Methods

That will be the saving grace if you are running it installed
using method 101 for example. (with 103, you would probably
still have a problem)

I didn't put the wire in, it was already there. I THINK it's 6mm2,
it looks like it from the outside, I've never investigated.
103-ish, it's laying loose in some places with insulation sometimes
on top, sometimes underneath, maybe sometimes both.

I wonder, all these people currently coming round (I've had 5 in 2
weeks) wanting to add huge amounts of loft insulation with government
grants - do they check the wires before adding piles of insulation? I
doubt it.

Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job,

They didnt die by fire.

so presumably someone murdered them?

Nope. At least one of them was electrocuted when he as actually
stupid enough to staple the foil insulation to the joists and ended up
doing that right thru the power wiring that had not been turned off.

We actually had the govt go back and test all of those for live insulation
installs.

At leas one of them died of heat stroke. The temperatures in ceilings
with metal roofs and 45C outside have to be measured to be believed.

Another was actually stupid enough to let the house occupier's 7 year
old kid pass him the insulation thru a hole in the roof, with the kid
walking
around on the peaked roof with bare feet. Fortunately that kid survived
fine. One of the neighbours videoed it and it was splashed across out
equivalent of your BBC evening TV news and caused one hell of a stink.

Quite a few of the installers were illegals, mostly indians.

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for
a lot longer and the issue is the occupier or the owner is not aware of
that until the roof starts collapsing, especially at night, when they are
sleeping".

First place I put a smoke detector was the attic.

This isnt the attic, its the roof space. There arent
too many that put smoke detectors in there.

The govt approved insulation installers certainly didnt and there's
be a hell of a problem with the batterys even if they did anyway.

The govt just killed the scheme and the minister got sacked.

Is this dialogue for real, I ask?

Adam, I think we need a few of your expletives here.

On Mar 10, 10:15*pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 21:40:14 -0000, John Rumm wrote:
On 10/03/2012 20:30, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 20:10:38 -0000, NT wrote:

On Mar 10, 7:54 am, "ARWadsworth"
wrote:
Lieutenant Scott wrote:
I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16 amps
ish, while I've never seen a lighting circuit have a fuse/breaker of
anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit that
safely
uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

10A is probably the largest size MCB you will see in a house for the
lights.
You might see 16A used in factories etc. BTW it's not 16A lighting
cable,
look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

If one went with 6A lighting rings, using lets say 3.5A cable, it
could be:
only when not buried in insulation: 0.33mm2
buried: 0.44 mm2

For the cfl/led only user, we could reduce a 10 room lighting ring
down to... say 50w per room allowance = 500w = 2A and use 1.3A cable,
0.16mm2 would work even if buried in insulation.

I'm using 26 watts (four 75W equivalent spots) in this room and it's lit
very brightly.

Many rooms will use less than 50w of CFLs, leaving a higher budget for
the larger rooms. One could budget 20w max for small rooms like loo &
bathroom.

And the use of RCDs would enable the earth conductor to shrink to a
similar size. Shock voltage would go up, but the RCD would limit it to
such brevity as to be safe.

Voltage goes up? How?

If you are getting a shock from something due to a fault (i.e. touching
something made live by a fault, or "indirect contact" as it used to be
known). Then you can assume that the earthing will ensure the fault is
cleared quickly, and that limits the shock duration.

However you also get fortuitous equipotential bonding effect brought
about by the earth connection that will tend to lower the touch voltage
(if you imagine two lengths of wire of equal CSA - one connected to
earth (0V) and one to mains, you would expect the the arrangement to act
like a potentiometer wire, and the voltage with respect to earth would
be half mains at the fault). If you start making the resistance of the
earth larger (i.e. by making it thinner), then the touch voltage at the
fault will rise.

Not if the live is also thinner.

True. With very thin wire its cheap to have equally thick earth wire,
which would make shock voltage lower than today's T&E circuits. As
long as the shock didn't come from a 30A circuit, in which case the
lighting earth would probably vapourise. But the RCDs should protect
it and clear it at some point.


One could go even further: with an RCD there's very little theoretical
need for double insulation or earthing, one could simply use very thin
speaker wire.

It's the fire hazard that would concern me more. Speaker wire could get
snagged easily.

a tad over 2A is unlikely to do it much harm...

A minor short could easily occur if it's flimsy wire, which can cause a fire.

Either don't make the insulation flimsy, or do and have a little
consideration for where the wire goes. Bell wire isnt damaged by
normal use and abuse - but then its far from 0.16mm2.

Conductors can easily be reinforced by simply including string in the
cable. Another approach I'm a lot less sure about is to use copper
clad steel to increase conductor strength.


Anyway, if you're not earthing, then brass lighting fixtures wouldn't be
protected against loose live wires,

The RCD does that. Or one can mandate only plastic and double
insulated metal fittings on such circuits.


plus that annoying guy that checks
your house when you sell it would put a red X on a few parts of his report.

Not if such a scheme were accepted. Here I'd be quite happy in
principle for lighting to go on a 3 core 2A bell wire ring, for CFL
users its perfectly effective and safe, as long as its installed
correctly. For 2nd world applications one could dispense with the
earth conductor, relying on RCD and fitting insulation. For 3rd world
one could reduce conductor size to 0.16mm2 and reduce insulation to
speaker wire proportions.


That is what the RCD was designed to mitigate.

RCD won't pick up you touching live and neutral. *With the earth it's more likely you touch earth instead/aswell, which will trip it.

There's no safety scheme in use that I know of, at least in domestic
properties, that offers any L-N shock protection beyond insulation. L-
N shocks are excepional.


Anyway, if you are blue
sky thinking, you can do away with the surveyor! (not that they ever do
much other than say of you want the electrics checked, get a specialist)

Just how do you do away with a surveyor commissioned by the buyer of your house?

I dont see any point in installing such things unlawfully. Its only
useful when widespread and accepted. Call it an eco-circuit for
acceptance. FWIW surveyors dont check electrical installs. If you
wired your house up with iron wire in hosepipe they'd say the same
thing as always, get the electrics checked.


Current practice is to supply just an 8A feed per flat in at least
some of the eastern bloc,

For the entire flat or just the lighting?

Entire flat I would expect. 8A for lighting would hardly be exceptional....

Yes, the whole flat. I've seen it in aluminium, it looked like fatter
bellwire.

I'd find it very difficult to keep to 8A. *So that's no cooking then?

A medium performance ring can run on 1kW. A microwave sized fan oven
does fine on 1kW. 1kW consumption microwaves with about 400w cooking
power exist in Britain, they work adequately.

I've cooked on 500w rings too, 3rd world type equipment with bare live
elements. Its way too low to be practical, a pan of water takes 20
minutes.

No electric kettles?

8A is 2kW, no problem with kettles.

I saw an eastern bloc kettle with a speaker wire type lead (a few
minutes doesn't need much copper) and no element. Instead there were
just 2 bits of metal at the bottom connected to L&N, it was an
electrode kettle. I'd prefer a real 1kW kettle though.

A kettle that was 5 or 600w was ok for a cup or 2, but too slow when
full.

*Even a hoover is using most of that allowance.

typical hoover from the 70s uses about 500w. You can get modern
effective ones that use under 200w (Oreck). Or just use a powerful 1kW
machine.


*I wonder how many nails get put in the master fuse holders.....

(having said that, DNOs often design their distribution systems on the
assumption that the diverse load of each house is something around 8 to 10A)

In this country?


Its actually easy to live on 2kW max, or less. Its just a matter of
choosing your appliances with a clue or two, and adopting a policy to
avoid overload. It only takes a little thought to massively trim down
our luxury consumption levels. Even washing machines work well enough
with a 1kW element - they don't spin and heat at the same time.


NT

On Mar 10, 8:32*pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 20:25:33 -0000, NT wrote:
On Mar 10, 12:29 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 12:21:52 -0000, John Rumm wrote:
On 10/03/2012 01:44, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 01:37:31 -0000, Frank Erskine
wrote:

On Sat, 10 Mar 2012 00:44:52 +0000, John Rumm
wrote:

On 09/03/2012 20:07, Lieutenant Scott wrote:
On Fri, 09 Mar 2012 13:46:33 -0000, NT wrote:

Surely it would be best to do as they suggest and have 30A cable in a
star topology. You could have as many sockets as you like on a single
line of 30A cable.

A 30/32A radial is a "standard circuit", so nothing to stop you from
using it.

Its not commonly used since it required 4.0mm^2 T&E which is harder to
work with.

Mumble years ago I requested a 30/32A supply to a test bench. Our
internal power tech did it (in proper steel conduit) using stranded
4mm^2, which he reckoned was much easier to handle in conduit than
solid core.
I never did investigate what the composition of the stranded wire was
- probably a successor to 7/0.036.

Solid core seems a little silly really. One strand, easier to break?
Stiffer, harder to bend round corners? Point?

Its easier to dress and stays where you put it, its cheaper to make, and
flexibility (in the way the flex is flexible) is of no real benefit in
fixed wiring.

(although even T&E is coarsely stranded in the larger sizes)

Yes I suppose flex would flop about too much when you're trying to install it.

no, but it does sag afterwards where visible. ITs also a piontless
spend of money

Wire don't cost much compared to the other things you're fitting, like the light fixtures.

No. But why spend more for no reason.


NT

Lieutenant Scott wrote:
On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed
wrote:

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote























Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally
dead.

The fire presumably happened AFTER they'd finished the insulation
job, so presumably someone murdered them?

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it
done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and
spreads for a lot longer and the issue is the occupier or the
owner is not aware of that until the roof starts collapsing,
especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

Yes, it's below the attic.

It's under the bridge

--
Adam

brass monkey wrote:
"Rod Speed" wrote in message
...
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
John Rumm wrote
Lieutenant Scott wrote

A good illustration of how instincts can be misleading
;-)

With installation method 101 (which is what I described
above), its already somewhat out of spec (installed
cable rated at 27A). If it were method 103 then its
significantly under rated for the application since the
cable is only rated at 23.5A in that situation:

http://wiki.diyfaq.org.uk/index.php?...lation_Methods

That will be the saving grace if you are running it
installed using method 101 for example. (with 103, you
would probably still have a problem)

I didn't put the wire in, it was already there. I THINK
it's 6mm2, it looks like it from the outside, I've never
investigated. 103-ish, it's laying loose in some places
with insulation sometimes on top, sometimes underneath,
maybe sometimes both.

I wonder, all these people currently coming round (I've
had 5 in 2 weeks) wanting to add huge amounts of loft
insulation with government grants - do they check the
wires before adding piles of insulation? I doubt it.

Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally
dead.

The fire presumably happened AFTER they'd finished the insulation
job,

They didnt die by fire.

so presumably someone murdered them?

Nope. At least one of them was electrocuted when he as actually
stupid enough to staple the foil insulation to the joists and ended
up doing that right thru the power wiring that had not been turned
off. We actually had the govt go back and test all of those for live
insulation installs.

At leas one of them died of heat stroke. The temperatures in
ceilings with metal roofs and 45C outside have to be measured to be
believed. Another was actually stupid enough to let the house occupier's
7
year old kid pass him the insulation thru a hole in the roof, with the
kid walking
around on the peaked roof with bare feet. Fortunately that kid
survived fine. One of the neighbours videoed it and it was splashed
across out equivalent of your BBC evening TV news and caused one
hell of a stink. Quite a few of the installers were illegals, mostly
indians.

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it
done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and
spreads for a lot longer and the issue is the occupier or the
owner is not aware of that until the roof starts collapsing,
especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

This isnt the attic, its the roof space. There arent
too many that put smoke detectors in there.

The govt approved insulation installers certainly didnt and there's
be a hell of a problem with the batterys even if they did anyway.

The govt just killed the scheme and the minister got sacked.

Is this dialogue for real, I ask?
D
Adam, I think we need a few of your expletives here.

At least dennis is genuinely stupid and not just making it up like these
two.

--
Adam

On Sun, 11 Mar 2012 01:11:50 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazd7rheytk5n5@i7-940...
On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed
wrote:

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for
a
lot longer and the issue is the occupier or the owner is not aware of
that
until the roof starts collapsing, especially at night, when they are
sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

Yes, it's below the attic.

Then go there FFS.

That's where I am now. Why am I communicating with someone childish enough to call themselves "brass monkey" anyway?

--
http://petersparrots.com
http://petersphotos.com

They say confuscious does his crosswords with a pen.

"Lieutenant Scott" wrote:


That's where I am now. Why am I communicating with someone childish
enough to call themselves "brass monkey" anyway?


Dunno, why do you think that is, PHucker? Perhaps next time you sit on a
high horse you may wish to make sure that its hooves are not made from
clay?

On Sun, 11 Mar 2012 01:21:13 -0000, NT wrote:

On Mar 10, 10:15 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 21:40:14 -0000, John Rumm wrote:
On 10/03/2012 20:30, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 20:10:38 -0000, NT wrote:

On Mar 10, 7:54 am, "ARWadsworth"
wrote:
Lieutenant Scott wrote:
I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16 amps
ish, while I've never seen a lighting circuit have a fuse/breaker of
anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit that
safely
uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

10A is probably the largest size MCB you will see in a house for the
lights.
You might see 16A used in factories etc. BTW it's not 16A lighting
cable,
look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

If one went with 6A lighting rings, using lets say 3.5A cable, it
could be:
only when not buried in insulation: 0.33mm2
buried: 0.44 mm2

For the cfl/led only user, we could reduce a 10 room lighting ring
down to... say 50w per room allowance = 500w = 2A and use 1.3A cable,
0.16mm2 would work even if buried in insulation.

I'm using 26 watts (four 75W equivalent spots) in this room and it's lit
very brightly.

Many rooms will use less than 50w of CFLs, leaving a higher budget for
the larger rooms. One could budget 20w max for small rooms like loo &
bathroom.

I forgot to say LEDs. CFLs use far too much electricity.

And the use of RCDs would enable the earth conductor to shrink to a
similar size. Shock voltage would go up, but the RCD would limit it to
such brevity as to be safe.

Voltage goes up? How?

If you are getting a shock from something due to a fault (i.e. touching
something made live by a fault, or "indirect contact" as it used to be
known). Then you can assume that the earthing will ensure the fault is
cleared quickly, and that limits the shock duration.

However you also get fortuitous equipotential bonding effect brought
about by the earth connection that will tend to lower the touch voltage
(if you imagine two lengths of wire of equal CSA - one connected to
earth (0V) and one to mains, you would expect the the arrangement to act
like a potentiometer wire, and the voltage with respect to earth would
be half mains at the fault). If you start making the resistance of the
earth larger (i.e. by making it thinner), then the touch voltage at the
fault will rise.

Not if the live is also thinner.

True. With very thin wire its cheap to have equally thick earth wire,
which would make shock voltage lower than today's T&E circuits. As
long as the shock didn't come from a 30A circuit, in which case the
lighting earth would probably vapourise. But the RCDs should protect
it and clear it at some point.

I'm trying to imagine a situation where you could get a shock form the live of a socket but be earthed by a light on the ceiling. Without being a trapeze artist....

One could go even further: with an RCD there's very little theoretical
need for double insulation or earthing, one could simply use very thin
speaker wire.

It's the fire hazard that would concern me more. Speaker wire could get
snagged easily.

a tad over 2A is unlikely to do it much harm...

A minor short could easily occur if it's flimsy wire, which can cause a fire.

Either don't make the insulation flimsy, or do and have a little
consideration for where the wire goes. Bell wire isnt damaged by
normal use and abuse - but then its far from 0.16mm2.

Conductors can easily be reinforced by simply including string in the
cable.

String is stronger than wire?

Another approach I'm a lot less sure about is to use copper
clad steel to increase conductor strength.

Anyway, if you're not earthing, then brass lighting fixtures wouldn't be
protected against loose live wires,

The RCD does that. Or one can mandate only plastic and double
insulated metal fittings on such circuits.

How can an RCD protect it? Since the fitting isn't earthed, there will be no current flow to earth. The thing will sit there with a live chassis.

plus that annoying guy that checks
your house when you sell it would put a red X on a few parts of his report.

Not if such a scheme were accepted. Here I'd be quite happy in
principle for lighting to go on a 3 core 2A bell wire ring, for CFL
users its perfectly effective and safe, as long as its installed
correctly.

It would really annoy the luddites who want to use incandescents, but I suppose we have to force them off their drug somehow.

For 2nd world applications one could dispense with the
earth conductor, relying on RCD and fitting insulation. For 3rd world
one could reduce conductor size to 0.16mm2 and reduce insulation to
speaker wire proportions.

That is what the RCD was designed to mitigate.

RCD won't pick up you touching live and neutral. With the earth it's more likely you touch earth instead/aswell, which will trip it.

There's no safety scheme in use that I know of, at least in domestic
properties, that offers any L-N shock protection beyond insulation. L-
N shocks are excepional.

Exactly, which is why with the presence of the earth, it's more likely your shock involves earth instead of neutral.

Anyway, if you are blue
sky thinking, you can do away with the surveyor! (not that they ever do
much other than say of you want the electrics checked, get a specialist)

Just how do you do away with a surveyor commissioned by the buyer of your house?

I dont see any point in installing such things unlawfully. Its only
useful when widespread and accepted. Call it an eco-circuit for
acceptance. FWIW surveyors dont check electrical installs. If you
wired your house up with iron wire in hosepipe they'd say the same
thing as always, get the electrics checked.

They test to make sure a metal light fitting is earthed.

Current practice is to supply just an 8A feed per flat in at least
some of the eastern bloc,

For the entire flat or just the lighting?

Entire flat I would expect. 8A for lighting would hardly be exceptional...

Yes, the whole flat. I've seen it in aluminium, it looked like fatter
bellwire.

I'd find it very difficult to keep to 8A. So that's no cooking then?

A medium performance ring can run on 1kW. A microwave sized fan oven
does fine on 1kW. 1kW consumption microwaves with about 400w cooking
power exist in Britain, they work adequately.

I've cooked on 500w rings too, 3rd world type equipment with bare live
elements. Its way too low to be practical, a pan of water takes 20
minutes.

And longer when you spill the water in the live element.....

No electric kettles?

8A is 2kW, no problem with kettles.

But that uses all the power allowance up. If someone else wants to do something else, like your boiling water to add to the cooking on your stove for example.

I saw an eastern bloc kettle with a speaker wire type lead (a few
minutes doesn't need much copper) and no element. Instead there were
just 2 bits of metal at the bottom connected to L&N, it was an
electrode kettle. I'd prefer a real 1kW kettle though.

Two bits of metal in the water? Doesn't that cause electrolysis, and the production of rather flammable hydrogen and oxygen?

(having said that, DNOs often design their distribution systems on the
assumption that the diverse load of each house is something around 8 to 10A)

In this country?

Its actually easy to live on 2kW max, or less. Its just a matter of
choosing your appliances with a clue or two, and adopting a policy to
avoid overload. It only takes a little thought to massively trim down
our luxury consumption levels. Even washing machines work well enough
with a 1kW element - they don't spin and heat at the same time.

Mine is cold wash - it washes just as well as 30/40C that most people use.

--
http://petersparrots.com
http://petersphotos.com

The fact that a believer is happier than a skeptic is no more to the point than the fact that a drunken man is happier than a sober one -- George Bernard Shaw

On Sun, 11 Mar 2012 01:22:44 -0000, NT wrote:

On Mar 10, 8:32 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 20:25:33 -0000, NT wrote:
On Mar 10, 12:29 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 12:21:52 -0000, John Rumm wrote:
On 10/03/2012 01:44, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 01:37:31 -0000, Frank Erskine
wrote:

On Sat, 10 Mar 2012 00:44:52 +0000, John Rumm
wrote:

On 09/03/2012 20:07, Lieutenant Scott wrote:
On Fri, 09 Mar 2012 13:46:33 -0000, NT wrote:

Surely it would be best to do as they suggest and have 30A cable in a
star topology. You could have as many sockets as you like on a single
line of 30A cable.

A 30/32A radial is a "standard circuit", so nothing to stop you from
using it.

Its not commonly used since it required 4.0mm^2 T&E which is harder to
work with.

Mumble years ago I requested a 30/32A supply to a test bench. Our
internal power tech did it (in proper steel conduit) using stranded
4mm^2, which he reckoned was much easier to handle in conduit than
solid core.
I never did investigate what the composition of the stranded wire was
- probably a successor to 7/0.036.

Solid core seems a little silly really. One strand, easier to break?
Stiffer, harder to bend round corners? Point?

Its easier to dress and stays where you put it, its cheaper to make, and
flexibility (in the way the flex is flexible) is of no real benefit in
fixed wiring.

(although even T&E is coarsely stranded in the larger sizes)

Yes I suppose flex would flop about too much when you're trying to install it.

no, but it does sag afterwards where visible. ITs also a piontless
spend of money

Wire don't cost much compared to the other things you're fitting, like the light fixtures.

No. But why spend more for no reason.

Because it's negligible in comparison with the whole job.

--
http://petersparrots.com
http://petersphotos.com

Which sexual position produces the ugliest children?
Ask your mum.

On Sun, 11 Mar 2012 06:53:30 -0000, ARWadsworth wrote:

Lieutenant Scott wrote:
On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed
wrote:

Lieutenant Scott wrote
Interesting, I'll inform my neighbour who's getting it
done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and
spreads for a lot longer and the issue is the occupier or the
owner is not aware of that until the roof starts collapsing,
especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

Yes, it's below the attic.

It's under the bridge

When are you going to grow up?

--
http://petersparrots.com
http://petersphotos.com

Confuscious say: "Man who sit on tack get point!"

"Lieutenant Scott" wrote in message
newsp.waz4kig3ytk5n5@i7-940...
On Sun, 11 Mar 2012 01:11:50 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazd7rheytk5n5@i7-940...
On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...
On Sun, 11 Mar 2012 00:26:24 -0000, Rod Speed

wrote:

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads
for
a
lot longer and the issue is the occupier or the owner is not aware of
that
until the roof starts collapsing, especially at night, when they are
sleeping".

First place I put a smoke detector was the attic.

Don't you have a home to go to?

Yes, it's below the attic.

Then go there FFS.

That's where I am now. Why am I communicating with someone childish
enough to call themselves "brass monkey" anyway?

Beats me, lieutenant.

On Sun, 11 Mar 2012 01:00:41 -0000, Rod Speed wrote:

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job,

They didnt die by fire.

so presumably someone murdered them?

Nope. At least one of them was electrocuted when he as actually
stupid enough to staple the foil insulation to the joists and ended up
doing that right thru the power wiring that had not been turned off.

We actually had the govt go back and test all of those for live insulation installs.

I don't see what's wrong with stapling it, although stapling through a wire was stupid.

At least one of them died of heat stroke. The temperatures in ceilings
with metal roofs and 45C outside have to be measured to be believed.

I saw someone build a new house in Scotland with a metal roof. Why on earth would someone want to live in a tin shack, especially in a place with so much LOUD rain.

Another was actually stupid enough to let the house occupier's 7 year
old kid pass him the insulation thru a hole in the roof, with the kid walking
around on the peaked roof with bare feet. Fortunately that kid survived
fine. One of the neighbours videoed it and it was splashed across out
equivalent of your BBC evening TV news and caused one hell of a stink.

If the kid and his parents are happy with it, I don't see the problem. I certainly climbed on my parents roof for fun when I was that age.

Quite a few of the installers were illegals, mostly indians.

Maybe we should start supplying their country with free condoms.

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for a lot longer and the issue is the occupier or
the owner is not aware of that until the roof starts collapsing, especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

This isnt the attic, its the roof space. There arent
too many that put smoke detectors in there.

That's what I mean by attic. What distinction are you making? There's the rooms you live in, then there's the triangular bit above (and to the side if your upstairs is within the roof).

The govt approved insulation installers certainly didnt and there's
be a hell of a problem with the batterys even if they did anyway.

The house owner should have one in there. The battery is changed by going up through the hatch and changing it, just like any other smoke alarm.

--
http://petersparrots.com
http://petersphotos.com

"Do you like Kipling?"
"I don't know, I've never kippled."

On Sun, 11 Mar 2012 06:54:53 -0000, ARWadsworth wrote:

brass monkey wrote:
"Rod Speed" wrote in message
...
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
John Rumm wrote
Lieutenant Scott wrote

A good illustration of how instincts can be misleading
;-)

With installation method 101 (which is what I described
above), its already somewhat out of spec (installed
cable rated at 27A). If it were method 103 then its
significantly under rated for the application since the
cable is only rated at 23.5A in that situation:

http://wiki.diyfaq.org.uk/index.php?...lation_Methods

That will be the saving grace if you are running it
installed using method 101 for example. (with 103, you
would probably still have a problem)

I didn't put the wire in, it was already there. I THINK
it's 6mm2, it looks like it from the outside, I've never
investigated. 103-ish, it's laying loose in some places
with insulation sometimes on top, sometimes underneath,
maybe sometimes both.

I wonder, all these people currently coming round (I've
had 5 in 2 weeks) wanting to add huge amounts of loft
insulation with government grants - do they check the
wires before adding piles of insulation? I doubt it.

Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally
dead.

The fire presumably happened AFTER they'd finished the insulation
job,

They didnt die by fire.

so presumably someone murdered them?

Nope. At least one of them was electrocuted when he as actually
stupid enough to staple the foil insulation to the joists and ended
up doing that right thru the power wiring that had not been turned
off. We actually had the govt go back and test all of those for live
insulation installs.

At leas one of them died of heat stroke. The temperatures in
ceilings with metal roofs and 45C outside have to be measured to be
believed. Another was actually stupid enough to let the house occupier's
7
year old kid pass him the insulation thru a hole in the roof, with the
kid walking
around on the peaked roof with bare feet. Fortunately that kid
survived fine. One of the neighbours videoed it and it was splashed
across out equivalent of your BBC evening TV news and caused one
hell of a stink. Quite a few of the installers were illegals, mostly
indians.

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it
done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and
spreads for a lot longer and the issue is the occupier or the
owner is not aware of that until the roof starts collapsing,
especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

This isnt the attic, its the roof space. There arent
too many that put smoke detectors in there.

The govt approved insulation installers certainly didnt and there's
be a hell of a problem with the batterys even if they did anyway.

The govt just killed the scheme and the minister got sacked.

Is this dialogue for real, I ask?
D
Adam, I think we need a few of your expletives here.

At least dennis is genuinely stupid and not just making it up like these
two.

Do you believe what he's said about the government scheme is incorrect?

--
http://petersparrots.com
http://petersphotos.com

Should crematoriums give discounts for burn victims?

On Sun, 11 Mar 2012 10:35:31 -0000, Steve Firth wrote:

"Lieutenant Scott" wrote:


That's where I am now. Why am I communicating with someone childish
enough to call themselves "brass monkey" anyway?


Dunno, why do you think that is, PHucker? Perhaps next time you sit on a
high horse you may wish to make sure that its hooves are not made from
clay?

Steve, you're the biggest loser known in newsgroups so keep out of it.

--
http://petersparrots.com
http://petersphotos.com

HELP WANTED:
Baiters. Local fishing boats need 4 baiters to bate hooks for tourists. Must have strong hands and work hard. Good pay-$15 per hour, and benefits.
After 6 weeks, 2 best baiters will be promoted to masterbaiters. Apply in person to Jon at the Gulf Marina.

On Sun, 11 Mar 2012 10:40:18 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.waz4kig3ytk5n5@i7-940...
On Sun, 11 Mar 2012 01:11:50 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazd7rheytk5n5@i7-940...
On Sun, 11 Mar 2012 00:50:13 -0000, brass monkey wrote:


"Lieutenant Scott" wrote in message
newsp.wazc8unqytk5n5@i7-940...


Don't you have a home to go to?

Yes, it's below the attic.

Then go there FFS.

That's where I am now. Why am I communicating with someone childish
enough to call themselves "brass monkey" anyway?

Beats me, lieutenant.

Go beat yourself.

--
http://petersparrots.com
http://petersphotos.com

The longest word in German is DONAUDAMPFSCHIFFAHRTSELEKTRIZITAETENHAUPTBETRIEBSW ERKBAUUNTERBEAMTENGESELLSCHAFT, "the club for subordinate officials of the head office management of the Danube steamboat electrical services" (name of a pre-war club in Vienna), according to 1996 Guinness.

"Lieutenant Scott" wrote:
On Sun, 11 Mar 2012 10:35:31 -0000, Steve Firth wrote:

"Lieutenant Scott" wrote:


That's where I am now. Why am I communicating with someone childish
enough to call themselves "brass monkey" anyway?


Dunno, why do you think that is, PHucker? Perhaps next time you sit on a
high horse you may wish to make sure that its hooves are not made from
clay?

Steve, you're the biggest loser known in newsgroups so keep out of it.

Oh look the empty claim that you and Pounder both make - just before you
run off whimpering for mummy claiming the bad man kicked your arse, again.

Huge wrote:

My study has (mumble, mutter) 76 sockets in it.
they're mostly Olson power strips;

Yes, I quite like those, they're nice and sturdy, but they're not the
most compact of designs.

ARWadsworth wrote:

It's under the bridge

So who's Big Billygoat gruff?

Bill

Lieutenant Scott wrote:

Two bits of metal in the water? Doesn't that cause electrolysis, and
the production of rather flammable hydrogen and oxygen?

It's AC

Bill

On Sun, 11 Mar 2012 11:14:51 -0000, Steve Firth wrote:

"Lieutenant Scott" wrote:
On Sun, 11 Mar 2012 10:35:31 -0000, Steve Firth wrote:

"Lieutenant Scott" wrote:


That's where I am now. Why am I communicating with someone childish
enough to call themselves "brass monkey" anyway?


Dunno, why do you think that is, PHucker? Perhaps next time you sit on a
high horse you may wish to make sure that its hooves are not made from
clay?

Steve, you're the biggest loser known in newsgroups so keep out of it.

Oh look the empty claim that you and Pounder both make - just before you
run off whimpering for mummy claiming the bad man kicked your arse, again.

I've seen at least 15 people killfile you in the driving group.

--
http://petersparrots.com
http://petersphotos.com

A father is someone who carries pictures where his money used to be.

On Sun, 11 Mar 2012 12:59:40 -0000, Bill Wright wrote:

Lieutenant Scott wrote:

Two bits of metal in the water? Doesn't that cause electrolysis, and
the production of rather flammable hydrogen and oxygen?

It's AC

Causing H2 and O2 to appear at both surely? You just reverse the production every half cycle.

--
http://petersparrots.com
http://petersphotos.com

Golfer: "Please stop checking your watch all the time, caddy. It's distracting!"
Caddy: "This isn't a watch Sir, it's a compass!"

Lieutenant Scott wrote:

On Sun, 11 Mar 2012 11:14:51 -0000, Steve Firth wrote:
[snip]

Oh look the empty claim that you and Pounder both make - just before you
run off whimpering for mummy claiming the bad man kicked your arse, again.

I've seen at least 15 people killfile you in the driving group.

Bless, and when did they grant you access to their killfiles, eh? You
can't even tell lies in a convincing manner you tosser. For ****s sake
give it up and shut the **** up, you're just embarassing yourself now.

On Sun, 11 Mar 2012 14:08:31 -0000, Steve Firth wrote:

Lieutenant Scott wrote:

On Sun, 11 Mar 2012 11:14:51 -0000, Steve Firth wrote:
[snip]

Oh look the empty claim that you and Pounder both make - just before you
run off whimpering for mummy claiming the bad man kicked your arse, again.

I've seen at least 15 people killfile you in the driving group.

Bless, and when did they grant you access to their killfiles, eh? You
can't even tell lies in a convincing manner you tosser. For ****s sake
give it up and shut the **** up, you're just embarassing yourself now.

Only someone with a complete lack of deduction like yourself would need access to the killfiles to tell that you're in them.

--
http://petersparrots.com
http://petersphotos.com

Landing: A controlled mid-air collision with a planet.

On Sun, 11 Mar 2012 14:08:31 -0000, Steve Firth wrote:

Lieutenant Scott wrote:

On Sun, 11 Mar 2012 11:14:51 -0000, Steve Firth wrote:
[snip]

Oh look the empty claim that you and Pounder both make - just before you
run off whimpering for mummy claiming the bad man kicked your arse, again.

I've seen at least 15 people killfile you in the driving group.

Bless, and when did they grant you access to their killfiles, eh? You
can't even tell lies in a convincing manner you tosser. For ****s sake
give it up and shut the **** up, you're just embarassing yourself now.

http://groups.google.com/group/uk.re...621eace9aeb11f

http://www.mac-help.com/t198755-stev...usion-kid.html

http://www.diy-forum.net/re-mrsa-cou...ng-t53835.html

http://newsgroups.derkeiler.com/Arch.../msg01595.html

--
http://petersparrots.com
http://petersphotos.com

Landing: A controlled mid-air collision with a planet.

Lieutenant Scott wrote:
On Sat, 10 Mar 2012 07:54:28 -0000, ARWadsworth
wrote:
Lieutenant Scott wrote:

I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16
amps ish, while I've never seen a lighting circuit have a
fuse/breaker of anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit that
safely uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A MCB

I suppose you could use even thinner wire.

In theory yes.

However 1mm and 1.5mm have become the standard for lighting circuits (that
are a radial and not a ring due to the ability to calculate the maximum
load). The main reason for this is both cables can handle the reduction in
current carrying capacity when covered in the insulation that lighting cable
usually encounters without having to do any calculations and they serve
about the right sort of length required for most house lighting circuits and
still keep the voltage drop with accepted requirements.




10A is probably the largest size MCB you will see in a house for
the lights. You might see 16A used in factories etc. BTW it's not
16A lighting cable, look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

Ah so 16A becomes 8A in insulation. Doesn't that mean we should be
using huge cables for ring mains?

You could read the article and then read this one.

http://wiki.diyfaq.org.uk/index.php?...g_A_Cable_Size

--
Adam

John Rumm wrote:
On 10/03/2012 10:53, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 07:54:28 -0000, ARWadsworth
wrote:

Lieutenant Scott wrote:

I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16
amps ish, while I've never seen a lighting circuit have a
fuse/breaker of anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit
that safely uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

I suppose you could use even thinner wire.

10A is probably the largest size MCB you will see in a house for
the lights.
You might see 16A used in factories etc. BTW it's not 16A
lighting cable, look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

Ah so 16A becomes 8A in insulation. Doesn't that mean we should be
using huge cables for ring mains?

You need each leg to be good for 21A when used in that configuration,
which 2.5mm^2 is usually comfortably inside, but it does depend on the
exact details of the installation. If the cable is installed in
insulation and this can't be avoided, then you will need to uprate to
a larger cable, or change your circuit design etc. With modern
insulation practices, it is something the designer needs to pay more
attention to.

That should read 20A per leg:-)

--
Adam

On Mar 11, 12:59*pm, Bill Wright wrote:
Lieutenant Scott wrote:
Two bits of metal in the water? *Doesn't that cause electrolysis, and
the production of rather flammable hydrogen and oxygen?

It's AC

Bill

That means you get a mixture o fhydrogen and oxygen a both electrodes.
Excellent!

On Mar 11, 5:13*pm, "ARWadsworth"
wrote:
John Rumm wrote:
On 10/03/2012 10:53, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 07:54:28 -0000, ARWadsworth
wrote:

Lieutenant Scott wrote:

I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16
amps ish, while I've never seen a lighting circuit have a
fuse/breaker of anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit
that safely uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

I suppose you could use even thinner wire.

10A is probably the largest size MCB you will see in a house for
the lights.
You might see 16A used in factories etc. BTW it's not 16A
lighting cable, look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

Ah so 16A becomes 8A in insulation. Doesn't that mean we should be
using huge cables for ring mains?

You need each leg to be good for 21A when used in that configuration,
which 2.5mm^2 is usually comfortably inside, but it does depend on the
exact details of the installation. If the cable is installed in
insulation and this can't be avoided, then you will need to uprate to
a larger cable, or change your circuit design etc. With modern
insulation practices, it is something the designer needs to pay more
attention to.

That should read 20A per leg:-)

--
Adam- Hide quoted text -

- Show quoted text -

Talking of safety, you should see the wirenuts the Yanks use.
http://en.wikipedia.org/wiki/Wire_nut

On Sun, 11 Mar 2012 17:28:58 -0000, harry wrote:

On Mar 11, 5:13 pm, "ARWadsworth"
wrote:
John Rumm wrote:
On 10/03/2012 10:53, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 07:54:28 -0000, ARWadsworth
wrote:

Lieutenant Scott wrote:

I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16
amps ish, while I've never seen a lighting circuit have a
fuse/breaker of anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit
that safely uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

I suppose you could use even thinner wire.

10A is probably the largest size MCB you will see in a house for
the lights.
You might see 16A used in factories etc. BTW it's not 16A
lighting cable, look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

Ah so 16A becomes 8A in insulation. Doesn't that mean we should be
using huge cables for ring mains?

You need each leg to be good for 21A when used in that configuration,
which 2.5mm^2 is usually comfortably inside, but it does depend on the
exact details of the installation. If the cable is installed in
insulation and this can't be avoided, then you will need to uprate to
a larger cable, or change your circuit design etc. With modern
insulation practices, it is something the designer needs to pay more
attention to.

That should read 20A per leg:-)

--
Adam- Hide quoted text -

- Show quoted text -

Talking of safety, you should see the wirenuts the Yanks use.
http://en.wikipedia.org/wiki/Wire_nut

I've seen those used in my CAR behind the stereo on the speaker wires. They are absolutely awful and I replaced them - they just kept coming apart. Do the yanks actually use these for the MAINS?!?

--
http://petersparrots.com
http://petersphotos.com

What's meaner than a pit bull with AIDS?
The guy that gave it to him.

In article op.wa0pqih3ytk5n5@i7-940,
Lieutenant Scott wrote:
Talking of safety, you should see the wirenuts the Yanks use.
http://en.wikipedia.org/wiki/Wire_nut

I've seen those used in my CAR behind the stereo on the speaker wires.
They are absolutely awful and I replaced them - they just kept coming
apart. Do the yanks actually use these for the MAINS?!?

Yes - but only on those awfully safe radials you love.

--
*Puritanism: The haunting fear that someone, somewhere may be happy.

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

On Sun, 11 Mar 2012 19:01:20 -0000, Dave Plowman (News) wrote:

In article op.wa0pqih3ytk5n5@i7-940,
Lieutenant Scott wrote:
Talking of safety, you should see the wirenuts the Yanks use.
http://en.wikipedia.org/wiki/Wire_nut

I've seen those used in my CAR behind the stereo on the speaker wires.
They are absolutely awful and I replaced them - they just kept coming
apart. Do the yanks actually use these for the MAINS?!?

Yes - but only on those awfully safe radials you love.

They are safer in some ways and more dangerous in others.

The disconnection of one of the halves of the ring is quite likely. For example a loose wire in the back of a socket.

--
http://petersparrots.com
http://petersphotos.com

Two hands working can do more than a thousand clasped in prayer

Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Lieutenant Scott wrote
Rod Speed wrote
Ours didnt. And we had a few of them killed

What exactly do you mean by "a few of them killed"?

A few of the insulation installers ended up quite literally dead.

The fire presumably happened AFTER they'd finished the insulation job,

They didnt die by fire.

so presumably someone murdered them?

Nope. At least one of them was electrocuted when he as actually
stupid enough to staple the foil insulation to the joists and ended up doing that right thru the power wiring that
had not been turned off.

We actually had the govt go back and test all of those for live insulation installs.

I don't see what's wrong with stapling it,

Thats why you dont get to decide how it must be done.

although stapling through a wire was stupid.

Got him the darwin award.

Corse plenty of others risk killing someone else, particularly if they staple it with
the power turned off and dont even notice the problem they have produced.

At least one of them died of heat stroke. The temperatures in ceilings with metal roofs and 45C outside have to be
measured to be believed.

I saw someone build a new house in Scotland with a metal roof. Why on earth would someone want to live in a tin
shack,

Metal decking survives storms much better than tiles do,
and lasts a lot long than that abortion, roofing felt does too.

especially in a place with so much LOUD rain.

It isnt hard to fix that. You just have insulwool immediately under
the decking with chicken wire forcing it against the decking.

I didnt bother myself, it doesnt rain that heavy enough to matter here.

Another was actually stupid enough to let the house occupier's 7 year old kid pass him the insulation thru a hole in
the roof, with the kid walking around on the peaked roof with bare feet. Fortunately that kid survived fine. One of
the neighbours videoed it and it was splashed across our equivalent of your BBC evening TV news and caused one hell
of a stink.

If the kid and his parents are happy with it, I don't see the problem.

His parents werent around at the time.

I certainly climbed on my parents roof for fun when I was that age.

This was a VERY wet roof.

Quite a few of the installers were illegals, mostly indians.

Maybe we should start supplying their country with free condoms.

Rajiv Gandhi tried forced vasectomys. Didnt last long.

and some house fires as a result too.

We killed the govt grant scheme because of the utter fiasco.

Interesting, I'll inform my neighbour who's getting it done......

http://www.adelaidenow.com.au/news/s...-1225698129364

Thats the one that got killed, look at the date.

"Because it's in an area that's undetected, it smoulders and spreads for a lot longer and the issue is the occupier
or the owner is not aware of that until the roof starts collapsing, especially at night, when they are sleeping".

First place I put a smoke detector was the attic.

This isnt the attic, its the roof space. There arent
too many that put smoke detectors in there.

That's what I mean by attic. What distinction are you making?

An attic usually has a floor etc that you can walk on.

There's the rooms you live in, then there's the triangular bit above (and to the side if your upstairs is within the
roof).

Hardly anyone puts smoke detectors in the roof space and there
is a problem with even hearing them if you do, let alone the batterys.

The govt approved insulation installers certainly didnt and there's
be a hell of a problem with the batterys even if they did anyway.

The house owner should have one in there.

You'd need more than one.

The battery is changed by going up through the hatch and changing it, just like any other smoke alarm.

Pity about how they work out that the battery needs changing.

On 11/03/2012 17:13, ARWadsworth wrote:
John Rumm wrote:
On 10/03/2012 10:53, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 07:54:28 -0000, ARWadsworth
wrote:

Lieutenant Scott wrote:

I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16
amps ish, while I've never seen a lighting circuit have a
fuse/breaker of anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit
that safely uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

I suppose you could use even thinner wire.

10A is probably the largest size MCB you will see in a house for
the lights.
You might see 16A used in factories etc. BTW it's not 16A
lighting cable, look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

Ah so 16A becomes 8A in insulation. Doesn't that mean we should be
using huge cables for ring mains?

You need each leg to be good for 21A when used in that configuration,
which 2.5mm^2 is usually comfortably inside, but it does depend on the
exact details of the installation. If the cable is installed in
insulation and this can't be avoided, then you will need to uprate to
a larger cable, or change your circuit design etc. With modern
insulation practices, it is something the designer needs to pay more
attention to.

That should read 20A per leg:-)

Yup, quite possibly ;-)


--
Cheers,

John.

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

On 10/03/2012 22:15, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 21:40:14 -0000, John Rumm
wrote:

I'd find it very difficult to keep to 8A. So that's no cooking then? No
electric kettles? Even a hoover is using most of that allowance. I
wonder how many nails get put in the master fuse holders.....

(having said that, DNOs often design their distribution systems on the
assumption that the diverse load of each house is something around 8
to 10A)

In this country?

Yup, diversity.

You can draw 100A if you need, but the calculations are based on the
averaged load spread over a large number of houses. Most of which will
be only drawing a few amp for most of the day. Big distribution systems
are designed using statistical probabilities, not maximum theoretical load.


--
Cheers,

John.

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

On Mar 11, 10:37*am, "Lieutenant Scott" wrote:
On Sun, 11 Mar 2012 01:21:13 -0000, NT wrote:
On Mar 10, 10:15 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 21:40:14 -0000, John Rumm wrote:
On 10/03/2012 20:30, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 20:10:38 -0000, NT wrote:

On Mar 10, 7:54 am, "ARWadsworth"
wrote:
Lieutenant Scott wrote:
I see. Why are lighting circuits never rings, and why does the
lighting wire sold in DIY stores always seem to be rated at 16 amps
ish, while I've never seen a lighting circuit have a fuse/breaker of
anything other than 5/6A.

The point of the ring is to allow 20A cable to form a circuit that
safely
uses a 32A MCB.

There would be no point in doing that is you were using 16A cable
with a 6A
MCB

10A is probably the largest size MCB you will see in a house for the
lights.
You might see 16A used in factories etc. BTW it's not 16A lighting
cable,
look at

http://wiki.diyfaq.org.uk/index.php?...es#Cable_Sizes

If one went with 6A lighting rings, using lets say 3.5A cable, it
could be:
only when not buried in insulation: 0.33mm2
buried: 0.44 mm2

For the cfl/led only user, we could reduce a 10 room lighting ring
down to... say 50w per room allowance = 500w = 2A and use 1.3A cable,
0.16mm2 would work even if buried in insulation.

I'm using 26 watts (four 75W equivalent spots) in this room and it's lit
very brightly.

Many rooms will use less than 50w of CFLs, leaving a higher budget for
the larger rooms. One could budget 20w max for small rooms like loo &
bathroom.

I forgot to say LEDs. *CFLs use far too much electricity.



And the use of RCDs would enable the earth conductor to shrink to a
similar size. Shock voltage would go up, but the RCD would limit it to
such brevity as to be safe.

Voltage goes up? How?

If you are getting a shock from something due to a fault (i.e. touching
something made live by a fault, or "indirect contact" as it used to be
known). Then you can assume that the earthing will ensure the fault is
cleared quickly, and that limits the shock duration.

However you also get fortuitous equipotential bonding effect brought
about by the earth connection that will tend to lower the touch voltage
(if you imagine two lengths of wire of equal CSA - one connected to
earth (0V) and one to mains, you would expect the the arrangement to act
like a potentiometer wire, and the voltage with respect to earth would
be half mains at the fault). If you start making the resistance of the
earth larger (i.e. by making it thinner), then the touch voltage at the
fault will rise.

Not if the live is also thinner.

True. With very thin wire its cheap to have equally thick earth wire,
which would make shock voltage lower than today's T&E circuits. As
long as the shock didn't come from a 30A circuit, in which case the
lighting earth would probably vapourise. But the RCDs should protect
it and clear it at some point.

I'm trying to imagine a situation where you could get a shock form the live of a socket but be earthed by a light on the ceiling. *Without being a trapeze artist....

Quite.

One could go even further: with an RCD there's very little theoretical
need for double insulation or earthing, one could simply use very thin
speaker wire.

It's the fire hazard that would concern me more. Speaker wire could get
snagged easily.

a tad over 2A is unlikely to do it much harm...

A minor short could easily occur if it's flimsy wire, which can cause a fire.

Either don't make the insulation flimsy, or do and have a little
consideration for where the wire goes. Bell wire isnt damaged by
normal use and abuse - but then its far from 0.16mm2.

Conductors can easily be reinforced by simply including string in the
cable.

String is stronger than wire?

Is it? news to me.


Another approach I'm a lot less sure about is to use copper
clad steel to increase conductor strength.

Anyway, if you're not earthing, then brass lighting fixtures wouldn't be
protected against loose live wires,

The RCD does that. Or one can mandate only plastic and double
insulated metal fittings on such circuits.

How can an RCD protect it? *Since the fitting isn't earthed, there will be no current flow to earth. *The thing will sit there with a live chassis.

RCD protects against shock from live things by cutting the power if it
becomes live and you touch it.


plus that annoying guy that checks
your house when you sell it would put a red X on a few parts of his report.

Not if such a scheme were accepted. Here I'd be quite happy in
principle for lighting to go on a 3 core 2A bell wire ring, for CFL
users its perfectly effective and safe, as long as its installed
correctly.

It would really annoy the luddites who want to use incandescents, but I suppose we have to force them off their drug somehow.

Whats wrong with freedom of choice? If the 2A ring is safe, and I
believe it is, why cant I freely use it if I want? Why cant we choose?
Where has government gone awry?


For 2nd world applications one could dispense with the
earth conductor, relying on RCD and fitting insulation. For 3rd world
one could reduce conductor size to 0.16mm2 and reduce insulation to
speaker wire proportions.

That is what the RCD was designed to mitigate.

RCD won't pick up you touching live and neutral. *With the earth it's more likely you touch earth instead/aswell, which will trip it.

There's no safety scheme in use that I know of, at least in domestic
properties, that offers any L-N shock protection beyond insulation. L-
N shocks are excepional.

Exactly, which is why with the presence of the earth, it's more likely your shock involves earth instead of neutral.

Yes, shocks are almost always to earth.


Anyway, if you are blue
sky thinking, you can do away with the surveyor! (not that they ever do
much other than say of you want the electrics checked, get a specialist)

Just how do you do away with a surveyor commissioned by the buyer of your house?

I dont see any point in installing such things unlawfully. Its only
useful when widespread and accepted. Call it an eco-circuit for
acceptance. FWIW surveyors dont check electrical installs. If you
wired your house up with iron wire in hosepipe they'd say the same
thing as always, get the electrics checked.

They test to make sure a metal light fitting is earthed.

Sounds like you've not had a surveyor in


Current practice is to supply just an 8A feed per flat in at least
some of the eastern bloc,

For the entire flat or just the lighting?

Entire flat I would expect. 8A for lighting would hardly be exceptional...

Yes, the whole flat. I've seen it in aluminium, it looked like fatter
bellwire.

I'd find it very difficult to keep to 8A. *So that's no cooking then?

A medium performance ring can run on 1kW. *A microwave sized fan oven
does fine on 1kW. 1kW consumption microwaves with about 400w cooking
power exist in Britain, they work adequately.

I've cooked on 500w rings too, 3rd world type equipment with bare live
elements. Its way too low to be practical, a pan of water takes 20
minutes.

And longer when you spill the water in the live element.....

No electric kettles?

8A is 2kW, no problem with kettles.

But that uses all the power allowance up. *If someone else wants to

Why would one pick a kettle that uses all the available power? I
wouldnt.


do something else, like your boiling water to add to the cooking on your stove for example.

I saw an eastern bloc kettle with a speaker wire type lead (a few
minutes doesn't need much copper) and no element. Instead there were
just 2 bits of metal at the bottom connected to L&N, it was an
electrode kettle. I'd prefer a real 1kW kettle though.

Two bits of metal in the water? *Doesn't that cause electrolysis, and the production of rather flammable hydrogen and oxygen?

ac doesnt electrolyse


(having said that, DNOs often design their distribution systems on the
assumption that the diverse load of each house is something around 8 to 10A)

In this country?

Its actually easy to live on 2kW max, or less. Its just a matter of
choosing your appliances with a clue or two, and adopting a policy to
avoid overload. It only takes a little thought to massively trim down
our luxury consumption levels. Even washing machines work well enough
with a 1kW element - they don't spin and heat at the same time.

Mine is cold wash - it washes just as well as 30/40C that most people use..


NT

On Mar 11, 10:37*am, "Lieutenant Scott" wrote:
On Sun, 11 Mar 2012 01:22:44 -0000, NT wrote:
On Mar 10, 8:32 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 20:25:33 -0000, NT wrote:
On Mar 10, 12:29 pm, "Lieutenant Scott" wrote:
On Sat, 10 Mar 2012 12:21:52 -0000, John Rumm wrote:
On 10/03/2012 01:44, Lieutenant Scott wrote:
On Sat, 10 Mar 2012 01:37:31 -0000, Frank Erskine
wrote:

On Sat, 10 Mar 2012 00:44:52 +0000, John Rumm
wrote:

On 09/03/2012 20:07, Lieutenant Scott wrote:
On Fri, 09 Mar 2012 13:46:33 -0000, NT wrote:

Surely it would be best to do as they suggest and have 30A cable in a
star topology. You could have as many sockets as you like on a single
line of 30A cable.

A 30/32A radial is a "standard circuit", so nothing to stop you from
using it.

Its not commonly used since it required 4.0mm^2 T&E which is harder to
work with.

Mumble years ago I requested a 30/32A supply to a test bench. Our
internal power tech did it (in proper steel conduit) using stranded
4mm^2, which he reckoned was much easier to handle in conduit than
solid core.
I never did investigate what the composition of the stranded wire was
- probably a successor to 7/0.036.

Solid core seems a little silly really. One strand, easier to break?
Stiffer, harder to bend round corners? Point?

Its easier to dress and stays where you put it, its cheaper to make, and
flexibility (in the way the flex is flexible) is of no real benefit in
fixed wiring.

(although even T&E is coarsely stranded in the larger sizes)

Yes I suppose flex would flop about too much when you're trying to install it.

no, but it does sag afterwards where visible. ITs also a piontless
spend of money

Wire don't cost much compared to the other things you're fitting, like the light fixtures.

No. But why spend more for no reason.

Because it's negligible in comparison with the whole job.

Thats not a reason to spend more.


NT