On Sunday, 7 October 2018 21:01:12 UTC+1, John Rumm wrote:
On 07/10/2018 01:27, tabbypurr wrote:
On Saturday, 6 October 2018 01:23:59 UTC+1, John Rumm wrote:
On 05/10/2018 22:18, tabbypurr wrote:
On Thursday, 4 October 2018 20:42:04 UTC+1, John Rumm wrote:
On 04/10/2018 18:53, tabbypurr wrote:
On Wednesday, 3 October 2018 10:17:00 UTC+1, Tim Watts wrote:

It's a drop in the ocean of building a house

there are many ways one could reduce housebuild costs

and for that you want to reduce safety (lack of CPC)

No, it's already been pointed out that lack of lighting earth has
killed precisely no-one in decades.

How many have suffered serious injury from an unearthed metalwork made
live by a fault?

How many hospital admissions?

How many burns?

How many bruises and lacerations?

How many cases of atrial fibrillation?

do you have the data?

I was asking you, since you seem to count any incidence of injuries
similar to these as being in some way not relevant.

There are some reasonably well broken down figures in some of these docs:

http://www.hassandlass.org.uk/

(based on surveys and extrapolation rather than collected stats though)

several documents and hundreds of pages. Feel free to give a specific reference!

Try the 2002 Data pdf linked on the front page - about two thirds of the
way though.

either give us a page or don't


Not sure I would want to count US practice with electrical systems as
being indicative of much other than how not to do it. (from memory, they
have tens of thousands of electrical deaths per year)

that is not the point, the point was that it's normal to for requirements to be removed.

A moment ago you were claiming they were not removed.

both occur. Are you claiming to not be aware of this?

A borrowed neutral
on a lighting circuit probably never actually killed anyone, however
there are good sound reasons why its not permitted now.

To quote your own words from the wiki: "mains fatally electrocutes
around 20 people a year in Britain, and shocks over a million"

You may not be able to do much to reduce the 20, but one can still make
big inroads into the million.

Where does the million come from?

Those are *YOUR* words (you added them to the main voltage wiki article)
- where did you get them from?

Having just read the mains voltage article I see no such material.

http://wiki.diyfaq.org.uk/index.php/..._Voltage_or_LV

Last sentence.

Added by you on 29th March 2011 at 7:26

http://wiki.diyfaq.org.uk/index.php?...62&oldid=15261

that must have come from a thread here as I don't have the info at my end.

(I seem to recall the doc in question being dissected here in the past.
Probably a ESC/ESF publication)

Ya know we are surrounded by risks that kill substantial numbers of people. Those are the ones to tackle.

But we are discussing your proposed alterations of BS7671, so keep on
topic.

I am

You logic does not work here though does it? We all agree that
substantial number of people are not killed by electrical installations
in the UK, so any change you propose to BS7671 will have to have some
other justification.

which has been given already

and increased fire risk due to removing the sheath.

not seeing how it causes a fire risk. This sort of cable would only
be for situations where it's not liable to get damaged in
installation nor open to touch by end users after installation.

That pretty much rules out anywhere in a domestic setting. (think in
terms of rodent damage and any number of other ways cables are
vulnerable even when not readily accessible to the end user).

buried in plaster is fine. Between floor/ceiling is ok where not open to rodents, which new builds aren't.

You had better tell the rodent!

I don't see new builds full of mousable holes. Victorian places yes.


Think also of the techniques we use to prove an electrical system is
safe and working correctly, like using insulation resistance testing.
How is your installation going to test with hidden lengths of poorly
insulated twin cable?

why would you make it poorly insulated? The outer sheath of T&E is not required to get good hipot insulation readings.

Funny how damaged outer insulation can result in different readings then...

the whole point of red/black/brown/blue insulation is that it is more than sufficient for the job.

Note also that insulation degrades with age, and the environment will
have an effect (temperature, humidity, chemical exposure as well as
physical abrasion etc). One of the purposes of the outer sheath of the
cable to to protect the internal conductors and their sheaths from some
of this degradation.

Degradation is caused by
- sun exposure, which does not happen to buried wiring, and takes numerous decades
- abrasion, which normally occurs with cables exposed to the means to move them. Buried house wiring is not a prime candidate there.
- rubber insulation, which is not being proposed

Most insulation resistance failures on new installations are caused
during installation of the cable. Either while pulling, threading, or
fixing, or by follow on trades (e.g. a plasterer's trowel damaging the
cable insulation etc). Suggesting that a less robust cable be used in
places which will later become inaccessible is counter productive.

Cable is cheap, labour is not, and any damage done during installation
will cost far more in labour to fix, than using an appropriate cable in
the first place.

that's a choice for each builder & electrician, depending on how often that happens for them

NT

How are you going to assess round trip circuit resistances when you have
unknown lengths of smaller CSA conductors dotted about the place?

How does that make sense? No-one is suggesting running 1A wire on a 6A breaker.

You suggested you could use bell wire in some parts of the installation.
Even if adequately protected by the circuit protective device, you still
have a problem with testing if the whole circuit is not wired with the
same CSA conductors all round.

Why would you put 1mm2 in a 1.5A circuit? If you did, the circuit would still pass its resistance requirement.

Perhaps I have misunderstood your argument, but to be honest, I really
don't care.

1.0mm^2 T&E is likely to remain the minimum size used for fixed wiring
on lighting circuits, and I can't think of any sensible reason to use
something inferior.

On Sunday, 7 October 2018 21:08:08 UTC+1, John Rumm wrote:
On 07/10/2018 13:13, Jim K wrote:
George Miles Wrote in message:
I guess most injuries from lighting circuits result from falling off the ladder not the electrickery itself

I expect there are good number are people lacerating their hands on
broken bulbs. Probably a few shocks for people trying to extract the
lamp base from the fitting after the glass bit came off in their hands.

[g]


Especially if some ****wit has made the ladders out of matchstick
thin timber...

Please don't give him ideas... that's a whole new thread!

ladders like that are common in the 3rd world. Lashed together sticks basically. I made mine much stronger.


NT

On 08/10/2018 21:32, wrote:
On Sunday, 7 October 2018 20:34:40 UTC+1, John Rumm wrote:
On 07/10/2018 01:40, tabbypurr wrote:

John insists that while the connections may be bare & live and
that's ok, the lampholder absolutely must be earthed.

No, the wiring regs have insisted on this since 1966, it was not
something that I just thought up.

they have. The point was that you're convinced it's necessary.

Indeed I am, as are many informed people. Necessary on two levels - the
regulatory; that is what the regs say, so that is what you need to do,
but also practically, that you will reduce the number of electrical
injuries, and house fires as a result of the measure.

You are also missing the bigger picture, The lighting point must
have an earth provision, but this is not particularly for the
benefit of the lamp holder, but for the vast array of class I lamp
fixtures with exposed metalwork.

Yet again, decades of experience of all types of light fittings on
unearthed circuits shows otherwise.

The only justification you seem to be able to produce for this claim is
that there is not a substantial death rate directly from electrical
installations. However that was also the case in 1966. So why do you
suppose the requirement was introduced then?

It was wholly reasonable to
insist on earths when disintegrating rubber wiring was common, today
it's not like that.

Rubber wiring was not commonly in use in 1966, and the 14th edition was
not going to apply retrospectively.

There are plenty of multi "arm" style chandelier fittings where
its almost impossible to change a lamp without handling the
metalwork of the fixture. These really do need earthing, and are
also quite prone to becoming live under fault conditions (typically
when the retaining nut on the lamp holder gets loose and allows
someone to rotate the who lamp holder multiple times when trying to
get a stuck bulb out. Eventually fracturing the wire internal to
the fixture).

I wouldn't choose to leave the chandeliers I had years ago unearthed.
That's all historic equipment though, not modern regs compliant.

Ah, realisation dawns.

Does all this historic equipment suddenly vanish, or is it still out there?

Class I fittings are still "regs compliant" anyway, and still freely
available for sale. In many cases the quality of the available gear has
not improved.

There are plenty of lethal scenarios we can imagine - some
happen repeatedly IRL, and some just don't.

And some people come up with half baked ideas to save the world by
focussing on the wrong statistic.

That's unrealistic. Lots of people come up with lots of ideas to save
money. Some work out, some don't. It's one of the major drivers of
improvement of quality of life.

Well lets leave this one shall we. I am sure I am not going to change
your mind.

Personally I feel you are flogging a dead horse here. ISTM that using
bell wire or similar in mains installations would have negative safety
implications, and more importantly end up costing more overall rather
than less in real life. It would also make house wiring less easy to
adapt and extend.


--
Cheers,

John.

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

On 08/10/2018 21:34, wrote:
On Sunday, 7 October 2018 20:36:41 UTC+1, John Rumm wrote:
On 07/10/2018 01:11, tabbypurr wrote:
On Friday, 5 October 2018 23:59:10 UTC+1, John Rumm wrote:
On 05/10/2018 22:09, tabbypurr wrote:
On Thursday, 4 October 2018 20:37:11 UTC+1, John Rumm wrote:
On 04/10/2018 18:59, tabbypurr wrote:
On Wednesday, 3 October 2018 11:28:11 UTC+1, John Rumm wrote:

My prediction for the day: Bell wire has absolutely no future in
household electrical circuit wiring.

It's already used today for mains wiring - but not in Britain.

And that is the way it can stay...

Why do you suppose with have massively lower electricity related injury
rates and death rates than many other countries? Its because we insist
on higher standards and better quality materials.

Correct. The uk also generally fails to repeal requirements that have turned out to not be required.

There are many examples of practices and guidance introduced and then
removed in later editions / amendments.

Yup, and some not.

Care to cite one?

If you think all BR must be followed in order to have a safe effective house

I did not say that so move on.

I asked you to cite a requirement from BS7671 that you believe is now
redundant and should be removed.

there's an awful lot you don't know.

Now that is true. Its why I keep learning.




--
Cheers,

John.

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

On Tuesday, 9 October 2018 06:31:47 UTC+1, John Rumm wrote:
On 08/10/2018 21:32, tabbypurr wrote:
On Sunday, 7 October 2018 20:34:40 UTC+1, John Rumm wrote:
On 07/10/2018 01:40, tabbypurr wrote:

John insists that while the connections may be bare & live and
that's ok, the lampholder absolutely must be earthed.

No, the wiring regs have insisted on this since 1966, it was not
something that I just thought up.

they have. The point was that you're convinced it's necessary.

Indeed I am, as are many informed people. Necessary on two levels - the
regulatory; that is what the regs say, so that is what you need to do,

the existence of a regulation is not an argument for that regulation to be needed

but also practically, that you will reduce the number of electrical
injuries,

I've yet to see data that demonstrates that

and house fires as a result of the measure.

or that

You are also missing the bigger picture, The lighting point must
have an earth provision, but this is not particularly for the
benefit of the lamp holder, but for the vast array of class I lamp
fixtures with exposed metalwork.

Yet again, decades of experience of all types of light fittings on
unearthed circuits shows otherwise.

The only justification you seem to be able to produce for this claim is
that there is not a substantial death rate directly from electrical
installations. However that was also the case in 1966. So why do you
suppose the requirement was introduced then?

It was wholly reasonable to
insist on earths when disintegrating rubber wiring was common, today
it's not like that.

Rubber wiring was not commonly in use in 1966, and the 14th edition was
not going to apply retrospectively.

On the contrary in '66 most wiring in houses was rubber insulated. The change to pvc was at that time recent-ish.


There are plenty of multi "arm" style chandelier fittings where
its almost impossible to change a lamp without handling the
metalwork of the fixture. These really do need earthing, and are
also quite prone to becoming live under fault conditions (typically
when the retaining nut on the lamp holder gets loose and allows
someone to rotate the who lamp holder multiple times when trying to
get a stuck bulb out. Eventually fracturing the wire internal to
the fixture).

I wouldn't choose to leave the chandeliers I had years ago unearthed.
That's all historic equipment though, not modern regs compliant.

Ah, realisation dawns.

Does all this historic equipment suddenly vanish, or is it still out there?

the existence of historic noncompliant equipment is hardly news. It's only refitted in a tiny percentage of cases.


Class I fittings are still "regs compliant" anyway, and still freely
available for sale. In many cases the quality of the available gear has
not improved.

you've not seen the historic light fittings I have then. I'm familiar enough with China specials, but many things of the past were much worse.

There are plenty of lethal scenarios we can imagine - some
happen repeatedly IRL, and some just don't.

And some people come up with half baked ideas to save the world by
focussing on the wrong statistic.

That's unrealistic. Lots of people come up with lots of ideas to save
money. Some work out, some don't. It's one of the major drivers of
improvement of quality of life.

Well lets leave this one shall we. I am sure I am not going to change
your mind.

Personally I feel you are flogging a dead horse here. ISTM that using
bell wire or similar in mains installations would have negative safety
implications, and more importantly end up costing more overall rather
than less in real life. It would also make house wiring less easy to
adapt and extend.

The latter point is true, but I don't think people for whom 360w per circuit is plenty are likely to start installing excessive lighting levels. 500w halogens are history now. Also as the years roll by lighting power will drop a lot further as LEDs get much more efficient.


NT

On Tuesday, 9 October 2018 06:35:17 UTC+1, John Rumm wrote:
On 08/10/2018 21:34, tabbypurr wrote:
On Sunday, 7 October 2018 20:36:41 UTC+1, John Rumm wrote:
On 07/10/2018 01:11, tabbypurr wrote:
On Friday, 5 October 2018 23:59:10 UTC+1, John Rumm wrote:
On 05/10/2018 22:09, tabbypurr wrote:
On Thursday, 4 October 2018 20:37:11 UTC+1, John Rumm wrote:
On 04/10/2018 18:59, tabbypurr wrote:
On Wednesday, 3 October 2018 11:28:11 UTC+1, John Rumm wrote:

My prediction for the day: Bell wire has absolutely no future in
household electrical circuit wiring.

It's already used today for mains wiring - but not in Britain.

And that is the way it can stay...

Why do you suppose with have massively lower electricity related injury
rates and death rates than many other countries? Its because we insist
on higher standards and better quality materials.

Correct. The uk also generally fails to repeal requirements that have turned out to not be required.

There are many examples of practices and guidance introduced and then
removed in later editions / amendments.

Yup, and some not.

Care to cite one?

If you think all BR must be followed in order to have a safe effective house

I did not say that so move on.

I assume you don't think that, in which case you dont' believe all BR rules are necessary for safety. That was the point being made.


I asked you to cite a requirement from BS7671 that you believe is now
redundant and should be removed.

erm... something about lighting earths?

The requirement for 9.5mm clearance from plug pin to plug outer edge is another, albeit from a different BS. It made good sense when pins were unsleeved, now it's redundant.


NT

there's an awful lot you don't know.

Now that is true. Its why I keep learning.

On 10/10/2018 02:39, wrote:
On Tuesday, 9 October 2018 06:31:47 UTC+1, John Rumm wrote:
On 08/10/2018 21:32, tabbypurr wrote:
On Sunday, 7 October 2018 20:34:40 UTC+1, John Rumm wrote:
On 07/10/2018 01:40, tabbypurr wrote:

John insists that while the connections may be bare & live
and that's ok, the lampholder absolutely must be earthed.

No, the wiring regs have insisted on this since 1966, it was
not something that I just thought up.

they have. The point was that you're convinced it's necessary.

Indeed I am, as are many informed people. Necessary on two levels -
the regulatory; that is what the regs say, so that is what you need
to do,

the existence of a regulation is not an argument for that regulation
to be needed

Whether you believe its necessary or not does not matter, you still need
to comply with the requirement.

but also practically, that you will reduce the number of
electrical injuries,

I've yet to see data that demonstrates that

and house fires as a result of the measure.

or that

And, at this stage 50 years later you are not going to either...

Yet again, decades of experience of all types of light fittings
on unearthed circuits shows otherwise.

The only justification you seem to be able to produce for this
claim is that there is not a substantial death rate directly from
electrical installations. However that was also the case in 1966.
So why do you suppose the requirement was introduced then?

Are you going to hazard a guess as to why the rules were changed then?

It was wholly reasonable to insist on earths when disintegrating
rubber wiring was common, today it's not like that.

Rubber wiring was not commonly in use in 1966, and the 14th edition
was not going to apply retrospectively.

On the contrary in '66 most wiring in houses was rubber insulated.

Most *existing* housing stock in '66 may have had at least some rubber.

There would not have been much new rubber going in by that date as PVC
had been available for quite number of years at that point.

However its a moot point, since new rubber insulated cable does not have
any of the failings that we associate with it now (i.e. its not
installed in its "disintegrating" state). So rubber insulation alone
would not have been a justification for adding a CPC to lighting circuits.

The change to pvc was at that time recent-ish.

From the mid 50s

Personally I feel you are flogging a dead horse here. ISTM that
using bell wire or similar in mains installations would have
negative safety implications, and more importantly end up costing
more overall rather than less in real life. It would also make
house wiring less easy to adapt and extend.

The latter point is true, but I don't think people for whom 360w per
circuit is plenty are likely to start installing excessive lighting
levels. 500w halogens are history now. Also as the years roll by
lighting power will drop a lot further as LEDs get much more
efficient.

That will be mostly true, but its not not a justification for a lower
spec of cable than 1.00 mm^2 T&E IMHO, since that is really the minimum
you need for adequate robustness to survive both installation and use.

Class I fittings will remain, so the CPC must also be retained.

The trend for ever better insulated and more air tight housing will
increase the requirements for forced ventilation. Combine that with the
rules on bathroom electrics, and it still makes the lighting circuit the
ideal to take power for things like extractors and shaver sockets. So
extra capacity on lighting circuits is not a bad thing.

Lastly from an installers point of view, having to carry yet another
size of cable is just more hassle and more money tied up in stock. (some
electricians don't even keep 1.0mm^2 in stock, and opt for 1.5 as their
minimum).

--
Cheers,

John.

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

On 10/10/2018 02:44, wrote:
On Tuesday, 9 October 2018 06:35:17 UTC+1, John Rumm wrote:

If you think all BR must be followed in order to have a safe
effective house

I did not say that so move on.

I assume you don't think that,

I would have said so if I did.

in which case you dont' believe all BR
rules are necessary for safety. That was the point being made.

You flip from the specific to the general as if that in some way
supports the specific.

For example Part P is a BR "rule" that I believe has little or no
benefit for safety. Earthing lighting circuits however I feel was a very
worthwhile rule change. The fact that I don't believe part P is a good
idea, does not change my opinion on lighting circuits.

I asked you to cite a requirement from BS7671 that you believe is
now redundant and should be removed.

erm... something about lighting earths?

Can you find anyone else to support the idea that we should go back to
unearthed lighting circuits?

The requirement for 9.5mm clearance from plug pin to plug outer edge
is another, albeit from a different BS. It made good sense when pins
were unsleeved, now it's redundant.

Pin clearances are also intended to make it impossible to plug the earth
in upside down, thus opening the shutters. (a reason many 4 way
extension leads are not actually compliant)


--
Cheers,

John.

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

On Wednesday, 10 October 2018 12:29:56 UTC+1, John Rumm wrote:
On 10/10/2018 02:39, tabbypurr wrote:
On Tuesday, 9 October 2018 06:31:47 UTC+1, John Rumm wrote:
On 08/10/2018 21:32, tabbypurr wrote:
On Sunday, 7 October 2018 20:34:40 UTC+1, John Rumm wrote:
On 07/10/2018 01:40, tabbypurr wrote:

John insists that while the connections may be bare & live
and that's ok, the lampholder absolutely must be earthed.

No, the wiring regs have insisted on this since 1966, it was
not something that I just thought up.

they have. The point was that you're convinced it's necessary.

Indeed I am, as are many informed people. Necessary on two levels -
the regulatory; that is what the regs say, so that is what you need
to do,

the existence of a regulation is not an argument for that regulation
to be needed

Whether you believe its necessary or not does not matter, you still need
to comply with the requirement.

that is not relevant

but also practically, that you will reduce the number of
electrical injuries,

I've yet to see data that demonstrates that

and house fires as a result of the measure.

or that

And, at this stage 50 years later you are not going to either...

Yet again, decades of experience of all types of light fittings
on unearthed circuits shows otherwise.

The only justification you seem to be able to produce for this
claim is that there is not a substantial death rate directly from
electrical installations. However that was also the case in 1966.
So why do you suppose the requirement was introduced then?

Are you going to hazard a guess as to why the rules were changed then?

It's a moot point. I don't have any difficulty in believing it was down to the widespread existence of disintegrating rubber cable insulation with consequent hazard, a situation that has vanished today never to return. But it's moot.

It was wholly reasonable to insist on earths when disintegrating
rubber wiring was common, today it's not like that.

Rubber wiring was not commonly in use in 1966, and the 14th edition
was not going to apply retrospectively.

On the contrary in '66 most wiring in houses was rubber insulated.

Most *existing* housing stock in '66 may have had at least some rubber.

There would not have been much new rubber going in by that date as PVC
had been available for quite number of years at that point.

However its a moot point, since new rubber insulated cable does not have
any of the failings that we associate with it now (i.e. its not
installed in its "disintegrating" state). So rubber insulation alone
would not have been a justification for adding a CPC to lighting circuits..

sure it was. The experience with pvc & polythene insulated cables was at that time limited to a decade or so, no-one knew how the cables would survive long term. So precaution againt the widespread serious problem of disintegrating cable looked highly realistic at that time.

The change to pvc was at that time recent-ish.

From the mid 50s

Personally I feel you are flogging a dead horse here. ISTM that
using bell wire or similar in mains installations would have
negative safety implications, and more importantly end up costing
more overall rather than less in real life. It would also make
house wiring less easy to adapt and extend.

The latter point is true, but I don't think people for whom 360w per
circuit is plenty are likely to start installing excessive lighting
levels. 500w halogens are history now. Also as the years roll by
lighting power will drop a lot further as LEDs get much more
efficient.

That will be mostly true, but its not not a justification for a lower
spec of cable than 1.00 mm^2 T&E IMHO, since that is really the minimum
you need for adequate robustness to survive both installation and use.

Lots of houses have had low voltage (ie not mains) wiring installed with much thinner conductors out of reach that has proven reliable over time.

Class I fittings will remain, so the CPC must also be retained.

I'm sure you're already familiar with why that is a nonsequitur.


The trend for ever better insulated and more air tight housing will
increase the requirements for forced ventilation. Combine that with the
rules on bathroom electrics, and it still makes the lighting circuit the
ideal to take power for things like extractors and shaver sockets. So
extra capacity on lighting circuits is not a bad thing.

Sure. Extractor fans are in the region of 20w or so, running part of the time. Shaver sockets ditto, with some running 24/7 charging toothbrushes. Those have no difficulty running on a 360w circuit.


Lastly from an installers point of view, having to carry yet another
size of cable is just more hassle and more money tied up in stock. (some
electricians don't even keep 1.0mm^2 in stock, and opt for 1.5 as their
minimum).

Some see it that way. The reality though is that lots choose to install bellwire in situations where they could have used 1mm or 1.5mm^2 T&E.


NT

On Wednesday, 10 October 2018 12:40:24 UTC+1, John Rumm wrote:
On 10/10/2018 02:44, tabbypurr wrote:
On Tuesday, 9 October 2018 06:35:17 UTC+1, John Rumm wrote:

If you think all BR must be followed in order to have a safe
effective house

I did not say that so move on.

I assume you don't think that,

I would have said so if I did.

in which case you dont' believe all BR
rules are necessary for safety. That was the point being made.

You flip from the specific to the general as if that in some way
supports the specific.

No. But really I think this has been explained more than once already.

For example Part P is a BR "rule" that I believe has little or no
benefit for safety. Earthing lighting circuits however I feel was a very
worthwhile rule change. The fact that I don't believe part P is a good
idea, does not change my opinion on lighting circuits.

I asked you to cite a requirement from BS7671 that you believe is
now redundant and should be removed.

erm... something about lighting earths?

Can you find anyone else to support the idea that we should go back to
unearthed lighting circuits?

I've not looked. Years ago I did find one person that talked of going back to bare iron wire buried in plaster. I looked at that & concluded it was not safe or energy efficient.


The requirement for 9.5mm clearance from plug pin to plug outer edge
is another, albeit from a different BS. It made good sense when pins
were unsleeved, now it's redundant.

Pin clearances are also intended to make it impossible to plug the earth
in upside down, thus opening the shutters. (a reason many 4 way
extension leads are not actually compliant)

it simply does not do that. I'm talking about the required distance from the plug pin to the outer edge of the plastic plug.

And afaik people trying to open shutters to stick bare wires in is another issue relegated to the history books, at least in this country.


NT

On 10/10/2018 12:40, John Rumm wrote:
On 10/10/2018 02:44, wrote:
On Tuesday, 9 October 2018 06:35:17 UTC+1, John RummÂ* wrote:

If you think all BR must be followed in order to have a safe
effective house

I did not say that so move on.

I assume you don't think that,

I would have said so if I did.

in which case you dont' believe all BR
rules are necessary for safety. That was the point being made.

You flip from the specific to the general as if that in some way
supports the specific.

For example Part P is a BR "rule" that I believe has little or no
benefit for safety. Earthing lighting circuits however I feel was a very
worthwhile rule change. The fact that I don't believe part P is a good
idea, does not change my opinion on lighting circuits.

I asked you to cite a requirement from BS7671 that you believe is
now redundant and should be removed.

erm... something about lighting earths?

Can you find anyone else to support the idea that we should go back to
unearthed lighting circuits?

The requirement for 9.5mm clearance from plug pin to plug outer edge
is another, albeit from a different BS. It made good sense when pins
were unsleeved, now it's redundant.

Pin clearances are also intended to make it impossible to plug the earth
in upside down, thus opening the shutters. (a reason many 4 way
extension leads are not actually compliant)

But if you can't do that, how can you plug your shaver in in an
emergency?

SteveW

On 07/10/2018 17:18, Scott wrote:
On Sun, 7 Oct 2018 10:40:00 +0100, "dennis@home"
wrote:

On 07/10/2018 01:34, wrote:
8

Let's settle on 1.5A circuits, permitting upto 360W of lighting.
There are plenty of flats where 2 such lighting circuits are more
than enough. These would replace the current 2x 6A circuits. There is
no extra cost there, just savings.

Why have two circuits?
It can't bee to maintain some lights as that wouldn't work without
battery backup.

If one circuit is faulty and the other is not, some lights would work.
This is the system I have. I have a number of RCBOs so that if one
trips only part of the circuitry is affected.

Doesn't help much though.
You still can't see where you want to.

On Friday, 12 October 2018 21:30:16 UTC+1, dennis@home wrote:
On 07/10/2018 17:18, Scott wrote:
On Sun, 7 Oct 2018 10:40:00 +0100, "dennis@home"
wrote:
On 07/10/2018 01:34, tabbypurr wrote:
8

Let's settle on 1.5A circuits, permitting upto 360W of lighting.
There are plenty of flats where 2 such lighting circuits are more
than enough. These would replace the current 2x 6A circuits. There is
no extra cost there, just savings.

Why have two circuits?
It can't bee to maintain some lights as that wouldn't work without
battery backup.

If one circuit is faulty and the other is not, some lights would work.
This is the system I have. I have a number of RCBOs so that if one
trips only part of the circuitry is affected.

Doesn't help much though.
You still can't see where you want to.

it's standard practice to have at least 2 lighting circuits, idea being the house/flat doesn't descend into complete darkness.


NT