In article ,
Andy Burns wrote:
Jim x321x wrote:

it seems likely to me that more accidents are likely to be caused by
a house's power being unexpectedly cut off due to a RCD misdiagnosing
a fault - especially at night. Elderly an infirm people suddenly
finding themselves walking around in pitch darkness, having to fumble
their way to the CU.

Hence newer installations having at least two RCDs with circuits split
between them, or RCBOs per circuit, so that faults on one circuit affect
fewer (or no) other circuits ... rather than being in pitch darkness you
could get a bit of light from upstairs reaching downstairs, or use
floor/table lights instead of ceiling lights etc.


when I redecorate out stairwell - which is quite an epic, in going put in
an LED fitting in the ceiling; 2Ds only last about 4 years. And - I'm going
to get one with an emergency battery pack.

In article ,
John Rumm wrote:
On 22/06/2015 12:52, Graham. wrote:
On Mon, 22 Jun 2015 10:54:02 +0100, John Rumm
wrote:

On 22/06/2015 09:06, Brian-Gaff wrote:
Well, I've never come across any rented property that has the very latest
fuse box/rcd. But that may just be coincidence. I do not go around checking
everyones houses I visit for rcds, only that a blind person can safely reach
the reset buttons!

Indeed - how would you cope with re-wireing a BS3036 style fuse?

I bet Brian could do that with no problem.
I bet you and I could do it blindfolded it we tried, I never have!

More than likely - but familiarity is the key (and knowing what you are
trying to achieve)

For an unskilled user attempting to identify the failed fuse, locate the
right rating of spare fuse wire, effecting the replacement and then
getting the fuse back into the CU - all in the dark, when you have never
even bother looking at the fuse box in the past, is quite a "big ask"!
Especially when compared to finding which MCB has tripped and flipping
the switch.

I've re spooled plenty of 35mm cassettes using a changing bag, and
loaded various film sizes into the spiral if a developing tank in
complete darkness.

Indeed, same here.

I always have a small pen knife in my pocket with a screwdriver that
would be adequate to rewire a wylex fuse as well. I suspect I am in the
minority though when it comes to preparedness for fuse re-wiring ;-)

In our previous house, which used wired fuses, I always had ready wired
spare fuses to hand.

I'm not suggesting for a moment that a sighted person in the dark
equates to a blind person. That would indeed be arrogant.

I would expect a sighted person in the dark to perform substantially
less well than a blind one.

In article ,
John Rumm wrote:
On 22/06/2015 11:18, Mike Clarke wrote:
On 22/06/2015 11:05, John Rumm wrote:
For your installation with relatively few circuits, the "nicest"
solution would be an "all RCBO" installation. That is one where you use
RCBOs (Residual Current Circuit breaker with Overload protection) - i.e.
a combined MCB and RCD in one. That way you get the best of both worlds
RCD protection on every circuit, but also perfect discrimination - a RCD
trip will only deactivate the circuit with the fault and leave the rest
untouched.

The OP mentioned separate upstairs and downstairs light circuits. It's
possible that the landing light might have "borrowed" the neutral from
downstairs. If so this would need to be rectified before RCBO's could be
used for these two circuits.

Indeed - there are a few potential problems to crawl out of the
woodwork. Probably worth anyone thinking o doing their own CU swap,
having a read through of:

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


I did mine in the late 70s - shortly after we moved in here. The
Electricity Board man came at 8am - first call - to isolate. I suggested
that if he came back at 10am to reconnect, I'd be able to put the kettle on
when he'd finished. He arrived at 10- on the dot - and we had the kettle
going shortly afterwards.

In article ,
wrote:
On Monday, 22 June 2015 11:05:10 UTC+1, John Rumm wrote:
On 22/06/2015 09:56, Jim x321x wrote:
John Rumm wrote in
:

with the existing setup, and I rarely get any inexplicable tripping
of the circuit breakers. As far as I am aware, the old fuse boxes
(even when fuses contained fuse wire) did what they were designed
to do, with no problems.

They did what they were supposed to - and will still do so. The main
thing your current setup lacks is RCD protection.


Thanks to all for the excellently helpful advice.

If I added an RCD covering the entire house (without replacing the
existing fuse box which is already fitted with MCBs, would that
constitute a change to the wiring and thus require building control
notification?

Firstly you don't want a single RCD covering the whole house - that is
a practice that was common during the 15th edition, but is deprecated
now since it offers no "discrimination" in the event of a fault (i.e.
the fault will take out the supply to the whole house, not just the
circuit causing the problem). So many circuits on one RCD are also
more prone to nuisance tripping in the first place.

A single RCD is moderately likely to not even work.

mine has - more than once. But if a single one doesn't work, why should
more than one?

In article , Graham.
wrote:
On 22 Jun 2015 09:05:02 GMT, Jim x321x wrote:

wrote in
:

My house was built and wired in the 1980s and has an old-style fuse
box.

The old fuses have all been repeplaced with cirquit-breakers plugged
into

the fuse sockets.

There can be issues with doing this. Certain designs have gaps between
the MCBs and the cover which would fail modern ingress protection
rating against poking things in. Also the plug-in MCBs sometimes have
a lower breaking capacity than 'conventional' MCBs.

Thanks. I have to admit, that there *is*, arguably an issue with the
plastic cover that originally covered all the fuses. The subsequently-
installed MCBs stick out to far to allow the old cover to be attached.
So I simply left it off. My thinking was that MCBs should probably be
in plain view anyway, because one should be able to access them
quickly. Also, unenlightened tenenats and/or their guests might not
know where the MCbs are located if they were all covered with an opaque
plastic cover that's screwed on.

I suppose I could quite easily modify the cover to make it deep enough
to cover the MCBs without obstructing free flip-switch operation.

BTW, I am in England, so not bound by regional Scottish regulations.

Jim

I used to have a Wylex CU with the old style push button retrofit MCBs.

The face of the cover had been removed so it just formed a frame around
the breakers. I don't remember if the original cover had been modified,
or if it was a special item supplied with the MCBs

If you modify the cover corectly, you are left with a retaining frame which
holds the MCBs in place/

On 22/06/2015 16:57, AL_n wrote:
GB wrote in :

(some will argue that the chances of being killed by an electric shock
in the home in the UK is vanishingly small,

About the same as the chance of winning the lottery (give or take a
factor of 10), yet many people buy lottery tickets.


Given a choice of the two, I'd probably opt for the lotter win.


As all marriages end either in divorce or death, it's amazing that
divorce is not more popular, really.

On Monday, 22 June 2015 15:47:38 UTC+1, John Rumm wrote:
On 22/06/2015 11:37, nt wrote:
On Monday, 22 June 2015 11:05:10 UTC+1, John Rumm wrote:
On 22/06/2015 09:56, Jim x321x wrote:
John Rumm wrote in
:

with the existing setup, and I rarely get any inexplicable
tripping of the circuit breakers. As far as I am aware, the
old fuse boxes (even when fuses contained fuse wire) did
what they were designed to do, with no problems.

They did what they were supposed to - and will still do so.
The main thing your current setup lacks is RCD protection.


Thanks to all for the excellently helpful advice.

If I added an RCD covering the entire house (without replacing
the existing fuse box which is already fitted with MCBs, would
that constitute a change to the wiring and thus require building
control notification?

Firstly you don't want a single RCD covering the whole house -
that is a practice that was common during the 15th edition, but is
deprecated now since it offers no "discrimination" in the event of
a fault (i.e. the fault will take out the supply to the whole
house, not just the circuit causing the problem). So many circuits
on one RCD are also more prone to nuisance tripping in the first
place.

A single RCD is moderately likely to not even work.

True, but the failure rate is not high enough to make that relevant I
would say. (IIRC, 15% of those that have never been tested may fail to
operate when they should - but that sill leaves 75% that will work and
potentially prevent an injury)

What I meant is in some cases you will have no power because the install trips the RCD when powered

Would doing this significantly improve the house's safety rating
in the eyes of, say, a house-purchaser's surveyor?

Only if the purchaser is sufficiently clued up. You may find an
older CU etc would be commented on during a survey, but only in as
much as the surveyor might comment that you could get an
electrical report if concerned.

Surveys say get it checked regardless. A buyer that understands RCDs
- few do - is one that can do the job themselves if they want.

Indeed. Hence my comment about it not being something that will help
"sell" a house.

So if your only reason for the change is to make the house more
saleable, I would not bother. If however you are planning to carry
on living there, then its worth it (IMHO) for other reasons.

Work out the cost & size of risk reduction. Compare with other
options. The benefit per pound is far from top of the list.

If your only criterion is avoidance of death due to electrocution, then
the argument is plausible, since from a statistical point of view you
may as well ignore the risk of death - its low enough to be insignificant.

Death risks all come with injury risks too. Its harder to get injury risks, but if you tabulate them its still not a priority on the table of preventable risks.

None of that however diminishes the effectiveness of a RCD at preventing
shock injury - the occurrences of which are commonplace rather than
rare. (100's K of hospital admissions per year)

How do you conclude that all those are injuries? Last time they wanted to admit me all I needed was tea & aspirin.


NT

"GB" wrote in message
...
On 22/06/2015 16:57, AL_n wrote:
GB wrote in :

(some will argue that the chances of being killed by an electric shock
in the home in the UK is vanishingly small,

About the same as the chance of winning the lottery (give or take a
factor of 10), yet many people buy lottery tickets.


Given a choice of the two, I'd probably opt for the lotter win.


As all marriages end either in divorce or death, it's amazing that divorce
is not more popular, really.


It's a close run race. And there all those thousands of separated but not
divorces couples.


--
Adam

"Andy Burns" wrote in message
o.uk...
wrote:

Andy Burns wrote:

Why does an RCBO require a functional earth, when an RCD doesn't?

The earth connection enables the RCBO to trip even with a lost neutral
connection.

I'm curious why have we ended-up with RCBOs that generally do have an FE
connection and RCDs that generally don't?

Cost?

http://www.eaton.com/Eaton/OurCompan...ses/PCT_255273

But then Eatons RCBO do have an earth lead.
--
Adam

Charles Hope wrote:

when I redecorate out stairwell - which is quite an epic, in going put in
an LED fitting in the ceiling; 2Ds only last about 4 years. And - I'm going
to get one with an emergency battery pack.

The batteries only last about 4 years, if you're trying to avoid having
to access it again, might be worth modifying the wiring so the battery
is e.g. in the loft for easy access ...

"Robin" wrote in message
...
wrote:
For renting you would also need mains powered interlinked smoke
detectors.


In England? I'm not a landlord but several neighbours are and from their
chatter I thought even the new regs which apply from October only required
a smoke alarm on every floor - ie no need for mains powered or interlinked
in a bog standard non-HMO.

What new regs?

BTW I have been suggesting for years that landlords and home owners whilst I
am there for other work and making a mess of a wall whilst installing a
cable for some other job should fork out a litle bit extra for a mains
powered interlinked smoke alarm install.


--
Adam

"Jim x321x" wrote in message
...
Graham. wrote in newsb8goalbvo9ptee6d1njgjotrlv5snr5um@
4ax.com:

I used to have a Wylex CU with the old style push button retrofit
MCBs.

The face of the cover had been removed so it just formed a frame
around the breakers. I don't remember if the original cover had been
modified, or if it was a special item supplied with the MCBs



That sounds like a good idea. That would stop say, a toddler from poking a
knife past the back of the MCB and barbequing himself, wouldn't it? I
might
do that myself. (Cut the face off the cover, and then fix the remaining
part where it was intended to be.)


The cover probably has knockouts on it to do that.

--
Adam

In article , Andy Burns
wrote:
Charles Hope wrote:

when I redecorate out stairwell - which is quite an epic, in going put
in an LED fitting in the ceiling; 2Ds only last about 4 years. And -
I'm going to get one with an emergency battery pack.

The batteries only last about 4 years, if you're trying to avoid having
to access it again, might be worth modifying the wiring so the battery
is e.g. in the loft for easy access ...

a sensible idea - but I'd expect a bit longer life from the btateries.

In article , ARW
wrote:
"Jim x321x" wrote in message
...
Graham. wrote in
newsb8goalbvo9ptee6d1njgjotrlv5snr5um@ 4ax.com:

I used to have a Wylex CU with the old style push button retrofit MCBs.

The face of the cover had been removed so it just formed a frame
around the breakers. I don't remember if the original cover had been
modified, or if it was a special item supplied with the MCBs



That sounds like a good idea. That would stop say, a toddler from
poking a knife past the back of the MCB and barbequing himself,
wouldn't it? I might do that myself. (Cut the face off the cover, and
then fix the remaining part where it was intended to be.)


The cover probably has knockouts on it to do that.

The later ones certainly did

wrote in message
...

Someone going to hospital because they got scared doesn't mean they're
injured.

They would be better off going to the launderette.



--
Adam

wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Smoke alarms would be my number 1 - even if they are just battery powered
ones.

Number 2 would be to have an escape plan if there was a fire and the smokes
sounded.

And number 3 for safety in the home IMHO is RCD protection at the CU (at
least for the socket circuits).

--
Adam

"Graham." wrote in message
...


I don't see that as a failure rate, just additional work to be done to
rectify the earth leakage faults that may have unknowingly have been
present for decades.



What is wrong with rectifying a fault?


--
Adam

On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population. Expert concensus is half these deaths are readily avoidable by healthier eating, not smoking & some exercise. These are the number 1 priorities.

The rest of the list is different here versus US. Traffic accidents, septicaemia & medical errors featuer highly here, all of which are fairly straightforward to reduce.

Accidents: diy causes no lack of those, so getting informed re power tool risks etc.

Diabetes risk can be reduced by avoiding high sugar diet.


Smoke alarms would be my number 1 - even if they are just battery powered
ones.

There were 1000 deaths a year in house fires before they became the norm, now its about 200.


Number 2 would be to have an escape plan if there was a fire and the smokes
sounded.

And number 3 for safety in the home IMHO is RCD protection at the CU (at
least for the socket circuits).

20 odd deaths a year there.

I think we suffer warning fatigue. 'Yes I know I've heard it 1000 times but don't know how to' sort of thing. Its good to look at diy specific risks but I think its good to slot them into the big picture.


NT

wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse
box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by healthier
eating, not smoking & some exercise. These are the number 1 priorities.

A lifesyle choice is not relevant to diy or general risks in the house.


--
Adam

ARW wrote:
"Robin" wrote in message
...
wrote:
For renting you would also need mains powered interlinked smoke
detectors.


In England? I'm not a landlord but several neighbours are and from
their chatter I thought even the new regs which apply from October
only required a smoke alarm on every floor - ie no need for mains
powered or interlinked in a bog standard non-HMO.

What new regs?

draft at present:
http://www.legislation.gov.uk/ukdsi/...33439/contents

summary from draft ex.memo:

"2.1 These Regulations require landlords in the private rented sector in
England to ensure that a smoke alarm is equipped on every storey of
their rented dwelling when occupied under a tenancy, and that a carbon
monoxide alarm is equipped in any room which contains a solid fuel
burning combustion appliance. They also require landlords to ensure that
such alarms are in proper working order at the start of a new tenancy.
In addition, the Regulations amend the conditions which must be included
in a licence under Part 2 or 3 of the Housing Act 2004 ("the 2004 Act")
in respect of smoke and carbon monoxide alarms."

Landlords responsible for testing alarms at start of each tenancy but
AIUI *not* periodically thereafter.

BTW I have been suggesting for years that landlords and home owners
whilst I am there for other work and making a mess of a wall whilst
installing a cable for some other job should fork out a litle bit
extra for a mains powered interlinked smoke alarm install.

No quarrel from me. I installed a possibly absurd 7 smoke/heat in this
3-bed terrace (including one in the loft) on the basis the earlier the
warning of fire behind a closed door the better the chance of getting
out. Just not what the draft regs require for run-of-the-mill lets.

--
Robin
reply to address is (meant to be) valid

On Monday, 22 June 2015 18:54:49 UTC+1, GB wrote:
As all marriages end either in divorce or death, it's amazing that
divorce is not more popular, really.

But both people get divorced; most of the time only one partner gets widow(er)ed.

So you have a 50% chance of getting less than half the money with divorce vs a 50% chance of getting all the money if you live or not caring if you die.

Should I sell my RCDs on ebay and buy lottery tickets with the money?

Owain

On 22/06/2015 19:28, wrote:
On Monday, 22 June 2015 15:47:38 UTC+1, John Rumm wrote:
On 22/06/2015 11:37, nt wrote:
On Monday, 22 June 2015 11:05:10 UTC+1, John Rumm wrote:
On 22/06/2015 09:56, Jim x321x wrote:
John Rumm wrote in
:

with the existing setup, and I rarely get any
inexplicable tripping of the circuit breakers. As far as
I am aware, the old fuse boxes (even when fuses contained
fuse wire) did what they were designed to do, with no
problems.

They did what they were supposed to - and will still do
so. The main thing your current setup lacks is RCD
protection.


Thanks to all for the excellently helpful advice.

If I added an RCD covering the entire house (without
replacing the existing fuse box which is already fitted with
MCBs, would that constitute a change to the wiring and thus
require building control notification?

Firstly you don't want a single RCD covering the whole house -
that is a practice that was common during the 15th edition, but
is deprecated now since it offers no "discrimination" in the
event of a fault (i.e. the fault will take out the supply to
the whole house, not just the circuit causing the problem). So
many circuits on one RCD are also more prone to nuisance
tripping in the first place.

A single RCD is moderately likely to not even work.

True, but the failure rate is not high enough to make that relevant
I would say. (IIRC, 15% of those that have never been tested may
fail to operate when they should - but that sill leaves 75% that
will work and potentially prevent an injury)

What I meant is in some cases you will have no power because the
install trips the RCD when powered

That's hardly an ongoing problem... it means you have either a fault, or
too much combined leakage. Both fixable, neither relevant since no one
will be fitting a single whole house RCD anyway.

So if your only reason for the change is to make the house
more saleable, I would not bother. If however you are planning
to carry on living there, then its worth it (IMHO) for other
reasons.

Work out the cost & size of risk reduction. Compare with other
options. The benefit per pound is far from top of the list.

If your only criterion is avoidance of death due to electrocution,
then the argument is plausible, since from a statistical point of
view you may as well ignore the risk of death - its low enough to
be insignificant.

Death risks all come with injury risks too. Its harder to get injury
risks, but if you tabulate them its still not a priority on the table
of preventable risks.

That is nonsense, as you are well aware.

None of that however diminishes the effectiveness of a RCD at
preventing shock injury - the occurrences of which are commonplace
rather than rare. (100's K of hospital admissions per year)

How do you conclude that all those are injuries?

These are the cases where either an ambulance was called or someone went
/ was taken to A&E.

They will include the full range of injuries from a mild burn - no real
treatment required, to life changing and permanent injury / disfigurement.

I have posted links to the stats before. Even if we are only talking
about 20K serious injuries, that is ample justification for spending a
couple of hundred quid on your home for your family's protection in my
view.

If we apply your logic, there are only 10s of K serious car accident
injuries a year, so why waste money on seatbelts or MoT tests?

Last time they
wanted to admit me all I needed was tea & aspirin.


--
Cheers,

John.

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

On Monday, 22 June 2015 22:53:32 UTC+1, John Rumm wrote:
What I meant is in some cases you will have no power because the
install trips the RCD when powered
That's hardly an ongoing problem... it means you have either a fault, or
too much combined leakage. Both fixable, neither relevant since no one
will be fitting a single whole house RCD anyway.

And of course we do some basic tests before we reconnect circuits (or even better, before we disconnect the old board) don't we...?

I have posted links to the stats before. Even if we are only talking
about 20K serious injuries, that is ample justification for spending a
couple of hundred quid on your home for your family's protection in my
view.

Having cut through a live cable protected by 30A fuse wire (which didn't blow) and seen the resulting fireworks (and hole in my cutters) I'm quite happy to have MCBs and RCDs. A new dual-RCD consumer unit is only about £50 now.

Owain

wrote:
On Monday, 22 June 2015 22:53:32 UTC+1, John Rumm wrote:
What I meant is in some cases you will have no power because the
install trips the RCD when powered
That's hardly an ongoing problem... it means you have either a
fault, or too much combined leakage. Both fixable, neither relevant
since no one will be fitting a single whole house RCD anyway.

And of course we do some basic tests before we reconnect circuits (or
even better, before we disconnect the old board) don't we...?

I have posted links to the stats before. Even if we are only talking
about 20K serious injuries, that is ample justification for spending
a couple of hundred quid on your home for your family's protection
in my view.

Having cut through a live cable protected by 30A fuse wire (which
didn't blow) and seen the resulting fireworks (and hole in my
cutters) I'm quite happy to have MCBs and RCDs. A new dual-RCD
consumer unit is only about £50 now.

And what would you estimate as the cost of fitting it plus putting right
whatever the installer decides needs to be done before re-energising? I
ask as it's unlikely the OP would have asked the questions he did if he
were competent to DIY a change of CU.


--
Robin
reply to address is (meant to be) valid

"ARW" wrote in news:mm9lev$mlf$1@dont-
email.me:

do that myself. (Cut the face off the cover, and then fix the remaining
part where it was intended to be.)


The cover probably has knockouts on it to do that.

--
Adam


I just looked. It DOES!! (I could KISS you! I cut along the groove with
a stanley knife and hey-presto, I now have the cover back on, minus the
face. Now it all looks so much more respectable!

It's as if Wylex anticipated the coming of the MCB!

Jim

On 23/06/2015 10:50, Robin wrote:
wrote:
On Monday, 22 June 2015 22:53:32 UTC+1, John Rumm wrote:
What I meant is in some cases you will have no power because the
install trips the RCD when powered
That's hardly an ongoing problem... it means you have either a
fault, or too much combined leakage. Both fixable, neither relevant
since no one will be fitting a single whole house RCD anyway.

And of course we do some basic tests before we reconnect circuits (or
even better, before we disconnect the old board) don't we...?

I have posted links to the stats before. Even if we are only talking
about 20K serious injuries, that is ample justification for spending
a couple of hundred quid on your home for your family's protection
in my view.

Having cut through a live cable protected by 30A fuse wire (which
didn't blow) and seen the resulting fireworks (and hole in my
cutters) I'm quite happy to have MCBs and RCDs. A new dual-RCD
consumer unit is only about £50 now.

And what would you estimate as the cost of fitting it plus putting right
whatever the installer decides needs to be done before re-energising? I
ask as it's unlikely the OP would have asked the questions he did if he
were competent to DIY a change of CU.

I guess that depends on the size of the CU and the location in the
country. I would have thought £150 - £200 would be the minimum including
parts.


--
Cheers,

John.

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

On 22/06/2015 20:06, Charles Hope wrote:
In article , Andy Burns
wrote:
Charles Hope wrote:

when I redecorate out stairwell - which is quite an epic, in going put
in an LED fitting in the ceiling; 2Ds only last about 4 years. And -
I'm going to get one with an emergency battery pack.

The batteries only last about 4 years, if you're trying to avoid having
to access it again, might be worth modifying the wiring so the battery
is e.g. in the loft for easy access ...

a sensible idea - but I'd expect a bit longer life from the btateries.

My emergency lights have been in seven or eight years so far - still on
the same batteries.


--
Cheers,

John.

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

On Monday, 22 June 2015 21:51:09 UTC+1, ARW wrote:
nt wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse
box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by healthier
eating, not smoking & some exercise. These are the number 1 priorities.

A lifesyle choice is not relevant to diy or general risks in the house.

Risks and the cost of avoiding them are 100% relevant to risks and the cost of avoiding them

On Monday, 22 June 2015 22:53:32 UTC+1, John Rumm wrote:
On 22/06/2015 19:28, nt wrote:
On Monday, 22 June 2015 15:47:38 UTC+1, John Rumm wrote:
On 22/06/2015 11:37, nt wrote:
On Monday, 22 June 2015 11:05:10 UTC+1, John Rumm wrote:
On 22/06/2015 09:56, Jim x321x wrote:
John Rumm wrote in
:

A single RCD is moderately likely to not even work.

True, but the failure rate is not high enough to make that relevant
I would say. (IIRC, 15% of those that have never been tested may
fail to operate when they should - but that sill leaves 75% that
will work and potentially prevent an injury)

What I meant is in some cases you will have no power because the
install trips the RCD when powered

That's hardly an ongoing problem...

its an issue with the op's plan. For an op with limited understanding it is also liable to be an ongoing problem, fwiw

it means you have either a fault, or
too much combined leakage. Both fixable,

by the op? I dont assume so

neither relevant since no one
will be fitting a single whole house RCD anyway.

aiui the op was considering it

So if your only reason for the change is to make the house
more saleable, I would not bother. If however you are planning
to carry on living there, then its worth it (IMHO) for other
reasons.

Work out the cost & size of risk reduction. Compare with other
options. The benefit per pound is far from top of the list.

If your only criterion is avoidance of death due to electrocution,
then the argument is plausible, since from a statistical point of
view you may as well ignore the risk of death - its low enough to
be insignificant.

Death risks all come with injury risks too. Its harder to get injury
risks, but if you tabulate them its still not a priority on the table
of preventable risks.

That is nonsense, as you are well aware.

really? do tell

None of that however diminishes the effectiveness of a RCD at
preventing shock injury - the occurrences of which are commonplace
rather than rare. (100's K of hospital admissions per year)

How do you conclude that all those are injuries?

These are the cases where either an ambulance was called or someone went
/ was taken to A&E.

They will include the full range of injuries from a mild burn - no real
treatment required, to life changing and permanent injury / disfigurement.

so obviously not the number of injuries. Maybe you're not familiar with how the nhs works on this point.


I have posted links to the stats before. Even if we are only talking
about 20K serious injuries, that is ample justification for spending a
couple of hundred quid on your home for your family's protection in my
view.

If we apply your logic, there are only 10s of K serious car accident
injuries a year, so why waste money on seatbelts or MoT tests?

that has nothing to do with what I said

Last time they
wanted to admit me all I needed was tea & aspirin.


NT

On 22/06/2015 22:32, wrote:

Should I sell my RCDs on ebay and buy lottery tickets with the money?

What a splendid question!

Assuming that you don't replace the RCDs:

About 1 in 1000 : You'll win some amount, probably modest, and never be
electrocuted. You'll be a winner overall.

About 999 in 1000: You'll win nothing, and never be electrocuted. You'll
neither win nor lose.

About 1 in 1,000,000 : You'll be electrocuted, in which case what you
have won won't matter, and for some brief period of agony you'll regret
your decision.

On 23/06/2015 10:50, Robin wrote:
wrote:
On Monday, 22 June 2015 22:53:32 UTC+1, John Rumm wrote:
What I meant is in some cases you will have no power because the
install trips the RCD when powered
That's hardly an ongoing problem... it means you have either a
fault, or too much combined leakage. Both fixable, neither relevant
since no one will be fitting a single whole house RCD anyway.

And of course we do some basic tests before we reconnect circuits (or
even better, before we disconnect the old board) don't we...?

I have posted links to the stats before. Even if we are only talking
about 20K serious injuries, that is ample justification for spending
a couple of hundred quid on your home for your family's protection
in my view.

Having cut through a live cable protected by 30A fuse wire (which
didn't blow) and seen the resulting fireworks (and hole in my
cutters) I'm quite happy to have MCBs and RCDs. A new dual-RCD
consumer unit is only about £50 now.

And what would you estimate as the cost of fitting it plus putting right
whatever the installer decides needs to be done before re-energising? I
ask as it's unlikely the OP would have asked the questions he did if he
were competent to DIY a change of CU.

Probably depends on the area of the country... I would have thought a
straight swap would start at £200 - £300.


--
Cheers,

John.

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

On 22/06/2015 21:51, ARW wrote:
wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style
fuse box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down
the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by
healthier eating, not smoking & some exercise. These are the number 1
priorities.

A lifesyle choice is not relevant to diy or general risks in the house.

Not only that, as had been pointed out at various times, one insures
against losses that one can't otherwise replace. I would include wife
and children in that category, so a one off premium of a couple of
hundred for smoke alarms and RCDs sounds like a very worthwhile investment.


--
Cheers,

John.

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

On 23/06/2015 13:07, wrote:
On Monday, 22 June 2015 21:51:09 UTC+1, ARW wrote:
nt wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse
box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by healthier
eating, not smoking & some exercise. These are the number 1 priorities.

A lifesyle choice is not relevant to diy or general risks in the house.

Risks and the cost of avoiding them are 100% relevant to risks and the cost of avoiding them

Let see if we can avoid the great throng of straw men wandering this way...


--
Cheers,

John.

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

On 23/06/2015 14:43, GB wrote:
On 22/06/2015 22:32, wrote:

Should I sell my RCDs on ebay and buy lottery tickets with the money?

What a splendid question!

Assuming that you don't replace the RCDs:

About 1 in 1000 : You'll win some amount, probably modest, and never be
electrocuted. You'll be a winner overall.

About 999 in 1000: You'll win nothing, and never be electrocuted. You'll
neither win nor lose.

About 1 in 1,000,000 : You'll be electrocuted, in which case what you
have won won't matter, and for some brief period of agony you'll regret
your decision.

Remember you probably only play the lottery once or twice a week... you
use electricity in the home many times every day.

--
Cheers,

John.

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

John Rumm wrote:

Probably depends on the area of the country... I would have thought a
straight swap would start at £200 - £300.

I think that'd be v much the bottom of the range in London now the trade
has picked up again.

And then there are the "extras" like one place near here told they
needed *separate* main bonding for incoming gas and water. There was
10mm looped continuously MET-water-gas but the nice man even showed them
the picture in his little book to prove they needed to be separate

--
Robin
reply to address is (meant to be) valid

Jim x321x a écrit :
Elderly an infirm people suddenly finding themselves walking around
in pitch darkness, having to fumble their way to the CU. Surely that would
be a dangersous situation for some, no? It would be interesting to know the
statistics regarding how many people have suffered injury that way, vs. how
many have suffered injury due to a fuse failing to blow, or a MCB failing
to trip.

Indeed..

In the 1970's, I was with a crew working in a massive basement, several
hundreds of feet in size, pipes, obstructions, sumps and trip hazards
everywhere - installing massive pipes and pumps for a pumping station.
Total black out, even in full daylight outside. The site agent had
heard of RCD's and insisted everything be protected by a single RCD on
the 240v, which also supplied the 110v site transformer, which fed the
only lighting in the basement.

Every 10 minutes to an hour the RCD would trip out, leaving everyone in
complete darkness down there. Try explaining to a site agaent that the
risk of electrocution on a 55v to ground system is considerably less
than the risk of someone being seriously injured, with it tripping so
regularly leaving everyone in such circumstances in complete darkness,
feeling for the ladder to climb out.

On Tuesday, 23 June 2015 17:20:21 UTC+1, John Rumm wrote:
On 22/06/2015 21:51, ARW wrote:
nt wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style
fuse box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to people
doing idiotic things. RCDs reduce the risk. This is a long way down
the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by
healthier eating, not smoking & some exercise. These are the number 1
priorities.

A lifesyle choice is not relevant to diy or general risks in the house.

Not only that, as had been pointed out at various times, one insures
against losses that one can't otherwise replace. I would include wife
and children in that category, so a one off premium of a couple of
hundred for smoke alarms and RCDs sounds like a very worthwhile investment.

2 different issues lumped together, and a non sequitur. Maybe some of us just aren't into risk assessment.


NT

wrote in message
...
On Monday, 22 June 2015 21:51:09 UTC+1, ARW wrote:
nt wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse
box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to
people
doing idiotic things. RCDs reduce the risk. This is a long way down
the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by
healthier
eating, not smoking & some exercise. These are the number 1 priorities.

A lifesyle choice is not relevant to diy or general risks in the house.

Risks and the cost of avoiding them are 100% relevant to risks and the
cost of avoiding them


I do not consider telling a fat ******* to eat less less food to be DIY
related.

Fitting a lock on a fridge is DIY related.

--
Adam

On Tuesday, 23 June 2015 22:58:13 UTC+1, ARW wrote:
nt wrote in message
...
On Monday, 22 June 2015 21:51:09 UTC+1, ARW wrote:
nt wrote in message
...
On Monday, 22 June 2015 20:40:40 UTC+1, ARW wrote:
nt wrote in message
...
On Sunday, 21 June 2015 23:20:25 UTC+1, Jim x321x wrote:
My house was built and wired in the 1980s and has an old-style fuse
box.


Is there really a significant
increase in electrical safety with the modern RCD units?

There are 20 something deaths from shock a year, mostly due to
people
doing idiotic things. RCDs reduce the risk. This is a long way down
the
list of Risky Things in Life, so is the oposite of a priority.


So what what would you prioritize?

Look at the top 10 killers.
http://www.cdc.gov/nchs/fastats/lead...s-of-death.htm

The top 2 are heart disease & cancer. They kill half the population.
Expert concensus is half these deaths are readily avoidable by
healthier
eating, not smoking & some exercise. These are the number 1 priorities.

A lifesyle choice is not relevant to diy or general risks in the house..

Risks and the cost of avoiding them are 100% relevant to risks and the
cost of avoiding them


I do not consider telling a fat ******* to eat less less food to be DIY
related.

Fitting a lock on a fridge is DIY related.

So what. A DIY safety improvement is only worth doing if its not way down the list of what one can usefully do. RCDs have their upside, but at 20 something deaths versus over 100,000 a year they're just not the priority. Eat healthily, learn advanced driving, treat infections promptly & vigilantly, take proper precautions with power tools and so on. If all those plus dozens of others are done, then an RCD becomes worthwhile.

Funny how so many think electricity & gas a big risk, when really the most dangerous things we do are food shopping & smoking.


NT

Harry Bloomfield wrote in
:


Every 10 minutes to an hour the RCD would trip out, leaving everyone
in complete darkness down there. Try explaining to a site agaent that
the risk of electrocution on a 55v to ground system is considerably
less than the risk of someone being seriously injured, with it
tripping so regularly leaving everyone in such circumstances in
complete darkness, feeling for the ladder to climb out.


Sounds like a classic case of the 'Peter Pricipal' at play!

Can someone tell me if I can get away with a 45A MCB for a 8.5kW shower
without endagering life and limb? The manual tells me to use a 40A one, but
I just happen to have a 45A one. I ask, because those things aren't cheap.

Jim