Updating electrics. NICEIC - complete rewire.

[JohnW2]

Their main problem is that the protection they provide against overloads and short circuits is intended for the cables only. They do very little to protect people.

That's obviously true up to a point, although there are still plenty of Class I items (hence with "earthed metal casing") in most homes, in relation to which a fuse/MCB would appreciably "protect people".

That is why devices like RCDs, AFDDs and surge protection are required.

Fair enough in relation to RCDs, but do you really think that 'surge protection', or even AFDDs actually significantly 'protect people'?

As always, I'm not really being critical but merely trying to put your personal views/opinions into some perspective.

Kind Regards, John

 

[SUNRAY]

That looks similar to mine except not mcb...and it is interesting as the last electrician said he hadnt seen one in 20 years! (wylex)

There are loads of them out there, I reckon I've replaced (mostly assisted with) a dozen this year in rental properties.

I might put this off 6 months and save some cash so that a rewire if needed will not cause hardship, from what i have read here, i am not taking massive risks having a wylex for another six months- and logic suggests something that has caused me no issues in 20 years (1 fuse replaced, i called out an electrician to do it) is not going to suddenly become deadly.

It's not really the fact it's caused no problem for that time, the thing to look at is what other problems are there that an up to date CU will save you from.
such as from jan 2019:
the extension lead

in

Why I hate domestics

As a little follow up, the OP has been sorted since Christmas using an adaptable box/din/terminals. The 3c&e with a black sleeve was used as a neutral and been corrected. The 1mm radial has been changed to 2.5 and the whole place has had a good going over, adding all the marker sleeves. We now...

www.diynot.com

The tenant moved in last week and complained that one of the sockets is faulty. I checked it yesterday and gave it a clean bill of health.
Called back today as the rcd operated when they used Henry but the socket a few feet away was OK (a 15A radial, labelled lounge heater, on the non rcd half of the board as opposed to the ring). I checked both sockets dead and alive.
Then tried Henry with no problem.
"It tripped when my husband Hoovered the car"
I asked for the extension lead to check
"Oh there's nothing wrong with that, we've had it for years.":View attachment 156490

Thanks for all your patience, it really is appreciated

It's wha we're here for

 

[trwils]

There are loads of them out there, I reckon I've replaced (mostly assisted with) a dozen this year in rental properties.

It's not really the fact it's caused no problem for that time, the thing to look at is what other problems are there that an up to date CU will save you from.
such as from jan 2019:
the extension leadView attachment 276638 in

Why I hate domestics

As a little follow up, the OP has been sorted since Christmas using an adaptable box/din/terminals. The 3c&e with a black sleeve was used as a neutral and been corrected. The 1mm radial has been changed to 2.5 and the whole place has had a good going over, adding all the marker sleeves. We now...

www.diynot.com

The tenant moved in last week and complained that one of the sockets is faulty. I checked it yesterday and gave it a clean bill of health.
Called back today as the rcd operated when they used Henry but the socket a few feet away was OK (a 15A radial, labelled lounge heater, on the non rcd half of the board as opposed to the ring). I checked both sockets dead and alive.
Then tried Henry with no problem.
"It tripped when my husband Hoovered the car"
I asked for the extension lead to check
"Oh there's nothing wrong with that, we've had it for years.":View attachment 156490

It's wha we're here for

Wow, so- in simple terms modern CU give improved protection against electrocuting myself with faulty equipment / exposed wires etc.

 

[JohnW2]

Wow, so- in simple terms modern CU give improved protection against electrocuting myself with faulty equipment / exposed wires etc.

The RCD in a modern CU gives you some degree of such protection (but by no means total protection) - but, as I implied, I don't think that really applies to any of the other devices which you might find in a 'modern CU'.

Kind Regards, John

 

[SUNRAY]

Wow, so- in simple terms modern CU give improved protection against electrocuting myself with faulty equipment / exposed wires etc.

It cannot stop you getting an electric shock, which I promise hurts, but the design of RCD systems is to limit the duration of a live to earth shock to a level that is should not be fatal.
Nothing in a CU can prevent a live to neutral shock and its effect.

 

[thomp1983]

If your willing to wait 6 - 12 months can the second electrician not fit you in for the job?

 

[JohnW2]

It cannot stop you getting an electric shock, which I promise hurts, but the design of RCD systems is to limit the duration of a live to earth shock to a level that is should not be fatal.

Indeed. The OP asked about 'electrocution' (which theoretically should relate to fatal event) and, as I said, and RCD can provide some, but not 'total' protection against that - not the least because, as you go on to say ...

Nothing in a CU can prevent a live to neutral shock and its effect.

Another issue is that the effects of an electric shock on a human body are dependent on the energy delivered, which (for a person of given body resistance) depends upon the combination of the magnitude and duration of the current through them (see *** below), whereas as RCD can limit the duration, but not the magnitude of that current. Hence, if the current is very high (e.g. when skin is very wet), the limitation of duration by the RCD of the duration may not be enough to prevent serious effects (even including death).

[ *** as an illustration of that, in the case of a defibrillator (the intention of which is deliberately to have a major effect on the heart), the output is not chosen (and expressed) in terms of volts, mA, watts or milliseconds but, rather, Joules - more familiar to electricians as "Watt-seconds", 3,600,000 of which equate to 1 kWh. Typical shocks to adults from an external defibrillator (typically 120 - 360 Joules) therefore amount to 0.000033 - 0.0001 kWh (extremely small amounts of energy by electricians' standards!). Even at today's electricity prices, it would cost almost nothing to kill someone with electricity ]

However, returning to the original point I made, whilst RCDs do offer the (limited) protection we are discussing, without undertaking an almost ridiculous degree of 'barrel-scraping', I really don't see how SPDs (or even AFDDs) can offer any appreciable "personal protection", and I personally think it wrong for people to be 'frightened into believing' that such devices are necessary for their "personal protection".

Kind Regards, John

 

[SUNRAY]

...However, returning to the original point I made, whilst RCDs do offer the (limited) protection we are discussing, without undertaking an almost ridiculous degree of 'barrel-scraping', I really don't see how SPDs (or even AFDDs) can offer any appreciable "personal protection", and I personally think it wrong for people to be 'frightened into believing' that such devices are necessary for their "personal protection".

Kind Regards, John

If I'm honest I struggle to see what effect a SPD can be expected to offer to anything as the way we install them is likely to negate a large amount of the protection they are theroetically capable of. They certainly cannot offer any personal protection to animal life.

 

[JohnW2]

If I'm honest I struggle to see what effect a SPD can be expected to offer to anything as the way we install them is likely to negate a large amount of the protection they are theroetically capable of.

I don't disagree with that but, even if the were installed so as to optimise 'the protection they are theoretically capable of", then ....

They certainly cannot offer any personal protection to animal life.

... and I really don't feel much differently about AFDDs, do you?

As I often observe, I think that some of those now 'promoting' SPDs (some implying that they are 'required') probably need to reflect on the fact that it's not very long ago that they were (I think probably rightly) describing anything to do with "surge/spike protection" as "snake oil"!

... and as to where AFDDs came from, I really don't know. What is the problem that sufficiently needs a solution to justify their widespread, or universal, deployment?? Any ideas?

Kind Regards, John

 

[flameport]

What is the problem that sufficiently needs a solution to justify their widespread, or universal, deployment?? Any ideas?

Substandard manufacturing by white goods manufacturers and others.

 

[JohnW2]

Substandard manufacturing by white goods manufacturers and others.

Considerably more 'substandard manufacturing' than in the past (despite regulation which has generally tended to increase over time)?

In any event, in what way does an AFDD provide appreciable "personal protection" (protection against bodily harm to human beings) against whatever might be the consequences of such 'substandard manufacture'?

Kind Regards, John

 

[flameport]

AFDD provide appreciable "personal protection"

They don't. They prevent fires, which old rewireable fuses do not.

 

[JohnW2]

They don't. They prevent fires, which old rewireable fuses do not.

Quite so (but I do have to wonder how many significant fires they could/would prevent).

Don't forget that what started all this was my response to..

They are no more dangerous today than when they were installed 40/50/60 years ago. ... Their main problem is that the protection they provide against overloads and short circuits is intended for the cables only. They do very little to protect people.
....
They were appropriate for the time, decades ago when ......... Today most items are class II / double insulated and although that should make them safer, when items do become damaged it's a flimsy plastic case between you and live parts. .... Homes have vastly more electrical equipment in them, substantial amounts of it is portable, and plenty is used outside often. Many of them simply didn't exist 40 years ago.
That is why devices like RCDs, AFDDs and surge protection are required.

... which I felt (and still do feel) was potentially misleading.

Kind Regards, John

 

[flameport]

Anything can be misleading if you pick and choose which words you want to read.

Real life is not a legal document written by 100 high priced lawyers.
Neither is BS7671 or any other standard.

 

[JohnW2]

Anything can be misleading if you pick and choose which words you want to read.

It can indeed - but I highlighted bits to indicate how I suspect many people probably read (subconsciously 'chose to read') your words.

At least to me (and I imagine many others), your point seemed to be that CUs with only fuses do relatively little to "protect people" and, whilst that was 'appropriate decades ago', for reasons you list it is no longer appropriate today - and that this is why "devices like RCDs, AFDDs and surge protection are [now] required" - and I personally read that (in the context of the rest of the message) as meaning "required to protect people".

As you imply, others may have read it differently, and therefore disagree with me.

Real life is not a legal document written by 100 high priced lawyers. Neither is BS7671 or any other standard.

Very true - which is why I personally believe that decisions./advice should be based on solid evidence, rational argument and 'risk assessment', rather than in terms of current 'fashions' (even when they are adopted by things such as BS7671). However, again that is just my view, and some others will undoubtedly disagree.

Kind Regards, John