Ring Main at Consumer unit

Andy is suggesting that ANYTHING which is not compliant is at least a C2 for some reason

I most certainly am not. That is a gross misrepresentation.


  - Andy.

I think that is the way your post reads Andy. I am not trying to misrepresent you, but you said in simplified terms "because it doesn't comply with.... it is a C2". The implication of that is anything non-compliant is a C2, even if you don't mean it that way.


The problem I am trying to discuss here is the very complex one of assessing the "level of danger". Above someone said, again simplified, "given the right conditions, this could go bang". Is an Earth fault inherently dangerous? I think not, this is exactly why we have CPDs of various kinds, Zs Values within range, and all the other things. This kind of fault presents negligible fire danger, so ADS itself is dangerous now? I think not. In fact, given a bit more abuse a sheathed cable suffers from the same risk, and we virtually never see that fault it in real installations.


Some might say that using electricity at all is "dangerous" because there is a tiny risk of death. This is equally not borne out in practice because the number of deaths is tiny. Therefore we must make a reasonable assessment of the level of danger. This is where there is a problem, it is entirely to the Inspectors gain to magnify this risk, particularly if he is going to "repair" the defects he finds and therefore needs to convince the customer that the work is necessary.


You may have noticed the use of "risk" is present in the current Covid 19 scare. The words "safety or safe" is in every sentence from the Government or media. The risk is grossly overstated, and there is no cost/benefit analysis of the actions. About 1600 people die in the UK every day. Looking at the ONS statistics shows something very interesting, that after the first peak (actually old peoples home scandal) average death numbers have been less than the last 5 years for many weeks, the interval of data. Therefore I suggest that Covid is making the risk to most of us less! The real cause is not that, it is that a lot of old, ill or unlucky people died last year, rather than this year, which has slightly modified the statistics, the average age at death having changed very little.


Understanding risk is completely tied up with statistical outcomes. It is extremely easy to tell lies with badly produced statistics, or measuring the "wrong" or unsound data. It is done all the time, for many reasons, some deliberate some due to error or misunderstanding. The problem with statistics is also one of whether the result is "statistically significant" or not, a mathematical construction as to the likelihood of the statistic being true or not. With very low rates of outcome, the actual number change say from 4 a year to 10 a year has no value, although it is often posted as though it does.


With a very large number of installations and a very low number of deaths the statistics say that "on average they are very safe, whatever defects may be present". Your reply may be "but this one might be the unlucky one", it could but the level of risk is tiny compared to other causes of death, the roads for example. As we exist in this "dangerous" environment where we will die sometime, a consequence of life, risk should be comparative, not absolute, as otherwise, life might be staying in bed. Note that something like 3/4 of people die in bed, so statistically, that might not be a good idea, however safe it sounds!


Back to the OP, consider the potential risk, it is exceptionally tiny, did anyone die from touching primary insulation like this in the last 50 years, as long as it was in good condition? The answer to that is almost certainly NO, so it cannot be a C2. It is simply not statistically potentially dangerous.

You can conduct an in-service inspection of fixed wiring, with Report, to BS7671, or

- Clients' requirements permitting - to your own standard.


I suppose this alternative could be as simple as a simple dead count of bodies or incidence of fire, though you may run into a little difficulty in a Crematorium or Graveyard. You could get a waver; get them to sign something before they snuff it.


My little picture again. Actually, this is the one of the better bits of this Industrial:



















The cable management is earthed, sort of; more just by chance. The vast majority of the circuits never had a separate CPC, due to age of some of it.

The suspended ceiling is mostly isolated metal work; mostly due to the unearthed light fittings.

As I said, this is the good bit. You do not want to see the really bad bits.

But there are no dead bodies. I did ask.

There was an EICR on this Industrial 6 years ago.

Resounding Satisfactory, no observations. They could have at least said "no evidence of dead bodies, its a good un". Gave age of installation as 8 years.

It is not credible that things have changed in six years, but of course you will have difficulty in proving a negative.

It was a "BS7671 EICR", but the Inspector obviously applied their somewhat questionable "bang test engineering judgement". 

Is this a good thing?

Surely you can see the danger of an outside influence causing a fault here from say a vacuum cleaner falling onto the cable and causing a live to earth fault on a cable protected by possibly a 100 amp fuse. Perhaps someone’s decided to hang an umbrella on the tails (not unknown). Strangely the NICEIC, NAPIT, Electrical Safety First and probably 99% of electricians would code this C2 due to the potential danger. As I said earlier there’s two layers of protection missing here and it needs putting right. I’ll stick with C2 others can code or advise as they wish but on my EICRs with my signature it’s a C2.

I like
" - Clients' requirements permitting - to your own standard.

I suppose this alternative could be as simple as a simple dead count of bodies or incidence of fire, though you may run into a little difficulty in a Crematorium or Graveyard. "  Unexpected  dead bodies then I suppose..


Good to see the twizzle of g/y used as a fire proof support to the top left to stop cables dropping out of the trunking during a fire thus meeting AMD3 of the 17th, perhaps more in spirit than in substance.


 I presume the trunking lids are removed as either


1 they are too full and do not shut or

2 if you force the cable in it overheats.

or both ?


I'm sure it is fine in the sense of no live parts exposed yet and not a C1, and it looks quite like some stuff I have seen recently, but someone should have been shot when they went and left it like that in the 1st place.

(to be moderate...)

Anyone who can pass that as satisfactory without at least a C3 is dragging the business into disrepute.  There may well be factors like sharp edges and snag hazards that make damage to the thinner singles far more credible, then it is quickly into  C2 territory.

In many ways it is more dangerous than that fuseboard....

M.

No other problems and a C3 is probably indicated, along with a fairly strong letter pointing out that it needs to be corrected. However, Colin would give this a C2, on the basis he describes above. If not, why not? There are plenty of installations out there like this and we do not have loads of accidents. Why not? Because they are bad but not significantly dangerous without complex extenuating circumstances. Do you see the point that I am making and trying to explain?


This can be changed in many ways but the present 3 codes are not sufficient. I am fairly happy with C1 &2 but C3 needs to be extended. I suggest a code for specifically, poor quality installations, those which are incomplete or damaged and would not pass Chapter 51 or 52.  This should make the installation unsatisfactory, but not due to danger in our normal understanding of this.


Another code should be for changes to regulations since installation, this is very confusing to many customers, but should not make installations unsatisfactory. It is a common problem when adverts for electrical services say "Bringing up to latest regulations", making this sound mandatory.


Has anyone else got any other suggestions?

Has anyone else got any other suggestions?


Yes David, read the first seven words of 651.4 and lose the focus, dare I say respectfully, apparent obsession, on the eighth word as the fourth, fifth and sixth words shall (sic) also be recorded.............................


Regards


BOD not BAD, as I'm not trying to wind you up.

I venture to suggest that this simply illustrates that there is a range of expert opinion. Were one an expert witness in court, the duty would be to explain the reasonable range of expert opinion. One would then go on to explain why a particular point of view had been chosen. DZ, you prefer C3, but can you say that C2 lies outside the reasonable range of expert opinion?


To remind everybody: the OP was content with C2, but did not accept C1. I think that nobody in here would agree with C1.

dcbwhaley‍  The OP is conspicuous by his absence, I trust all is well.