Should Part P get scrapped?

[JohnW2]

I think we might agree there are as few deaths that could be down to things that Part P might prevent if working properly.

Possibly a tiny number but ....

Just one death is one too many.

As SimonH has said, that this a statement which indicates a complete lack of understanding and acceptance of risk/benefit considerations in the real world. Risks (incuding risks of death) exist everywhere, and the extent to which we should take action to try to reduce those risks depends upon the balance with convenience, cost, practicalities and 'downsides' of such actions.

If you feel that any reduction of 'avoidable' deaths is worthwhile, regardless of the 'costs' (in the broadest sense), then there is an almost endless list of things you should start campaigning for ... probably starting with dramatic reductions of (strictly policed/enforced) speed limits on all roads.

All DIY work should be banned completely or alternatively it should all be allowed and notifiable and the cost proportionate to the number of inspections required to get it right.

Despite our discussion here, regulation of electrical work is not going to go away. Banning DIY work would almost certainly not work, and would be far too difficult/expensive to police/enforce - unless a way could be found to cut off supplies of materials to DIYers - and that's almost certainly not going to happen, either. In realistic terms, improvements of the regulation system will have to relate to improvement of the quality of inspection/certification - and, as I've suggested, I think that probably should start with a banning of self-certification. As you have said, many of us have to accept routine scrutinisation of our work by third parties, and I don't think that electricians should be any exception.

Kind Regards, John.

 

[roberta1000]

There are quite a few Electrical Death Traps out there.
Some could be eliminated.

Well like many I've done a few inspections, rewires etc. in my time and found the usual assortment of faults but I'd hesitate to call many of them 'death traps'.

Without doubt the largest category of domestic safety risks that I've seen have been to do with frayed flex, taped-up joints, under-rated flex, knackered switches, over-rated fuses, extension leads and adaptors and so it goes on. None of it covered by any sort of regulation of course.

On the installation side the largest category of safety risks that I've seen have been to do with overheating plugs/sockets and tired wiring coming loose in fittings. Plenty of things that weren't to the regs of course but 'death trap' or even a major safety hazard - not in my professional estimation.

So following John's (?) comments about actual accident rates I'd be interested to know how many of the very very few fatalities that there are are down to installation issues and how many down to plain ordinary user carelessness. I know where my money would be.

Ahhh! the holiday, but back to work tomorrow.

 

[JohnW2]

Well like many I've done a few inspections, rewires etc. in my time and found the usual assortment of faults but I'd hesitate to call many of them 'death traps'.

That doesn't surprise me in the slightest. Definition of a 'death trap' is obviously a very subjective and emotive issue but, in terms of risk of electric shock (rather than fire), I can think of very few faults/errors with an installation that could be detected by testing which would directly (i.e. in the absence of a second fault) lead to electric shocks. If, by 'death trap' one is referring to an incipient/evolving fault which could possibly eventually evolve into something that might conceivably result in death, then many of us are probably driving some of those (which wouldn't be detected by a standard MOT test) around every day in our vehicles!

So following John's (?) comments about actual accident rates I'd be interested to know how many of the very very few fatalities that there are are down to installation issues and how many down to plain ordinary user carelessness. I know where my money would be.

The same place my money would be, I imagine! Adequate statistics to answer the question do not exist, but I strongly suspect that the great number of electric shocks, including fatal ones, are down to carelessness/ foolishness/ ignorance of users and DIYers (whilst doing the work), not to the installation at all - as above, there really aren't that many issues relating to an installation itself which can, in themselves, result in an electric shock. Even significant fires due to electrical installations are almost certainly very rare, too.

Although it's unfortunately too late to turn the clock of regulation backwards (now we've got it, it will never go away), one does have to wonder whether any regulation of domestic electrical work can, in reality, be justified on the basis of the risks of death or serious injury.

Happy return to work

Kind Regards, John.

 

[SimonH2]

Just one death is one too many.

As SimonH has said, that this a statement which indicates a complete lack of understanding and acceptance of risk/benefit considerations in the real world. Risks (incuding risks of death) exist everywhere, and the extent to which we should take action to try to reduce those risks depends upon the balance with convenience, cost, practicalities and 'downsides' of such actions.

Indeed. In the context of this thread, I can think of one way to eliminate electrical risks entirely - and that's to simply ban all electrical supplies, services, and devices. Job done, electrical deaths reduces to zero ... or at least apart from those caused by natural electricity aka lightning.

Clearly this would be an absurd extreme, but it demonstrates the point. While there is a risk with all things electrical (and we should try and reduce those as far as is reasonable, practical, and cost effective), there is a huge positive benefit from having easy to use lighting, heating, communications, etc, etc. I don't think it should be hard to see that the benefits far outweigh the risks.
Picking just one - how many accidents (and ensuing deaths) used to be caused by accidents with candles and oil lamps before electric lighting became the norm ? I suspect the numbers were higher than our electricity related accidents these days.

 

[mattylad]

All DIY work should be banned completely

Absobloodly not likely!

It's my house and I will damn well decide who does what to it, who does the wiring & piping, the wallpapering the decorating (its all DIY) and there is no court or government in the land that is going to tell me otherwise.

On the other hand, I and many others have had so called professional tradesmen in to do jobs that have been a complete load of sh1te, that have been done a lot better by DIY.

So no, DIY will NEVER be banned.

Cowboy tradesmen should be banned, they should be regulated and inspected even more, have higher fees to pay and all forced to wear pink frilly underwear. (see - some of you already do but I wont name names to spare ebee's blushes).

 

[JohnW2]

It's my house and I will damn well decide who does what to it ... On the other hand, I and many others have had so called professional tradesmen in to do jobs that have been a complete load of sh1te ... So no, DIY will NEVER be banned. ... Cowboy tradesmen should be banned, they should be regulated and inspected even more ...

Not being a great lover of 'the Nanny State', I agree essentially with a lot of that. To a large extent, I think that householders should be free to do what they like (and take full responsibility for) whatever they choose to do in/with their homes (subsequent purchasers should satisfy themselves, with inspections as necessary, about the adequacy/safety of everything - structural, electrical, gas, plumbing etc. etc.).

However, when people choose to pay professionals to undertake work for them, I think they deserve reassurances about the quality and safety (and compliance with regulations) of that work - and, given that 'black sheep' clearly exist, to my mind that means that self-certification should probably not be allowed.

Kind Regards, John.

 

[martinxxxxxx]

On fixing the faceplate ....

Oh no he didn't!

The RCD would have tripped in this case, even if you had not tested This is a tongue in cheek quote. I fully value testing, in the case above it may not have tripped the RCD straight away and then for a future electrician it would have been a pain to trace what was causing the RCD to trip when it did happen.

Obviously not impossible but, assuming there were some other loads on the installation at the time the new circuit was energised, I would suggest extremely unlikely - I bet that, even if you delberately tried, you would be very hard pressed to create a fault by screwing into the insulation of a neutral conductor that was detectable by IR testing but not low enough impedance to result in an RCD operating. Even if the insulation had been damaged, if there were not enough of a N/E path to trip an RCD, it is extremely probable that IR testing would reveal nothing at that time - so, if IR testing were undertaken (in a situtaion in which the RCD was not operating), it would probably give a sense of false reassurance (in the presence of a persiting fault) rather than anything else.

Kind Regards, John.

RCD will only trip at 30mA

e.g. a value of 1Meg resistance path thru the screw could result in a current of (230/1,000,000= 0.23mA)

Therefore if the current were higher than 0.23mA and lower that 30mA the circuit would be capable of not tripping the RCD but at the same time would fail the IR test.

It might be unlikely in your mind, but I think it is exactly what the authors of the regs have in mind when they prescribe testing for circuits at a higher voltage than they are used for.

That is the value of testing a circuit, otherwise we might as well say "it works" so it must be ok.

 

[JohnW2]

RCD will only trip at 30mA e.g. a value of 1Meg resistance path thru the screw could result in a current of (230/1,000,000= 0.23mA) ... Therefore if the current were higher than 0.23mA and lower that 30mA the circuit would be capable of not tripping the RCD but at the same time would fail the IR test.

With the proviso that you arithemtic is all wrong because we were talking about a N/E, not L/E fault, we all know that - but, what I was saying is that I believe that it is extraordinarily unlikely that the insulation could be breached/damaged such as to result in a fault path with a resistance too high to result in RCD operation but less than 1 MΩ. If you don't believe me, just try - take a piece of a new blue-insulated conductor and set up a jig to drive a machine screw into the insulation - and keep repeating the exercise until you get a resistance between the screw and conductor which is not either extremely low (less than a few Ohms) or at least a meg or two. I strongly suspect that you'd still be trying in 50 years time

It might be unlikely in your mind,

Yes, as above, I believe that it is incredibly unlikely - probably less likely than your being struck by lightening or winning the Lottery .... but, as you imply, that is merely my opinion, and I may be wrong ...

.... but I think it is exactly what the authors of the regs have in mind when they prescribe testing for circuits at a higher voltage than they are used for.

Goodness knows what they had in mind in prescribing that. With the sort and configuration of insulating materials we now use, it would be extremely unlikely that one would encounter a situation of insulation breakdown such that the IR measured at 500V would be significantly different from that measured at 250V (it could be different if we were talking of rubber or paper insulation). One could, indeed, satisfactorily measure resistances of several MΩ with a test voltage of just a few volts, and it's very unlikely that a measurement using 250V, let alone 500V would differ significantly.

That is the value of testing a circuit, otherwise we might as well say "it works" so it must be ok.

I'm as keen on detecting faults as you are - I just think that IR testing is extremely unlikely to pick up damaged insulation which is not resulting in a very low resistance that would cause an RCD (or, if it were a L/E fault, perhaps also an OPD) to operate. I would actually go as far as suggesting that IR testing could be potentially dangerous in this situation, since a satisfactory measured IR is likely to give one (perhaps unjustified) reassurance that insulation has not been damaged,even though serious damage may be present.

Kind Regards, John.

 

[martinxxxxxx]

but, what I was saying is that I believe that it is extraordinarily unlikely that the insulation could be breached/damaged such as to result in a fault path with a resistance too high to result in RCD operation but less than 1 MΩ. If you don't believe me, just try - take a piece of a new blue-insulated conductor and set up a jig to drive a machine screw into the insulation - and keep repeating the exercise until you get a resistance between the screw and conductor which is not either extremely low (less than a few Ohms) or at least a meg or two. I strongly suspect that you'd still be trying in 50 years time .

Maybe in the jig situation the above holds true, but imo irl there are other factors that such as small movement when the socket is used or condensation levels that can decrease the resistance - otherwise we would live in a world where intermittent faults did not occur. Can this be picked up by IR measurements at 500vdc? You say no; I'd be interested in others opinions on that one....

 

[Electrifying]

- but, what I was saying is that I believe that it is extraordinarily unlikely that the insulation could be breached/damaged such as to result in a fault path with a resistance too high to result in RCD operation but less than 1 MΩ. Kind Regards, John.

John,

Have I missed something here, or are you just 'prattling on' in your own little world again.

I had trapped the neutral conductor with the faceplate screw and pierced the insulation - the result being a direct short to earth when I tested IR N - E.

If I hadn't tested, the circuit would have been energised showing no problem, as the circuit was fed from a seperate, garage type CU, (along with the kitchen lighting).......the first I'd have heard about the fault is probably later that night, no doubt whilst I was eating my tea, when they put a load of some description on the circuit.......or turned the light on.

 

[JohnW2]

Maybe in the jig situation the above holds true, but imo irl there are other factors that such as small movement when the socket is used or condensation levels that can decrease the resistance - otherwise we would live in a world where intermittent faults did not occur.

Exactly my point - such a fault would be intermittent, but essentially dichotomous - i.e. at any moment in time one tested it, the 'fault resistance' would be either very low or essentially non-existant (i.e. very high) - I see no logical reason why the sort of 'mid-range' IR readings that have been proposed (detectable by IR testing but not low enough to operate an RCD) should ever occur. Condensation may sometimes be an issue, but not necessarily any more so when there is damaged insulation than when there isn't.

Can this be picked up by IR measurements at 500vdc? You say no; I'd be interested in others opinions on that one....

Dichotomously intermittent is dichotomously intermittent, regardless of voltage. The only situation in which insulation damage would be picked up by 500V IR testing but not otherwise be apparent is if the insulation underwent 'dielectric breakdown' at 500V and, with PVC, that would only happen of the insulation between the conductors concerned had been reduced to being incredibly thin (around 15 microns at 500V, IIRC), but not actually penetrated - not, I agree, totally impossible, but I would think extremely rare/improbable.

Kind Regards, John.

 

[JohnW2]

Have I missed something here, or are you just 'prattling on' in your own little world again.

It's really others, no me, that have brought this about

I had trapped the neutral conductor with the faceplate screw and pierced the insulation - the result being a direct short to earth when I tested IR N - E. If I hadn't tested, the circuit would have been energised showing no problem, as the circuit was fed from a seperate, garage type CU, (along with the kitchen lighting).......the first I'd have heard about the fault is probably later that night, no doubt whilst I was eating my tea, when they put a load of some description on the circuit.......or turned the light on.

Yes, I know - but someone then suggested that the RCD (assuming there was one) would have operated - and I responded by agreeing, provided that there was some load on the circuits served by the RCD. ... and the rest of the discussion evolved from that

It might seem a little low-tech, but does not your testing include making sure that the circuits actually 'work as intended' (e.g. lights come on when one operates a switch) before you 'leave the scene', as well as the measurements?

Kind Regards, John.

 

[EFLImpudence]

I had trapped the neutral conductor with the faceplate screw and pierced the insulation - the result being a direct short to earth when I tested IR N - E.

If I hadn't tested, the circuit would have been energised showing no problem, as the circuit was fed from a seperate, garage type CU, (along with the kitchen lighting).......the first I'd have heard about the fault is probably later that night, no doubt whilst I was eating my tea, when they put a load of some description on the circuit.......or turned the light on.

Where and by which method did you do the testing?

 

[scousespark]

In realistic terms, improvements of the regulation system will have to relate to improvement of the quality of inspection/certification - and, as I've suggested, I think that probably should start with a banning of self-certification. As you have said, many of us have to accept routine scrutinisation of our work by third parties, and I don't think that electricians should be any exception.

Kind Regards, John.

Are you suggesting that qualified electricians should not be able certify that they have staisfied building regs?

 

[Electrifying]

It might seem a little low-tech, but does not your testing include making sure that the circuits actually 'work as intended' (e.g. lights come on when one operates a switch) before you 'leave the scene', as well as the measurements?

Kind Regards, John.

Yes, but this whole discussion has evolved from you asking whether we should test 'minor' works to comply with Part P, and how much testing should be done.

I was trying to show that there is a method in the madness of the IEE when they suggest the tests required and the order that you should do them.

If I did it your way......the good old 'bang' test - then yes, I would have discovered there was a fault.

But that also would mean that I had energised a faulty circuit.........which is what the 'dead tests' are there for.