Design fault, is there a statute off limitation, could an electrician/plumber/firm be required to correct an installation fault 20 years latter.

[ericmark]

There is a post here where no earth has been run to a thermostat, and the green/yellow wire over sleeved and used as a line wire, even before 1966 it was only lights that did not require an earth running to them, I know there was some confusing about over sleeving the green/yellow in a multi-core cable, but it still needs an earth to be provided even if not used, so only where there are two multi-core cables could one of the earth wires be over sleeved, so we are looking at way before 1966 for this to have been permitted.

So it seems unlikely this was ever permitted, so if the installer was daft enough to put a sticker on the boiler saying who installed it, or any installation paperwork, could they be required to correct the bad design?

I know my car has had a recall at 20 years old, what about central heating systems, it is not a fault which has developed, it was always wrong from day one.

 

[JohnW2]

So it seems unlikely this was ever permitted, so if the installer was daft enough to put a sticker on the boiler saying who installed it, or any installation paperwork, could they be required to correct the bad design?

What do you mean by "required"?

As you know, electrical work never has been subject to any significant 'mandatory' regulations.

Kind Regards, John

 

[EFLImpudence]

The regulation regarding the running of a CPC to points where not needed is stated as being for possible future use.

Would that not be satisfied in this situation - before the recent specific prohibition of over-sleeving a g&y conductor?

 

[ericmark]

As you know BS 7671 or the book before that are not law, although can be used in a court of law, so when it is not adhered by, it is not cut and dried as to if illegal, clearly if a compliance certificate is issued or an installation or minor works certificate raised then unless listed as a deviation then they have broken the law.

But I have been picked up for leaving the key in an electrical panel, by the HSE, it should need a key or tool to access live parts, and leaving the key in the lock means anyone could access live parts if they are daft enough.

Some of the rules do seem to be a little OTT, but often it is simply one has not envisaged the situation which means they should be followed, late last year I came across the reason why all mains powered central heating controls should come from the same supply, I had solar panels and battery fitted and the single supply is now powered from that battery, had I powered the Nest Gen 3 thermostat from some other mains supply vie some USB adaptor powered from a different circuit to the boiler, with a power cut the central heating would still fail.

There is a point where fixed and non fixed wiring has different rules, common for a lawn mower to be class II, so from the wiring centre to a tank thermostat one could argue since only held in place with an expanding cord, the tank thermostat is not fixed, and being class II does not required an earth, so using the over sleeved earth core, bad practice, and no longer permitted, but in the 2008 version of BS 7671 it could be argued it was permitted.

However the thermostat cradle is clearly fixed, the thermostat may be class II, but we have needed an earth to be provided even for the lights unless suspended since 1966, so clearly breaking the rules.

Even the Nest Gen 3 heat link which is class II, it points out an earth is required when cables are run from it to power and collect data from the thermostat even when only 12 volt. So although often the earth connection is only a parking position for future use, it is required by some devices so as with ceiling roses an earth must be run, even if not required at the time of installing. And it has been that way for lights since 1966 and well before that date for other items.

 

[ericmark]

I found this report on prosecution due to poor installation and design I will admit many questions which include inspection and testing.

The dates it seems are accident 13 December 2017, installed 2013, court case March 2022.

I find the report somewhat lacking, there is 4 years between installed and accident so should have be inspected and tested as part of the inspection and testing of in service electrical equipment, but no reference is made to that. And things like "The macerator was not protected by an earth wire and there was no residual current device (RCD) to prevent fatal exposure to the electrical current." and "The earthing wire could be connected in a way that meant it was ineffective, and the equipment was also permanently live." leave me asking what had been missed, I would have thought pictures to show the error were in order to stop a repeat.

This

picture does little to help understand the errors.

However clearly we are responsible for our work 4 years after it was done, maybe it could go a lot longer? It seems only when there is a death do courts get involved, thus generating case law, but the cost of swapping a cable for one with an extra core is quite high, when compared with the cost of cable in the first place.

But when working on large jobs, some one some where will have written down run an x core cable from y to z so one can find out who made the error, but in domestic although the list of allowed work without notifying is short, at least in Wales, what has been done is very vague.

So for an example a two core and earth to a tank thermostat with a S plan is likely OK, only with a Y plan would it need a three core and earth, so who has decided to run a two core is important, was the cables pre-installed, with the idea it would be S plan, was it installed by same person who inspects and tests? I know years ago my son was employed as an electricians mate to wire new homes, and an electrician would visit the site around once a week to sign off the work he had set the mate to do.

I remember there was a problem with the builder changing the type of beam used, it plan was for pre-made beams with knockouts for cables and pipes, this was changed to wood beams and they needed drilling 1/3 from end for cables and pipes, this increased cable length so the ELI was too high, seem to remember one house had 20 amp MCB on the ring final as a result, it was decided too much work to renew cable, think latter houses had three rings instead of two.

It would be easy for some one to swap the 20 amp for 32 amp, and with today's RCD protection likely no problem, but back then before 2004 question is was an installation certificate ever raised? And now could it be found, and could the guy would signed it off be found or my son who wired it be found, he lived an a narrow boat at the time so of no fixed abode.

OK over 20 years ago so unlikely anyone would be looking at the original installer, seem to remember on same job the electrical firm was buying 4 mm² SWA as a good price, so garage wired 2.5 mm² to junction box on wall, and 4 mm² SWA to garage, it was only for lights and one socket, but bet today many have a lot more running on it and likely the 16 amp MCB has been changed.

I may have the installation certificate for the flat at my house, but bet the firm who wired it does not still have a copy. Showing they had not done work would be hard. Photostat copies are so easy to alter.