New CU and failed IR tests

[securespark]

Cars like Metro were taken out of production because they could not update them to meet new standards.

 

[JohnW2]

Cars like Metro were taken out of production because they could not update them to meet new standards.

I think that mine (a 1959 Triumph Herald) very much pre-dated the Metro!

Are you saying that, because they could not be updated to meet subsequent standards, they should be described as 'dangerous'?

Kind Regards, John

 

[EFLImpudence]

All cars are potentially dangerous and so is electricity.

 

[JohnW2]

All cars are potentially dangerous and so is electricity.

Quite so. Indeed, in some senses, even the 'safest' of cars is still 'dangerous', since it has the ability to result in injury or death.

You've really just introduced yet another term into the confusion - so we now have to decide how to distinguish between 'less safe', 'dangerous' and 'potentially dangerous'!

We clearly are not talking about a 'correct' and 'incorrect' issue!

Kind Regards, John

 

[ericmark]

Back to main question, if you find some thing is dangerous, can you leave it in that condition, my answer is no. So the whole idea of walking away from a job because the installation is dangerous is not an option. You have to make it safe, even if that is simple locking off or disconnecting.
As to an installation which does not comply with current regulations, that does not make it dangerous, so here the question is if the work is to repair or improve the safety of the installation, if so nothing really to stop you doing the work, or is the work to add some extra to the circuit be it cosmetic or practical, then the whole of that circuit must comply.

So change a socket because there is a crack, or even just a discolouration of the plastic is OK, to add a socket, whole circuit (not installation just that circuit) must comply. However that leaves some work in question, like swap a standard socket for a USB socket or a socket with brushed metal appearance, this becomes a grey area.

So my parents house, there was a problem, the installation 1954 had been added to many times over the years, around 2004 a new consumer unit fitted, found no earth converted to TN-C-S and also found many circuits would trip a RCD. Wanted to re-wire, but dad said I am not living in a building site, you can do that when I am gone, so around 2010 wanted major work to the kitchen, the contractor was warned the electrics were not very good, and county council job, so all t's crossed and i's dotted. The cure was a sub main, a 45A MCB fitted in existing consumer unit and SWA cable to new consumer unit in kitchen which was populated with RCBO's. So kitchen completely rewired, but also independent from rest of house. So in real terms mothers house had three sections.

1) Original house with no RCD protection.
2) Wet room and bedroom shower plus a few odd circuits including garage RCD protected.
3) Kitchen all RCD protected.

No longer like that, now whole house rewired, however for around 7 years the old was left as it was. Since the house in this tread has a new consumer unit, there is nothing to stop adding a satellite CU for under floor heating, garage, shed or any other area, you still have one isolator and one fuse (DNO fuse) which will isolate all. Unless dangerous there is no need to upgrade rest of house.

However there is a problem, I don't have a copy of regulations in force in 1954, OK I know some of the changes, 1966 for example earthing on lighting circuits, but I could not inspect and test a 1954 installation and say this installation complies with the regulations at the time of originally wiring. Also where new items have been fitted, were they permitted in 1954? So I know kitchen as original had a bulb and shade, my dad bought a 4 foot fluorescent tube fitting which simply plugged into the BA22d bulb holder, no different to fitting an energy saving bulb today, although this dates back to 1960's, latter he swapped this for a batten fitting screwed direct to ceiling, the term class II had not been invented then, so when kitchen was done they forgot the lights, and I had to pay a fortune for a Class II 2D light fitting.

So some thing as simple as a LED bulb, in the days of the tungsten bulb when the bulb was lit, it was rather hot, even if you did change it or remove it while lit, you would need a glove or other item to insulate from the heat, which would also insulate from electric at same time, but you can change a LED or CFL while it is running without your cap rapped around it, so you handle the lamp holder, shade and bulb with the power on. So more protection is required because the bulb type has changed, with an ES cap in 1954 did not matter if thread or centre was line, well not even called line then, but today it does, so transparent twin flex with no line/neutral marking in 1954 was OK, today with ES it's not, simply because of energy saving bulbs.

So we are professionals, and there comes a time where we have to stop hiding behind regulations, and we have to say, this is OK or this is dangerous without reference to the pages of BS7671.

 

[ban-all-sheds]

John originally wrote:

"I would hope that any electrician finding an installation (or part of an installation) that he/she felt represented a serious danger would do everything they could to dissuade the owner of the installation not to use it (or parts of it) until it was remedied".

I suppose that would apply whether or not a CU was to be changed.

Well, first of all we have to recognise the possibility of the existence of issues which have existed for years and have been dangerous all that time. Surely it is possible for checks to throw up the existence of problems which are dangerous whether or not a new CU is installed?

I suppose it's the age-old question of what is meant by 'dangerous' and 'safe' (or 'safer').

No, it's much simpler and more definitive than that.

I just wondered what sort of problem he (and you) had in mind.

I can't read his mind.

But a few things which immediately spring to mine are:

No cpc continuity.
Inadequate bonding.
Fault loop impedances too high to allow the OPD to work.
More digging on the above showing R1/Rn values so high as to suggest undersized cable.
Exposed live parts.

 

[JohnW2]

Back to main question, if you find some thing is dangerous, can you leave it in that condition, my answer is no. So the whole idea of walking away from a job because the installation is dangerous is not an option. You have to make it safe, even if that is simple locking off or disconnecting.

You say "... is not an option" but, at risk of repeating myself, the issue is that, whatever common sense or even 'morality' might say, I am not aware of any authority an electrician has to "lock off" or "disconnect" an electrical installation without the consent of the owner of that installation. All they can do is 'advise' - and if they take it upon themselves to do remedial work 'to make an installation safe' without the agreement/instruction of the owner, they cannot expect to necessarily be paid for that 'unsolicited' work.

Kind Regards, John

 

[ban-all-sheds]

whatever common sense or even 'morality' might say, I am not aware of any authority an electrician has to "lock off" or "disconnect" an electrical installation without the consent of the owner of that installation.

Moral authority.

 

[securespark]

Are you saying that, because they could not be updated to meet subsequent standards, they should be described as 'dangerous'?

I think so, yes, in comparison with a modern car.

You could extrapolate and say that in comparison with a Triumph Herald, a horse and cart is dangerous.

 

[securespark]

In the old days of Norweb, I (along with other "approved" electricians, had authority to cut seals to do board changes.

 

[JohnW2]

I think so, yes, in comparison with a modern car.

That's the point - you're making a comparative point - i.e. saying that it was 'less safe' than a modern car. However, back in the 60s, no-one would have dreamed of saying that my car was 'dangerous' by virtue of inadequacies of the standards to which it had been designed and built, would they?

Kind Regards, Jiohn

 

[JohnW2]

In the old days of Norweb, I (along with other "approved" electricians, had authority to cut seals to do board changes.

Fair enough, but I rather doubt that that authorisation extended to your removing and taking away the service fuse, did it?

Kind Regards, John

 

[securespark]

Not taking it away, but removing it, yes.

I also was furnished with some 60/ 80/ 100A fuses and seals. I would seal up when I was done, then leave a completed cert for Norweb to take away when they returned to seal up properly with their serially-numbered crimps.

 

[SUNRAY]

A simple 'That circuit is faulty and I am not prepared to connect it to the new CU that I install' is all it needs. That way the customer has the choice of getting a new CU but without the faulty circuits wired in or not having a new CU fitted by you.

I have refused to provide temp power at events to a few users over the years and an 'I'm not letting THAT faulty equipment compromise the whole installation.' has always been enough for the organisers. Having said that I will usually try to make their kit safe enough to use if I can.

 

[JohnW2]

A simple 'That circuit is faulty and I am not prepared to connect it to the new CU that I install' is all it needs. That way the customer has the choice of getting a new CU but without the faulty circuits wired in or not having a new CU fitted by you.

Exactly, and that's what I've been saying all along. If one undertakes adequate I&T before changing the CU then, as you say, one can give the the customer that advice (or ultimatum), so that it becomes their choice.

However, if (as per how this discussion stared) one does not do pre-change I&T, but goes ahead and changes the CU, and only then to discover that there are things about the installation which mean that one is not prepared to leave it energised, then one has (unnecessarily) created a difficult situation (presumably, even if the customer asked you to, you would not be prepared to reinstate the old CU and re-connect the 'faulty circuits' to it?).

Hence, as I've said, alway inspect and test first!

Kind Regards, John