New CU and failed IR tests

[EFLImpudence]

I am talking about changing a CU or not; not whether to leave the customer with disconnected circuits.

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.

The bonding is supposed to be upgraded so that should already be covered.

Exposed live parts would indeed be a danger, although that indeed may not even be noticed but would anyone refuse to have that rectified?

Fault loop impedance too high could be rectified with a lower rated OPD - possibly agreed temporarily.
The same for undersized cable although I find it hard to see how that would happen.
No cpc continuity shouldn't be too difficult to rectify.

I was always willing to do some rectifying within the original price which can be no more expensive than carrying out a virtual EICR before agreeing to do the work at all and seemingly to me would take far longer.

 

[JohnW2]

Not taking it away, but removing it, yes.

Yes, but you are talking about 'removing and then replacing' - not 'removing so that the dangerous installation cannot be used', aren't you?

Kind Regards, John

 

[securespark]

Yes.

 

[ericmark]

As said many times with domestic you are not permitted to make the property uninhabitable, unless you arrange an alternative for the residents, however I lived in a caravan where the only electrics other than road lights was a single 10W festoon lamp. OK it had gas, but I suppose you could provide battery lights, main thing which would make it uninhabitable would be no heat, and no cooking. In other words you could not draw the DNO fuse, but you could isolate most circuits.

However you can't really use a lock, it must be so any electrician can reinstate not just you. So tie rap the MCB open or drop tails, now to drop tails means access to CU unit, so tie wrap is only option, which means the little clips that fit onto the MCB to allow you to lock off, I don't have them for every make and those I have not willing to lose when some one else removes the tie wrap, so in real terms some sticky tape with do not remove written on it is likely best one can do. And you know as soon as you walk out of the door that will be removed.

So you simply write out a report (has to be in writing) hand it to client and leave. Very little extra you can do. So a year latter another electrician arrives, asks for paperwork and it says there is a fault. It does not however say if that circuit was left energised or not. But really he has done nothing wrong, he has clearly written down there is a fault. If the home owner continues to use it, how is that a fault of the electrician.

If there is a sink hole in the road, and some one puts up a sign road closed, and some silly chap ignores the sign and drives down the hole, you would not blame the council for not putting concrete blocks in the road so it was impossible to use the road, you would blame the chap for ignoring the signs. So if an electrician states in writing the circuit is not safe, if the home owner ignores that advice it's not the fault of the electrician.

Where I live however the notice would also need to be in Welsh

the Welsh translated into English reads "New faith order ahead." there are loads of examples of poor translation, and I would not know how to write do not energise in Welsh. Oh the sign should say

so not far out.

 

[PrenticeBoyofDerry]

Interesting comments guys, and in the main I agree with most of the comments.
When I am asked to replace an existing DB/CU I always I&T first, even when doing a full rewire, I will do some primary test on the supply.
So when there is an issue, then advise/recommendations can be offered to the client, then put right or left for another, if you advice is ignored!

But the issue I have with my original post/topic is: That in my opinion it is evident, that the installer (of replacement CU) did not carry out any prior testing of circuits before installing the replacement board. Then on finding that IR test failed thought it right to not connect these to RCDs, because of that IR failure, as other circuits are protected be RCDs and the orignal board (according to homeowner) had no RCD protection present at all.

The IR failure maybe posiblly down to a load that had not been disconnected, I cannot say for sure without further investigation. These test where performed by the installer, not me. So going on the evidence presented on their test sheet. So for me the tests show IR tests of 0 and 0.22MΩ. Does that not denote a code 1? So reterminating this circuit at all, would not be advisable and to think be installing on the non-RCD side is OK, is surprising!

The upshot of this the work was carried out by an electrician who's scheme provider, offer a 6 year warranty. So because of that, I have been advised not to get my hands dirty as it may invalidate that warranty?

 

[EFLImpudence]

When I am asked to replace an existing DB/CU I always I&T first, even when doing a full rewire, I will do some primary test on the supply. So when there is an issue, then advise/recommendations can be offered to the client, then put right or left for another, if you advice is ignored!

Could that not have been the case, here?

But the issue I have with my original post/topic is: That in my opinion it is evident, that the installer (of replacement CU) did not carry out any prior testing of circuits before installing the replacement board. Then on finding that IR test failed thought it right to not connect these to RCDs, because of that IR failure, as other circuits are protected be RCDs and the orignal board (according to homeowner) had no RCD protection present at all.

Or it could have been as above and, at least now, all the other circuits are covered by RCDs, so - safer than before.

The IR failure maybe posiblly down to a load that had not been disconnected, I cannot say for sure without further investigation. These test where performed by the installer, not me. So going on the evidence presented on their test sheet.
So for me the tests show IR tests of 0 and 0.22MΩ.

0.22MΩ (L-N) is not ideal but nothing to do with RCDs
0 on lighting is obviously no good. That can't be between L&N.
Do we know why the other socket circuit is not on an RCD either?

Does that not denote a code 1? So reterminating this circuit at all, would not be advisable and to think be installing on the non-RCD side is OK, is surprising!

It might be, but perhaps that was what was agreed with the customer.

Perhaps there is something else we don't know about.

The upshot of this the work was carried out by an electrician who's scheme provider, offer a 6 year warranty. So because of that, I have been advised not to get my hands dirty as it may invalidate that warranty?

Again, up to the customer, I suppose.

 

[ban-all-sheds]

I am talking about changing a CU or not; not whether to leave the customer with disconnected circuits.

But then you asked what problems I had in mind that would be problems whether or not a CU was changed:

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.

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

The point is that there can be genuine, extant problems which preclude a CU change that are nothing to do with "minor niceties", if you like, of regulation tweaks over the years since the original installation.

Some may be easily resolved, some less easily, some only with great difficulty. The issue is what happens if the owner refuses to allow rectification? Whether because of a "it's been like that for years and I've not touched it yet", or expense or disruption. If you've already replaced the CU, on what authority to you refuse to connect a circuit?

The bonding is supposed to be upgraded so that should already be covered.

How can you compel someone to have it done?

Exposed live parts would indeed be a danger, although that indeed may not even be noticed but would anyone refuse to have that rectified?

Ditto.

Fault loop impedance too high could be rectified with a lower rated OPD - possibly agreed temporarily.
The same for undersized cable although I find it hard to see how that would happen.

Someone re-jigs their bathroom, and extends the 10mm² shower cable with 2.5mm² [disclaimer]I've not done any calculations to see how realistic detection of that could be[/disclaimer], and a lower-rated MCB won't work.

No cpc continuity shouldn't be too difficult to rectify.

"I've just laid that laminate floor and papered the walls, if you think I'm going to let you damage any of that you've got another think coming".

I was always willing to do some rectifying within the original price which can be no more expensive than carrying out a virtual EICR before agreeing to do the work at all and seemingly to me would take far longer.

So when you have finished, what do you do about circuits which you are not prepared to reconnect?

 

[ban-all-sheds]

So you simply write out a report (has to be in writing) hand it to client and leave. Very little extra you can do. So a year latter another electrician arrives, asks for paperwork and it says there is a fault. It does not however say if that circuit was left energised or not. But really he has done nothing wrong, he has clearly written down there is a fault. If the home owner continues to use it, how is that a fault of the electrician.

Where's the proof that you left it unenergised, labelled, and told the owner in writing not to use it?

As said many times with domestic you are not permitted to make the property uninhabitable, unless you arrange an alternative for the residents.

What if your job had been to replace a CU which was dangerous or inoperable because of significant damage, but the residents were not in the class of vulnerable people to whom the local authority had a duty of care?

 

[EFLImpudence]

I suppose I am going to have to say "I don't know".

I have never come across such a situation - which is why I asked what was considered [too] dangerous to leave as it is or fit a new CU.

 

[ban-all-sheds]

It's at best tricky, at worst a minefield.

But discovering that there is a minefield by belatedly realising you are in the middle of one is probably the worst of all possible worlds.

 

[PrenticeBoyofDerry]

Could that not have been the case, here?

From what the homeowner has said it seems not.

Or it could have been as above and, at least now, all the other circuits are covered by RCDs, so - safer than before.

Well I suppose it could, but I don't really know. But the other strange thing is, a second socket circuit has also been excluded of RCD, but the test result on EIC, seem to suggest they are fine with regards to IR tests, reading at 89MΩ and 299MΩ

0.22MΩ (L-N) is not ideal but nothing to do with RCDs
0 on lighting is obviously no good. That can't be between L&N.
Do we know why the other socket circuit is not on an RCD either?

I agree nothing to do with RCDs, not a clue about other socket circuit. I have not carried out any testing, just what I am seeing documented on EIC

It might be, but perhaps that was what was agreed with the customer.

The homeowner/customer claims they have not agreed anything, just that the installer was not there long and cost a lot of money.

Perhaps there is something else we don't know about.

Maybe

Again, up to the customer, I suppose.

and me (in this case) The homeowner did indicate that they did not care much if the warranty has invalidated, providing things were safe/done correctly. I just held back as the scheme provider (NICEIC) were going to contact me and was advised not to do anything at that time. That has not happened yet!