Queries regarding Inspection Report I've just had completed

[Strima]

So how would EFLI testing on a ring final identify an incorrectly wired circuit and discontinuous conductors?

 

[Nigel]

So how would EFLI testing on a ring final identify an incorrectly wired circuit and discontinuous conductors?

If you are talking about end to end tests they are not R1 + R2 tests which is where the thread currently is.

 

[Darkwood]

He hasn't answered how an R1+R2 test will circumvent this problem either. Electrical testing is imperfect and is why an inspection of all the senses is more important.

To the contrary, I have explained on numerous occasions, it brings in a second practice you do not do so you do not entertain the idea, If I remove the shower cover take the Earth and L1 out of the terminals and the same at the distribution then parallel paths are removed and you are testing only the integrity of the cable earth, this is how I was taught, the reasons for doing so I was also taught that you thus eliminate parallel paths which may be unreliable and give false positives.
I don't know when you took your training but I am going back to the late 80's here, no RCD in boards, rewirable fuses and just seeing MCB' becoming the standard, like I said, I am no longer contesting what you are taught, I am asking in your professional opinion where an R1 + R2 can identify and hi-light issues which can be masked by doing a ELI then do you still accept that routinely doing R1 + R2 in domestic EICR's is a waste of time, I am not asking how you were trained to do it, I am asking given the dangerous situations that can be missed do you still consider R1 + R2 a pointless exercise?

R1 + R2 can confirm without parallel paths the cpc of the circuit, this can also be extended to ring mains where you can identify sockets that are spurred of the ring and also see if they are done so safely, an R1+R2 can identify multiple sockets on a single radial line of a spur and this is where a cable can overheat and no be protected by the front end device.
You cannot do this through energised tests as the results can be misleading and/or hiding hidden dangers.

 

[Nigel]

Can someone please explain how a circuit CPC can get a parallel path from?

 

[Darkwood]

Are you suggesting that a shower has a link from the CPC of the circuit to the pipework?

Strange question, have you ever seen a double insulated shower, the element, the copper tank are all usually earthed, if water is fed in copper pipe then you have a possible parallel path and you need to distinguish as I was taught that you are not testing the parallel path but the earthing conductor of the circuit unless both can serve the same purpose by design IE the armour of swa and using a core as earth.

 

[Darkwood]

Can someone please explain how a circuit CPC can get a parallel path from?

We are discussing reliance on the ELI test to confirm the integrity of the circuit cpc, unless you remove the cables physically to do the test then you may get parallel paths on circuits feeding boilers, showers, water heaters etc through copper pipework, this is not classed as a reliable earthing option although in the old days it was the method of choice, this then gives the possibility that a broken cpc in a circuit with such a parallel path could be passed as safe when in fact it is dangerous.
At some point in the last 3 decades there has been a shift in teaching methods and I am simply asking how it is justified given the scenarios I have pointed out. If it is simply down to industry risk assessment has found this scenario is so rare that it doesn't warrant the full routine of tests then fair enough, I can understand that, I however have simply asked using a professional opinion how one can be confident a circuit is safe to use if this dangerous situation may be missed by following current testing guidelines.

 

[Strima]

If you are talking about end to end tests they are not R1 + R2 tests which is where the thread currently is.

No I mean R1+R2 tests which would help identify correct wiring of the RFC. If you had a discontinuous conductor on a an RFC would an EFLI test pick this up? Would an EFLI test identify a spur off a spur?

 

[Nigel]

Strange question, have you ever seen a double insulated shower, the element, the copper tank are all usually earthed, if water is fed in copper pipe then you have a possible parallel path and you need to distinguish as I was taught that you are not testing the parallel path but the earthing conductor of the circuit unless both can serve the same purpose by design IE the armour of swa and using a core as earth.

Every single shower I have installed and/or worked on is always separated from the internal earths of the shower by a plastic inlet.

 

[Nigel]

We are discussing reliance on the ELI test to confirm the integrity of the circuit cpc, unless you remove the cables physically to do the test then you may get parallel paths on circuits feeding boilers, showers, water heaters etc through copper pipework, this is not classed as a reliable earthing option although in the old days it was the method of choice, this then gives the possibility that a broken cpc in a circuit with such a parallel path could be passed as safe when in fact it is dangerous.
At some point in the last 3 decades there has been a shift in teaching methods and I am simply asking how it is justified given the scenarios I have pointed out. If it is simply down to industry risk assessment has found this scenario is so rare that it doesn't warrant the full routine of tests then fair enough, I can understand that, I however have simply asked using a professional opinion how one can be confident a circuit is safe to use if this dangerous situation may be missed by following current testing guidelines.

I would suggest that if a sparks cannot look at a Zs reading and not know if it is where it should be in the realms of then they really should not be doing EICRs. If there is an odd reading then you can decide to dig deeper. A blanket decision to test R1+R2 is not, necessary for a competent tester.

 

[Darkwood]

Every single shower I have installed and/or worked on is always separated from the internal earths of the shower by a plastic inlet.

To be honest its been a while for me in domestic but that may be the case for the majority of showers now but I only chose that as an example, I just remember them been hard piped through no plastic, either way it was the hypothetical, if you struggle seeing the shower scenario then think boiler, water heater, immersion tank if that makes it easier... It was merely an example.

 

[Darkwood]

I would suggest that if a sparks cannot look at a Zs reading and not know if it is where it should be in the realms of then they really should not be doing EICRs. If there is an odd reading then you can decide to dig deeper. A blanket decision to test R1+R2 is not, necessary for a competent tester.

I agree to some extent but you missed my whole point, if you can get a false positive that means there is no indication that something is amiss, I don't think anyone will argue with you about a slightly higher reading on an ELI to what you expect will ring alarm bells, I am talking about dangerous circuits been masked by a parallel path thus not raising such concerns.

 

[Nigel]

No I mean R1+R2 tests which would help identify correct wiring of the RFC. If you had a discontinuous conductor on a an RFC would an EFLI test pick this up? Would an EFLI test identify a spur off a spur?

Personally I would measure across L-N when confirming the correct wiring of the ring final using the figure of eight test and then testing at each outlet on the circuit.

The R1+R2 test is to confirm there is a return path from every point, not that it is wired correctly although the results can be used to confirm this if wired in singles.

 

[Risteard]

To the contrary, I have explained on numerous occasions, it brings in a second practice you do not do so you do not entertain the idea, If I remove the shower cover take the Earth and L1 out of the terminals and the same at the distribution then parallel paths are removed and you are testing only the integrity of the cable earth, this is how I was taught, the reasons for doing so I was also taught that you thus eliminate parallel paths which may be unreliable and give false positives.
I don't know when you took your training but I am going back to the late 80's here, no RCD in boards, rewirable fuses and just seeing MCB' becoming the standard, like I said, I am no longer contesting what you are taught, I am asking in your professional opinion where an R1 + R2 can identify and hi-light issues which can be masked by doing a ELI then do you still accept that routinely doing R1 + R2 in domestic EICR's is a waste of time, I am not asking how you were trained to do it, I am asking given the dangerous situations that can be missed do you still consider R1 + R2 a pointless exercise?

R1 + R2 can confirm without parallel paths the cpc of the circuit, this can also be extended to ring mains where you can identify sockets that are spurred of the ring and also see if they are done so safely, an R1+R2 can identify multiple sockets on a single radial line of a spur and this is where a cable can overheat and no be protected by the front end device.
You cannot do this through energised tests as the results can be misleading and/or hiding hidden dangers.

Again I ask how disconnecting both ends of the cpc meets the requirements of an (R1+R2) test. The whole point of the test is to prove that the cpc is correctly connected which a completely disconnected cpc does not and cannot prove, and can be reconnected incorrectly therefore invalidating anything ascertained with the test. That isn't the recognised procedure for (R1+R2) testing.

 

[Darkwood]

You remove R1 and R2 at one end of the circuit and connect together (connector not a link from the earth bar to mcb), you then go to the other end and do the same but this time you put your meter across both R1 and R2, we were taught this method as it ensures you are only testing the circuit earth and not getting erroneous readings from what could be unreliable parallel paths, if it has changed and you were taught different then that be the case but throughout this thread I have expressed that doing it as you suggest can leave the circuit unsafe for the reasons expressed, I have on several occasions now said that if we forgot which is the method used now and taught can you not see the issues I raised and in your professional opinion are you still happy to walk away from an EICR knowing you may 'maybe on a rare occasion' have left a dangerous circuit..

I understand why you use your method.
I understand that is how they teach it now
I am not arguing that it is wrong as it expressed it may just be statistically so rare that it doesn't warrant proving the actual integrity of the cpc itself but just that you have a return path that passes requirements.

All of the above I understand, it is your professional opinion I am after and do you agree that your method can leave a dangerous situation in some cases?

If the answer is yes then I have made my point although I am not suggesting you are testing it wrong, clearly those minds that decide these matters will have factored such risks into their guidance.

I note when looking around the internet I found this is actually a subject raised on many occasions over the yrs and with conflicting answers depending where you sourced it but I have seen already a couple of older threads that do have this method been mentioned and expressing they were taught that way as was I.
Please remember I came from a generation where our Megger's were wind up (irrelevant I know) and domestic electrical safety was just basic, no RCD's or Arc detection devices in sight.
There was also a drive to change all lead piping into premises into plastic, this is probably why we had to be certain of cpc integrity and also that parallel paths were taken out of the equation as many circuits were losing earthing as it was lost by upgrades to gas and water mains, I will remind you that using the piping was once the method of choice so you can appreciate the risks in isolating it with plastic incomer. I also remember this caused a lot of hassle and people were reporting getting shocks at the time, it was even on the news if I recall so they then rolled out information leaflets to get your Earthing and Bonding checked before the works were done, some companies brought their own Sparks in to survey each installation and then quoted for any additional work to correct the installation before the work could be done.
This maybe why we have very different teachings but also shows you the obvious weakness/flaw in modern testing methods, wouldn't you agree.

 

[MFS Electrical]

Thank you very very much for taking time for a very informative response.

I've spoken to the electrician in question and tried to clarify what we needed to do to get a 'satisfactory'. I asked him if it would be cheaper for him to carry out the remedial works (c1 and c2) and therefore (if I'm understanding correctly, no requirement to perform another full EICR or if I carried out the remedial work and he then perform a full EICR again.

His response is never clear, he first advised that he wouldn't be able to do the work until after Xmas, he then started going on about downlights in the loft, I then said I'm talking about the C1 and C2 work not the C3's as I thought they were just recommendations and have no effect on whether a report gains a satisfactory or unsatisfactory. He responded that as far as he was aware all issues on the report had to be remedied but he advised me to check with building regs (uh?!).

I then stated that I was still struggling to understand why I needed to pay the full amount when originally he advised that the work would take aprox 3 hrs and he was only actually here for two because he couldn't carry out the dead testing due to the state of the CU and that he still had to go home and do the report and because it was so bad it took him longer than usual, he said it wouldn't be very nice if he rang me up and said the report is taking him longer than usual because of the state of things which he had to keep checking with NICEIC. When I said he could have still performed the dead testing another way he asked me how he could have done that!

In addition, I asked him why the certificate had "This is not a valid certificate/report" pre-printed all over it and apparently he said he sent me the wrong one...boy am I confused!!

I don't know whether I am dealing with somebody who is just trying to make my life as difficult as possible because I decided to do the electrics myself or whether he just isn't very good, even though out of 60 reviews he has 9.9/10, that's why I hired him.

You’ve been conned by someone who doesn’t have a clue how to do an EICR or what the actual codes mean. Get yourself another spark to do the EICR pronto IMHO the cert probably isn’t worth the paper it’s written on.