Well, it is in the sense that any C1s or C2s mean that the installation is "Unsatisfactory" (aka 'fail'), whereas no C1s/C2s means that the installation is 'Satisfactory' (aka 'pass').The EICR is not a fixed pass or fail like a car MOT ...
As often discussed, that's no different from some aspects of an MOT. Just as with EICRs, there are things which cannot (or cannot easily) be quantified, hence subjected to proscriptive pass/fail criteria ('limits'), and which hence rely on the judgement of an inspector - e.g. the amount of play in a bearing or steering joint, the amount of corrosion of brake pipes, the degree of rust in body parts etc. etc.... it is down to the inspector as to if he feels it is dangerous (C1) or potentially dangerous (C2) ...
Your calculation is obviously correct. I suppose that, since those figures are "by enquiry or by measurement", it's just possible that the 2.5 kA figure was obtained 'by enquiry', but that's a bit far-fetched and probably unnecessarily 'generous' to the perpetrator!Having read this thread with interest, and looked at the OP's EICR - isn't the PFC figure at the top of the second page also wrong ? I make the PFC 1.44KA for a Ze of 0.16 on 230V supply (230/0.16 = 1437). or am i missing something?
Since there is just one PEN at the origin of a TN-C-S installation, the PEFC and PSCC at the origin surely must be the same thing, mustn't they?The PFC is the greater of PSCC and PEFC so it could be correct but as the installation is recorded as TN-C-S this is unlikely.
The PFC is the greater of PSCC and PEFC so it could be correct but as the installation is recorded as TN-C-S this is unlikely.
Perhaps it is actually still TN-S but we are advised to treat such installation as TN-C-S.
Yes, I read that before, but didn't totally understand it.Perhaps it is actually still TN-S but we are advised to treat such installation as TN-C-S.
Ok. Strictly speaking I should have said:It surely would not make sense to 'treat an installation as TN-C-S' if visual inspection clearly indicated that there was no G/Y connecting the cutout to the MET, would it?
Well, all sorts of things could be.On the other hand, if inspection indicated that there was a connection between cutout and MET, then if there were also an (effective) TN-S connection to the MET ('in parallel' with the TN-C-S 'earth') then that would, indeed, result in the us usual situation of PEFC being greater than PSCC - but, again, that situation should be apparent on visual inspection.
I still don't really understand.Ok. Strictly speaking I should have said:
"Perhaps it is actually still TN-S but we are advised to treat such installation as PME."
As there is no option on the certificate for PME perhaps it has been recorded as TN-C-S and it is this that is the error.
Fair enough. In any event, we don't know where the 0.16Ω Ze 'came from', and the figures I posted above indicate that the recorded R1+R2 and corresponding Zs figures do nothing to support any particular value of Ze - as I showed, the figures for one of the circuits suggest a Ze of 0.02Ω, which would lead to a PFC at origin of 11.5 kA !I was merely pointing out that out of Ze 0.16, PFC 2.5 and TN-C-S, Licklieder was only considering that the PFC 2.5 might be the mistake.
As I understand it, the fact that the DNOs have neglected to maintain their TNS sheaths means that that sheath is connected to the Neutral conductor - somewhere.A DNO-supplied 'earth' has to be either TN-S or TN-C-S, and that's all the installation 'knows' (or cares) about.
Not at the premises but - somewhere.'PME' is something that DNOs do (have to do, at least in UK) to make TN-C-S a little 'safer' - but, again, an installation knows nothing about that. I suppose they could also 'PME' TN-S supplies if they wanted to, but I'm not aware of their doing that.
I'm not sure what real difference that makes to anything - after all, a TN-S sheath is always connected to the neutral 'somewhere', even if only at the tranny.As I understand it, the fact that the DNOs have neglected to maintain their TNS sheaths means that that sheath is connected to the Neutral conductor - somewhere.
That's the bit I'm having difficulty with - 'regarded' by whom, and in what context(s)?Because of that apparent TN-S supplies should be regarded as TN-C-S and/or PME.
... and, also 'once again', I agree with you. In fact, I'm not sure that the original suggestion was that it was necessarily the "division sum" which was wrong - merely that 230V, 0.16 and 2,500A do not 'work together' ... which, as you say, means that the 0.16 and/or 2,500A figures must be 'wrong' (and remembering that, at l;east in theory, either of both of those recorded figures could have been ascertained 'by enquiry').Once again - I was merely pointing out that the mistake in the figures could be because of multiple reasons; not dividing 230 by 0.16 and getting 2.5.
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