No. Logic tells us that 2 wire high current testing is always the better measurement to utilise. Low current loop testing is simply a compromise due to the use of residual current devices.
As I said, I do not dispute the fact that such is probably true BUT, as I also said, I think many (most?) people would be uncomfortable using the 'better' of two measurement results (both obtained using reputable and calibrated equipment) - particularly if the 'worse' of the two results were non-compliant with relevant regulations.
Well then I would dispute their logic. I wouldn't even entertain a low trip setting on non-RCD protected wiring.
If one doesn't believe that a particular mode of testing of a piece of test equipment gives accurate results (even if the manufacturers claims it does), then I don't think one should employ that testing mode.
It doesn't, because even the instrument manufacturers will state unequivocally that high current loop testing is the preferred means where possible.
I don't doubt that they do. However, they presumably will also make claims about the accuracy of 'no trip' measurements made with their equipment - so if such a test produces a result which, at the limit of the claimed accuracy, would still be 'non-compliant', then it would be hard to see how one could justify 'dismissing' that result, wouldn't it ?
You may be surprised to learn that they claim nowhere near the measurement accuracy which many seem to assume. They are more indicative.
I suppose that depends upon what you think would surprise me (and the 'many others'). My fluke 1652 only offers 'no trip' tests, and the claimed accuracy (for loop impedances up to 20 Ω) is:
I thought yours was a 1652b, the same as mine.As I replied to Securespark, that's because it is a Fluke which, I believe, is better than others and the one with the famous 'Hoover type name' being, I believe, particularly bad at it.
I think we've been through this before. Mine is just called "1652" (no "b"), but it seems that it is all-but identical to yourd. In particular, it has just one loop impedance option on the 'trst selector switch' ("Z|") and the manual contains the same statement as trhat which you've just posted, namely ....
Yes, I realised that. What I'm not certain of is whether your 'belief' is actually correct (I've certainly heard others suggesting that it may be).
Not exactly, they call it a two-wire loop measurement.
I know they do, but (as you illustrate) they then go on to tell one to 'select L-N'.
That's what I suggested, isn't it? However, what surprises me (and, I suppose, the reason I'd never thought about this before), is that they do not anywhere suggest that (with L-N 'selected') one can reverse the leads to get a high current L-E loop impedance measurement.
Yes, because that is the two connections that do the test.
No, you said your meter couldn't do it.
You don't reverse the leads; you just connect N to Earth. The meter doesn't know.
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