[recovery and rehydration break between bouts of extensive mowing ]
Kind Regards, John
Indeed I do, which made me mildly surprised that you were taking the 'OSG approach' However ....You know my views on the OSG.
Very good point. If one is talking about measurements (taken at ambient temperature), rather than calculations, then I have to agree/concede that the 'OSG approach' does make more sense, for the reason you give.I would think that reducing the maximum Zs value is easier than correcting all the measurements taken, bearing in mind that the meter can only measure what is there.
Fair enough, but I would think you could actually go much further than that - even the difference between 10° and 70° is only a factor or 1.24 (or 0.81 if you want it 'the other way up') and the effect on total Zs will be less than that (because of Ze), so you could probably be confident that any measured Zs which was less than about three-quarters of the BGB figure would be OK.However, in practice it is not so often necessary. ... When calculating or measuring the Zs it is far below the BGB given maximum maximum, for example, my own guide is that if it is less than a quarter that figure then I do not need to do any adjusting as all will be well regardless.
Perhaps, although the OSG's (very 'conservative') view is clearly that one should work on the basis of what the R1+R2 would be at 70°, and the BGB itself is pretty silent about what assumptions one is meant/allowed to make about temperature.I presume that the maximum maximums in the BGB are so that the installer can calculate whatever allowance for temperature is seen fit. ...None at all for a 6A lighting circuit, for example ???
Kind Regards, John