A
Ashley2
Is there any way of getting the PEFC if you only have the Ze?
Discuss Is there any way of getting the PEFC if you only have the Ze? in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net
I would have thought that the PFC is always measured (Taking the higher of the PEFC/PSCC), & then a calculation to ensure that the protective device is able to handle the PFC. This is correct
Some of the information given was as follows: Information to what?
The Ze given was 0.8Ω
The voltage given was 230 V a.c.
The protective device was 100A.
PEFC should be less than the 100A. This is why I asked whether there was a way of calculating the PEFC with the Ze given.
it is ohm's law I = V/R, so in the case you mention. I = 230/0.8 = 287.5A. what makes you think it should be <100A. the rating of the fuse has nothing to do with it.
The 100A information was already given, for the protective device, as was the Ze for the supply. And the question asked what the PEFC was. Bear in mind that this was a part B scenario for 2391, & the 100A for the protective device was already given, therefore, in the first instance, the PEFC must be less than the protective device.
I am looking at 435.5.1: which states that the breaking capacity rating of each protective device shall be not less than the prospective fault current at its point of installation". I strongly suspect that it is ohms law, but the 100A protective device was the mind boggler, taking into account 435.5.1.
the PEFC must be less than the protective device
I disagree, 2391 is supposed to be tough, it's supposed to make you think. If it was easy it wouldn't be worth havingKISS should be the motto in 2391.
I don't mean that, KISS, is basically to ensure that you focus on the issue, & in this instance the issue was Ohms law. But in an examination environment your are always looking for that one issue that 'they' might be trying to trip you on. In relation to KISS, I believe that it is relevant in all areas, & not just within this context. KISS focuses on that which is directly relevant, & in this case, Ohms law was directly relevant.I disagree, 2391 is supposed to be tough, it's supposed to make you think. If it was easy it wouldn't be worth having
Reply to Is there any way of getting the PEFC if you only have the Ze? in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net
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