On Tuesday, 18 August 2020 00:57:27 UTC+1, John Rumm wrote:
On 17/08/2020 23:04, tabbypurr wrote:
On Monday, 17 August 2020 22:29:49 UTC+1, Cursitor Doom wrote:

You frequently use the term "fault current" which crops up
frequently when professional electrical engineers are discussing
installations. However, for everyone else, it requires
clarification. I'm not an electrician, so I have no idea when you
use that term whether you're referring to *short circuit* current
or *earth leakage* current or something else altogether (unless you
use an example as you did above but even that's not watertight).
And then there's that lot that read this through Homeownershub -
God only knows what *they* make of it. ;-


The electrical wiring regs' meaning of 'fault' is a hard zero ohm L-N
short..

or L-E

John uses that meaning. Those of us that are more into
repairing things tend to use 'fault' to mean any failure to operate
correctly. The I with some Es seems to like to define existing terms
differently to everyone else, classic communication poor practice.

Being one who also repairs stuff, I am fully aware that the colloquial
use of "fault" is far less specific than that when used in engineering
and standards documentation for electrical systems.

No, the usage of 'fault' to mean zero ohm short only is specific to UK wiring regs not specific to engineering.


However if you are
going to have a meaningful discussion on fusing etc, it is quite
important that everyone uses a consistent set of terms when it matters.

Good luck with that


So sure, I am quite happy to agree that my radio may have a fault
because it can no longer receive FM, or the computer PSU has a fault due
to too much ripple on the 5V rail - but you do need a way of describing
and differentiating between when something has gone badly wrong and a
device is now trying to ingest the full output of the local substation,
Vs. its taking an amp and should only be drawing 50mA.