On 21/08/2020 03:18, Graham. wrote:
John Rumm Wrote in message:
On 20/08/2020 15:03, Andrew wrote:
On 18/08/2020 17:50, John Rumm wrote:
On 18/08/2020 16:03, wrote:
On Tuesday, 18 August 2020 15:58:52 UTC+1, John Rumm wrote:
On 18/08/2020 11:45, tabbypurr wrote:
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.

The UK wiring regs don't use "Fault" to mean zero ohm.

"Fault Current", is a specialist English and an engineering term used
by many, not only in the UK.

AIUI fault current does mean the current resulting from a zero ohm
connection from live to not live.

No, you can have line to line fault currents (and line to neutral is
also "live to live" if one is being a pedant)

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

Make up your own terms if you like, if you think it will help.

No need. 'Fault' is in widespread use to mean any failure, including
in engineering.

and "Fault Current" is not, So why use Fault if you mean Fault Current?



Coows scratching on a rural wooden post carrying HV 3-phase used to be
a common live-to-live fault.

That sounds like it could be bad news for the cow!

If it's any consolidation (to the cow) 1kV AC is *LOW* voltage

Probably not - cows (and other large quadrupeds) are particularly
sensitive to electric shock due to the ease with which they can get a
potential gradient applied across their legs.

(and the post did say HV 3-phase - so I am assuming 11kV or similar)


--
Cheers,

John.

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