On 24/06/2017 01:20, wrote:
On Saturday, 24 June 2017 00:51:15 UTC+1, Graham. wrote:
On Fri, 23 Jun 2017 16:02:56 -0700 (PDT), tabbypurr wrote:
On Friday, 23 June 2017 20:36:46 UTC+1, Tim Watts wrote:
On 23/06/17 20:05, NY wrote:
"Tim Watts" wrote in message
...
On 23/06/17 19:21, ss wrote:

What trip switch?

The over-current or earth leakage trip-switches in the "fuse box". Or in
extreme case the 60 A "company fuse" (which i think is always still an
old-fashioned melting-metal fuse). But I think you *did* know that.

The difficulty is when the short is not to earth and is a
lower-than-normal resistance but not a complete short, so you draw a
larger current (or a current through the wrong material, allowing it to
heat up) but not a current that is large enough to blow/trip the cutout.

It sounded to me like the PP thought there was some magic fire detecting
device...

Back to the point, the fuse in the fridge's plug would be the first to
go, unless there was an RCD *and* the appliance is a Class I (earthed)
device (which seems likely for a metal fridge).

But it's possible to start a fire with no serious overload - with the
right conditions, an amp at 230V can make things extremely hot - and if
the hot thing is next to a combustible thing...

The bimetal cutout on the fridge compressor, the plug fuse, the MCB, the RCD, the supplier's fuse and if present (very unlikely) an AFCI are all fire preventing devices. All of them only work on a percentage of fire causing faults.

I've never seen an AFCI, I see they are now common in the USA and that
they are prone to false tripping.

AIUI the 18th will make them common here. A workaround will be needed for old arcy sparky equipment.

The 18th edition draft makes a brief mention of them, but gives little
indication of when or how they would be used. It basically (at this
stage) allows for their use.

(I will post the draft text in another thread)


--
Cheers,

John.

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