On 22/09/2017 19:55, Scott wrote:
On Mon, 21 Nov 2016 22:13:13 +0000, John Rumm
wrote:

On 21/11/2016 21:45, bert wrote:
In article , "Dave Plowman (News)"
writes
In article ,
wrote:
How do you chose the "correct" fuse for an extension lead (assuming
the lead is designed for a 13A load)?

I can't imagine why you assume extension leads are all 13A rated. I
assure you they're not. 10A leads get a 10A fuse, 5A leads get a 5A fuse
etc. Hardly a challenge.

Rather silly given the average person won't have a clue how much current
things take. And if, say, a 5 amp fuse blew would likely fit a 13 amp
one.

Safer to make them all 13 amp. Much as has happened with all leads these
days.

How can a 13 amp fuse make it"SAFER" than a 5 amp one?

Not the fuse, the flex / appliance.

If you design your product so that it is adequately protected by a 13A
fuse, then there is nothing the user can do to make it unsafe.

If you design it so that its requires lower fusing, then it means there
is a danger of it having inadequate fault protection if the user fits a
13A fuse without appreciating the implications.

I have wondered about this. If an appliance is designed to EU
specifications (with a different plug for UK models) does this mean it
is designed to operate safely with a 16 amp fuse given that Euro and
Schuko etc plugs are unfused and I understand circuits are fused at 16
amps.

Yup.

Its ok for the "plug in" appliance itself to require protection by a
lower rated fuse, but in which case it must include that fuse *in the
appliance* itself - it can't rely on there being a fused plug. (note
this may not apply for and appliance designed to be hard wired to a circuit)

To be saleable anywhere in Europe, the flex on the appliance will have
to get adequate fault protection when protected by the typical 16A
circuit breaker common in continental Europe. So this is usually done
by a combination of specifying a minimum flex conductor cross sectional
area, and also by specifying a maximum length of flex.



--
Cheers,

John.

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