Mike Barnes wrote:
In uk.d-i-y, John Rumm wrote:
The crux of the issue is that if you have a circuit capable of
supplying a current significantly in excess of the rating of the
appliance flex, then you need a overcurrent protected plug. So its not
really anything to do with the circuit being a ring or not, even if
that is the most commonly encountered 32A circuit in the UK.

I agree, but most of the world doesn't have fused plugs. So is there a
major problem with, say, those 3A flexes running to laptop power bricks,
plugged into a radial circuit limited to (say) 16A??

In this case you are assuming that the internal overcurrent protection
in the PSU will protect the flex[1]. This does however leave a *small*
risk that the flex gets reused on another appliance with a higher load.

(However since the connector choice will usually limit what you can
connect the flex to anyway this is not usually a problem in real life,
unless someone gets inventive with home made adaptors - the telefunken
socket to four way socket outlet might prove interesting! ;-)

[1] This is a similar arrangement to the way a spur from a ring circuit
is protected - the protection from over current moving to the
destination end, and the protection from fault currents remaining at the
origin.

--
Cheers,

John.

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