On 26 Jan 2021 at 00:58:16 GMT, ""Rod Speed""
wrote:
"NY" wrote in message
...
"Tim Streater" wrote in message
...
I thought their "****ty two-pin sockets" were rated at more than 5 A. I
know that high-power devices like tumble-driers and washing machines (on
presumably electric fires) tend to be hard-wired in 220 V (like our
cookers are) but portable devices like hair drivers and vacuum cleaners
can be powered from a 2-pin power socket, so those sockets must be rated
for more than 550 W (110 V, 5A).
Ah, https://en.wikipedia.org/wiki/NEMA_connector says that 2-pin NEMA
(US) mains plugs are rated at 15 A.
They may be rated at 15A but the fire danger is still real enough. Partly
because the current is twice as high as we'd have it (so four times the
heating effect in the plug/socket) but also because their plugs are
unbelievably flimsy. Describing them as "****ty" is just me being polite.
Are you saying that a plug and a socket that are stated as being rated at
15 A can't really be used for that current because of the risk of
overheating? If they overheat, doesn't that mean (by definition) that they
*aren't* rated at 15 A?
And in fact you were even concerned that passing *5* A through the plug
and socket might cause overheating problems. So what *is* the maximum safe
current that does not cause overheating? Even less than 5 A?
I think in fact the problem is that those thin pins, and the fairly small
contact area between pin and socket, aren't *really* rated at 15 A even
though it stated that they are. So it's the rating that is wrong.
Nope, thats the rating and it isnt wrong.
Here in the UK, if the plug is rated for 13A, that means it is safe to run
a 3-bar electric fire (3 kW, which is 12.5 A at 240 V) through that plug
and socket without it overheating to dangerous levels (melting of
insulation) no matter how long it is left running. Presumably there is an
equivalent real-world figure for US 2- or 3-pin plugs - and it may well
not be as high as the stated 15 A!
Its 15A
Despite the rating and the fact that they often work alright, it's not
uncommon for UK socket/plug combinations to overheat with a long term load
around 10-12 amps.
--
Roger Hayter