It also depends on the type of load - in general 16A sockets are not used in the same "plug and play" way as the 13A domestics, but there is some of the same uncertainty in some settings, like building sites and some kinds of workshops

Certainly in "known load"  installations (I'm thinking of theatrical lighting and some types of outdoor events ) where the lamp load for one socket is very much planned and fixed as cables get installed, the rules are pushed a bit. Splitters that take a single 32A plug to  a couple of 16A sockets , with no fusing down, are quite common, though they are  a source of some teeth whistling and clucking noises from 'real' sparks. There is an assumption that the folk doing the set-up  are not random public, and are capable of adding up amps and not doing something too silly so both tails get a similar load and not one side dangerously over 16A..

Mike.

mapj1 said:

It also depends on the type of load - in general 16A sockets are not used in the same "plug and play" way as the 13A domestics

Problem with 13 A domestics is that BS1362 fuses tend not to be able to cope with starting currents of chunky machines in a well-equipped home workshop. One solution, which my friend did, is to machine a piece of brass rod to the appropriate dimensions. :-0

I suspect that a 13A plug without the fuse can withstand much higher currents without overheating.  The fuse is the biggest source of heat.

I suspect that a 13A plug without the fuse can withstand much higher currents without overheating.  The fuse is the biggest source of heat.

I cannot disagree. I don't think that I have ever felt a hot BS 1363 plug even connected to say, a 3 kW heater.

Chris Pearson said:

I cannot disagree. I don't think that I have ever felt a hot BS 1363 plug even connected to say, a 3 kW heater.

1. What damages some socket-outlets? Occasionally, it's an overheating plug.
2. I've seen plugs on some appliances where multi-way adaptors have been overloaded, or there are broken conductors in the flexible cable supplied by the plug.

I don't think that I have ever felt a hot BS 1363 plug

I've come across a few. Seemingly a few EV owners with granny leads have too. I suspect in some cases at least it's a combination of events - heat from the fuse warms the socket contact springs,which means they gradually loose their temper, which results in a poor connection, with increased resistance, and so more heat. Probably not helped with the move away from pretty substantial thermosetting (urea formaldehyde?) plugs with solid brass pins to thermoplastic moulded ones with reduced c.s.a pins to allow for pin sleeving. Less mass to absorb the heat, probably less thermally conductive housing and lower surface area for heat to escape from, combined with a plastic that deforms more when warmed.

   - Andy.

I have managed to burn myself quite badly on the pin tips of a 13A plug that had been overloaded for several minutes, but it was not in good shape, the brass being quite dull. It was  an older rubber backed kind and I did wonder if the rubber had exuded something nasty that caused the tarnishing to be particularly bad. Even so  I was a bit surprised, and more generally my experience is that when they fail it is indeed the live pin that gets it worst, presumably due to the overheating caused by the fuse itself, and that is a handful of times over as long as I can remember

And on one case the plug had welded into the socket, and both had to be removed as an item - oddly on a tumble dryer of ~ 8A rating, but in a relatively damp laundry room, and had been heavily worked.

machine a piece of brass rod Note, but do not copy!.. Some designs of 13A plug can be dismantled in a way that two can be made into one with a pair of neutral pins and no fuse. Again not right and a source of alarm to all who find it later....

More generally the dissipation within the 13A plug is not something that is as well handled as in the old BS4343 /IEC 60309 styles , which  are  much more generous with the volume of metal available  for heat dissipation and the ability to handle over load.

(perhaps a smaller fuse, as in a shorter lower resistance element of the same 13 A Rating would have been better. The 6kA survival requirement might have been harder to meet though.)

Mike