3 pin socket

[Diver Fred]

deleted - Duplicate

 

[Diver Fred]

I think its a bit of a stretch to justify 70 year old plugs because of some outlier case of a paranoid nightclub owner and his nefarious cleaners.

In fact, i think it probably a cautious thing to do to update the plugs as you really don't want to be plugging in very old stuff in to those things.
What if, for instance, a young lad was to find his grandads old drill in the shed, recognize the plug, and go into the house and plug it in, do you think the 70 year old insulation would be up to scratch?

There are far better ways of securitizing plugs and sockets other than using outdated standards.

All of the lights where I worked were connected via the 5Amp 3pin sockets a per your picture. I agree it's not common in domestic properties but in the old days of radial connections such connections were. Rewired 2 or 3 houses away from such plugs. Als used to be used for mains powered clocks.

 

[Diver Fred]

And if you want to be really difficult - Electrak

 

[Harry Bloomfield]

Als used to be used for mains powered clocks.

There was a special plug and socket made for clocks, which were sold as a pair, fitted with a 1amp (maybe 1/2 amp fuse).

 

[SimonH2]

Dorman even offered a round pin version of the fused plug for a time. The live pin forming the fuse, which in use could unscrew leaving the fuse in the socket and still live.

They were the standard plug & socket in the local shipyard when I were an apprentice <cough> decades ago. We called them "D&S" - Dorman Smith ? The idea being that since they were an "oddball" and not fitted anywhere else, little incentive to nick the plugs. I recall being told to use insulated pliers if anyone had a "live pin" come out in the socket - especially in an unswitched socket

It was also said that half the houses in Barrow were fitted with D&S sockets

At uni, some of the colleges had 5A sockets under the refectory tables. The 5A plug needs a much smaller hole than a 13A plug. Depending on the occasion, they could either use electric lights (plug & flex down the hole, light fitting seats in hole); or just slot a candle holder into the hole where candle lighting is desired.
In our college rooms, we had one or two 13A sockets which were on a metered power circuit (along with the lecky fire), and some 2A sockets on the lighting circuit that wasn't metered. The local Woolies sold many 2A plugs, and there was a trade in outgoing students selling them on to freshers. I even found a little immersion heater, 500W rating, designed for boiling a single cup of water - any chance to keep the lecky bill down

When my parents moved into their previous house, many of the socket plates had one 13A socket, and 2off 2A sockets protected by a fuse. Given that when it was built, the most common load would have been lighting, it meant more usable outlets than you'd get fitting double 13A sockets.
That's still a valid thing to consider. There are 5A, and to a lesser extent 2A, sockets that take up less space than a normal single accessory plate - so an opportunity to provide a number of sockets for lighting without having the "wall of sockets" effect you'd get with 13A sockets.

 

[JohnD]

There was a special plug and socket made for clocks, which were sold as a pair, fitted with a 1amp (maybe 1/2 amp fuse).

Also used for extractor fans, very handy as you could unplug for cleaning, maintenance or swapping for new, especially in a office or workroom where you might have dozens or hundreds of them, and they could be swapped in a couple of minutes and worked on elsewhere.

 

[JohnW2]

Also used for extractor fans, very handy as you could unplug for cleaning, maintenance or ...

Indeed - but no need for the past tense - they are still readily available, and it's not too long ago that I last installed one. This from TLC, albeit at an exorbitant price. I've usually used the smaller ones, which don't occupy s whole standard face plate ...

Kind Regards, John