Non-motoring > Random question No 3342. Miscellaneous
Thread Author: R.P. Replies: 30

 Random question No 3342. - R.P.
I was volunteering at our local theatre today (Lady in The Van - quite good) and as my attention went I noticed a large LED type spotlight - obviously quite knew on a girder just above head hight. It was disconnected from the mains and its trailing cable was wrapped around the girder and I noticed that the plug at the end was a large 3 pin plug with round pins. Is there a reason for this ?
 Random question No 3342. - Old Navy
Possibly a 15 amp plug. Hardly needed for a LED lamp but may be compatible with the existing pre LED system.
 Random question No 3342. - henry k
It is 15A plug. Still sold in the UK ( standard in South Africa).
I have several modern versions bought in SA in order to make my ow extension leads/ adapters prior to adapters becoming widely available.
Some have transparent bases so I called the ladies plugs ( you can view how they are wired!!
Tin hat ....

IIRC correctly 15A are widely used in lighting rigs etc in the theater / film world.
 Random question No 3342. - henry k
Ebay in SA shows

www.bidorbuy.co.za/item/220987690/Plug_Top_Dedicated_15A.html
A slim line version of standard plug
www.bidorbuy.co.za/item/205684301/Crabtree_Domestic_3_Pin_16A_White_Plug_Top.html

A search on Ggoogle for 16A plug south african will find examples
 Random question No 3342. - Zero
Round pin plugs used in the UK, mostly to differentiate circuits from standard 13 amp ring mains, usually lighting. All perfectly up to spec.
 Random question No 3342. - Kevin
Usually done for outlets of dedicated power circuits where you don't want Mrs Mop plugging in the vacuum cleaner or Bob the Builder using it for his kettle and power tools.
 Random question No 3342. - henry k
>> Usually done for outlets of dedicated power circuits where you don't want Mrs Mop plugging
>> in the vacuum cleaner or Bob the Builder using it for his kettle and power tools.
>>
Did not work in the old days when I worked at the BBC. still had important bits of kit switched off by the cleaners etc.
BBC used either A D&S plug ( but that was also used in some council housing estates) e.g Wimbledon Common.
www.plugsocketmuseum.nl/DormanSmith1.html
or a "special" plug with angled square pin and other round pins.
www.plugsocketmuseum.nl/British2.html
#!8 but I have never seen the innards
Wow - the old grey matter worked. this plug last seen by me 50+ years ago.

P.s.
Many will remember
i.ytimg.com/vi/D1L1M3BePtw/hqdefault.jpg

2A, 5A and 15A UK round plugs.

 Random question No 3342. - tyrednemotional
...most of my University was wired with Wylex sockets (late 60's early 70's).

www.plugsocketmuseum.nl/Wylex1.html

...the hall porters used to make a small fortune from the annual rental of plugs to subsitute for the "normal" 13A variety.

 Random question No 3342. - Timeonmyhands
They use the old 15amp plug top because there is no fuse in them, don't want to send electrician up to gantry to change a fuse.
 Random question No 3342. - Zero
>> They use the old 15amp plug top because there is no fuse in them, don't
>> want to send electrician up to gantry to change a fuse.

No fuse is one of the reasons a lot of sparks end up hanging from the ceiling smoking gently in the breeze
 Random question No 3342. - henry k
>> >> They use the old 15amp plug top because there is no fuse in them,
>> >>don't want to send electrician up to gantry to change a fuse.
>>
>> No fuse is one of the reasons a lot of sparks end up hanging from the ceiling smoking gently in the breeze
>>
Love that description.

Some of the first lessons I was told.
1. Do not mock a sparks working up a ladder with his hand in his pocket.
It is because if he gets a belt from the mains he cannot grab an earth with the other hand.
( no further effects mentioned )

2. If a sparks gets a belt kick the steps from under him.
Hopefully he will survive maybe with a few/many broken bones.

3. (One I smiled at. ) If you must test if something is live ( without a tester/meter ) then use the back of your hand.
If you do get a belt your muscles contract and your hand is thrown away from the source.

The good old days before Alf n Stanley. :-)
 Random question No 3342. - Old Navy
>> 3. (One I smiled at. ) If you must test if something is live (
>> without a tester/meter ) then use the back of your hand.
>> If you do get a belt your muscles contract and your hand is thrown away
>> from the source.
>>
>> The good old days before Alf n Stanley. :-)
>>

I remember that one from my firefighting training, when feeling your ay along a wall in nil visibility use the back of your hand (glove) for that reason.
 Random question No 3342. - Zero

>> Did not work in the old days when I worked at the BBC. still had
>> important bits of kit switched off by the cleaners etc.

I've had major data centres switched off the air by all sorts of things, even one that, unknown, was powered by by the tube line services that ran underneath.
 Random question No 3342. - CGNorwich
There were little plugs that you could plug into light sockets too I seem to remember.
 Random question No 3342. - bathtub tom
>> There were little plugs that you could plug into light sockets too I seem to
>> remember.

My father-in-law had that arrangement in his garage. I was working round his house and needed to drill a hole in something. He produced this old Wolf brand, aluminium bodied electric drill with a light bulb type bayonet, 2-pin plug on the end. I plugged it in and put my neon screwdriver on the body - it was live.

He had no idea of what the different wire colours meant and used to connect them randomly.
 Random question No 3342. - Fursty Ferret
Most plugs / sockets in theatre lighting are 15A because the dimmers are typically rated at 16A / channel.

Also, as Zero says it's to prevent non-lighting equipment being plugged into the dimmer as an inductive load is likely to knacker the dimmer.

Dredging back memories from my summer job as a lighting technician. :-)
Last edited by: Fursty Ferret on Sat 5 Mar 16 at 20:05
 Random question No 3342. - Ian (Cape Town)
Indeed.
The Snapper.
Opens with one twist of a screwdriver, and the prongs are colour-coded, so you can't wire it wrongly.
 Random question No 3342. - Dog
I have 3 x 15amp sockets in my dining room, which I plug the table lamps into. There are also 10 x 13amp sockets - overkill or watt!
 Random question No 3342. - zippy
I see these round pin sockets in hotel bedrooms quite frequently - sometimes in new hotels.

What can they be used for there?
 Random question No 3342. - Timeonmyhands
2 amp round pin sockets connected to the lighting circuit so you can turn off the standard lamp/uplighter from the wall switch.
 Random question No 3342. - Slidingpillar
Walsall gauge plugs can be fun.
tinyurl.com/zm6kat4
Same size and shape as a normal 13A plug, but with the pins turned through 90 degrees

They were used for some technical supplies in the BBC as a means to stop non-technical things being plugged in. As a result, they were kept in the stores. And yes, we did put one on somebodies kettle and watched them try to plug it in to a normal socket.
 Random question No 3342. - Harleyman
Ooh, I'd love to have watched that!
 Random question No 3342. - sooty123
At work we've had no end of different sockets for everything. Even though there is a wide range of volts and frequency from 200 dc to 415ac and just about everything in between, there's no end of different connectors. We used to have a huge box to 'cross connect' them all, they were called daleks. Very heavy god knows what they were made from, solid granite i think.
 Random question No 3342. - Robin O'Reliant
Who needs plugs?

Just poke the wires into the holes and jam them there with matchsticks. You lot really need to think outside of the box.
 Random question No 3342. - bathtub tom
>> Just poke the wires into the holes and jam them there with matchsticks. You lot
>> really need to think outside of the box.

Using your Yale key in the earth hole to raise the shutter first. No need for matchsticks, removing the key lets the shutter down on the wires.
 Random question No 3342. - R.P.
Well thanks...I'm suitably enlightened so to speak. !! Ill pick the 15 amp plug in the 16 amp circuit as my favourite...
 Random question No 3342. - Ted

Me ole mam used to do the ironing using the light socket above the ironing board. There was an adaptor so a bulb could be fitted as well. I was given some model railway stuff a while back including a Meccano controller which also plugs into a bayonet light socket. I've tried it and it doesn't do anything..and the casing isn't live. Destined for the bin, I fear.
 Random question No 3342. - henry k
>> Me ole mam used to do the ironing using the light socket above the ironing board.
>> There was an adaptor so a bulb could be fitted as well.
>>
You beat me too it.
I remember such an adapter.
It was a case of no other option as having a gas cooker there were no power sockets in the home. Just like this.
www.oldandinteresting.com/images/electriciron1938.jpg

It is an interesting situation if homes had an early electric cooker with slow to warm up electric rings then an electric kettle was needed.
The big wall switch incorporated ( initially a 15A socket) and later a 13A socket for the kettle.

www.ebay.co.uk/itm/MK-K5011WHI-Cooker-Control-Unit-with-Neons-Larger-Metal-Plate-Type-/160841527475

www.screwfix.com/p/british-general-45a-1-gang-double-pole-cooker-switch-white/45659
www.cef.co.uk/catalogue/products/4034095-50a-2-gang-dp-cooker-switch-with-neon
www.screwfix.com/p/1-gang-45a-cooker-control-unit-white/3285d

Interesting that the old big versions persisted for so long.

Finally - see what else is available :-( Scroll down.
www.alamy.com/stock-photo/unsafe-electrical-wiring.html
 Random question No 3342. - Slidingpillar
>> Me ole mam used to do the ironing using the light socket above the ironing board.
>> There was an adaptor so a bulb could be fitted as well.
>>
You beat me too it.
I remember such an adapter.


Got one somewhere, my father had a few and I kept one for the black museum. Probably used for his father's house which had hideously inadequate wiring.
 Random question No 3342. - Ted

When I started stepping out with current SWM, her dad's house was fitted with Wylex sockets. I changed them all to modern 13 ampers. I should have let SWM do it, she gained membership ot The Electrical Association for Women.....a qualification I don't think she ever used !

I was given a lot of stuff by an electrician pal...amongst it was a single gang light switch in a very fetching bright red plastic....haven't used it yet !
 Random question No 3342. - Ted
I have a 5 amp round pin socket and plug which I used in the last caravan for connecting some 12V dc appliance...probly the telly.

During the last major re-jigging of the parlour, I put in a separate ring main of 4 sockets run through a 2 gang switch by the door. This runs the 3 table lamps and the display cabinet...now all LED like the rest of the house. Convenient to switch them all on at once.
Last edited by: Ted on Sun 6 Mar 16 at 15:41
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