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AndiiT 28th Jun 2011 7:12 pm

Another unusual plug and some other questions
 
4 Attachment(s)
Hi,
A recent purchase of mains plugs to add to my collection brought with it a strange round pinned 3 pin MK branded plug which at first sight appears to be a "standard" 5 amp one. Closer investigation reveals that the pin spacing lies somewhere in between that of a 5 amp 3 pin and the Dorman and Smith Britmac "Wandsworth" 13 Amp plug. I have enclosed pictures of all three for comparison purposes.

It has been suggested that the plug in question may have been used in industry and, as the earth pin is of an odd design, maybe with a latching socket.

My other questions relate to the progression of plugs and sockets over the years - from a logical point of view it would seem that the two pin 5 amp was first followed by the 2 pin 15 amp, the three pin variants being produced later. That said where does the 2 and 3 pin 2 amp plug/socket combination fit in?
I know that Wylex plugs had an earth pin so were they produced after the 2 pin plugs and sockets?

These questions arise out of pure curiosity.

Thanks in advance

Andrew

Herald1360 28th Jun 2011 10:57 pm

Re: Another unusual plug and some other questions
 
ISTR a 10A 2-pin plug and socket existed- maybe some evolution of that?

MikeyPP 28th Jun 2011 11:24 pm

Re: Another unusual plug and some other questions
 
Does this help > http://en.wikipedia.org/wiki/BS_546

Leon Crampin 29th Jun 2011 10:48 am

Re: Another unusual plug and some other questions
 
I have a dim recollection of a 3 pin 5A plug being made which was interlocked with the switch on the socket. When the plug was inserted, the switch would move to "OFF" and once switched "ON" the plug was locked into position.

This would explain the ramp and the notch on the earth pin.

Leon.

ThePillenwerfer 29th Jun 2011 12:54 pm

Re: Another unusual plug and some other questions
 
I've got some old text-books from the '30s which say that on DC mains any socket above 2A must be switched and interlocked so the plug can't be pulled out with the juice on. I would suggest that these plugs were to work with such a socket.

- Joe

AndiiT 29th Jun 2011 9:25 pm

Re: Another unusual plug and some other questions
 
Quote:

Originally Posted by Leon Crampin (Post 444868)
I have a dim recollection of a 3 pin 5A plug being made which was interlocked with the switch on the socket. When the plug was inserted, the switch would move to "OFF" and once switched "ON" the plug was locked into position.

Hi,
I once owned a plug and socket combination like this some years ago, this was of the standard BS546 5 amp pin spacing, unlike the one shown in my pictures, the difference being that the socket I owned had a switch which would not move to the on position until the plug was inserted and the plug could not be removed once the switch was in the on position.

Regards

Andrew

dseymo1 29th Jun 2011 9:45 pm

Re: Another unusual plug and some other questions
 
That would make a lot of sense for DC, as it would of course prevent an arc being drawn on withdrawal of the plug.
Wouldn't be a bad safety idea for all mains sockets though.

MikeyPP 29th Jun 2011 10:23 pm

Re: Another unusual plug and some other questions
 
Maybe as a sort of precursor to sleeved pins to avoid partially removed plugs

russell_w_b 29th Jun 2011 11:13 pm

Re: Another unusual plug and some other questions
 
Wouldn't be to automatically operate the (interlocked) switch mechanism as the plug was inserted and withdrawn, would it?

Peter.N. 29th Jun 2011 11:53 pm

Re: Another unusual plug and some other questions
 
Regarding progression I can give my experience of this, which is not a lot. My grandparents house which was built in the early 1900s and presumably had electricity installed later only had two sockets in the whole house, a 2 pin 5a in the kitchen which looked like a tumbler switch with the socket on the top and a two pin 15a upstairs.

The house I was brought up in was built about 1937 and had 2 pin 5a and 2 pin 15a plugs, the houses the other side of town had Wylex plugs.

Just after the war, probably about 48/49 a new large council estate was built near us and was universally fitted with the 13a fused pin plugs centre picture.

Some houses of the period did have 3 pin plugs but I think it depended on the price of the house more than anything whether you got 2 or 3 pin plugs.

My grandparents house had ceramic fuse carriers house in a nice wooden box with a glass front. Ours had metal clad boxes with the exception of the lighting box which if I remember correctly was a MEM whith a knob on the front that pulled the fuse carrier out to switch the supply off.

All these houses were in the Bromley area.

Peter

Peter.N. 30th Jun 2011 9:40 am

Re: Another unusual plug and some other questions
 
Having thought about my last post there were a couple of errors. Our house had 5 amp and 10 amp plugs not 15a as I said, also we did have 3 pin plugs in the kitchen, one for the kettle and one for the cooker but all others were 2 pin.

Peter

ThePillenwerfer 30th Jun 2011 11:25 am

Re: Another unusual plug and some other questions
 
I think that in the old days, ie pre-war, a lot was down to the preference of whoever did the installation.

My house only had 15A 3-pin sockets, and not many of them, whereas further up the road they had a mixture of 5A and 15A in both 2 and 3-pin versions.

Also around here, and I've heard of them in other places 'Up North,' were some with a round central Earth pin with flat live and neutral at either side.

- Joe

Peter.N. 30th Jun 2011 2:27 pm

Re: Another unusual plug and some other questions
 
"Also around here, and I've heard of them in other places 'Up North,' were some with a round central Earth pin with flat live and neutral at either side."

I remember those too, mostly on the 'posh' side of town. What you say is probably quite right, the two halves were by different builders.

Peter

russell_w_b 30th Jun 2011 6:18 pm

Re: Another unusual plug and some other questions
 
'Posh' side of town, eh?

A glance through the 1929 'Sunco' catalogue finds component reference to 'competitive' installations, which I take to mean tendering for contracts, and components suitable for 'high-grade installation work' - which I take to mean the posh side of town: country houses, more salubrious residences, etc...

I was looking at lampholders, but the above applies to plugs and sockets. I particularly like the description which says: '...Designed to meet the modern requirements where lampholders are employed to carry the comparatively heavy load of irons, kettles, toasters, bowl fires, etc...'

AndiiT 30th Jun 2011 8:31 pm

Re: Another unusual plug and some other questions
 
Hi again,
Thanks for the information about "chronological progression" It's interesting that the choice of 2 or 3 pin sockets may have been down to nothing more than cost.

In the Village I spent my childhood in, which was a small mining village close to the North East coast of what used to be North Yorkshire, there were a multitude of different sockets fitted in houses all over the place.
One house had nothing but 2 pin 5 amp sockets, I seem to recall that this house had a gas oven and whistling kettle which may have been due to the the absence of any "high current" sockets in the kitchen. A house in the same street as this, a few doors away, had 2 pin 15 Amp sockets in two of the rooms and a 5 amp 3 pin in the Kitchen which was used for the Kettle!

Some houses had a combination of 3 pin 5 amp, 3 pin 15 Amp and the odd 13 Amp BS1363 socket which must have been added later.

The council estate was split in to two roads, with Dorman and Smith Britmac 13 Amp types (as shown in my picture) in most of the houses in one of the roads although some of the larger houses had 15 Amp 3 pin sockets for some reason. Whilst the other road had BS1363 13 Amp sockets.

One of my grandmothers friends owned a drapery and the living quarters at the back of the shop had Wylex sockets.

Has anyone been able to confirm yet whether my "unusual" 5 amp(?) plug is an industry special yet?

Andrew

ThePillenwerfer 30th Jun 2011 8:56 pm

Re: Another unusual plug and some other questions
 
Of course something else which should be borne in mind was that the supply voltage wasn't standardised so there may have been a convention to install different sockets to stop people from borrowing other peoples appliances and blowing them up.

- Joe

Herald1360 1st Jul 2011 12:28 am

Re: Another unusual plug and some other questions
 
Quote:

Originally Posted by AndiiT (Post 445406)
and a 5 amp 3 pin in the Kitchen which was used for the Kettle!

Not unreasonable at a time when a typical kettle was 1kW rather than the 2.4 or 3 common today. My parents had a SWAN 1kW kettle in the late 50s which I don't think was more than about 7-8 years old.

dominicbeesley 1st Jul 2011 9:48 am

Re: Another unusual plug and some other questions
 
Going back to the original plugs, does anyone have more information on the plugs and sockets that were used for DC and any associated standards? There's plenty about AC on the net and in textbooks but not a lot on DC.

Dom

Lucien Nunes 1st Jul 2011 10:40 am

Re: Another unusual plug and some other questions
 
At first, no plugs were standardised - every design was proprietary. In these days of standardisation and global trade we wonder at such an idea, but as the original concept of a socket outlet was only to allow a householder to move his appliance from one position to another, there was no great need. It didn't matter that Mr. Smith's standard lamp would not plug directly into Mr. Jones' living room, as they both bought the appliances without plugs and probably never moved them anyway.

The BS round pin designs developed out of one of the competing systems offered by Lundberg. There was a 10A gauge but this fell out of use in the 1920s. I don't think the type of socket chosen was much influenced by the voltage in use, again because it was unusual to move appliances around. It would have been decided by budget, habit, availability and the requirements of the architect, electrician or householder. For example, if 2-pin 5A sockets had been installed for lighting, and the electrician was called upon to add some points for electric heaters, he might choose 3-pin 15A for safety, without considering this to be a conflict. I.e. the points remained allocated for specific functions; lighting, heating, wireless etc and could be of different sizes on differently rated circuits. Thus 2-pin and 3-pin sockets co-existed for a very long time. In the early days, current for heating was sometimes charged on a different tarriff than that for lighting and heater points would often have had different plugs.

Take care not to confuse the many non-standard types. Britmac, Dorman & Smith, Niphan, Wandsworth (round pin), 'Wandsworth gauge' 13A, Lewden, Santon, Wylex, etc are all unrelated, some based on BS gauges, others not. Then there were the proprietary interlocking adaptations of BS gauges. MK, Crabtree and others made interlocked versions in addition to standard ones, that would usually interchange without interlocking, nor would they interlock with each other.

The MK plug in the picture above is an early interlocking type not made to BS gauge. This system captivated the plug when switched on and prevented the switch being operated without a plug present. The alternative method mentioned by Russell, in which the action of inserting and withdrawing the plug operated the switch, was adopted on the Wandworth type, another non-BS gauge. This had a slotted earth pin with an actuator pawl across, that engaged the lever of a tumbler switch as it went past. The other plug in your original picture, a DS fused plug, belongs to a different era. It was made as an alternative to BS1363 for ring-main circuits.

Most early sockets were intended for either AC or DC. There were no separate standards for the two, although some special features did develop that were unneccessary for AC. MK introduced shutters as an arc-quenching device, Wylex included a detent arrangement with sprung-loaded balls that ejected the plug suddenly as it passed the disconnection point. When electrical accessories with micro-break switches were introduced, they were marked 'AC only' to indicate their unsuitability for DC.

Lucien

dominicbeesley 1st Jul 2011 11:45 am

Re: Another unusual plug and some other questions
 
Thanks Lucien for a good overview!

Dom

AndiiT 1st Jul 2011 8:38 pm

Re: Another unusual plug and some other questions
 
Hi,
Thanks for the excellent information.

Quote:

Originally Posted by Lucien Nunes (Post 445491)
.....Take care not to confuse the many non-standard types. Britmac, Dorman & Smith, Niphan, Wandsworth (round pin), 'Wandsworth gauge' 13A, Lewden, Santon, Wylex, etc are all unrelated, some based on BS gauges, others not.......

I understand the difference between most of these "non-standards" but could you clarify, if able to, that the D&S ,presumably Dorman and Smith (Or was it Dorman and Smith Britmac?), or so I was told many years ago, is the same as the "Wandsworth" type?, which is what I have been led to believe from conversations elsewhere in these forums some time ago.

Quote:

Originally Posted by Lucien Nunes (Post 445491)
The other plug in your original picture, a DS fused plug, belongs to a different era. It was made as an alternative to BS1363 for ring-main circuits......

It's interesting that this was intended for ring main circuits and might explain why I have seen these sockets in some private dwellings as well as Council properties over the years.

Quote:

Originally Posted by Lucien Nunes (Post 445491)
The MK plug in the picture above is an early interlocking type not made to BS gauge. This system captivated the plug when switched on and prevented the switch being operated without a plug present....

Many thanks for clearing the plug mystery up, when you say early, what sort of era might it have been from?


Regards
Andrew

Lucien Nunes 2nd Jul 2011 12:44 pm

Re: Another unusual plug and some other questions
 
5 Attachment(s)
AFAIK Britmac and Dorman & Smith were unrelated at the time although they are now both under the Electrium banner along with Wylex and others (or is it now a Tyco brand?). The Wandsworth plug with automatic switch operation, that I mentioned above, is also unrelated to the DS. It was made by Wandsworth Electrical Ltd and available in the early 30's. Your MK interlocked type is probably mid 20's - early 30's. They are listed in Sunco 1929 but by 1936 MK seem to have been changing to BS gauges for interlocked types. The 15A is then described as having an earth pin 'not grooved or mutilated in any way.'

The non-BS and interlocking types are rare now, I am working on collecting a comprehensive assortment but with some difficulty. The last time I used Wandsworth was in 2002, in an old hall with wiring from the 1920s that had never been inspected or tested since. DS was in use for tech supplies at the BBC until fairly recently. Below are some mobile phone pics of related catalogue pages. Unfortunately I don't have any examples of either type of plug to hand to reveal the constructional details.

The sharp-eyed reader will have spotted a mistake in my earlier post where I typed 'Wandsworth gauge' instead of 'Walsall Gauge' when referring to the variant-BS1363 with reversed pin orientations.

Lucien

Lucien Nunes 2nd Jul 2011 8:43 pm

Re: Another unusual plug and some other questions
 
2 Attachment(s)
While at the workshop earlier I had a look in the unsorted fittings box and found a couple of examples to illustrate these types.

The first picture shows three easily confusable 2-pin plugs:

Left: BS 15A (displayed here using the Crater 6-way convertible plug)
Centre: MK 15A (the plug from which your 3-pin interlocking one derives)
Right: 10A (this example made by Sax)

The MK 15A pins lie between the 10A and 15A in diameter and centres.

The second picture shows (left) the DS 13A and (right) the Wandsworth, although I can't recall whether this is the 10A or 15A size - the markings are covered up by a strap that won't come off.

Lucien

AndiiT 3rd Jul 2011 9:15 am

Re: Another unusual plug and some other questions
 
Hi,
I have one of the Crater convertible plugs and one of the D&S adapters, identical to those shown in your pictures, in my own collection, along with a couple of different types of D&S plugs.

The D&S adapter that I have is simply an adapter but I seem to recall one which, as well as allowing two plugs to be connected, also had connections for a fixed appliance too - i.e. it could be used as a plug in its own right.

Apart from the D&S plugs and the MK ones in my original posting, everything else in my collection is to BS gauge.

Andrew

Brian R Pateman 3rd Jul 2011 1:43 pm

Re: Another unusual plug and some other questions
 
A colleague of mine worked in the design office of Dorman Smith (no and) and knew the designer of the DS plugs.

Evidently he was quite a perfectionist and it took them such a long time to get the fused version to market that the BS 1363 was firmly ensconced.

They were widely used in the new council estates which sprang up before and after WW2, I met them frequently during the 1960s in Huntingdonshire anyway.

AndiiT 3rd Jul 2011 1:54 pm

Re: Another unusual plug and some other questions
 
Quote:

Originally Posted by Brian R Pateman (Post 446007)
........They were widely used in the new council estates which sprang up before and after WW2......

As I mentioned some of the houses on the council estate in my childhood village used D&S plugs and sockets, these houses were rewired in the mid 1970s so the plugs were in use right up to that time!

As an aside I have only ever seen the White/Ivory coloured D&S plugs for sale in Woolworths, but can only ever recall seeing black ones actually in use.

Andrew

glowinganode 3rd Jul 2011 4:16 pm

Re: Another unusual plug and some other questions
 
Since we can assume commercial products are legislation driven, then three pin plugs must have been marketed to satisfy a requirement for an earthing conductor (cpc).
Earthing of electric kettles in kitchens seems a good place to start, does anyone know which edition of the regs this was first mentioned?
Rob.

Lucien Nunes 3rd Jul 2011 7:57 pm

Re: Another unusual plug and some other questions
 
1 Attachment(s)
Quote:

I seem to recall one which, as well as allowing two plugs to be connected, also had connections for a fixed appliance too
Yes, this adaptor is of that type, see pic. Whilst it is generally well engineered, the cable entry layout is crude, which suggests it was an afterthought. There is no positive clamping arrangement and very little room for the conductors.

Quote:

commercial products are legislation driven
I don't think this was as generally true then as it is now, perhaps because it was not necessarily an offence to supply non-compliant goods provided that no claim of compliance was made. Nonetheless, the IEE regulations did require the use of plugs and sockets meeting applicable British Standards, although the regulations themselves were non-statutory. It is probably safe to say the tide of opinion on which the regulations were based was reflected in the best quality products of the time.

The critical period for the emergence of 3-pin was during the 20's and 30's. I don't have a copy of the 9th edition of the IEE wiring regs (1927) but in the 10th edition (1934) we find in regulation 1001(E) a requirement to earth all exposed conductive parts of appliances, and a note specifically deprecating the use of reversible 2-pin plugs and lampholder plugs while recommending appliances of all-insulated construction. The implication here is that non-reversible 2-pin plugs would be suitable if such appliances were chosen, and we find reference to the proper connection of non-reversible 2-pin plugs and sockets in 607 (H) and (K). Plugs of this type were available in the era but never caught on, probably due to the lack of all-insulated appliances. Thus, if these regulations were in part responsible for the obsolescence of 2-pin, the lack of polarisation of existing types seems to have been of primary concern.

Incidentally, when visualising the wiring of a 3-pin plug in 1934, don't forget that brown was the colour for earth in a flexible, green at that time being one phase of 3-phase AC.

Lucien

glowinganode 3rd Jul 2011 8:05 pm

Re: Another unusual plug and some other questions
 
Thanks Lucien, a mine of information as ever.
There is a hole in my library between 1910 and 1940 when a lot of changes took place.
You talk about non-reversable two pin plugs being acceptable, would this have been with a TNC system (ie. Live and PEN), or insulated items only?
I know the 12th edition (1950) mentions single pole fusing, and a permanent connection between neutral and earth as in TNS.
It's interesting you suggest that the regs lagged behind the manufacturers.
Rob.

ThePillenwerfer 4th Jul 2011 11:47 am

Re: Another unusual plug and some other questions
 
This may be a bit OT and if so I apologise.

This morning I collected a Ferguson 104A radio complete with its original instruction card. This is the same as for the 104U and says that if, when connected to a DC supply, nothing happens after a reasonable warming-up period to reverse the plug. It also suggests doing this on AC to reduce hum.

This set came out in 1940 and Ferguson seem to have been taking 2-pin or lamp-holder plugs as the norm then.

- Joe

Tractorfan 4th Jul 2011 5:34 pm

Re: Another unusual plug and some other questions
 
Hi,
The instruction leaflet for my KB radiogram actually recommended cutting the earth lead off if it was to be fitted with a two pin plug! Those were the days, eh? :)

Since living here I've seen some odd specimens of French plugs & sockets. I'll try and post a few.

Cheers, Pete:thumbsup:

Brigham 7th Jul 2011 5:02 pm

Re: Another unusual plug and some other questions
 
That would be the correct procedure in the circumstances. Leaving the earth lead showing might cause it to come in contact with live metalwork inside the plug, causing the very danger which it is intended to relieve.
I always cut the earth lead off flush with the outer braiding when using 3-core flex in a twin-core situation. It eliminates any possible future confusion.

michael cumming 10th Jul 2011 9:45 pm

Re: Another unusual plug and some other questions
 
I have an Ever Ready 15 amp plug with three pins on, it looks like a normal plug you can still get but the three pins are round, it does have an earth. Im not sure of its application though because of the amps and those pins, however i have seen those tiny miniture plugs which are triangle in shape an have three round pins. it cost 19p originaly which says it maybe after decimal was switched to and P. I have never seen a large three round pin socket to take this plug though.

matthewhouse 11th Jul 2011 6:22 pm

Re: Another unusual plug and some other questions
 
How big is big? 15 amp round pin plugs and sockets are still widely used, size is a bit bigger than a 13A plug with thick round pins. Photos here. Mostly only used for stage lighting these days as they are unfused, chunky and can easily carry the current used in larger stage lights.

AndiiT 11th Jul 2011 8:40 pm

Re: Another unusual plug and some other questions
 
Quote:

Originally Posted by michael cumming (Post 448097)
I have an Ever Ready 15 amp plug with three pins on......

Ever Ready Produced 13 Amp BS 1363 Fused plugs and 15 Amp BS 546 plugs in similar housings - which were very "angularly" square; there was also a 5 amp BS 546 version which was, basically, a "shrunken" version of the 15 Amp one.
I don't think that the BS 546 ones were fused but I have seen BS 546 fused plugs made by other manufacturers.

I am not sure if I have a 15 amp Ever ready plug in my collection but think I may have a 5 amp one, if/when I find it/them I'll post pictures.

Regards
Andrew

ThePillenwerfer 11th Jul 2011 8:59 pm

Re: Another unusual plug and some other questions
 
2 Attachment(s)
Here you are.

- Joe

robin0577 13th Jul 2011 9:08 pm

Re: Another unusual plug and some other questions
 
1 Attachment(s)
Indeed, 15A BS546 connectors remain the norm for theatre use in the UK, modern exapmles shown below. The main reasons for their continued use being to distinguish between dimmed sipplies and raw mains supplies, and to enable all the fuses or circuit breakers to be in a central location for easier fault finding and repair.
Note that sleeved pins have never become a requirement for these plugs, although a couple of manufacturers have chosen to add that feature. This often raises some eyebrows when it comes to P.A.T. especially in educational environments.
However, the production volumes of these connectors are now so low compared to BS1363 that the cost is becomming close to prohibitive and some users are switching to the more common (Europe-wide) BS4343 16A "Ceeform" plug, at less than half the price.

ianj 14th Jul 2011 4:34 pm

Re: Another unusual plug and some other questions
 
Our house in Acton, West London was wired for the Wylex plugs. We left there in 1981, and it was still the same. The ironmongers at the top of the road kept a drawerful of them and I was always sent up for one to fit on the end of something new. There must have been a local demand around the roads for them.

multivalve 25th Jul 2011 1:06 pm

Re: Another unusual plug and some other questions
 
Our old village house was wired with 2-pin sockets. It was advertised in 1938 as being 'fitted with electric light'. Eventually my parents were advised to convert to 3-pin (still 5 amp) as it would be safer. We did so. On looking later I discovered the separate new earth wire from the sockets ran to somewhere just under the floor- where it ended! Incidentally to this story, the mains supply was DC from the local mill which was powered by turbines. Generated at 270 volts in order to charge a room full of lead acid batteries to 250 volts, it gave varying voltage to the village according to the time of day-or night- and how far you lived from the mill. The local shop would always ask where you lived when you bought a light bulb, and it was advisable not to use it in the early hours when the batteries were charging and the voltage drop in the overhead wires was low! (One useful aspect of DC was the ability to charge the radio 2v accumulator by running the house supply through it, with dire warning to parents not to use more than a 100w anywhere in the house. That worked until the meter reader found out, and as he also ran the radio battery charging station he wasn't at all happy).

Lucien Nunes 25th Jul 2011 10:50 pm

Re: Another unusual plug and some other questions
 
Quote:

I discovered the separate new earth wire from the sockets ran to somewhere just under the floor- where it ended!
Were all the sockets connected together but not to earth (implying a purposeful scheme that was left unfinished) or was each socket equipped with a dummy earth wire that stopped just out of sight?

Quote:

The local shop would always ask where you lived when you bought a light bulb
Can you imagine this today? There's a lot of ephemeral electrical history packed into your post!

Lucien

neon indicator 30th Jul 2011 1:28 pm

Re: Another unusual plug and some other questions
 
Quote:

Originally Posted by matthewhouse (Post 448234)
How big is big? 15 amp round pin plugs and sockets are still widely used, size is a bit bigger than a 13A plug with thick round pins. Photos here. Mostly only used for stage lighting these days as they are unfused, chunky and can easily carry the current used in larger stage lights.

The British 15A and 5A etc still the standard in South Africa. Kenya changed from the 15A to 13A system, but I'm not sure when.

Antlong 4th Aug 2011 10:04 pm

Re: Another unusual plug and some other questions
 
Hello all,

"DS was in use for tech supplies at the BBC until fairly recently."

I don't think I've ever seen the fact that the DS plugs had a screw-in fuse which acted as the live pin; when they were ceased in my bit of the BBC I came across a number of these fuses which were actually the same size as a BS1363 so I cut all the threaded portions off...

Well, it was a long time ago!

"I discovered the separate new earth wire from the sockets ran to somewhere just under the floor- where it ended!"

A friend paid quite a lot of money in North London to have his large house rewired; a few years later it was found that every single fitting had but a few inches of new cable which was twisted to the old cable just outside the plasterbox!

Regards Ant

AndiiT 4th Aug 2011 10:39 pm

Re: Another unusual plug and some other questions
 
Quote:

Originally Posted by Antlong (Post 454968)
.......which were actually the same size as a BS1363 so I cut all the threaded portions off.......

As a youngster/teenager, I remember seeing the same thing done to a few DS fuses, especially if someone had moved from a property with DS sockets to one with BS1363 outlets and had no further use for the DS plugs which they invariably didn't leave behind for the new occupants!!

Andrew

G3gener 11th Oct 2011 3:48 am

Re: Another unusual plug and some other questions
 
Here is an excerpt from "The Principles And Practice Of Modern House-Construction | by G. Lister Sutcliffe" published in 1900. The link given is to Part IV,Wiring and Lamps.

http://chestofbooks.com/architecture...ps-Part-4.html

So there you see a plug and socket arrangement in the UK as far back as 1900. It looks like a standard 5A plug. In 1904 Hubbell invented and manufactured the flat-blade plug that became the US standard.

robin coleman 24th Oct 2011 9:06 pm

Re: Another unusual plug and some other questions
 
i am starting to collect a few plugs and sockets does any one know if there are any old crabtree catalogues about

I am starting to collect a few plugs and sockets. Does anyone know if there are any old Crabtree catalogues about?

emeritus 14th Jan 2012 3:12 am

Re: Another unusual plug and some other questions
 
The information on the "Wandsworth" sockets was most informative. They were used on the Becontree council estate in Essex until the houses were rewired in the 1960's. They were still being used in a Becontree barber's shop that I used to visit in the early 1970's. I always wondered why the earth pin was slotted!

Regarding the date of introduction of mains plugs, I have some GEC catalogues for 1893 and 1912.

The 1912 catalogue only lists 2 pin plugs for domestic use, "Midget" gauge at 3A [ apparently corresponding to the later 2A plugs] ; 5A "Standard" gauge that is still used as the UK shaver plug, 10A "Union" gauge, and "Goliath" gauge 25A. Mechanically robust plugs rated at 25A and 50A for use in theatres were also available. Also illustrated was a range of Concentric mains plugs that were essentially larger versions of the present coax TV plug interface. Apparently the Royal Navy used them. Switched sockets were not available.

A range of earthed connectors was available for industrial and naval use. Reference is made to a Board of Trade report of 1910 that discusses the properties of and defects of the earthed mains connectors then available which I am trying to track down [the IET library doesn't have a copy].

The 1893 catalogue lists 5A, 10A and 20A 2 pin plugs, with a choice of switched and unswitched sockets, together with the once-universal BC adaptor and its ES cousin. In addition, Coaxial plugs were available in 5A and 10A versions that were essentially larger versions of the present low voltage DC power plugs. The 2 pin plugs appear to have been available prior to 1893, but the coax plugs were new. GEC seemed to have been keen on promoting them as most of the illustrated electrical appliances of the 1893 catalogue are depicted fitted with the coax plugs.

It could be that the what is now the UK 2pin 5A shaver plug gauge can trace its origins back to at least 1893, making it a contender for the oldest mains plug gauge [other than lamp bases] that is still in use.

robin coleman 14th Jan 2012 10:21 am

Re: Another unusual plug and some other questions
 
I have just started collecting electrical fittings, are there any books on the subject?

Ed_Dinning 14th Jan 2012 8:02 pm

Re: Another unusual plug and some other questions
 
Hi Robin, I may be wrong but I don't think anyone has ever written a history of mains plugs and sockets (but try querying the IET library, or post a request on the IET forum).

If you are lucky try googling the various electrical companies and see if there are copies of their caralogues on line. The BVWS did a repro of the Brown Bros catalogue some years ago which had a few illustrations in.
You can also look at old trade magazines as well as books such as "Practical Electrical Engineering". These were often in many weekly parts and assembled into a 4 or 5 volume set.


Happy hunting, Ed

robin coleman 14th Jan 2012 8:17 pm

Re: Another unusual plug and some other questions
 
Thank you Ed I have some of the Engineer magazines which I got from you. I have looked in the Army and Navy catalogues but have not seen any. I may decide one day to write a book on the subject just like they did in the Shire series books on Hobbies and Collecting.

ppppenguin 14th Jan 2012 8:26 pm

Re: Another unusual plug and some other questions
 
The Amberley Working Museum has an extensive library of early electrical periodicals, books etc. The honarary curator of the electrical collection is John Narborough who is very knowledgeable. He can be contacted va the museum.

http://www.amberleymuseum.co.uk/


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