Talk:BS 546

message: thumb|250px|A group of BS 546 plugs, sockets and adaptors.
Here is a group shot of some BS 546 plugs, an inline 5A 2 pin socket and a couple of adaptors.
I have more of these plugs & sockets than are shown here including some wall sockets. If anyone can think of some good photos to take for this article (angles, group shots, insides, etc.) then I can do so. Ziltro 16:23, 3 February 2006 (UTC)
thread_title:  Photo - group shot 

message: this is a very good article.  A few points to add for completeness: - 
Each of the three sizes - 2, 5 and 15 amp - had a 2 pin and 3 pin version.  Unlike other plug systems (e.g. Australian) the 2 and 3 pin versions differed by gauge and diameter so were not compatible.  I have no idea why the design deliberately ruled out compatibility - this seems pointless.  The 2 and 15 amp 2 pin versions dropped out of use as a result, while the 5A version remained in use for longer, both because of its use as a shaver plug and because of the widespread availablility of adaptors (strictly speaking, these 2-pin variants probably pre-dated BS546 and were not covered by it).  
The BS 1363 standard first made an appearance in 1947 and gradually replaced the BS546 types - in the UK, Ireland, most of the countries that were still ruled by the British at the time, plus a few others - e.g. Saudi Arabia (alongside the US system).  India, Pakistan and South Africa were by then independent, so did not adopt BS 1363.  For some reason the replacement by BS1363 was slower in Hong Kong than elsewhere.  Whilst adaptors that allowed different BS546 types to mate used to be very common, those allowing mating between BS1363 and 546 were less so, other than those allowing the 5A, 2 pin size to be used in 13 A sockets.
:on the subject of adaptors apparently socket doublers with 15A pins and 13A sockets are considered a rare and highly prized (and hoarded) item in the theatre lighting industry. Plugwash 23:57, 15 June 2006 (UTC)
replies: text: Nice to know, I got given one recently! I shall have to photograph it. I thought they were quite common in some other country/ies though? Ziltro 04:20, 8 December 2006 (UTC)
thread_title:  BS 546 

message: Someone has requested that this be cleaned up for tone.  I assume the problem is particularly with the discussion of 2a 2 pin, which is indeed quite familiar.  But is there anything else folks think needs improving? Bryson430 00:21, 8 December 2006 (UTC)
thread_title:  Tone? 

message: I eventually decided to learn SVG and measured & created these drawings. They are pretty close sizes for comparison, but are not the sizes from the regs because I don't know what they are! If anyone knows what the 'official' dimensions are then I can update these files with them. Shown looking at the socket (note titles if you view the SVG) but measured diameters are taken from the pins. Ziltro 04:20, 8 December 2006 (UTC)
thread_title:  Diagrams 

message: In what BS socket fit an Europlug???
The 5A 2pin ?
http://en.wikipedia.org/wiki/Europlug
79.230.182.250 (talk) 23:01, 18 April 2010 (UTC)
thread_title:  BS socket and Europlug 

message: Nowhere in this category can I find any mention of British BC plugs, which were very popular up until the 1970s. Theyre not BS546, so dont belong in this article. These bayonet cap plugs fitted into bulb holders, and were how upstairs appliances such as irons, electric blankets, and heaters used to be powered. AFAIK they never conformed to any BS, and were thus effeectively banned in the early 70s.
I'd put this mention elsewhere, but there isnt really anywhere else to put it.
Tabby 16:58, 29 June 2007 (UTC)
replies: text: "BC Adaptors" enabling 2 pin Europlugs to be connected to a lamp socket were also available. However BC adaptors and plugs were widely misused (overloading and the use with three wire appliances with the earth wire cut) in a dangerous manner. Does the British standard legislation make it unlawful to sell Schuko (European) or NEMA (American) plugs in the UK ? 213.40.115.69 (talk) 12:47, 8 August 2009 (UTC)
replies: text: With the exception of shavers and toothbrushes, it is illegal to sell domestic appliances in the UK which are fitted with anything but a UK standard plug. Mautby (talk) 14:34, 20 March 2013 (UTC)

text: http://www.plugsocketmuseum.nl/SouthAfrica2.html provides an interesting read about BS 317 → BS 372 → BS 546 BC plugs and sockets, which were indeed used in the UK (and more recently in South Africa)  — Preceding unsigned comment added by 78.147.197.1 (talk) 00:48, 14 December 2017 (UTC)
thread_title: BC plugs

message: In theory 15 amp plugs were proposed to be used for larger appliances (e.g. electric heaters) while smaller appliances (e.g. radios, table lamps etc) were supposed to use 5 amp. In practice this was found to be inconvenient and in many households the 15 amp plug was used for everything.
How widespread is the 5 Amp version of BS 546 in these countries ? Is the 5 Amp version always used for low current applications or is (as was the case in the UK) 15 Amp universally used  for everything ? -- 80.229.222.48 (talk) 19:14, 16 November 2007 (UTC)
thread_title:  5 Amp BS 546 in India, Sri Lanka, Nepal, and Namibia, 

message: The 15A 3Pin is the only current domestic wall socket standard in South Africa. In the article there is a statement about it "almost always" having a switch in countries where it is the current standard. In the case of South Africa the "almost" can be deleted as the regulations make a switch mandatory. Heavier current items such as stoves and geysers are "hard wired" into the supply with a dedicated trip-switch on the distribution board. The 5A 2Pin type is still found on older appliances but has been replaced by the Europlug in current trade and manufacture. The 5A 3Pin plug is becoming very rare and is no longer made or sold at all although many people still have adapters for them. The CEE 7/7 plug has also appeared on appliances, usually in 2pin non-polarised form. Adapters for 15A3Pin to Europlug and CEE7/7 are widely available. Roger (talk) 19:26, 25 January 2008 (UTC)
replies: text: No longer made or sold at all is a very strong statement do you have evidence to back it up or are you just going on what you see in your local wholesalers or worse DIY stores? Plugwash (talk) 23:58, 25 January 2008 (UTC)
replies: text: You're asking me to prove a negative? If you show me just one example of a 5A 3Pin plug or socket in a current South African manufacturer's catalog, I will withdraw my statement. Roger (talk) 06:59, 26 January 2008 (UTC)
replies: text: Atlantic Lighting and Electrical Distributors in Booysens, Johannesburg stock the 5A 3Pin plug Gary van der Merwe (Talk) 09:39, 14 November 2008 (UTC)

text: I'm going to do the WP:BOLD thing and remove Namibia from the "list" of countries that have 5A wall sockets - it is simply not true. All "sources" out there that say so got their info from here! Roger (talk) 16:06, 19 February 2012 (UTC)
thread_title:  South Africa 

message: The page seems to perpetuate a theory that the 5A BS546 is the standard for this country.  From where does this information derive? Pre-independence South West Africa was effectively a fifth province of South Africa and on my many visits there (in both hotels and private houses) the standard sockets were the 15A variety - I know because it fitted all of my South African gear without a problem.
I have seen this 5A "fact" presented on a few popular web sites but I have never seen any official back-up for this and I suspect that there is a fair degree of mutual self-support for this misplaced hypothesis.
Echoing Roger's comments:- in my many years in RSA I never came across a domestic 5A socket (i.e. on a standard 4x4" or 4x2" plate).  I did find (and use) 5A plugs, and regularly bought 5A sockets on 2.5" circular fittings that were used with industrial conduit systems.  I wired up workshop fluorecent tubes and battery back-up lighting with these. I only ever came across the 2A varieties back in the UK.
Oxonhutch (talk) 21:20, 4 February 2009 (UTC)
replies: text: I'm going to do the WP:BOLD thing and remove Namibia from the "list" of countries that have 5A wall sockets - it is simply not true. All "sources" out there that say so got their info from here! Roger (talk) 16:06, 19 February 2012 (UTC)
thread_title: Namibia

message: Why do the pins on a 15 Amp BS546 plug appear to have a larger diameter than those on a European Schuko plug (4.8 mm) despite the latter having a slightly higher (16 amp) current rating ? What are the official pin daimaters/spacings for the various BS546 plugs ? 213.40.115.69 (talk) 12:59, 8 August 2009 (UTC)
replies: text: Someone has posted a table in the article. "15 Amp" BS546 plug have a live/neutral pin diameter of 6.9mm (Earth pins are larger) Even "5 Amp" plugs have a live/neutral pin diameter of 5.1mm (probably derived from imperial). It does seem odd that European plugs are rated for 16 Amps when their pin diameter is only 4.8mm. Maybe its because BS546 tends to use brass pins while the pins on European plugs tend to be some other material (nickel ?) although this is not always the case so can anyone else come up with a better explanation ? 86.112.87.162 (talk) 15:10, 24 December 2010 (UTC)
replies: text: Although pin diameter is related to maximum current capacity, the pins on most plugs have a maximum capacity that is much larger than the nominal rating of the plug.  The pins on the 15 Amp plug, for example, could easily carry 30 Amps or more.  That the plug is rated for 15 Amps is purely a decision that the designer took.  Compare the pin size of the IEC Connector.  This has much smaller pins but can still carry up to 15 Amps (see the C13 and C15 types). 86.169.33.6 (talk) 16:40, 2 June 2012 (UTC)
thread_title: Pin diameter

message: The article makes no mention of the 15A 2 pin plug, which I'm sure was part of this standard at one time. They were widely used in older British houses before rewiring in the 1960s. I can't update the article myself as I'm unsure of their status. --80.176.142.11 (talk) 17:43, 28 September 2009 (UTC)
replies: text: There is not, and has never been, a 2 pin BS 546 plug/socket.  BS 546 deals only with earthed plugs and sockets. Mautby (talk) 14:36, 20 March 2013 (UTC)
thread_title:  15A 2 pin plug 

message: BS 546 is an old British Standard for domestic AC power plugs and sockets. .
:It was also used on DC mains systems. 213.40.128.233 (talk) 20:46, 2 November 2009 (UTC)
replies: text:  The cover of the 1950 edition on Scribd says AC 50/60 Hz (was there ever much 60 Hz in the UK?). Scrbid kills my computer so I didn't look at more than a couple of pages, but there was no mention of DC. --Wtshymanski (talk) 20:53, 13 September 2011 (UTC)
replies: text:  (What we now call) "BS 546" plugs were around long before the 1950's (they were developed in the mid-late 1920's) DC supplies were quite common back then -even after 240v/50Hz standardisation "legacy" DC systems continues in many areas for several decades. It is highly likely that BS546 plugs were used on DC supplies. The BS546 standard may not have been completly formally ratefied until 1950 but in the athmosphere of the preceeding decades (when standards would have been more piecemeal and ad-hoc) it was likely that they were used in all manner of configurations. 192.65.220.73 (talk) 14:44, 19 January 2012 (UTC)
replies: text: This makes sense but it's frustrating that we can't find sources for this. The same problem exists with the NEMA connectors; for all you can tell from Wikipedia, they might as well have been raked out of the remains of a crashed flying saucer. --Wtshymanski (talk) 15:43, 19 January 2012 (UTC)
thread_title:  Not just AC 

message: Since we now have an idea of where the two pin plugs came from (BS 372 Part I) maybe we should now restore them to this article and make BS 372 a redirect to this article?  After all since BS 372 Part II was the three pin plugs and sockets of BS 546, I can't see giving BS 372 an article of its own. Carolina wren (talk) 01:00, 14 December 2012 (UTC)
replies: text: Because BS 546 replaced BS 372 part II does not seem a very good reason for assuming a connection between BS 546 and BS 372 Part I.  We know that the two parts originated in different earlier BS standards, and that there is not a commonality between the dimension of the 2 pin plugs in Part I and the 3 pin plugs in Part II.  If anyone has access to BS 372 and can provide real information then a separate article might be justifiable. Mautby (talk) 19:09, 21 December 2012 (UTC)
replies: text:  They are both standards for British round pin plugs, and they overlap by describing the same plugs in at least some cases.  Perhaps it would need to be renamed to British round pin plugs and sockets with the various current and obsolete standards being redirects to the relevant sections. Carolina wren (talk) 05:56, 23 December 2012 (UTC)
replies: text:  An anon asks "Does BS372 merit an article of its own ?".  I, for one, would love to read a comprehensive overview article about the evolution of plug statndards in the UK (or anywhere), but I don't think an article on BS372 would pass the WP:N hurdle. --Wtshymanski (talk) 14:05, 20 March 2013 (UTC)
replies: text:  See "History needed" section above. Mautby (talk) 14:39, 20 March 2013 (UTC)
thread_title:  BS 372 

message: It's fairly evident from the values in the dimensions table that they are all binary fractions which have converted to thousandths of an inch and rounded down in the conversion.  Does anyone have access to the older standards so as to document when dimensions such as 75/128 in became 0.585 in? Carolina wren (talk) 19:29, 2 October 2013 (UTC)
replies: text: Carolina wren, I see where you are coming from, but you are making assumptions which WP does not permit.  Let me give you some examples, if you look at the oldest BS for plugs and sockets, BS 73 (1915) you will find that the original dimensions are given in different forms depending on the type of dimension.  Some examples: pin diameter and pin spacing are given in decimal fractions for both imperial and metric units, but pin length is given in vulgar fractions for imperial and decimal fractions for metric.  So, the original imperial definition of a 5 A two pin plug pin spacing is 0.656 inch, the diameter 0.199 to 0.201 inch, and the length 5/8 inch.  You simply cannot make assumptions as to the effects of rounding if a dimension has never been stated as a vulgar fraction.  The only dimension which may be stated in WP is that given in the standard, not what you assume may be its derivation.  For that reason I am reverting your comment in the main article as it is misleading.  It is also unnecessary as editors who wish to modify factual data should not do so on the basis of assumption.  Long obsolete standards can be quite difficult to track down, BSI do of course have them, but will charge you big fees, £100 plus for each photocopy of a standard.  Alternatively you may use the  BSI library for a fee of £20/hour for non-members.  The IET archive is NOT a source for old standards, so the best solution is to use a major reference library such as the British Library or the National Library of Scotland.  Access to current standards, and some previous versions, is available free via many public libraries using the BSOL online system.  Deucharman (talk) 21:12, 2 October 2013 (UTC)
replies: text: Even if you feel that the embedded comment was inaccurate as the reasoning of how the current decimal values came to be, I think a comment (either hidden as I had it so that only an editor would see it, or in the visible text) emphasizing that the decimal inch values given in the table are exactly as the standard has them is in order.  Otherwise, there will be people trying to make future "helpful" edits in the future to "correct" the rounding from round to down to the commonly taught round to near.  While you said "It is also unnecessary as editors who wish to modify factual data should not do so on the basis of assumption.", the sad fact is they will.  Without additional info, those values simply look too much like "wrongly" rounded numbers, and hence people will try to "correct" them, as has already happened.  Some of that help will occur after both of us have ceased editing Wikipedia, as we inevitably will some day (unless the afterlife gets a Wi-Fi hotspot by then), so simply reverting that error when it occurs is not an optimal solution.  Taking preventative measures is what is needed. Carolina wren (talk) 21:35, 2 October 2013 (UTC)
replies: text: I hope my addition fits the need? Deucharman (talk) 21:56, 2 October 2013 (UTC)
replies: text:  Quite adequately. I think it would be interesting to include information in the History section on the evolution of the tolerances and when changes from binary fraction to decimals occurred, but that is a low priority need, and could even be saved for when, if ever, we get articles on those precursor standards. Carolina wren (talk) 00:35, 4 October 2013 (UTC)
thread_title:  BS 372 or earlier standards and decimalization 

message: A proposal has been made by Jeh to redefine the present AC power plugs and sockets article, and its related detailed articles, of which this is one.  The proposal can be found at  Move all detail info to group-specific articles? 
In an attempt to move this forward I have prepared a draft of one of the articles suggested in the proposal: "AC power plugs and sockets - British and related types".  This combines the British related elements of the AC power plugs and sockets article with the full BS 1363 and BS 546 articles. The draft can be found in my sandbox: User:Deucharman/sandbox.  Please do not edit my sandbox, but make all comments and suggestions at  Move all detail info to group-specific articles?.  I have also placed a request for comments on the BS 1363 page. Deucharman (talk) 16:47, 27 December 2013 (UTC)
thread_title:  Proposal to create new detailed group articles about AC power plugs and sockets <br/> Request for comments