Talk:AC power plugs and sockets: British and related types

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Creation of article[edit]

Created following a proposal made by Jeh to redefine the present AC power plugs and sockets article, and its related detailed articles. This detail new article combines the British related elements of the AC power plugs and sockets article with the full BS 1363 and BS 546 articles. The proposal can be found at Move all detail info to group-specific articles?

See old talk-pages for merged articles Talk:BS_546 and Talk:BS_1363

Deucharman (talk) 12:49, 4 January 2014 (UTC)

Not just AC[edit]

The title of this article is not entirely correct as DC mains supplies were in common usage in parts of Britain right up to the late 1950`s and BS 546 (and earlier) connectors were often used on such supplies. (talk) 14:05, 30 May 2014 (UTC)

An interesting observation, but one which points to the absence of a historical note on DC supplies rather than the need to change the title. The three types in contemporary use are all specified in terms of AC only. The status of BS 1363 was clarified three years after it was originally published when the words "for A.C. circuits up to 250 Volts (not intended for use on D.C. circuits)" were added to the title by amendment No. 3 in May 1950. The title of BS 546 (as shown in the Lede) is "Two-pole and earthing-pin plugs, socket-outlets and socket-outlet adaptors for AC (50-60 Hz) circuits up to 250 V" - the AC reference having been added by amendment No. 8 in May 1999 (which also removed all references to DC operation in the text). We should also remember that the title derives from the main article AC power plugs and sockets. FF-UK (talk) 15:42, 30 May 2014 (UTC)
Not just up to the late 1950's, D.C. supplies could still be found in some districts through to the late 1960's, admittedly in dwindling numbers by that time. (talk) 22:53, 3 December 2015 (UTC)

Plugs which do not reach production, and Chargers[edit]

Editor Pol098 has recently made a number of useful improvements to the article, but they are also introducing topics and statements which are inappropriate. It is important to realise that folding plugs are not a new form of BS 1363 plug, but they are compatible plugs introduced by means of the creation of special dedicated standards, they have not been certified to BS 1363 but to BS 1363 as modified by those dedicated standards under the regulation which permits such approvals.

Pol098 has been speculating as to the reasons why such plugs may only be available in non-earthed form as part of a cord set with an IEC 60320 C7 connector, I believe that this comes under the classification of WP OR, or possibly just synthesis, but I know of no authoritative source to support the speculation (however reasonable the speculation may be). The SlimPlug utilizes non-interlocked pins which means that it is easy to lock open the two live pins while the earth pin remains in the retracted position, in that configuration it can be plugged into the type of socket where the shutters are operated by the simultaneous insertion of the two live pins alone, clearly unsatisfactory for an appliance where the appliance requires an earthed connection. Pol098 cites the designer of SlimPlug as saying (regarding an earthed plug) "We did propose to the certifying body ASTA that we be allowed to produce one, but they ruled that the public (that's you) couldn't be trusted to deploy the earth pin. They said that is was easier to spot that an normal plug had been badly wired than to spot that the earth pin on Slimplug had not been deployed." This is a somewhat simplistic statement, and the company is clearly frustrated, but coming as comment (as opposed to a specification) from the company themselves is unlikely to qualify as a WP reliable source. The original wording stating that the products are available "as part of a complete power lead terminating in an IEC 60320 C7 unpolarized connector" is sufficient without further speculation.

Pol098 has described the plugs as "the 5A SlimPlug and the 3A ThinPlug" but as both are available only as cord sets with the IEC 60320 C7 connector (rated as 2.5A) then this is clearly unreliable and should not be stated.

Pol098 has reintroduced material relating to the Min Kyu-Choi folding plug design (such material was removed from the former BS 1363 article some years ago as being inappropriate). Min Kyu-Choi's design contains features which precluded it from ever receiving certification as a plug, and as such is simply one of many mains plug designs which have been unsuccessfully floated in the UK, either because they were fundamentally unsafe (such as the one in question) or simply were uneconomical because, as with most other countries, there is no realistic chance of the UK adopting a new electrical infrastructure with an alternative non-compatible plug design. A charger with integrated power pins, inspired by the plug design, has become a product, but there is nothing special about a charger with folding pins, there are many on the market, and as this article is about plugs and not chargers, then I see no justification for introducing the Mu charger - it is simply outside of the scope of this article. Even the WP article on Battery chargers (which would be a more logical place) contains no information on specific models.

I express my appreciation to Pol098 for those edits which are improvements, but I have removed the inappropriate material and sincerely request that it not be reinserted. FF-UK (talk) 15:43, 23 July 2014 (UTC)

I hope we get some more viewpoints on this (not very important) issue. I agree that folding plugs are not a new form of BS 1363 plug, but fail to see what it has to do with the article. The flowers that bloom in the spring, etc.

Pol098 has been speculating ..: some of what I said can, on reflection, be described as speculation until supported by sources. I have removed what I said about the reason for the plugs only being available as part of a two-pin made-up cable, and replaced it with sourced information from a manufacturer's Web site (with fairly similar meaning). ... coming as comment (as opposed to a specification) from the company themselves is unlikely to qualify as a WP reliable source: we can get into lawyers' arguments about the rules here, but if the manufacturer explains to customers in FAQ format their reasons for not doing something, I think it is relevant.

The original wording stating that the products are available "as part of a complete power lead terminating in an IEC 60320 C7 unpolarized connector" is sufficient [to explain why there's no cloverleaf version?] without further speculation: "speculation" here could be called a weasel word; the manufacturer gives the reason. One of the questions that will interest readers of this article may well be "when is the cloverleaf version appearing"; the answer is apparently "not in the foreseeable future".

Pol098 has described the plugs as "the 5A SlimPlug and the 3A ThinPlug" but as both are available only as cord sets with the IEC 60320 C7 connector (rated as 2.5A) then this is clearly unreliable and should not be stated. The manufacturers give these figures (3A, 5A), possibly violating the rules rather than being unreliably sourced. Yes, the figures could well be left out. The figures are pretty meaningless anyway fo anything but marketing; I doubt any 700W+ equipment uses this connector.

The Thinplug and Slimplug are cable assemblies; they fall within the scope of the article as they inherently include a plug, and the article discusses the folding property of the plug part. The Min Kyu-Choi Mu Plug was designed as a plug, and is an interesting design in itself. The three folding plugs have been incorporated into power adaptors (USB chargers in fact); I don't thing this stops them from being described as plugs—I'd be interested in opinions on this point, essentially does the Mu Plug legitimately fall within the scope of this article. As I see it many USB chargers combine a plug integrated with an electronics module in a small (typically plug-sized) casing; brief mention of the plug aspect here seems appropriate to "AC power plugs - British", though discussion of the electronics and properties of power adaptors clearly isn't. Something like "this plug has been integrated into a very compact USB charger", no more. In this case the Mu Plug, as integrated into the charger, is relevant.

Here is the last wording I used, followed by FF-UK's. I would add a short sentence on the use of these folding plug designs on USB chargers if there is consensus. FF-UK has done good work on this article. I don't find this discussion in any way objectionable, and hope FF-UK agrees; disagreeing and discussing brings out points, and generally gives rise to a better article. I present this for FF-UK and, hopefully, others who have an opinion.
Due to the size of the usual BS 1363 plug, attempts have been made to develop a compatible folding plug certified to that standard. As of July 2014 two of these had been approved for sale, the 5A SlimPlug[1] and the 3A ThinPlug.[2] They are available as part of a complete power lead terminating in a two-pin IEC 60320 C7 unpolarized connector;[3] versions with a three-pin IEC 60320 C5 "cloverleaf" connector are not manufactured due to issues of regulatory certification with the earth connection.[1] In 2009 the ThinPlug received a "Red Dot" award [4] for product design. Another folding British AC power plug, the Mu Plug, started its development as a cable plug[5][6] and was placed third in the Dyson Awards,[7] but was ultimately not produced in that form.[8]
Due to the size of the BS 1363 plug, attempts have been made to develop a compatible folding plug. As of July 2014 two folding plugs have been certified under specially developed ASTA Standards.[1] SlimPlug[2] which complies with ASTA AS153 and ThinPlug[3] which complies with ASTA AS158. SlimPlug is available only as part of a complete power lead terminating in an IEC 60320 C7 unpolarized connector.[4] In 2009 the ThinPlug received a "Red Dot" award [5] for product design, the first product, also a power lead terminating in an IEC 60320 C7 unpolarized connector[6] became available in 2011.
  1. ^ Cite error: The named reference ASTA was invoked but never defined (see the help page).
  2. ^ [2]
  3. ^ ThinPlug
  4. ^ Alan Winstanley. "Slimplug Compact UK Power Lead". Retrieved 2014-07-23. 
  5. ^ [3]
  6. ^ ThinPlug

I'd add a brief comment not directly related to this: in an article for non-specialists, I think terms like IEC 60320 C7 are not good; people at large will not understand without following a link. Using the correct term is of course OK, but it means a lot more if we say "two-pin figure-of-eight" or IEC 60320 C7 (two-pin figure-of-eight), etc.; but even the experts will understand even without the code. Best wishes, Pol098 (talk) 18:09, 23 July 2014 (UTC)

FWIW, Pol098's version above looks clearly superior, including more useful information while taking very little extra space. I don't know what the long-term significance of the Mu plug will be, but it very loudly trumpeted at the time and "what happened to it?" is a question I imagine some readers would be curious about. As for the current ratings, they are clearly claimed by the manufacturers and apparently correspond to the included fuses. Regardless of what the C7 connector is rated for and whether they are safe current levels for the complete lead assembly, the 5A and 3A figures appear to accurately describe the mains plugs themselves.
For example, I appreciate the extra adjective in "the usual BS 1363 plug", because it makes it easier to understand that these are BS 1363 plugs, just unusual ones. (Oh, and you're right about wantine a wikilink to IEC 60320 C7 (talk) 11:57, 23 August 2014 (UTC)
Since the introduction of BS 1363, there have been many attempts to produce non-standard plugs to a similar format which have not been approved for use and can not therefore be legally offered to consumers. Some examples can be found at:
None of these other theoretical products are mentioned in this article either. The Min Kyu-Choi design for a plug (note, not to be confused with the Mu charger to a different design) does not meet any standard and it would be illegal to offer it for sale, on that basis it is very hard to see why it should be mentioned in this article as it simply does not exist beyond a dead-end prototype. The fact that it was "very loudly trumpeted at the time" is the result of a lack of due diligence on the part of the awards committee, the BBC and various journalists, but that does not warrant coverage here.
Non-rewireable plugs are required to be permanently marked with the rated current of the fuse which is fitted by the manufacturer, both 3A and 5A are approved sizes for the flexible cable fitted to SlimPlug and ThinPlug. All regular BS 1363 plugs are capable of 13A, but a regular non-rewirable plug fitted to the same size cable is also required to be marked as 3A or 5A, not 13A! There can be no question that a cord set including an IEC 60320 C7 appliance connector cannot be rated at more than 2.5A. We cannot know the potential maximum rating of either SlimPlug or ThinPlug unless they are certified as part of a cord set with some other appliance connector. Any attempt to do otherwise is WP synthesis which is not permitted.
Regarding the comment about the extra adjective in "the usual BS 1363 plug", because it makes it easier to understand that these are BS 1363 plugs, just unusual ones, this is missing the point that they are not BS 1363 plugs, they are approved BS 1363 compatible plugs. It is not clear why there is any discussion about wikilinking to IEC 60320 C7 as that appears to have been in place since the article was created! Pol098's suggestion of adding the figure of 8 description is a good one which has now been implemented.
Regarding chargers with built in plug pins, there are many of these on the market with folding pins, the fact that one of these, the ThinCharger, uses the same pin configuration as the ThinPlug does not mean that we should include reference to chargers with folding pins in this article. The international definition of a mains plug (from IEC 60664-1) is an "accessory having pins designed to engage with the contacts of a socket-outlet, also incorporating means for the electrical connection and mechanical retention of flexible cable". Because of that last clause it is easy to see that chargers do not meet this definition, they are not classified as plugs, and are not described in any WP article about plugs and sockets. FF-UK (talk) 17:42, 23 August 2014 (UTC)

Non-rewireable plugs are required to be permanently marked with the rated current of the fuse which is fitted by the manufacturer, both 3A and 5A are approved sizes for the flexible cable fitted to SlimPlug and ThinPlug. All regular BS 1363 plugs are capable of 13A, but a regular non-rewirable plug fitted to the same size cable is also required to be marked as 3A or 5A, not 13A! There can be no question that a cord set including an IEC 60320 C7 appliance connector cannot be rated at more than 2.5A. We cannot know the potential maximum rating of either SlimPlug or ThinPlug unless they are certified as part of a cord set with some other appliance connector. Any attempt to do otherwise is WP synthesis which is not permitted.

Er, it seems you have the definition of WP:Synthesis exactly backward. The paragraph quoted combines rules from several sources, particularly IEC 60320, to infer the conclusion that such a cable assembly cannot be rated for a higher current. This is clearly synthesis of several sources to reach a conclusion. In my ignorance, it is not clear, and therefore is questionable, that a plug that looks like a C7 connector, and intermates with a C8 receptacle, cannot be rated for higher current. For example, the C7/C8 couplers are apparently rated for 10A in North America, so the connector demonstrably doesn't rapidly catch fire at the 5A level.
On the other side, I have the direct and unambiguous manufacturer's claim that their cord sets contain a "figure of 8" plug (I cannot find mention of IEC 60320 anywhere), are equipped with a 5A fuse, and are rated for 5A. No synthesis required, it's a direct statement. I'm not saying that manufacturers' claims are never wrong, but you need a greater weight of evidence to infer that it is incorrect. (talk) 03:55, 24 August 2014 (UTC)
The WP restrictions on Synthesis relate to the content of the article, they do not place limitations on the critical thinking and analysis which is involved in the determination of whether a source can be considered as a WP Reliable Source. Clearly, if a source is claiming something other than that which is permitted by the relevant standards, then it may not be considered a reliable source in respect of those claims. There is, as far as I know, no separate American specification for a figure of 8 connector, but if there were it would not impact on the situation regarding a cord set to British standards. IEC 60320-1 clearly states that C7 is rated at 2.5A 250V. The fact that a power cord manufacturer erroneously claims otherwise is irrelevant. BS EN 60799 requires that the appliance connector in a cord set complies with IEC 60320-1, not some imagined alternative that looks like a C7 but is rated differently! Perhaps you should take a look at the C7 connectors on ThinPlug and SlimPlug cables, they are clearly marked 2.5A. FF-UK (talk) 10:44, 24 August 2014 (UTC)
Just to add, technically it is an extrapolation that the rating of the plug is at least as high as the cord set it is an integral part of, but that seems like a much smaller leap than saying "this standards document says it's impossible", and the article could say the rating applies to the cord set at the expense of a little bit of wording awkwardness. (FWIW, SlimPlug claim to be working on a new 13A rated model.) (talk) 04:28, 24 August 2014 (UTC)
The above comment is just further speculation. In the context of this discussion, the main benefit of the linked video is that it shows a number of other folding plugs that did not make it to the market (these are in addition to the plugs I have linked to above). Please note that the video is over five years old, raising a question as to whether the claim it contains of a further product rated at 13A (which is still not on the market) is realistic? Certainly nothing that changes the article. FF-UK (talk) 11:01, 24 August 2014 (UTC)

"There is no separate American specification for a figure of 8 connector." Now that's a nonsense statement, Any country is free to enact its own electrical safety rules which may contradict the IEC's in any or all details. I can point to a great many manufacturers selling 125V 10A rated cables with C7 connectors with proper agency certification. Oh, look, here's a list of seven of them from Digi-key, a very reputable distributor of electronic parts.

Perhaps the fact that they're claiming certification from UL, CSA and NOM rather than the IEC or BSA explains the difference?

But this is all tangential to the main point, which is that you appear to badly misunderstand WP:Synthesis: taking a direct claim is not synthesizing. Saying that BS EN 60799 requires IEC 60320-1 requires a C7 connector to not be used to carry more than 2.5A, now that is synthesis from multiple sources. Rather than making legalistic arguments that it's impossible, have a look at the manufacturers' claims, clearly visible on the their web page, and try to figure out how they did it. Both feature ASTA approval claims quite prominently. "They're lying" is one possibility. If you think so, feel free to ring the ASA. (talk) 11:01, 24 August 2014 (UTC)

If you believe there is a US standard for a figure of 8 connector please tell us what it is. All the cables that you have used as illustrations say that an IEC 60320 connector is used, but that is, indisputably, a 2.5A connector. In any case, what manufacturers of cables rated at 125V claim as their current rating has no possible significance when it comes to the approval of a UK plug/cord set. I had already enlarged on the subject of synthesis 17 minutes before you posted your comment, so do not propose going over that again. FF-UK (talk) 11:22, 24 August 2014 (UTC)
I don't know U.S. standards; you can probably find it as quickly as I can. UL 498 seems to be the master one. It does not call out particular connectors very much, but rather is a general test procedure to see how much current a given assembly can carry. (Section 183, p. 217.) It does, however, refer to UL 1681 for some connectors, requiring that the upper limits defined there be used as maxima. But I haven't found a copy of that standard yet to see what it says.
That said, my point regarding the N.A. current rating of C7 connectors was limited to the assertion that they can be operated at those current levels without prompt gross failure, so a limitation to a lower current level is a result of human rules, not a physical limitation of the form factor. Perhaps there is some additional document somewhere that neither of us are familiar with that grants exceptions to the standards you have quoted. The specialty plugs already got particular scrutiny simply due to their unusualness. I know with regard to building codes, the upside to such senior interest is that they can also grant variances (talk) 13:40, 24 August 2014 (UTC)
So what this comes down to is that you do not know, you are just guessing and making assumptions, which is precisely what WP does not allow. You have no evidence whatsoever that the C7 can be safely used above its rating, but you collect a bunch of websites which clearly, but mistakenly, quote the rating of the flexible cable used in the cord set as the rating of the cord set itself. As these sites also clearly state that they use the C7 connector we know that actual rating is 2.5A, and in each case there is obviously a mistake on the sellers part. Why are you so desperate to introduce spurious 'facts' into the article, based on such obvious errors? FF-UK (talk) 13:57, 24 August 2014 (UTC)
When you say "above its rating", which rating do you mean? I pointed out a dozen C7 connector products whose rating is 10A. That constitutes ample evidence that a C7 connector can be made which is safely rated above 2.5A. On that basis, I challenge your assertion that a product cannot be made with a C7 connector and a safe operating rating of 5A. (talk) 22:50, 24 August 2014 (UTC)
Ah, found it! I was looking for a standards document, but there's a more direct way. Here is an actual UL certification, from the horse's mouth, for a 10A C8 to C7 extender. (That page has a link to the datasheet proper which gives the part number and the relevant UL file number.) Thus, the certifying agency confirms the manufacturer's claim of a 10A rating for its YP-31 C8 connector and its YC-13 C7 connector.
I believe that constitutes definitive proof that there exist C7 connectors rated for 10A service by a major rating authority, (talk) 01:01, 25 August 2014 (UTC)
It does appear that, while you have not found a standard which specifies that C7 is rated at higher than 2.5A, you have found proof that (in the US) UL allow the rating of the IEC standard to be ignored in a cable rated at 125V, well done. However, this has no status in the UK where adherence to the ratings in IEC 60320 is required. Both of the C7 connectors fitted to the cord sets in question are clearly marked as being rated at 2.5A. The result is that you still cannot synthesize a rating for the folding plugs beyond that of the lowest rated part of the cord sets, and those cord sets are the only form in which the SlimPlug and ThinPlug are permitted to be sold. FF-UK (talk) 07:29, 25 August 2014 (UTC)
Let me make this absolutely clear: we have both read direct, unambiguous quotes from the manufacturers claiming ratings of 3A and 5A, respectively. Those are sources of moderate reliability, so the statement should stand unless rebutted by a more reliable source.
I have also (unnecessarily, but it seemed to be a sticking point) proved that the physical C7 connector is both physically capable of safely carrying currents even larger than that without significant danger, and some rating agencies are willing to certify it for such use. (FWIW, UL testing is performed at 150% of rated load.) Therefore, I strongly object to your attempt to synthesize a conclusion that the products are not rated for the manufacturer's claimed ratings in the UK without some evidence more direct than concatenating multiple standards. Particularly as it is not clear that there are not (and quite plausible that there are) additional rules providing for variances, exceptions, or alternative testing procedures.
Permit me to quote verbatim from WP:Synthesis#Synthesis of published material:

"A and B, therefore C" is acceptable only if a reliable source has published the same argument in relation to the topic of the article. If a single source says "A" in one context, and "B" in another, without connecting them, and does not provide an argument of "therefore C", then "therefore C" cannot be used in any article.

Your chain of logic contains considerably more than one source and two steps, but if we let A=BS EN 60799 and B=IEC 60320-1, the above certainly applies.
(As with all things, the above rule only comes in to play if someone challenges the assertion. I do make such deductive jumps quite regularly during normal editing, as WP:V does not require me to cite each and every non-contentious statement. But in case of contention, that is the rule.)
The rating embossed on the plug is useful guidance, but not necessarily definitive. Injection molds are very expensive, while both folding-plug manufacturers appear to be small, struggling companies; quite plausibly the factory producing the assemblies already had a C7 mold and it was not worth the expense of creating a new one. This might cost a few lost sales to pedants, but by reducing the price allow more sales to others. (talk) 09:16, 25 August 2014 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── "This is not a forum for general discussion of the article's subject."

This conversation has gotten way out of hand. In the article itself the amount of space and number of references which are assigned to these two relatively unimportant products is more than adequate, and should not be expanded to include non-existent products or power supplies. As far as the rating argument goes, the article adequately defines that the folding plugs are only available with C7 connectors, which should be more than enough information, what these plugs might be capable of if they were marketed with other connectors is hypothetical, and does not belong in an encyclopedic article. I checked the references and see that there is no current rating for the slimplug in the specifications. On the FAQ page, against "What is the maximum current that the lead can handle?" it says "The plug is fitted with an 5amp fuse as this is the maximum current that the cable can handle." which does not constitute a claim that the cord set is rated at anything other than its lowest rated component, the C7 connector. I suggest that this conversation is ended with no change to the article.


An anonymous editor, IP, recently added imperial (fractional inch) dimensions to this article, which I reverted. That editor has since left the following on my talk page:

Er... I included inches because the dimensions make more sense in inches. Especially for nominal dimensions. 22.2 mm is a peculiar number. But 7⁄8 inch is a nice round fraction! The pins are 1⁄4±0.005×5⁄32±0.003, with a 60° taper on the last 1⁄16 inch. I gave asymmetric dimensions to the pin lengths (and only the pin lengths) because, unlike all other dimensions, the inch dimensions correspond to the lower bound of the metric range. (I expect they were originally −0/+1⁄32, or perhaps +0.04", but haven't been able to find a pre-1985 copy of the standard to verify.)

The editor is making assumptions and using unwarranted WP synthesis in this edit, which is not allowed. BS 1363 has never been specified in fractional inches, the early versions contained dimensions in decimal inches, but that is of no significance as BS 1363 has been entirely metric for 30 years.

Please do not introduce irrelevancies into the article. FF-UK (talk) 19:22, 23 August 2014 (UTC)

I thought I'd start with a one-on-one discussion before promoting it here, but sure.
First of all, for reference, the version as I edited it:
BS 1363-1 specifies the dimensions of plug pins and their disposition with respect to each other in precise, absolute terms.[1] The dimensions were originally specified in decimal inches with asymmetric tolerances and redefined as minimum and maximum metric dimensions in BS 1363:1984. The line and neutral pins have a rectangular cross section 6.4×4.0 mm (​14×​532 inches), 17.2+1
(​1116 in) long and with centres 22.2 mm (​78 in) apart. The protective-earth pin is a rectangular cross section 8.0×4.0 mm (​516×​532 in), 22.23+1
(​78 in) long and with a centre line 22.2 mm (​78 in) from the line/neutral pin centre line.
Dimensions are chosen to provide safe clearance to live parts. The distance from any part of the line and neutral pins to the periphery of the plug base must be not less than 9.5 mm (​38 in).
My point is that, as with the Saturn V rocket and Viking landers, the original was designed in inches, and even though the normative dimensions have been converted to metric, this is soft metric; it is hard to understand why those dimensions were chosen until one realizes that they are round numbers in inches. Another example is all the 2.54 mm and 1.27 mm dimensions in electronics.
Not only is it common to give dimensions in two systems for the benefit of the benighted (wink) Americans who make up a large number of Wikipedia readers, even for UK-specific articles, but in cases like this it also illuminates the design process. The power pins are 1/4 inch wide, spaced 7/8 inches apart. I haven't found a copy of BS 1367:1967 on line (this site claims to have a 933K PDF, but they've managed to hide the actual link) to verify, but it was and is standard imperial-unit machining practice to choose nominal dimensions in binary inch fractions, but actually write them in decimals on formal drawings. Every machinist knows that 0.062 inch is 1/16 inch. It's technically 0.0625, but everything past the third decimal place is excessive precision.
If we were trying to report the exact limits in the standard, it would of course be best to use the same units. But this is trying to report nominal dimensions. That is already an extrapolation from the standard, which only gives upper and lower bounds. The current text simply assumes symmetric tolerances and averages them. Even though this could be called WP:OR, please do not remove it on my account; I do not challenge it because I think it is a perfectly reasonable extrapolation from the source material. But I do claim the right to shout tu quoque when someone argues that 6.4×4.0 mm is more official than an inch dimension when neither dimension appears in the standard.
The question here, for others to weigh in on, is whether inch dimensions help or hinder the comprehensibility of the section. I would very much like additional opinions on the subject. (talk) 21:46, 23 August 2014 (UTC)
This "benighted American" is insulted by the suggestion that those of us who are interested in the technicalities of such things need spoonfeeding with inches, that is an uncalled-for insult! Please stick with the simplicity of nominal mm measurements and stay away from excessive detail on tolerances. I also suggest that linking to sites with bootleg copies of foreign standards is not a very clever approach.
Dimensions in inches SHOULD be included when the metric figures shown in the current version of the standard were derived directly from the original inch specifications. While many people might immediately recognize many obvious conversions (how I tire of seeing references to 25.4mm video tape or 6.35mm jack plugs!), it may not be immediately obvious for all conversions nor even obvious at all to the younger metric--only generation. It's important to emphasize that the dimensions were originally specified in "round" inch measurements, not just some apparently random millimeter figure. (talk) 23:03, 3 December 2015 (UTC)
@ That's what I thought. If you'd like to take a crack at it again, you can use something like {{Convert|6.4|xx|4.0|mm|in|frac=32|abbr=on}} to get "6.4 × 4.0 mm (14 × 532 in)". (talk) 03:23, 19 January 2016 (UTC)
It is entirely wrong to suggest the use of fractional inches as these have NEVER been used in BS 1363. FF-UK (talk) 14:21, 19 January 2016 (UTC)
It is common practice in Wikipedia to present measurements in both metric and imperial units. The source doesn't enter into it. This is not trying to present the 1947 spec, but the current spec translated into inches for the convenience of readers. (talk) 08:10, 20 January 2016 (UTC)
On the other point, I don't have a copy of BS 1363:1947 handy, but the figure caption at Metrication in the United Kingdom#1965 onwards says that the ground pin width was specified as "1⁄4 inch". Binary fractions were and remain the customary way to use inch dimensions. (Indeed, that's the primary reason that Template:convert has a |frac= parameter at all.) All machinists are aware that even if presented in three-place decimals, they "really mean" fractional inches. 0.062 is 1/16, 0.094 is 3/32, etc. (talk) 08:24, 20 January 2016 (UTC)
BS 1363:1947 uses decimal inches, not fractions, as stated in the article and in my original post on this subject at the top of this section. What 'all machinists are aware" of is hardly significant is it? FF-UK (talk) 14:56, 20 January 2016 (UTC)

BS1363 (and BS546) compared with other standards[edit]

Should the article not include section comparing the relative characteristics and merits of British plugs and those used in the rest of Europe (particulaly Schuko) ? BS1363 is often claimed [4] to be the worlds safest plug by virtue of individual fusing and shuttering however some [5] dispute this claiming that the individual fusing is either unnecessary or so poorly implemented as to present safety issues of its own (through overheating) And that the higher current rating (16A) of Schuko provides more of a safety margin for heavy loads (such as tumble driers) while the fact that BS1363 only connects at the tip of the pins gives them very little contact area (hence more risk of overheating -particularly with worn sockets) whereas the round pins of Schuko (and BS546) allow for a much larger contact area. (talk) 19:13, 3 October 2014 (UTC)

If appropriate sources could be found then such a section would be a useful addition, but it would correctly be placed in the main AC power plugs and sockets article. Is anyone aware of any published serious comparative study? Clearly, the discussion quoted, and many others like it, are just opinions with no serious study behind them. I also note the unfounded claims that "BS1363 only connects at the tip of the pins gives them very little contact area" and "the round pins of Schuko (and BS546) allow for a much larger contact area", on what is this based? The minimum length of flat pin on a BS 1363 plug available for contact is 5.85mm, the comparative length for the round pin Schuko is 6.5mm. You must also take into account the differences in making good contact to a flat pin with flat contacts, and to a round pin with rounded contacts, the actual contact surface for the latter tends to be very small. FF-UK (talk) 09:51, 4 October 2014 (UTC)
I suspect the merits of flat v's round pins (before even considering the other characteristics of plug design) could be an interesting and extensive subject in its own right. When well implemented individual fusing of plugs has a lot of safety advantages even on radial circuits. Shuttered sockets and sleeved pins are not completely unique to BS1363. Sleeved pins only became mandatory in the 1980's. Shutters were specified from the outset but have since been adopted for other types of socket as well. (talk) 22:12, 25 December 2014 (UTC)

Article title[edit]

The use of the hyphen seems nonstandard; should the article be moved to something like AC power plugs and sockets in Great Britain? (This is just a sanity check; don't treat it as a formal move request yet.) --SoledadKabocha (talk) 04:33, 30 August 2015 (UTC)

Please see archived talk section for main AC power plugs and sockets article: and several subsequent sections. There was considerable discussion on this before and after this subsidiary article was created. FF-UK (talk) 06:59, 30 August 2015 (UTC)
Ok, sorry for not noticing that, but if I wanted to reopen the discussion, where should I do so? Presumably that would take place on the parent article's talk page (Talk:AC power plugs and sockets)? (I will only pursue this further when I find a specific Manual of Style section to cite.)
Some investigation shows that no similarly-titled articles exist for regions other than Britain and a major contributor to the "considerable discussion" was later blocked as a sockpuppet. --SoledadKabocha (talk) 21:32, 30 August 2015 (UTC)
I do not understand why you are keen to revisit this? It is unfortunate that the other articles were not created as planned, you may like to consult Jeh who apparently made the original suggestion to split the article, and had offered to take care of the "AC power plugs and sockets - American and related types" article. I had wondered why Deucharman disappeared, thanks for linking to that info. FF-UK (talk) 06:32, 31 August 2015 (UTC)
As for the MoS concern, the best I can find so far is that neither WP:Article titles#Disambiguation nor the related WP:NCDAB explicitly authorizes this use of a hyphen (which should really be some form of dash anyway). Most of WP:MOSDASH does not mention article titling; it only expressly allows a dashed title in the context of "Instead of a hyphen, when applying a prefix to a compound that includes a space." --SoledadKabocha (talk) 19:00, 31 August 2015 (UTC)
Jeh (talk · contribs) would not have been successfully notified because you mistakenly left the "User:" out of the link target. (His/her talk-page banner and editnotice seem to imply that we should continue the discussion here.)
I discovered while looking at Talk:AC power plugs and sockets/Archive 4#Requested move that Mautby (talk · contribs) is another sock with the same master as Deucharman, but that could be beside the point. --SoledadKabocha (talk) 19:33, 1 September 2015 (UTC)
Re the NEMA article, Real Work happened. Re the hyphen here, I find nothing in MOS that says article titles cannot be structured in such a way. MOS does say that the hyphen should be changed to an en dash and a redirect created from the form with the hyphen, to facilitate searches. (Perhaps we should also create redirects with doubled hyphens, and with an em dash, and with all in both spaced and unspaced variations.) This elicits from me a tired groan; I think hyphen-twiddling is extreme silliness (Wikipedia is not a print encyclopedia, en dashes in place of hyphens interfere with text searches within articles, and anyway, how do we know if the fonts used on a reader's machine honor the distinctions between hyphen, en dash, and em dash as intended by MOS?) but I would have no objection. Or, heck, we could just leave alone what isn't broken.
I wasn't aware that Mautby/Deucharman/SSHamilton had been discovered and permablocked as socks, but I applaud, and I thank SK here for inadvertently bringing that to my notice. One of the reasons I didn't get back to the NEMA article was having to deal with near-constant objections from that "group" anytime I dared to opine on anything in this area. Jeh (talk) 21:11, 1 September 2015 (UTC)
Re this specific rename suggestion, careful: These plug types are not only used "in Great Britain". Again: Not broken, don't fix. Jeh (talk) 21:20, 1 September 2015 (UTC)

Okay, so I was knowingly a bit sloppy (hence the strikethrough in my original post). But if we were to move this article to an unpunctuated title, what title would you suggest? (Emphasis on "if" — I don't mean to object that strongly to "not broken, don't fix.") --SoledadKabocha (talk) 06:35, 2 September 2015 (UTC) (+ 06:47, 2 September 2015 (UTC))

Alright... why was the article moved in defiance of no consensus here for a change? Jeh (talk) 23:18, 11 September 2015 (UTC)
Jeh, having just returned from vacation, I echo your query! FF-UK (talk) 11:55, 13 September 2015 (UTC)
FF-UK I already asked for explanation at User talk:GreenTintedSixtiesMind - suggest you do the same. Jeh (talk) 13:49, 13 September 2015 (UTC)
FF-UK No response to either of our queries and it's done no more editing since. What should we do? I'm inclined to go through Requested Moves (since the old name is now a redirect that's been edited).
I'm also inclined to report GTSM for disruption. Unless I'm doing something wrong, character search shows that in many cases he "moved" pages onto their original name! (But this is still destructive, as in the process he edited redirect pages, which will make further moves of those pages impossible without admin assistance.) Jeh (talk) 09:30, 15 September 2015 (UTC)
Re this article, personally I think the hyphenated (dashed if one insists) name is preferable. Per WP naming guidelines (WP:PARENDIS), one uses xxx (yyy) where there is also xxx (zzz) and they are two very different meanings of xxx. For example, Rock (geology) vs. Rock (music). That is not the case here. The same section also says "Commas and round brackets are the only characters that can be used to separate a disambiguator in an article title", but this is not a case of disambiguation, it's a case of more precise specfication. Perhaps, as indicated in that paragraph, we could use a colon (:) instead. Or even a comma, as in mil-type parts designations. The funny thing is that even though WP:TITLE says that, WP:DASH contains specfiic language that does allow for dashes in titles. Jeh (talk) 09:30, 15 September 2015 (UTC)
Jeh I will be pleased to support that approach. FF-UK (talk) 16:48, 16 September 2015 (UTC)
FF-UK ok, I've moved this one to the colon form. Since there was no existing redirect from the colon form I was able to do this without assistance. Jeh (talk) 04:04, 23 September 2015 (UTC)
Jeh Seems like a good solution, and makes a lot of sense. Thank you. FF-UK (talk) 06:27, 23 September 2015 (UTC)

BS 4573 (UK shaver plug)[edit]

The article doesn't give dimensions (pin spacing, pin diameter etc) for the BS 4573 plug. Would be interesting to see how these compare with the Europlug with which it's sometimes confused. (talk) 21:05, 16 January 2016 (UTC)

They are already there, take another look. FF-UK (talk) 23:08, 16 January 2016 (UTC)
I have reverted recent changes to this article which were wholly erroneous, the reference cited has apparently been misread as it does not support the claim made. The only valid reference for plug dimensions are the relevant standards, and the article, as reverted, is correct. FF-UK (talk) 16:07, 18 January 2016 (UTC)
Is the text of these standards available online or do you have access it to it. If so why not correct any errors in the dimensions table rather than deleting it completely ? Any source which cannot be proven to be incorrect is valid for Wikipedia although primary sources (such as the relevant standards) is obviously preferable provided it is readily available. (talk) 12:52, 27 January 2016 (UTC)
Actually having looked at the whole thing again some of the figures do look a bit suspect so I've removed them from the table until we can get clarification of the accurate dimensions. -apologies (talk) 13:12, 27 January 2016 (UTC)
Once again, the dimensions are, as stated in the section, the same as those of the 5 A plug specified in the obsolete BS 372:1930 part 1 which is shown in the table above the section. They do not need to be restated! The BS 4573 plug does not have a specific current rating in the standard, therefore one cannot be claimed. It is not valid to compare a plug which is dedicated to shavers and toothbrushes only with the general purpose Europlug, in any case, this article is about British plugs and sockets, not other European plugs and sockets! If you want to read the BS 4573 standard, try your local library, many have access to the online British Standards database, otherwise you have to buy it. The Europlug is already mentioned in this article, with a link to the Europlug article. The latter works differently to any other mains plug in that the plug pins themselves provide the resilience necessary to achieve a contact with socket contacts of a greater size than the plug, whereas normally plug pins are rigid and are intended only to fit sockets with resilient contacts designed for the specific plug. I have again reverted these unnecessary and misleading additions. FF-UK (talk) 14:22, 27 January 2016 (UTC)
The purpose of the table was to illustrate the difference in dimensions between the BS 4573 and the Europlug with which the former is easily confused by casual observers on account of its somewhat similar appearance. The fact that some (not all) sockets will accept either type and that devices fitted with Europlugs often make their way (lawfully or otherwise) onto the UK/Irish market adds to the confusion. (talk) 14:59, 27 January 2016 (UTC)
Such a purpose would be better served by a photograph of the two plugs adjacent to each other (pin to pin) which would make clear the different spacing, different diameter and, very important, the fact that the Europlug pins converge. I will endeavor to make such an image as soon as I have the opportunity. With regard to the legality of Europlugs in the UK, the governing regulations are the Plugs and Sockets etc. (Safety) Regulations 1994 (S.I. 1994/1768). These require an appliance to be fitted with a BS 1363 plug, however there is an exception under Schedule 1, regulation 4 “Excluded electrical devices”, item 5: "Any non–rewirable or any moulded–on Europlug (that is to say any plug conforming with BS EN 50075) which is designed for the purpose of connecting to a shaver supply unit conforming to BS 3535: Part 1 any electrical shaver, toothbrush or similar appliance; and for the purposes of this paragraph the expression “shaver supply unit” shall have the meaning given to it in BS 3535: Part 1." FF-UK (talk) 11:26, 28 January 2016 (UTC)

Dangers, Risks, Criticisms[edit]

On the topic of an obsolete standard this article correctly states, "A fuse that worked loose could end up protruding from the socket, electrically live and posing a shock hazard, when the plug was removed."

However, the article neglects to mention a similar threat is present in BS 546 plugs because round pins gradually unscrew themselves. Prolonged use can result in wobbling/loose pins, moving wires inside the plug, and danger of pins remaining in the socket when the plug is removed. Overall, this article lacks the various criticisms and counter-arguments for each standard. — Preceding unsigned comment added by (talk) 10:08, 8 October 2016 (UTC)

Regarding the loose fuse, the Dorman and Smith plug was a proprietary design which has never been the subject of a standard, obsolete or otherwise.
Regarding the comment on a supposed pin problem in BS 546, there would need to be a reliable source for such a comment before it could be introduced into the article. FF-UK (talk) 17:41, 8 October 2016 (UTC)

One can buy, cheaply, in the UK, adaptors which will accept the live and neutral pins of an upside-down plug if the adaptor shutter is missing, broken, or pushed aside; if the live and neutral sockers were further from the edge of the plastic, the earth pin would prevent such insertion. And adaptors made of thermoplastic can melt if overloaded, and later the cooled plastic makes it almost impossible to remove the plug. I have witnessed these things, which should be forbidden by the applicable standard(s). (talk) 17:46, 9 April 2017 (UTC)


This article, although it purports to cover all AC power plugs, does not cover 3-phase plugs and sockets. It therefore seems to be missing a section. FreeFlow99 (talk) 12:02, 1 March 2017 (UTC)

What was missing was the note regarding multiphase and industrial plugs and sockets which appears at the head of the main article AC power plugs and sockets and now appears at the head of this article also. FF-UK (talk) 22:28, 1 March 2017 (UTC)

Socket covers[edit]

I have been told to express my concerns on the talk page. My primary concerns are twofold:

1, FatallyFlawed and Plugsafe are self-published unreliable sources, and should not be included. FatallyFlawed's existence and arguments can be sourced to the reliable Daily Telegraph, which I have done.

2, the removal of the Electrical Safety Council's statements that they do not see socket covers as a safety hazard. I see no reason for these to be removed; the opinions of one of the UK's leading electrical safety organizations should be included, especially when they differ from other groups' views.

I also object to the phrasing of the statement "The UK government does not collect statistics of injury or accidents related to use of socket covers" and prefer my alternative "No recorded deaths have been attributed to the use of socket covers". The first seems to imply that deaths have been caused to my ears, which we can't say without a reliable source, while both convey that there is some ambiguity. The "socket covers are unneccesary" statement should be attributed to the government, as it used to be. — Preceding unsigned comment added by (talk) 09:03, 30 May 2017 (UTC)

Anon. IP - I suggest that you take careful note of WP:SOURCE, in particular, under the heading Self Published Sources the reference to "an established expert on the subject matter, whose work in the relevant field has previously been published by reliable third-party publications" and also the heading Self-published or questionable sources as sources on themselves.
Your references to Electrical Safety Council's statements are outdated, for the current policy of ESC see:
"The UK government does not collect statistics of injury or accidents related to use of socket covers" is an accurate statement. The current position of the UK Government is reflected in the referenced statements from the Department of Health (NHS) and Department for Education. You should note that the DoH alert refers to Fatallyflawed as a reference source, and does not use the "socket covers are unnecessary" phrase, only that socket covers can be dangerous.
There are no grounds for your persistent removal of material from this article and you appear to be engaging in Wikipedia:Edit warring having so far made four removal edits in the space of less than 24 hours, a clear contravention of the policy. Please refrain from further contentious editing FF-UK (talk) 10:38, 30 May 2017 (UTC)
While we can use primary sources as subjects on themselves, it is better to use secondary sources, like the Telegraph and IET articles provided, which cover all the necessary points. The self-publish source guidelines themselves say that self-published sources, no matter their accuracy, should only be used where secondary sources do not provide the necessary information.
The Electrical Safety Council's statements are not outdated, they are the only statements they have made on the safety of socket covers, not whether they are necessary.
While indeed "The UK government does not collect statistics of injury or accidents related to use of socket covers" is technically accurate, it implies that people have been killed by socket covers, which is original research.
The "opinion of the government" is in fact an opinion of the NHS, which the Deparment for Education quotes as something to consider, not as a policy statement. (talk) 11:02, 30 May 2017 (UTC), I appreciate that you are new to WP, but please try to follow the conventions of the Talk Pages by indenting your responses by one space further than the comment above Help:Using_talk_pages#Indentation and signing your contributions Help:Using_talk_pages#Identifying_yourself
I have taken the liberty of adding indentations for you.
You wrote: "it is better to use secondary sources, like the Telegraph and IET articles provided". Please note that those articles date from 2008 and 2012 respectively and do not contain the latest available information!
You wrote: "The Electrical Safety Council's statements are not outdated, they are the only statements they have made on the safety of socket covers, not whether they are necessary." You are ignoring the current policy of ESC which is titled "Policy on Socket Blanking Plugs" and dated 30 November 2015, this is their most recent pronouncement on the subject and not the old 2009 and 2013 comments that you have dug up! Please note, the current policy is confined to reassurance that BS 1363 sockets are safe and actually does not mention socket covers except in the title! (The reason for this is quite simple, the ESC themselves are not known to have conducted any research on socket covers, and so have no basis for making any comments on their value of safety, they leave that to others.)
The statement: "The UK government does not collect statistics of injury or accidents related to use of socket covers" is a simple fact, your inference is unjustified and irrelevant.
You wrote: "The "opinion of the government" is in fact an opinion of the NHS" - I suggest that you read it again, it is quite clearly issued by the Department of Health, which is part of the UK Government!
I see that you have offered no defence of your unreasonable removal of the Mark Coles (IET) statement that: "Socket-outlets to BS 1363 are the safest in the world and have been since they were first designed in the 1940s. Socket protectors are not regulated for safety, therefore, using a non-standard system to protect a long established safe system is not sensible." And, likewise, your removal of the MK statement that "MK goes to great lengths to ensure that all its BS 1363 plugs and sockets are safe. Inserting incorrectly dimensioned products into a socket-outlet can both damage the socket and reduce its safety". Both these statements are from impeccable sources and go to the heart of the issue, clearly they belong in this section of the article. JimmiCheddar (talk) 13:43, 30 May 2017 (UTC)
What information do the Telegraph and IET articles lack? Pretty much nothing that is actually contained within the article.
The ESC's statement is dated 2008 not 2015, they merely reviewed it then! The 2009 and 2013 statements are still notable (and not outdated) as the only statements the ESC has made on the actual safety of socket covers, and they have not made any retraction of the statements or referral to those who argue against socket covers.
The statisics statement can be replaced with my proposed statement "No recorded deaths have been attributed to the use of socket covers" which contains the exact same information without the implication. You may not see the inference, but I do, and undoubtley at least some other reader will to.
It is the opinion of the Department of Health, not the government. The Department for Education merely mentioned it as something to consider, without explicitly condemning socket covers.
The MK statement was removed because it was unsourced and anyway came from an unreliable source - the FF website. This is standard WP procedure. I judged the Mark Coles statement fairly irrelevant, as it merely restates what is already said on the page. (talk) 13:58, 30 May 2017 (UTC), You really have no idea do you? You are just making things up! Your further comment about the Electrical Safety First policy is a perfect example. The review date is the date at which the policy statement was last updated! First, a small example, the first line states "In the opinion of Electrical Safety First", but as the name "Electrical Safety First" has only been in use since 2014 (it used to be called "the Electrical Safety Council") it is blatantly obvious that their policy has been reworked since 2014! Now, for some more substance, check out this CAPT report from 2010 on a now withdrawn "Which?" report which quoted from the then Electrical Safety Council policy some words which are no longer part of their policy, they have been withdrawn! And here is an archive copy from February 2015 of a website which quotes from the 21 July 2011 version of the Electrical Safety Council policy, again, different words to today! Why did they change the policy and remove any suggestion that concerns over safety covers were unjustified? Because it has become clear that the concerns ARE justified, and that is primarily down to the work of Fatallyflawed. When "Which?" realised that their earlier report was incorrect, they withdrew it for the same reason. I have lived in the US since before Fatallyflawed was set up in about 2008, but I can tell you that there was significant concern about UK socket covers amongst British electrical engineers and electricians back in the 80s and 90s. Fatallyflawed was a latecomer to the scene, but they are the people who have made the difference and whose work has resulted in a widespread understanding of the dangers and the beginnings of official action to deal with the problem (I admit that I would have joined them if I still lived in UK). They are, without doubt, the most reliable source on the subject!
As for your idea that the Department of Health is not part of the government, that is just plain ignorance! JimmiCheddar (talk) 16:47, 30 May 2017 (UTC)
Well said JimmiCheddar, this anonymous IP has revealed themselves as nothing more than a time waster who does not understand WP policies. FF-UK (talk) 19:22, 30 May 2017 (UTC)

External links modified[edit]

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  1. ^ BS 1363-1:1995+A4:2012, fig. 4a