Talk:Mains electricity by country

Devices

I tried to make a change from Power cords with type A plugs which are rated at only 125 V may present a safety hazard. to Devices with type A plugs which are rated at only 125 V may present a safety hazard. but it was reverted. Note that this whole talk page is about this one note. First, none of the 120V appliances that I check have a voltage rating on their power cord. Not on lamps, extension cords, or anything else. I suspect that the actual case of using cords rated at 125V is low. Second, connecting appliances designed for 120V to 240V power sources is likely hazardous. A hair dryer will run at 4x the power, with the fan also running much faster. Hopefully the thermal sensor will go pretty fast. Devices with iron core transformers (less and less popular, but still many around) are usually not universal voltage. The rectifiers or capacitors are often not rated double, and will fail, likely catastrophically. And third, it seems to me that power cords are also devices (though not appliances) and so are not excluded by the change. And finally, I still have not seen a reliable reference for the original note. While it might seem obvious, as I understand it, it still needs a reference. Gah4 (talk) 17:09, 13 September 2016 (UTC)

No comments so far., so I decide to actually go read the NEC. As far as I can tell, the lowest rating for power cords in the US NEC is 300 volts. As this the for English readers, it seems that the primary audience for 120V countries is the US. Someone else can find it in the Canadian NEC. Of there are no 125V power cords, then we don't need this whole note. Japan uses 100V, and might have lower voltage cords. I can't read Japanese at all, so someone else will have to find that one, but most likely they will read the Japanese Wikipedia. If someone has a better refrence than the NEC, I would be happy to look at it. Gah4 (talk) 02:05, 14 September 2016 (UTC)

Gah4, The NEC is concerned with the installation of electrical conductors and equipment in premises. It is NOT concerned with appliances or power cords for appliances. The relevant American Standard for plugs is NEMA WD 6-2016 which defines the plugs and outlets used in the USA and Canada. NEMA WD 6-2016 Figure 1-15 (Type A) and Figure 5-15 (Type B) both define the rating of those plugs as 125 V. The international standard for Type B is IEC 60906-2, "IEC system of plugs and socket-outlets for household and similar purposes – Part 2: Plugs and socket-outlets 15 A 125 V a.c. and 20 A 125 V a.c."

Mains_electricity_by_country#Voltage_rating_of_plugs_and_power_cords includes an image of plugs which depicts photographically the two standard methods by which the voltage ratings for American plugs are indicated. Gah4, your own lack of familiarity with the way that American plug and power cord ratings are indicated is really of no significance. What is significant is what it says in the relevant standards, and the way the ratings are actually indicated. The article is about voltages and plugs, not appliances. The current wording is appropriate! FF-UK (talk) 08:42, 14 September 2016 (UTC)

That is why I looked to see what the NEC says about it. I suppose they aren't relevant either. Note that most people are more interested in using actual appliances than just plugging in plugs. Gah4 (talk) 16:23, 14 September 2016 (UTC)

Gah4 Looks like you did not bother to read the part where I explain that the NEC is really NOT relevant! It covers only installations. FF-UK (talk) 16:35, 14 September 2016 (UTC)

I saw it, but I didn't see the reference. Looks to me that once you plug it in, it counts as an installation, and the NEC applies. I suppose unplugged it doesn't, but most people find that things work better plugged in.

But mostly, I still don't see why you make a big thing out of something that likely isn't a problem, but try it ignore something that really could be a problem. People come here before they take appliances to other countries, not just plugs. It doesn't seem like a bad idea to remind people that things other than plugs could be a problem. Gah4 (talk) 04:55, 15 September 2016 (UTC)

You're missing the point that the limiting factor is the part with the lowest rating. Per NEMA (as quoted above) there are no NEMA Type A or B plugs rated for anything above 125 volts. Jeh (talk) 08:19, 15 September 2016 (UTC)

Why not say plugs then, as it seems that the NEC doesn't allow cords (wire) rated below 300V. Also, others could rate the safety of plugs, even if NEMA doesn't. Many devices have plugs with no cord, and are rated up to 240V. This comment suggests that those devices are unsafe. Do we have an actual reference to any actual unsafe type A plug attached to a 240V rated appliance? Even more, one that is unsafe at higher voltage, but safe at 125V? And with the popularity of adapter plugs, that device would be unsafe in any country with over 125V, even without type A outlets. The lack of this note on other countries seems to suggest that they are safe with adapter plugs in those countries. Gah4 (talk) 13:06, 15 September 2016 (UTC)

From NEMA Connector, The dimensions and configurations for NEMA connectors are given in ANSI/NEMA standard WD-6.[2] Underwriters Laboratories maintains UL Standard 498,[31] which specifies construction performance (e.g.: durability, electrical safety, and fire-resistance) for NEMA connectors. These additional requirements allow connectors to be manufactured to be compliant with the National Electrical Code. sounds like UL is responsible for the safety standard, and that all have to comply with NEC for safety. It does not suggest that plugs are unsafe at higher voltages. Certainly using NEMA 1 or NEMA 5 outlets at higher voltages can be confusing to users, and plugging in appliances not designed for that voltage can be dangerous, but I don't see any suggestion that NEMA 1 plugs on 100-240V appliances is a safety hazard. Anyone with a reliable source reference otherwise? Gah4 (talk) 16:33, 15 September 2016 (UTC)

There is no reason to believe that a plug certified at 125V is safe at higher voltage. Also, if there is no flexible cord, then, by definition, there is no plug! (plug = 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 cables or cords IEC Electropedia. A device with built in plug pins is a direct plug-in equipment (direct plug-in equipment = equipment in which the mains plug forms an integral part of the equipment enclosure so that the equipment is supported by the mains socket-outlet IEC Electropedia). There is no reason to disbelieve that a direct plug-in equipment certified for use up to 240V is unsafe at that voltage.

Gah4, please take another look at the NEC, section 90.2 "Scope" makes it perfectly clear that the NEC is concerned with installations. Neither a plug attached to a portable appliance, or a direct plug-in equipment can be described as an installation. The NEC has nothing to say about ratings of plugs, or the ratings of flexible appliance cords.

See NEC section 400, which covers flexible cables, and also 400.10 (A), (B), and 400.12, plugs for those cables. Gah4 (talk) 08:40, 19 September 2016 (UTC)

Yawn, once again, please take note of the overriding section 90.2 which confirms the scope of the NEC - INSTALLATIONS. Only when flexible cords and plugs are used as part of an installation are they the subject of the NEC! 400.10 lists the way in which the use of flexible cords is permissible as part of an installation. FF-UK (talk) 09:39, 19 September 2016 (UTC)

You mean like 400.10 (A)(3), including portable luminaries, portable and mobile signs or appliances? Appliances like some might take to other countries? And that they might plug in, in those countries? Gah4 (talk) 10:02, 19 September 2016 (UTC)

What part of the word "Scope" do you not understand? The Standards for appliance plugs and cords are determined by NEMA and UL, not the NEC! FF-UK (talk) 15:12, 19 September 2016 (UTC)

Mains_electricity_by_country#Voltage_rating_of_plugs_and_power_cords and Mains_electricity_by_country#Some_countries_use_Type_A_and_Type_B_sockets_at_greater_than_125_V do make the point about the importance of appliance rated voltage "Using an appliance, plug or power cord which is not appropriate for the territory (e.g. one rated for 125 V with a 230 V supply) may constitute a safety hazard" and "may be suitable for chargers and power supplies incorporating Type A pins, providing they have a suitable voltage rating". However, there is good reason to add the specific note for countries where a US type outlet (suggesting a 115V supply) is used at a higher voltage. FF-UK (talk) 19:22, 15 September 2016 (UTC)

OK, but appliance, plug or power cord is a little long for the note, so I thought devices would include all of them. Can we put "appliance, plug or power cord" in the note? Does that make everyone happy? Gah4 (talk) 20:33, 15 September 2016 (UTC)

There is no need to change what is already there. FF-UK (talk) 21:38, 15 September 2016 (UTC)

Required

Plugs and power cords have a rated voltage (V) and rated current (A) assigned to them by the manufacturer, and these values are required to be marked on the plug. Who is it that requires this? I seem to have a large number that don't have a voltage or current rating. Not cheap no-name brand one from third world countries, but one that are from well known manufacturers. Seems that they don't know about this requirement. Gah4 (talk) 00:15, 16 September 2016 (UTC)

The overarching standard for "Plugs and socket-outlets for household and similar purposes" is IEC 60884-1. The section on marking is 8, and this includes:

8.1 Accessories shall be marked as follows:

– rated current in amperes;

– rated voltage in volts;

– symbol for nature of supply;

– manufacturer's or responsible vendor's name, trade mark or identification mark;

– type reference which may be a catalogue number;

The general requirements of this standard are normally adopted into the national standards of the country concerned. For instance:

(British) BS 1363 section 7

(French) NF C 61-314 section 8.1

(Australian) AS/NZS 3112 section 2.12

(Indian) IS 1293 section 8.1

(Chinese) GB.2099.1 section 8.1 (note, China is one of the countries which uses a version of NEMA 1-15 rated at 250V).

The US requirement is in UL standard 498, table 163.1 (plugs) and table 163.4 (receptacles). FF-UK (talk) 10:38, 16 September 2016 (UTC)

Diagram or pictures?

I reverted the removal of a nice diagram. It is much easier, when someone wants to know which type of plug or socket they have, to look at the diagram. It might be nicer to have one that went horizontally across the page, maybe with each one a little bigger, but it isn't so bad the way it is. I vote for the diagram over the pictures, if the redundancy is too much. Some of them are similar enough that it is hard to tell from the pictures. Gah4 (talk) 16:04, 28 October 2016 (UTC)

I have re-reverted! The diagram is superfluous, inaccurate, incomplete and not to a common scale. If the diagram were better it might be worth keeping. Some examples of errors: Some of the diagrams appear to be sockets and some plugs. Type A should depict a polarised plug. Type C is not that shape at all! Type D is not a round plug. That is not a Type H! That is not a Type K! Type I should be shown as a round plug. Type M and Type N are simply missing. FF-UK (talk) 16:19, 28 October 2016 (UTC)

I don't know where that diagram came from. Maybe someone can find a better one, that fits better on the page, and is closer to scale. From the article, it seems that omitting M and N isn't unusual. Gah4 (talk) 16:57, 28 October 2016 (UTC)

I like the diagram in principle. It is not critical for identification that type A depict a polarized plug (non-polarized variants do exist). Certainly having all the plugs to the same scale is not critical either. And it is completely unnecessary to show every last detail of a plug's shape. Jeh (talk) 18:02, 28 October 2016 (UTC)

What should the convention be for denoting a male vs. a female contact? Filled-in vs. outline? This appears to be using filled-in = male contact, outline = female in the plug, opposite for the receptacle. Jeh (talk) 18:17, 28 October 2016 (UTC)

As far as the convention goes, I believe that what Jeh says is correct for the pins, but this diagram is showing outlines which in some cases are plugs, and in others are sockets! (eg, the type I diagram is clearly copied from this socket: and that is just one particular manufacturer's implementation of a socket rather than any sort of acceptable generalisation. I start from the position that the existing illustrations are all that is required, there is no need for futher juvenile pictures. But, much worse than that, the quality of this diagram is so low that it must not be allowed here, no way, absolutely NO! JimmiCheddar (talk) 18:36, 28 October 2016 (UTC)

I start from the position that the existing photographs are NOT all that is required. For one thing, scrolling down through the page checking a plug or socket against each picture is inefficient (one might as well argue "we don't need a table of contents when we have the section and subsection heads in-line in the article"). For another, the pictures show just one implementation instead of a generalization. ALso, I must add: your vehemence is noted, but is not compelling to agreement with your position. Rather the opposite. Jeh (talk) 18:47, 28 October 2016 (UTC)

I would like just to admit that this diagram is vector and may be easely edited and improved Yanpas (talk) 19:25, 28 October 2016 (UTC)