Have just been perusing the MK Electric on-line catalogue and was checking out their 15Amp 127V Socket Outlets . The data sheet describes them as “American Style” yet they are rated 127V and are not UL or CSA listed. The standard covering their design is given as SSA: 444: 1985. Which standards authority is SSA? It might give me a clue as to the intended market for these devices.

Other interesting difference with the NEMA prototype is the shuttering of the slots. I would also be interested to see how the terminals are labeled. ‘L, N, E’ I suspect from the datasheet though it is not that clear. No mention of brass and silver terminals as I doubt the intended customer uses white as the neutral/grounded conductor. Polarization is the same but I see that outside of America, the earth pin is definitely up!

That socket is intended for the middle eastern market. Saudi Arabian Standards Organization (SASO) issues SSA numbers.

These outlets are used alongside UK style BS1363 which also have an SSA code. MK makes both of them on UK-type plates so they can be installed easily. American plates and boxes would be very problematic.

127V 50Hz is used in quite a few Middle Eastern and caribbean countries. It's an oboselete European standard that was used in a very similar way to 120V in the US.

i.e. circuits were either 127V + 0
or 127+127 giving you a potential difference of around 220V between the two terminals but 127V between either terminal and ground.

However it's survived in places outside the EU but as far as I'm aware is being phased out as it is rather difficult to get 127V 50hz appliences. US appliences designed to be used on 50/60Hz work "ok-ish" on 127V but it's pushing the upper limit a bit particularly if there's any kind of a voltage spike. There are a lot of stories of US appliences plugged into outlets that seemed to be US standard being wiped out.

In most instances you'll find 127V is used almost exclusively for lighting with 220V used for almost everything else.
However, most countries that use 50Hz are converging on Cenelec (european) standards and adopting 230V L + 0V N for single phase and 400V for 3-phase.

Interestingly, MK has a very large presence in many places that would have had a lot of contact with the UK / former british colonies.
So you'll find MK plugs, sockets, systems and distribution / manufacturing businesses in places like India, HK / China and various Middle Eastern and african countries.

Also, I think MK's version of a NEMA outlet is actually pretty good. Shutters sould be a nice addition!


[This message has been edited by djk (edited 12-28-2003).]

So was this same configuration of plug/socket used in Europe on 127V + 0 before obsolescence? I have likewise been trying to establish what plugs were used in the British Isles when the, now long-gone,110-0-110V DC systems were in vogue. Was a 110V supply ever tapped in this system?

Hutch,

No I don't think that configuration of plug was used in Europe as far as I am aware it was either 2 round pins or light bulb sockets. Although I am not 100% sure as Europe's had endless different standards in the old days. I know 127V remained in exsistance in parts France post WWII but I have never seen a NEMA style outlet even in the oldest French house.

Centre tapped systems with 2 hot terminals supplying 220V between them have remained in service for much longer though. This is partly the reason that connector systems like Schuko etc are not polarised

I guess NEMA sockets would prevent the accidental connection of 127V appliences to 220V sockets though so would make a lot of sense in installations where the system is still in use.

As for the British DC system I think paul UK could give more detail but as far as I know they used BS546 style 3-pin polorised plugs and a 2-pin ungrounded and unpolarised plug which was similar to Europlugs but with shorter fatter pins. (not unlike the current UK shaver plug)
The old British system had a LOT of plug configurations all of which were incompatable so most homes were full of adaptors.

I am also not 100% sure when they standardised on 240V 50Hz or what other systems were around.

The Republic of Ireland was very boring and never really used DC systems in domestic/industrial supply in the 20th century. Although various local arrangements exsisted in the late 1800s and into the 1910s and even early 20s. The ESB rapidly standardised on 220V 50hz (with a earth-bonded neutral) and 380V 4-wire 3-phase in 1926 and the independent supply systems were bought up by the ESB under an act of parliament, connected to the fledgling national grid and standardised.

So I have never seen reminants of DC systems other than in UK photos.

Hutch,
the 127V+0 system remained in use at least into the 1970's in parts of Europe. I'm not sure when the system was introduced, but it must have been a long time ago. From another thread we have learnt that the American plug is from the 1920's. I believe the round European plug is older than that, although I have no proof. To this day, shucko plugs carry a DC rating.

Saudi Arabia has been influenced by both American and European practice and use 60 Hz, 127/220V. This makes the choice of an American style socket which fits into a British style box perfectly logical. I know of no other country in the Middle East that uses 60 Hz or 127V.

[This message has been edited by C-H (edited 12-29-2003).]

I was talking to someone who spent some time working over there and he said

US type plugs, BS1363, Schuko and old BS546 all found in various places and as far as he was aware the system was supplying both voltages and it seemed to depend on who had been involved in the electrification of a particular area. He said you had to be careful what you plugged in as you couldn't guarentee that a European/British outlet meant 220V or that a NEMA outlet meant 127V.. He'd also been warned of 50 and 60hz supplies being used depending on what part of the country you were in so all equipment had to be capable of working on both, just like in Japan.

It's a strange country and it's rather difficult to get any information about anything and censorship etc is taken to extremes. e.g. all internet access is provided through the ministry for communications and is strictly monitored and it's not generally legal to recieve foreign television by satellite.

However, 127V 50Hz is a problematic system as you can't get appliences so in general it's being phased out of use.

Some places, particularly close to North America, simply switched frequency to 60hz and lowered voltage slightly.. which is what I'd expect Saudi Arabia has prob. done, at least officially. Even slightly lowering the voltage without switching frequency would open up a whole range of 110-120V appliences that can function on 50 or 60Hz.

Others are using 127-127 to give compatability with European appliences and gradually moving to 230-0 bit by bit.

Switching frequency is a pretty drastic measure to take though so I would suspect the migration to 230V would be much more common.



[This message has been edited by djk (edited 12-29-2003).]

Small aside — On use of shuttered receptacles {outlets} in the US, [formally called “tamper resistant”] the only one I know of is http://www.hubbellcatalog.com/wiring/catalogpages/page_I04.pdf [page bottom] and http://www.hubbellcatalog.com/wiring/section-i-datasheet.asp?FAM=HProducts&PN=HBL8200SG

They are required In hospital pediatric locations by NEC Article 517. Maybe another reader can post more information about their use in the US. Hospitals and NEC517 are not my strong suit.

Bjarney,

the protection mechanism described in the Hubble catalogue is quite different from that used on the European receptacles. The Hubble version is rather sofisticated with two switches that need to be depressed at the same time for the outlet to work. The European shutters are simple mechanical barriers which prevent an object from being inserted.

The 200/400 to 250/500V DC systems, aw found in the old sections of some British towns were generally used with conventional BS546 plugs. Keep in mind that as far as residential servive was concerned, houses generally took only a 2-wire 200 to 250V service, with half the houses having a positive "live" and half having a negative "live" wire.

I think what Hutch is querying though is what was used in the very early days when some districts had a 110/220V DC supply. I'm not sure how far back our round-pin plug specifications go -- They may have been used on those early 110V systems.

Exactly the same dimensions as the current shaver plug in fact, although without the shielded pins which are common on the latter nowadays.

I'm not sure when the decision was made to standardize, but the conversion program took many years to complete. Full standardization at 240V was finished only in the early 1970s, and up until that time radio, TV, and other more sensitive equipment was fitted with a voltage range adjustment.

Prior to standardization the declared nominal voltages were anything in the range of 200 to 250V, usually in 10V steps. That's why most old wiring devices were rated for 250V maximum.

[This message has been edited by pauluk (edited 12-30-2003).]

It always seems very strange to me that they didn't just go the extra mile, given that the UK were joining the common market etc (Was CENELEC in exsistance?)

and standardise on 220V or at least 230V

On the 250V thing all wiring devices here are also rated 250V.. including some very definitely European fittings like old schuko plugs and sockets.

Only MCBs and RCBs are rated 220 or 230V


[This message has been edited by djk (edited 12-30-2003).]

I've never heard of anything but round pin ungrounded plugs being used here. Sweden had a weird 127V DC plug that looked a bit like an ungrounded Brazil (?) plug. I'd really _love_ to know what style of plug was used with DC here in Austria, but I've never heard of one. The only thing I ever saw was a plug looking like a NEMA 220V plug, but I don't know whether it was from Austria. 127V Delta w/o neutral is still in use in some European countries, whereas 127 + 0V has been phased out long ago.
BTW it seems China still makes BS 1363 plugs without shielded pins, I just got four of them that are claimed to be new (an Ebay purchase, four plugs and a socket for 1 Euro).

I've seen a few very strange versions of BS1363-compatible plugs attached to appliences sold here, particularly from China and other far eastern manufacturers.

No sheaths on pins
No fuse!
Plug body far too narrow.

Also many of the BS1363 adaptors sold online are leathal and not at in complience with the specs.

Most of the manufacturers obviously have no idea why the fuse is actually required and seem to think it's just some strange quirky UK safety obcession and thus don't bother including one.

Many of these adaptors also have unsheathed pins.

As for the plug-in xformers..

Why don't they contain a BS1362 fuse? I've never yet seen one that does including from reputable manufacturers like nokia, ericsson, sony etc..

Why do practically all of these plugs seem to think that the configuration for a BS1363 socket is with the earth pin on the bottom? With the exception of some of the mobile phone manufacturers all of these plugs have their lables on upside down and the cable exsits from the top when inserted into a UK/Irish socket!

Even worse, we have a few sockets fitted tight under kitchen cabinates and it's impossible to plug some xformers into them as the bulky bit is higher than the socket itself.

I've regularly seen diagrams of UK sockets with the ground pin on the bottom too.
and having a plug sitting like that does actually eventually cause cable damage.. as quite a few mobile phone adaptors have shown me

Oh yes, and do you usually have to open the plug body (screw) to replace the fuse? I thought the fuse carrier is accessible without tools.

Ragnar said:


As far as I've ever seen, Brazil uses either European round-pin plugs or American parallel flat pin plugs for A/C.

Voltage is anywhere from 110 to 240 -- at 60 hertz, depending on what part of the country or what city you are in.

Don't go by the receptacle configuration.

From what I've read, the USA used standard two-pin plugs for low-voltage DC systems on farms as well as AC.

Ranger, do you have a picture by any chance of what you're talking about?

The molded plugs generally have the fuse in a carrier which you access from the pin-side of the plug, but on the standard rewireable types you have the remove the cover to get at it.

This is the plug I'm talking about. Maybe I mixed that up with Argentina or some other Latin-American country.



and the matching plug:

Ranger:

Yes. That looks more like an Australian/Argentinian plug at first glance.

Although the ones used for standard domestic AC 220 volts in Australia & Argentina have wider flat blades and are at a more pronounced angle -- picture bending the blades on an American plug...well I gues you've all seen those.

HAPPY NEW YEAR EVERYONE!!!!
>HUGS< to all of you

"Why don't they contain a BS1362 fuse? I've never yet seen one that does including from reputable manufacturers like nokia, ericsson, sony etc.."

I think that the properly designed, (reputable) ones contain miniature non-replaceable overcurrent and thermal fuses, on the basis that if they fail they are just discarded. There would be no purpose served by providing an accessible fuse. I wouldn't dispute that there may be unsafe non-compliant ones around.

On the earlier topic of standards in Saudi, I can well believe that the prevailing system is that of the supplier nation.
I've never actually been there, but I was involved a few years ago in specifying a turn-key installation involving a building and lots of electronic gear.
We were permitted to supply all the specialised equipment at UK standards, and I was told that the building would have dual installations with UK supplies for "our" equipment, and some Saudi standard which I think was 127 volts 60Hz for domestic equipment. I recall that I couldn't understand the logic, (or economics) of having 50Hz and 60Hz supplies in the same place.

Anyway, It's now just four hours to 2004 here, so cheerio and a Happy new year to everyone.

You can still buy DC plugs in Sweden, although with a different design. These are intended soley for low voltage. Typical applications would be boats and campers.

Picture here

Actually, upon looking closer at the pictures of the plug & socket for DC that Ragnar posted, the pins seem a bit reminicent of Israeli plugs.

My friend from across the hall is an airline stewardess for an airline that regularly flies the New York to Tel Aviv route. She promised to bring me back a male plug (and possibly a female connector also).

The Israeli plug pins are more oblong -- picture round pins with the sides shaved straight. Three pins placed in a triangular formation with the angling of the straight sides of the L & N pins opposite to that of the Australian/Argentinian plugs.

See this:



and this:


Israeli sockets will accomodate Europlugs for Class-2 devices like TVs and house-hold fans for instance. But you can't jam a CEE-7/7 (Schuko) plug into them...

I've found BS546 2 and 5Amp used here for low voltage DC applications on boats in Ireland.

Typically 12 or 24V DC

I always think it's rather dangerous to suggest that tourists should bring BS546 adaptors to Ireland as the system is rarely used for normal 230V power sockets. You could end up plugging into a lighting circuit which could even be dimmed, low voltage DC etc.

I don't like the use of BS546 lighting sockets in hotel rooms for that reason. You're quite likely to have someone attempt to use an adaptor or even push a europlug into the outlet (they fit in the 5A variety normally used for lamps)

I far prefer the use of the "klik" system



and although it looks like it might, I don't think it mates with NEMA

Looks like the Israeli socket has a built-in fuse, the small round thing at the bottom right of the wall plate.

Looks more like the manufacturers name badge to me.

I noticed both lights and sockets in an old French house I lived in had little screw in fuses.

Why was this? Ring / Bus wiring structure?

Ragnar,
That's a brand-name marking, isn't it?, not sure, but that's what it looks like to me.
djk,
these plugs have the thinnest of pins and I think you'd be hard pressed to plug a NEMA plug into that socket.
Also I think that them "klik" sockets have a shuttering system, that entails that them 2 pieces of plastic on the plug have to mate with a device in the socket.
(Darn, must have posted around the same time as djk!)

[This message has been edited by Trumpy (edited 01-02-2004).]

The good quality units used here do indeed incorporate a one-shot thermal overload on the primary side. There have been concerns in recent years about some cheap imported units which have no protection though.

Like DJK, I've also seen 2 and 5A BS546 used for 12V DC on boats and RVs. Most new installations use a specific 12V connector though, with two small, flat blades both set at a slightly outward angle from vertical to provide polarization.

How about this as a novel use for a BS546 2A socket!?



I think the "646" on the webpage is a typo.

Yeah it's quite similar to the Italian phone socket too.

Lets just hope they never visit a country that uses BS546 2Amp for its intended purpose and decide to plug in their laptop!

I'm not sure how modems handle 230V 50Hz

Local telephone sockets are rapidly becoming a bit irrelevant anyway these days.

All phones, modems etc use RJ11 sockets these days and quite a lot of the world uses RJ11/12 sockets on the wall.

I notice Apple ships computers with an RJ11 lead and an adaptor for the area they're being shipped to.

Thankfully, Telecom Eireann adopted RJ11/12 outlets back in the 1970s when they decided to introduce modular sockets.

The BT system seems to be a blatent rip-off of it though It's exactly the same design made slightly bigger, in white plastic and tweeked a bit.

Certainly a typo on the MK page. If I recall correctly BS646 is actually the standard for the small cartridge fuses available in ratings up to 5A. They used to be employed widely in clock connectors, shaver adapters, and the few BS546 5A plugs which were available in fused versions.

I have to confess that I'm not a fan of either the U.S. modular connectors or the BT-copycat versions. I much prefer the old GPO 1/4-inch jacks on the American 4-prong telephone plugs -- Both are much more rugged.

Hutch and DJK,

That doesn't surprise me. Old-time domestic telephone installations in Colombia used to use two-round-pin (Europlug type) sockets.

The plugs looked like slimmer and flimsier versions of replaceable Europlugs. However they were made so that you had to unscrew the pins themselves, wrap the wire and then screw the pin back down.

Effectively this design would limit you to very thin wire only -- such as the kind used for telephone cords.

I pity European tourists to Colombia trying to plug in their hair dryer or laptop into the phone socket....

I've seen similar 2-pin phone sockets in Greece as well, but they were quite a bit smaller than Europlugs and definitely incompatible.