ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades A world standard plug system???

Some moulded-on NEMA plugs have thick strong pins (same as the Australian counterparts) made of solid brass (or iron) that you cannot bend at all with your bare fingers without damaging the rubber or plastic housing.

Others are folded brass pieces that can bend into odd shapes. It all depends on the (usually Chinese) manufacturer of the cordset. It seems like the folded brass blades are more common though.

Also, some replacement plugs have thick, non bendable brass solid blades and others have what are called "spring-action" folded brass blades which because they're flexible, are supposed to make better contact with the receptacle contacts.

Paul:

The insulated tips are a result of me looking (too) deep into the drawings and dimensions of present European plugs (all of them) and the suggested IEC plug. You see, I wanted to push the metal as far back towards the plug face as possible to maximise the area where it makes contact with the metal parts of the socket. The problem is that with a conventional design, the pins make contact very soon after the plug is inserted. Therefore, the insulating sleeves need to be long. However, much of the length at which the plug is live is not used when it is fully inserted. This is a result of the rounding of both pins and recieving metal parts inside sockets. The rounds aren't used once the plug is fully inserted. Roughly 3-4 mm of the insertion way is lost this way. By making the rounded tips insulated, it is possible to extend the useful metal length of the pins.

Yes, I understand that you couldn't follow that, but it's hard to describe something in a foreign language But take a Shucko/French/Italian whatever socket apart and insert the plug and watch when it makes contact. I think you will find that only a few millimetres of the pins are in contact with the socket when the plug is fully inserted.

No problem -- I understand your point exactly. In fact if you open up many brands of British receptacles you'd find a similar situation where once fully seated the tips of the pins and not actually contacting anything.

As for explaining in a foreign language, rest assured that your English is excellent! Hands up how many of us in here can speak any Swedish? No, me neither...

I understood it perfectly also, C-H.

Your English is much much better than my Swedish....

Hell...the only things I can say in Swedish is IKEA.

And I wish one of my friends would stop calling me SVENSKA!!

I just read that the Australians have proposed making the common appliance connector the world standard plug/socket system. If implemented, it would pretty much become the only system used. It sounds simple, but there are some technical hurdles to be overcome. (Things like child safety, suitability for outdoor use, current carrying capacity and probably more.)

C-H

Are you talking about the one that's commonly used for connecting computer power cords?

Male inlet:


Female outlet:


There's gotta be a way to also provide for shuttering for these guys...but at least they're shrouded and the female's contacts are deeply recessed - and the holes are small enough.

Shuttering is a must in my opinion: Imagine a child putting a trailing socket the mouth... Shutters would reduce this risk dramatically.

Outdoor use would require an outer "cover" for the trailing socket, to have somewhere to put the lid and to protect it from water. Using such a cover would also make it difficult for a child or pet to put a socket in the mouth.

The 16A version is more suitable than the common 10A version.

[This message has been edited by C-H (edited 02-24-2003).]

A shuttered version of these IEC sockets is available, I have seen them here in the UK.
They are sold in the form of an adaptor that plugs into a 13A socket with 2 or 4 shuttered IEC sockets, intended for hifi & tv equipment.

C-H said ...

"I just read that the Australians have proposed making the common appliance connector the world standard plug/socket system."

That's a turn-up for the books as Tommy Cooper used to say ... as I proposed a modification of the Australian standard!

BTW C-H, what does the 16A version look like? Have you got a picture?

Thanks

The IEC connector is used on heavy appliences here in Ireland (and in the UK) for things like 2.5 KW electric kettles, sandwich toasters etc. Even seen it on vacuum cleaners. It's not actually all that safe and I certainly wouldn't like to see it as a wall plate.

You can very easily insert a small metal object into one of the "slits" on the socket. It's not shuttered it allows you to pull the plug out by the cord etc.

As for the breaking / bending pins problem. A british plug would physically break before the pins would bend they're very solid brass no way you'd bend/break them even if you hit it with a hammer or put them into a vice.

The only signifigant problem I find with BS1363 plugs is that if you leave them on the floor they tend to fall with all 3 pins sticking up. They tend to sit on their backs (which are flat) by default (cable exits thru the bottom)

The problem: you unplug something, plug is sitting on the floor and you get up in the dark and walk on it! While the pins arn't sharp, if you come down on them hard enough with your foot you'll do yourself quite a painful injury.

I've never seen any other plug system that does this!

Other than that one problem they're actually a very good system and probabally the most recent design of connector in use (and were revised in the 70s and 80s to include sheething on the phase and neutral). Schuko (and its derivitives) & the US standard have been around for much longer and haven't really adapted to cope with modern safety demands. The UK system was designed primarly as a safety device and was even refered to in Ireland as a "safety plug" when Schuko and BS 546 were being phased out of use.

Its definitely a system that is very well able to cope with modern demands. If the ring circuit is used correctly it's also very useful. Modern homes have a lot low wattage appliences thesedays and with the ring circuit design it's much easier to have sufficient sockets installed. E.g. in Ireland the regulations require 10 outlets in a kitchen as a recomended minimum! Generally people don't add sockets or break the rings. You can insert a europlug into older style BS 1363 sockets if you bypass the shuttering but you physically can't fit full 16 amp schuko pins into the "holes" they're too wide. I've noticed that newer sockets now have 3-way shuttering, i.e. you have to insert an earth pin and then push both L & N in simultaniously (europlugs won't open the shutters only correctly sized pins will open it)

A typical modern home here would have at least 4 outlets per room and it's rare to see a single wall plate in a modern installation. Older installations tended to have one per room, seems common to have 1 or 2 in France. I would rather have properly installed and functioning british style ring circuits than endless adaptors as I've seen in France.

The other comment about the ring circuit is that there is no high incidence of electrical fires here caused by ring circuits. They've been in use for years and they have never caused any problems. However, DIY electrical work on any circuit architecture (radial or ring) is likely to cause problems! I've seen sockets added to lighting circuits, into cooker circuits etc by DIYers!