ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Who built this?

C-H

What's your homepage address?

I think I've seen 20A plugs in French stores which have a different pin configuration to the regular 16A styles.

djk, http://electricity.does.it

C-H,
I never knew that all of the Pacific Islands used the Aus/NZ plug configuration.
How about American Samoa?.

Trumpy,
According to my database - where you find American Samoa between Algeria and Andorra - the sockets are American, Australian and German. As it is reported as 120V only, the Australian and German sockets are probably unusual.

The Australian influence on the world of things electrical is clearly disproportional to its size. A whole bunch of countries have adopted its system. Even China!

I wonder whether China's reasons are more to do with trade than anything else. By adopting the Aussie/Kiwi system they can manufacture huge quantities of devices to cover domestic use and at the same time export to the comparatively-close Australian market.

The Chinese also use the American two-pin plug and the European two-pin plug.

Yeah, yeah, I know the Chinese knock-off of the American plug doesn't have holes in the pins and the pins are a millimeter shorter, but that's not a significant difference to affect operation if that same plug were stuck into an American-market socket.

Apparently the Chinese use the two-pin American plug for un-grounded small appliances (like table lamps and clock-radios) and the Aussie-style plug for larger Class 1 devices (computers, washing machine etc.)

I've read that the Australians require their plugs to be ROUND and adhere to a strict set of dimensions, while I've seen the Chinese-market "Oz-Plugs" with octagonal, round, square form factors.

Therefore these won't fit into an Aussie trailing socket (which must be shrouded and recessed) on an extension cord.

Sven,
Why do the plugs in the US have holes in the pins?, is there some sort of retention system in the socket that mates with this?.
All of our 3-pin plugs in Aus/NZ, have to conform to AS 3112 and as you said, this is a very exacting standard.
Regarding the extension cords, just a simple recess on the cord connector(female Line socket) saves 10 lives per year from electrocution from partly inserted plugs, especially in damp areas.
I know I will sleep better tonight, knowing this statistic!.

We already had many discussions on the holes here. Basically there are 3 theories.
1: The holes are intended to "lock" the plug insode the receptacle. I've seen some NEMA receptacles that definitely do this. They have a small protruding "ball" on the contact springs.
2: They're intended to clean the contacts.
3: They're only used to hang the plugs during the manufacturing process.
4: They're there to save metal.
2-4 seem rather weird to me, #1 is proven to be correct.

What Ragnar says about the little dimple in the receptacle's contacts is true.

However I've noticed this is mostly the case with cheaper connectors that rely on the spring action of a singlemetal blade and the opposite wall of its plastic housing. So the plug pin is held between one strip of spring-metal and a plastic "wall". The dimple will "lock into" the hole in the plug pin to help hold it in a bit.

These "single-wipe" receptacles are normally found in cheap household extension cords and the single contact tang looses its spring-action quickly. The plugs tend to fall out, wiggle and loosen.

GOOD quality receptacles will rely on spring action of two (or even three or four!) blades. These are called double-, triple- or quadruple-wipe contacts and do not necessarily need the little hole.

You will commonly see double-wipe contacts in cheap residential-quality sockets and triple and quadruple wipe in a lot of industrial and better commercial quality wall receptacles and replacement extension cord connectors. These hold the plugs tighter and last much much longer. Sometimes they hold the plugs so tight you need a good amound of pull to get them loose.

That's a good thing.

Pins and contacts for molded plugs and connectors are stamped out in strips that are then broken off when the wires are crimped to them and before they are ready for the rubber to be molded around them. If you look at a transparent molded-on plug, you will see what I'm talking about.

I don't know what role the holes would play in this...and why the Australian and Chinese-market parallel-pin plugs don't have those holes when they're manufactured the same way pretty much.

The hole is optional.