I have a very unusual problem. I'm upgrading my homepage, going throuh it step by step to verify the information. Boy, do I find errors!

Currently, I'm trying to figure out what frequency the electrical system in Tuvaly (a very, very small island country) is.

In this case I have a photo:



Is this American, Australian or British?

C-H,

A secure installation!

I don't recognize any equipment in your picture, but was taking a look at your site. You've been busy collecting information I see! It looks good.

I have a suggestion, in the US area you should also have a photo and specs for a Polarized ungrounded plug where one blade is wider than the other. That is more common by far (I think) than the non-polarized plug.

Bill

[This message has been edited by Bill Addiss (edited 05-03-2003).]

C-H

the transformer on the left of the picture looks similar to the ones we use over here in England,
but the one on the right does not look familiar.

could you get a close shot of the transformer identification labels, this would help.

John H

C-H very impressive data base, sorry I can not help with your question.

I agree with Bill that the polarized plugs are more common for lamps and audio/video equipment.

Bob

Bill and Bob, thanks for the kind words!

{Makes mental note to add polarized plug to type A page.}

The photo is from an overenthusiastic tourist who have dozens of photos from his trip to Tuvalu on his website.

I don't expect anyone to recognize the particular transformers, I only wanted to know country of origin. Does the warning signs give a lead? They don't tell me as a Swede anything, but I thought you who live in English-speaking countries might recognize them.

The reason is that the sockets are reported as Australian, the system as the British/Australian 240/415V and the history book tells it was a British colony. But, the frequency is reported by some sources as the American 60Hz... It can happen - a small number of countries have "mixed" systems like this, but it is rare. In most cases it indicates an error in the information. I'm gonna be an expert in colonial history soon

I know I'm pedantic, but the gaps and errors in the list annoy me.

I'm writing a full explanation of everything in the database, a FAQ and a description of the different electrical systems. Only trouble is that it takes some time.

I tried to blow up the pic, but it got to blurred. I couldn't read the upper sign.
Concerning cell phone systems: Austria has GSM 900/1800, soon UMTS, Germany ditto.

C-H,
That transformer unit on the right looks vaguely familiar, I think it may have been built by ABB Systems, if this is any help.
I checked up on a travel guide for Tuvalu and it said that the power supply is 240VAC 60Hz, there was also a website on the page
www.tuvalu.tv , so you may find something there, there's even a Forum there!.

[This message has been edited by Trumpy (edited 05-03-2003).]

May I take this forum as opportunity to correct your amps at outlet. It's 20A instead of 16A

C-H,
I congratulate you on your desire to get your data as accurate as possible. I've also looked through the various lists and been annoyed by the contradictions.

As John mentioned, the gear on the left is similar to some British types, even down to the same shade of gray.

The lower sign on the gate poses more questions. 11,000 volts is the standard local distribution level used in the U.K., which seems consistent with the adoption of 240/415 LV systems and a British colonial past.

However, the style of the sign (black block at the top, "DANGER" in a red oval) is much more American than British. The U.K. has never, to the best of my knowledge, used that style of danger sign.

Well, thanks! It was worth a try. I'll leave the frequency at 60Hz with a comment that it could be wrong.

Trumpy,
you could be right on the right one. The transformer looks like the ones in Sweden, which are of course usually made by ABB. But, then again, I don't know what transformers look like in other countries.

Belgian,
Thanks for your input. I know that you have 20A circuits, but can you connect a 20A appliance to a socket? I was under the impression that the French/Belgian socket was rated for 16A. Or are special 20A sockets common? I'm happy to correct the information if I'm wrong.

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.

Ah... Are we getting the hole truth?