Most of us have seen the charts showing different voltages and power socket pin configurations for various countries. Some even show what sort of telephone socket is in use.
But what of the lamp sockets?
My usual assumption is that areas that have been under British influence use B22 and elsewhere uses E27. I have seen some reference to B22 being used in Europe. If so where? Are there any 120V areas using B22?
I thought it amusing looking through a US specialty light bulb site seeing what they charge for B22 based 230-250V light bulbs...nearly ten times the cost of what you buy them here for...admittedly if you want to buy a 120V E27 bulb here it's the same thing.

I'm wondering if our E-26 lamp sockets would accept an E-27 based lamp, and vice-versa.

Supposedly the diameters are different by a millimeter; which, in something like that, would make a big difference.

The authors of such charts assume that you will buy lightbulbs locally if you need to. In many countries, this is an easier problem to solve than getting a new computer cord, and nearly always cheaper, if indeed the problem ever arises at all. That is not to say I haven't wondered the same thing. It is amazing that we essentially have only two generally common incandescent bulb bases for the whole planet, as opposed to what, eight different receptacles?

What exactly is the difference between E26 and E27? The threads are the same but I believe E27 is a longer base, meaning a European bulb would fit an American socket but the reverse might not be true. I seem to remember a German customer of one of my former employers who brought several lamps over from Germany, and had no problem getting American bulbs to fit. Which Edison-base countries use E26 and which use E27?

Here is the difference between E26 and E27.

I can say with some confidence that Indonesia uses an Edison base, although I don't know which one. I have an oil lamp from Indonesia which uses an old light bulb for the oil reservoir, a bottlecap for the wick holder, and the lid of a candy tin for the base. Since the bulb base is cut in half, I can't match it to an American base.

Mexico uses Edison base. The UK we know, and I forgot to check when I was in France (I wasn't an ElectroGeek back then). That's all the countries I've been to.

France uses both (if memory serves)

I can definitely confirm a (British) E27 lamp fits a US lampholder, I have table lamps I purchased in Ohio, they simply got rewired and earthed (grounded). The lampholders were rated 250v 660w so got reused, saved matching threads

I didn't know there were E27 bulbs in the UK.

Folks,
There are a lot of different types of lampholders.
Not only your Incandescents, but you have Halogen Linear, Halogen Single Ended and your smaller Halogen Burners.
Not forgetting Fluorescent, Tombstone and all the variations of that theme.
It's a mine-field.

Never heard of E26.?
Don't forget all the miniature ones for pilot lights like E5.5 etc.
And as Trumpy says it's a mine-field.

Germany E27, E14
France E27, E14, B22

Doesn't mean that you can't get B22 in Germany. Just unusual so not at the next drugstore, but at the electrician's.

And an endless number of sockets for low voltage and .......


[This message has been edited by Wolfgang (edited 01-12-2006).]

I had no idea of the E26 base until I saw mention on the antique light bulb site...they seemed to think it was of different diameter.
So, I got out some genuine Yankee light bulbs and some Aussie E27's along with both kinds of holder. Well, I couldn't notice any difference in diameter...both screwed into each others sockets just as loose/tight as they would in the 'correct' ones.
What was clearly evident is the US bulbs have a shorter base...with some Aussie E27 sockets the contact at the bottom wasn't made even when fully screwed in. Screwing an Aussie bulb into the US socket leaves more of the thread exposed which could be a shock hazard.

This is particularly important for grids with two live/hot wires (without neutral). There might be a live thread even when the lamp is switched off.

Wolfgang

They've been around a long time for "special" fittings, although BC was always the norm in regular domestic applications.

Edison bases seem to have become more common in recent years as we've been importing more European light fixtures.

That's quite true, there are probably at least a hundred different bases when you add all the different 2-and 4-pin compact fluorescents. What I was referring to is that here in the US, most table lamps and residential fixtures use an E26 base, and you will always be able to find bulbs to fit that in any supermarket. If you decide you want MR16s instead, that's your call, but the default--the least expensive and overwhelmingly most common option--is the same all over the country. I knew DC bases were common in the UK, Australia, and India, and I knew there was some difference between E26 and E27. What I didn't realize is the number of countries that use both E27 and DC.

In the US, there are something like 160 different receptacle configurations recognized by NEMA, and at least dozens of others can be found, but there is no reason the average traveller needs to carry adapters for any but NEMA 5-15 and 1-15. It's sort of the same thing with light sockets.

[This message has been edited by yaktx (edited 01-12-2006).]

I have fitted E27 bulbs to US sockets several times without much trouble. They do leave a lot of thread exposed, but not more than some old Austrian sockets.

Greece and Spain seem to use B22. In case of Greece that's even weirder since _all_ of the Gear I've seen used seems to have been German, mostly Siemens. The panels were a mix of Diazed and DIN rail gear, almost exclusively Siemens Germany. Sockets were typical German/Austrian/... Schuko, including the mounting with claws (one at my hotel room pulled out of the wall, that's why I know), wiring is done with either flex conduit (PVC) or German/Austrian only flat NYIF style cable. The old switches look somewhat British, the new ones definitely Continental.

Another thing about Greece... usually wiring has some local specialties, like the color of conduit, shape of boxes,...
The recent Greek wiring I saw in a half-finished building could have been in Austria. Perfect match.