Why so hard to get Edison screw lamp holders?

[charles]

I've just fitted an MK pull light switch which had "Made in China" moulded into it.

[Bob Eager]

I have bayonet lamp holders which are safe. There is an internal shutter which is only closed when the bulb is rotated into place.

I usually use the MK 1150WHI.

[Robin]

Well all your undergarments 'could' leap simultaneously one foot to the left; but it's not very likely. So if such risks with E27 etc were significant I would have thought there'd be clear and unequivocal evidence by now given the length of time they've been in use and the installed base across the world.

[Tim Streater]

No, they just put up with the increased fire risk. In the US and others of course, it's much worse again due to their use of cheeseparing 120V.

[Jethro_uk]

You assume the people that mandate change are working for the public good. I don't.

One narrative could be the ES design arose because it was the cheapest possible to deliver (probably using existing tooling). As it was introduced, any evidence of the risk would have been mixed in with other factors (given the novelty and rarity of electric lighting).

By the time the risk from lose-arcing bulbs is emerging, there's an entire industry resting on their production. Any change is going to involve a lot of (shareholders) money.

And that's how things remained.

Of course now we have low energy bulbs, the risk is reduced - maybe eliminated. Giving the ES fitting - and the factories that produce for it

- a competitive edge. Which is why we now see them when they were rare as hens teeth in the UK in the 70s and before.

I'll drop my theory in the face of supporting evidence.

[Scott]

Curiouser and curiouser, said Alice.

[Tricky Dicky]

I understand that wheras with BC polarity did not apply, but with ES you had to observe polarity by connecting Live to the central terminal and neutral to the thread.

Richard

[Robin]

And the evidence of increased fire risk from Edison screw compared with bayonet cap is....?

[Robin]

I wa not assuming that (or anything). I was looking for data.

Oh it's a very nice theory. (But then so were phlogiston and luminiferous aether). I'd just like some evidence to support it.

[Tim Watts]

Hager-Ashley have had safe BC holders for years. Even the ES type can be made safer (side contact at the base, plastic threads).

[Scott]

And how do you do that if a lamp is fitted with a two-pin plug, such as a europlug?

[Terry Casey]

They look like unglazed porcelain to me.

Don't they also tend to have switching arangement in the base these days so that the centre contact is only energised when the bulb is screwed fully home?

[Scott]

Yes, but how do you know that the centre contact carries the live?

[Richard]

Stick your finger in?

[Jethro_uk]

Well as I noted, it's likely to be historic now, as most bulbs aren't incandescent and don't draw the current which would cause a fire.

I guess you might be able to infer something if fires started by overheating electrics have diminished in line with the uptake of CFL/LED bulbs. But unless there's a fat government grant in it, I really can't be bothered. I suppose I could take a punt that some moronic Brexiter with more money than sense might commission such a poll, but it would be a bit against the SOP thus far of just making shit up :)

[Scott]

I suspect it was done that way at one time. I think that's more okay with 110 volts than it is with European voltage.

[Tim J]

You don't need to with the side contact at the base.

[Scott]

I thought the argument was that it might be possible to touch the 'screw' part of the bulb?

[Tim J]

Doesn't matter when the screw part is plastic or ceramic with a side contact at the bottom.

[Scott]

True obviously in that particular set of circumstances but I have seen plenty of ES bulbs where the construction is metal. I think we are discussing the safety of the system in general rather than the specifics of certain bulb types.