Why so hard to get Edison screw lamp holders?

[Tim J]

We are actually talking about the safety of particular bulb socket types and if you care about the risk with ES sockets, its easy to use ES sockets which have no risk.

[%]

hi scott

[Scott]

Maybe I have missed something, but how do you ensure there is no risk of touching the metal part of the bulb if the polarity is reversed? I appreciate the risk is low for pendant lights on the ceiling but for a lamp fitted with a non-polarised plug (such as a europlug) polarity must be 50/50.

And how do you use 'ES sockets which have no risk' if a table lamp is fully manufactured on delivery? Can they be retrofitted?

[Bob Eager]

With a contact only at the base (inner end) of the screw thread in the HOLDER, the metal thread on the BULB doesn't become (potentially) live until the bulb is nearly all the way in (and presumabley the metal part is now shrouded).

[Tim J]

By ensuring that it isnt in contact with the side contact until it has been screwed right into the socket and having the non conducting screw socket cover the metal part of the bulb completely.

I

You can obviously only buy table lamps which have non conducting screw sockets and side contact that only contact the bulb when the bulb is fully screwed into the socket.

[Scott]

Really? Is there a recognised international marking to make consumers who do not have electrical skills aware of this?

[Tim J]

Yep.

Is there a recognised international marking to make consumers

Don't need one.

[Scott]

Okay, I'll ask around tomorrow how to see how many of my friends would feel competent in carrying out this task: 'Would you be able to identiify a table lamp with non conducting screw sockets and side contact?' .

[Tricky Dicky]

Yes it is peculiar that ES is widely adopted in Europe, in the USA system for which it was developed they at least have polarised plugs.

Richard

[Tim Streater]

Not originally. My house there, built prolly in the 30s, had a number of 2-pin unpolarised, 2-pin polarised, and 3-pin sockets.

[charles]

Not always - the 2 pin (either way up) is quite common.

[Scott]

Is USA +55V / -55V (you know what I mean)?

[ARW]

What when you unscrew it?

Called at the electrical wholesalers today and someone in the shop asked for a E27 pendant holder. They can get them but they were not in stock.

My first question was "Have you got any E40 pendant holders?"

Oddly enough the hydroponics shop next door did have them.

[Tim Streater]

No.

[tabbypurr]

no. 110v or 110-0-110 split phase.

NT

[tabbypurr]

E40 has long been standard for a lot of high power lamps including discharge grow lamps. It's been around over a century.

NT

[Tim J]

Nope, its actually +115V / -115V but not on those 2 pin plugs.

[Tim Watts]

No it's 110-0-110 with 220V sockets/appliances being powered phase-antiphase

(Though I have seen some references to 2 of the 3 120degree phases rarely being used for the higher voltage giving some 190V)

[PeterC]

Assuming still stocked, Ikea has singles or threes already wired, v. cheap.

[Scott]

Thanks. I think I knew that at one time. Maybe I was thinking of building sites.

Merry Christmas to all in uk.d-i-y.