The Bayonet Lightbulb
 

Are bayonet caps on lightbulbs on the way out? As far as I know, the bayonet fitting has been standard across the UK ever since AC mains electricity was provided to the general population. However, on a visit to B&Q today, I found that the majority of light bulbs, particularly LED, even the so-called "vintage" style ones, seemed to come with SES fittings, either large or small? To be fair, I have been seeing a gradual increase in stock of bulbs with these types of fitting for some time. Should I be replacing the bayonet fittings on the lights in my home with SES sockets?

Re: The Bayonet Lightbulb
 

Probably the lamps are made in China and ES (E27) holders are more widely used world wide than BC (B22) so they make the more popular base.

John

Re: The Bayonet Lightbulb
 

I think the bayonet is on its way out, yes: on the recent 'large' light-fittings I've bought I've chosen ES, and elsewhere SES or GU10-type twist-lock are ubiquitous.

The market for 'big' bulbs [standard-size ES or Bayonet] must be in significant decline: the days of a room having one big pendant bulbholder with a 60- or 100-Watt bulb hanging from the ceiling are long gone.

Re: The Bayonet Lightbulb
 

Not around here they aren't !
Kitchen, bathroom and lounge have recessed spots. Bedrooms, hall ways and landing have big dangly singe bulbs and will stay that way while I live here. :)

Re: The Bayonet Lightbulb
 

ES is probably fine when the supply voltage is 110 but given that many lamps do not take account of live and neutral it's very easy to come in contact with a live screw metalwork.

Peter

Re: The Bayonet Lightbulb
 

All fittings with ES / SES holders sold in the UK and Europe, whether portable or permanently installed, are required to have correctly identified polarity from supply terminals to lampholder. When installing as part of the fixed wiring, polarity at the lampholder is a mandatory test. Many types of lampholder now have a screw thread that is either plastic or an isolated metal collar. The lamp cap makes contact with a separate contact finger once it is almost completely engaged and recessed within the holder, resulting in a similar level of safety (danger?) to a BC holder even in the event of reversed polarity.

There is an incentive for manufacturers to sell ES fittings in the UK as both are acceptable here and it avoids making two versions. Conversely, they could not sell B22 in many other markets.

Re: The Bayonet Lightbulb
 

ES and SES bulbs may be widely available these days, but it still seems to be difficult to find sockets for them in the UK shops.

Re: The Bayonet Lightbulb
 

As John and Lucien say, it's about world market share (and possibly Ikea!)

Re: The Bayonet Lightbulb
 

I always found the Continental preference for screw-fit light bulbs and reversible mains plugs slightly scary. Of course, there were times and places with a supply of 127V P-N and 220V P-P, so the outside would be live whichever way around the plug was inserted!

There are definitely more screw-fit lampholders around than there used to be. Probably because modern, low energy bulbs are less sensitive to voltage variations than the old tungsten filament types, so they are worth importing ..... And if the fitting is made of soft plastic that can't withstand as much heat as the old urea formaldehyde resin, then it avoids a possible fire hazard if a tungsten filament bulb won't physically fit in the holder.

I have also seen adaptors, both ways around.

Re: The Bayonet Lightbulb
 

I have some bayonet to ES adapters that I used when I had some freebie fluorescents given to me. Only problem was the bulb partially poked down below the shade :-)

Re: The Bayonet Lightbulb
 

Yes they are, nothing politically meant here but a statement of fact, the EU wants to unify the ES thread across Europe in line probably with the rest of the world.
I am not sure I am happy with a screw thread that could potentially be live, and I am not happy with the fact that these days I now just cannot pick a bulb up in the store and walk away with it without opening it to check if it's an ES or bayonet or some flaming size or the other.

With advent of LED lights they have just created a problem that was not there, if both the ES and Bayonet are on the way out anyway.

Re: The Bayonet Lightbulb
 

If the screw is live, someone has wired it incorrectly but in any case you should always turn the light off to change the bulb. Most risks are the same whichever base is in use. As has been said many times, lamp holders can't really be described as safe.

Re: The Bayonet Lightbulb
 

Be careful if buying some of the cheaper BC to ES adapters that are for sale on the Internet. The bulb's screw thread may be exposed and has a 50/50 chance of being Live depending on which way round the adapter is plugged in.

Re: The Bayonet Lightbulb
 

It is difficult to find table lamps with anything other than ES lampholders these days. I had a job finding small reading lamps with BC lampholders around 20 years ago. When we went looking for lampshades at Christmas, I noticed that all the ones form IKEA came with removable adaptors so they could be used with either the smaller BC or the larger ES lampholders.

Regarding polarity, I am sure that there was a thread here a couple of years ago where it was observed that it was permissible connect an ES lampholder either way round in a fixed wiring installation, but there must have been at least one change of regulations since then. The widespread use of non-polarised 2 pin plugs in Europe would mean that it is a 50:50 chance whether the central contact of a table lamp's lampholder is connected to L or N.

Re: The Bayonet Lightbulb
 

Same thing appears to be happening DownUnder.

Looking through the the supermarkets globe shelves, most now seem to be ES rather than Bayonet.

Re: The Bayonet Lightbulb
 

Regarding live terminals. you can get BC lampholders where the contact pins only become live when pushed in. So less chance of a shock from an empty lampholder.
Not possible with ES.
John

Re: The Bayonet Lightbulb
 

I suppose you could just about make a switched screw-in lampholder, at least in the 27mm. size; but the contact separation on the side contact would be necessarily small and probably not offer much protection in real life.

Re: The Bayonet Lightbulb
 

In the UK you are guaranteed a solid belt if you contact a live ES but in countries with no neutral you tend to get a half hearted belt.

Peter

Re: The Bayonet Lightbulb
 

Re #13, I believe that the thread of the ES base used in the US has one less turn than the European ES base. Perhaps the adaptors in question are designed for use with US bulbs. The adaptors I have are provided with substantial skirts that adequately shield the metal base.

Re: The Bayonet Lightbulb
 

Hi,
IKEA sell reasonably priced adapters for converting BC Holders to ES/SES.
Regards - Mike