GU10 & GU16 downlight sockets

[Delicatedave]

I have some GU16 bulbs and lamp wire but how come when I search for sockets to put these in the ceiling I have guess which ones fit. The only time I see distinguishing is when they are labelled GU10 do people just guess? What's the secret ?

[Jeremy Harris]

6 minutes ago, Delicatedave said:

I have some GU16 bulbs and lamp wire but how come when I search for sockets to put these in the ceiling I have guess which ones fit. The only time I see distinguishing is when they are labelled GU10 do people just guess? What's the secret ?

 

 

Do you mean MR16 lamps?  These have two pins that poke out of the back and which push-fit into the lamp holder socket.  Often MR16 lamp holders have a floating socket on a bit of cable, that is pushed on to the rear of the lamp, with the lamp then being secured by a bezel around the front.  An alternative is the type of free-floating MR16 lamp holder, as used on twin catenary wire type installations, where the pin socket is the only part, and the lamp is just held by the friction of the pins in the socket at its base.

 

GU10 is a bayonet style fitting, more commonly used for 230 VAC lamps (but can be used for 12 V lamps occasionally).  A GU10 lamp holder will often use the bayonet fitting at the base to both make the electrical contact with the lamp and also provide the mechanical support to hold it in place.

 

Neither the  MR16 or GU10 specification defines the voltage of the lamp, they are only definitions that define the mechanical shape and size of the lamp and its interface to a lamp fitting.  In general, most GU10 lamps tend to be 230 VAC and most MR16 lamps tend to be 12 V (either AC or DC), but this isn't always the case.

[Delicatedave]

No, the downlight sockets. I'm just venting really to be honest.

[ProDave]

I am not sure what you mean by a "downlight socket" That is not a term in common use.

 

You normally buy a downlight as a complete assembly with the bezel any brackets it needs and a connector to go on the lamp, and a termination box to joun the lighting wiring to the flying tails of the lamp holder.  Which bit are you trying to buy on it's own?

 

You can certainly buy replacement GU10 and MR16 lamp holders on their own, which is a good thing because the MR16 lamp holders in particular are a rubbish design.  They are not really capable of taking the higher current required of a 12V Halogen lamp and burn out with regular monotony. One of the reasons I dislike 12V lighting.  In contrast the GU10 lamp holders are very good, and I really think it is time we scrapped the BC and ES light fittings (which are dangerous things) and used the GU10 base for "ordinary" lamps.

[Jeremy Harris]

7 minutes ago, Delicatedave said:

No, the downlight sockets. I'm just venting really to be honest.

 

 

Which ones, though?

 

GU16 doesn't exist as a mechanical interface spec, as far as I know.  MR16 does,  as does GU10, but they are radically different in the design of the base part of the lamp.

 

In general, the majority of 12 V downlighters use MR16 lamps, and the majority of 230 VAC downlights use GU10 lamps.  Both have about the same front face size, but the lamp holder design is very different.

[Delicatedave]

What I mean was whatever the secret word for this is. In my logical head something that holds a light socket. But for some reason the terminology is all different. Some might call it a lamp holder but that's the wire connection. Being dyslexic all this physically hurts my head ? Here's what I was talking about, you can argue among each other what it's called ? because I found it using "DOWN LIGHT FITTING MR16" it's not ideal in design but it'll do.

[Jeremy Harris]

Just now, Delicatedave said:

What I mean was whatever the secret word for this is. In my logical head something that holds a light socket. But for some reason the terminology is all different. Some might call it a lamp holder but that's the wire connection. Being dyslexic all this physically hurts my head ? Here's what I was talking about, you can argue among each other what it's called ? because I found it using "DOWN LIGHT FITTING MR16" it's not ideal in design but it'll do.

 

That is an MR16 downlight, that takes any lamp with an MR16 base.

[Delicatedave]

9 minutes ago, Jeremy Harris said:

 

 

Which ones, though?

 

GU16 doesn't exist as a mechanical interface spec, as far as I know.  MR16 does,  as does GU10, but they are radically different in the design of the base part of the lamp.

 

In general, the majority of 12 V downlighters use MR16 lamps, and the majority of 230 VAC downlights use GU10 lamps.  Both have about the same front face size, but the lamp holder design is very different.

Yea that was a typo or confrustration ?

[ProDave]

9 minutes ago, Delicatedave said:

What I mean was whatever the secret word for this is. In my logical head something that holds a light socket. But for some reason the terminology is all different. Some might call it a lamp holder but that's the wire connection. Being dyslexic all this physically hurts my head ? Here's what I was talking about, you can argue among each other what it's called ? because I found it using "DOWN LIGHT FITTING MR16" it's not ideal in design but it'll do.

Strictly speaking that holds the light bulb, and the "light socket" is free floating and plugs onto the back of the bulb.

 

Why are you having trouble finding those?

[Temp]

8 hours ago, Delicatedave said:

I have some GU16 bulbs and lamp wire but how come when I search for sockets to put these in the ceiling I have guess which ones fit. The only time I see distinguishing is when they are labelled GU10 do people just guess? What's the secret ?

 

As I understand it MR16 and GU10 are only standards for the electrical socket (eg the bit the light bulb pins fit into). Those can be fixed or floating in the light fitting.

 

The dimensions of the bulb itself isn't part of the MR16 or GU10 standards. 

 

Halogen bulbs are mostly a standard size but CFL and LED can still vary a mm or two. I've come home with GU10 LED bulbs only to discover they don't fit my down lights.

 

https://www.wholesaleledlights.co.uk/blog/2012/04/does-the-size-of-my-gu10-led-bulbs-matter/

 

Unfortunately, there is no one standard measurement to GU10 design, but you will find that most traditional halogen bulbs measure approximately 53mm in height and 50mm in diameter across their circular front face.

 

[ToughButterCup]

On 08/03/2020 at 18:18, Temp said:

[...]

I've come home with GU10 LED bulbs only to discover they don't fit my down lights.

[...]

 

Honest to God, it was easier in the old days when you only had one of this and maybe two of that. 3 Hours today fussing about GU10 downlighters (backbox) and their little quirks and foibles. And then match them to the right GU10 bulb of the right Lumen capacity, the right diameter, the right depth.

 

Roll on 6pm, pub.?