GU5.3 12v or 240v - how to identfy

[JohnW2]

I cannot find a definitive description of all the types - perhaps no one knows.

Same problem here - I was rather surprised!

No second letter or U, X, Y or Z is the base shape - but doesn't say what shapes.

Maybe - but the meaning of "U" I quoted came from some on-line source (which I can no longer find!). I've found no explanations about Y or Z, but is seems that X may in indicate 'special', whatever that means!

Kind Regards, John

 

[utterlydiy]

OK,

My next question,

If I went through the expense of purchasing 12 GU10 lamp holders and 6w LED Lamps from Amazon/Fleabay replacing my 12 GU5.3 50w lamps, holders and 12 transformers which are in the kitchen/diner used approx 4 hrs a day.
Approx how long would it take to break even, also what percentage of saving going to LED over Halogen.

thanks

 

[EFLImpudence]

Some clues - but not comprehensive.

http://www.eaglelight.com/category/lighting_tutorials.bulb_base_types/

 

[JohnW2]

If I went through the expense of purchasing 12 GU10 lamp holders and 6w LED Lamps from Amazon/Fleabay replacing my 12 GU5.3 50w lamps, holders and 12 transformers which are in the kitchen/diner used approx 4 hrs a day. Approx how long would it take to break even ....

Well, in terms of running costs, that's 72W vs. 600W, hence a saving of 528W. If they're on 4 hours per day, that would be a saving of 2.112 kWh/day, about £0.34/per day if you were paying 16p per kWh.

As for how long it would take you to break even (in terms of running costs only), you need to divide the total cost of the capital outlay by £0.34 to determine the number of days to break-even. For example, if you forked out, say, £100, it would take about 294 days (i.e. about 10 months). The calculation gets more complicated if one tries to estimate replacement costs for the two approaches.

Kind Regards, John

 

[JohnW2]

Some clues - but not comprehensive.

Yes, I found that one, and others like it, but they all lump together G3.5 and GU3.5 (and also GX5.3 and GY5.3), hence don't really help in trying to work out what (if anything!) is the difference!

Kind Regards, John

 

[333rocky333]

If I recall correctly, it's a bit more complicated than that - I have a feeling that the "U" refers to there being some means of 'mechanical retention', not necessarily a bayonet (i.e. it could be provision for a spring clip). I don't know what "X2 and "Y" mean (as in "GXxx and GYxx).

I may be wrong, but most holders originally for a Glass/Globe lamp, become prefixed G, G4 G5.3 etc, though because of the various types they use GU which i understood was "universal" for the basic common version.
similar to a "FS" fleurescent starter known as a FS U
GY im aware has insets in the side, i think they were for use with GY lampholders that i believe have side clips, I assume for use where lamps falling out may be hazourdous.
GX I asume is another variation

http://www.donsbulbs.com/cgi-bin/r/t.pl/socket.base.html

A few more holders and pics here, is there not anthing in the Diynot Wiki, if not maybe there should be.

 

[JohnW2]

I may be wrong, but most holders originally for a Glass/Globe lamp, become prefixed G, G4 G5.3 etc,

Yes, I think we are agreed on that bit.

... though because of the various types they use GU which i understood was "universal" for the basic common version.

There seem to be differing statements about that. I've quoted one I found (relating to provision for retention), EFLI thinks that it refers more generally to 'base type' and you have now suggested a third possibility.

As far as I can make out, very few sizes come in both a Gxx and GUxx variant (e.g. I've never seen G5.3). The one exception is G4 and GU4, both of which seem to be easily found. We therefore maybe ought to try to find out what (if anything!) is the difference between a G4 and a GU4!

Kind Regards, John

 

[333rocky333]

I assume your looking at lamps, maybe lampholders would give more insite.
I wonder if the mix ups come from lamps pin to pin measurement being mixed up with lampholder types.
maybe due to the heat say from a higher wattage lamp, thats where a high temp holder comes in,possibly a GX base,
though likely any same pin lamp will fit it, including GX and the GU "Universal"


Id put my money on a G4 and a GU4 being the same, due to the small physical size and the low wattage, theres no other variants.
Whereas 5.3 for example , theres various forms all basically G5.3 pin lamps, but possibly warrant different lampholders, GU, GX, GY etc.
of which GU tended to be the common one, but really just a plain G5.3 lamp
Well thats my opinion

 

[JohnW2]

I assume your looking at lamps, maybe lampholders would give more insite.

No, I've tried looking at both.

Id put my money on a G4 and a GU4 being the same ....

You might loose your money, then - I've just found this (click here) , which says

"The G4 and GU4 both have the same diameter pins and pin spacing. The difference is that the GU4 typically involves a pair of grooves on the sides of the lamp for a clip to hold the lamp in place...."

That seems consistent with the statement I found and mentioned earlier, that a "U" indicates that the lamp includes provision for a form of 'retention'.

Kind Regards, John

 

[333rocky333]

dont recall ever seing a lampholder with clips on for the so called GU4 lamp have you.
When these codes came out, im sure there was recessed holders that the lamp pushed into, possibly an american thing, not so relevant in the uk

Theres these but only seen them used on 5.3 lamps, though the pin holes are slots for a range of lamps usually

Im quessing then capsules are G4 and Mr11 are possibly GU4 generally

 

[JohnW2]

dont recall ever seing a lampholder with clips on for the so called GU4 lamp have you.

No, but I've only very rarely seen a G4/GU4 lampholder of any sort

Im quessing then capsules are G4 and Mr11 are possibly GU4 generally

Looking around, it seems that all the MR11s are called GU4, but that those called G4 generally look something like this:

Kind Regards, John

 

[333rocky333]

That seems to make sense with regards to G4 Gu4 then
Your pic shows a led version of whats called a " G4 capsule lamp", they usually push into a flat base with two holes and no clip.
Often seen, in them small under counter lights.

Whereas what the bloke in your previous link states, a GU4 base is fitted to a MR11 lamp, which as you know is a smaller version of the more common MR16, or as he calls it a "directional lamp", due to the weight, fits in a so called GU4 holder with clips, i asume to hold the lamp secure.

However in the uk at least, most so called GU4 lamps will likely be found fitted in so called G4 lampholders (with no clips), in downlights, restrained by a 35 mm circlip.

With all this Led stuff i wonder if its gone up the wall, as your pic shows that would only fit a G4 holder( no clips) which is ok as its intention is a capsule lamp replacement.
therefore a MR11 halogen replacement, Led version , should in theory be made with a GU4 Base to fit a GU4 holder (with clips), if they exist.

As per my theory, a GU4 is "universal" so as to fit, if needbe a holder with these clips, the shape and dimensions being standardised.
whereas it now seems to me, that a G4 or whatever can have any shape base on proviso , the pins are 4mm centres, as per your led shown

comparing G5.3 capsules with GU5.3 mr16 seems to have same results.

Just need to know what GY and GX lamps are then, im quessing maybe to do with temperature

 

[EFLImpudence]

I think, as I found and said earlier, the second letter is the shape of the base - although I still cannot find a site which describes that shape.

No second letter, as above G5.3 G4, appear to have no base - logical.

There are some HERE which show some GX and GY and they do have different bases.



There appear to be also some mistakes - as in the first in the list of GU10.

 

[ericmark]

Seem to remember the GZ10 lamp has a dichroic reflector so only light is reflected not the heat, this means cooling to back of lamp, so there is no taper on the base, so a GZ10 lamp holder will take both GZ10 and GU10 lamps, but a GU10 holder will not take a GZ10 lamp, there is also a version with a spike in centre GU10L2 I think which will only take the LED or Cold Cathode lamps to comply with the L2 building regulations which require that the holder will not take non energy efficient lamps with new builds.

As to pay back time, at £12 per hour and 5 minuets to change a bulb, because LED bulbs last longer then must be looking at a saving of around £10 with labour costs alone as old type were always failing. Using 40W less at 16p per kWh then saves around 16p every 25 hours. However you have to compare like for like and a typical LED GU10 bulb does not have 2 inches of lit area, often only the centre inch is lit, so the surface at which the lamp is aimed will have a huge impact as to the amount of light reflected so the amount of light getting into the room compared with the light being absorbed by dark areas like the floor.

I have 2 GU10 LED lights at side of bed as reading lamps, they can be moved to shine anywhere in the room, using my camera to measure the light, I aimed them at bed, then at ceiling, camera aimed at wall showed 4 times the light when lamps aimed at the ceiling. If you get so frosted translucent plastic around 6 inches across and place it in front of the lights to spread the light they light many rooms better, it seems size does matter. So with a 10W LED lamp 1 inch across and a LED lamp same wattage but 6 inches across the latter lights the room far better.

So if looking for efficiency then you would not use GU10 fittings for general lighting, on the bed head to read with great, on a light bar to light dark corners without running wires great, to light up pictures on the wall great, to light shop window displays great, but for general lighting even 2 inches is too small, with LED versions reducing surface area often to one inch they are useless.

Of course if you use 10 x 3W then a lot better than 5 x 6W because of surface area. I have just had mothers house rewired, and to start with there were no lamp shades, simply adding lamp shades white of course has made the rooms brighter, one would expect it to make it darker as they must be absorbing some light, but in fact it has made the rooms brighter as it has spread out the light.

Clearly every room is different and there is no one size fits all. But also at this time of year we need to heat rooms. The tungsten lamp sent out radiant heat, this heat did not directly heat the air but heated items like our bodies, so at night it made us feel warmer, so central heating could be set lower, so the tungsten bulb in doors saved energy as less energy is used by the central heating. I asked the energy saving trust about this, they admitted that using tungsten bulbs could save energy but no field trials have been done and it would vary house to house. With electric heated houses tungsten bulbs would save money, with gas because gas is so much cheaper likely using LED lamps will save money.

So to swap tungsten to LED to reduce maintenance, or to reduce air conditioner use works well. But to reduce energy used it will depend on where you live and design of house so north Scotland likely no saving, London likely they will save energy because London is warmer.

 

[JohnW2]

Whereas what the bloke in your previous link states, a GU4 base is fitted to a MR11 lamp, which as you know is a smaller version of the more common MR16, or as he calls it a "directional lamp", due to the weight, fits in a so called GU4 holder with clips, i asume to hold the lamp secure. ... However in the uk at least, most so called GU4 lamps will likely be found fitted in so called G4 lampholders (with no clips), in downlights, restrained by a 35 mm circlip.

Yes, that all sounds reasonable, but .... (with my highlighting added) ...

With all this Led stuff i wonder if its gone up the wall, as your pic shows that would only fit a G4 holder ( no clips) which is ok as its intention is a capsule lamp replacement. therefore a MR11 halogen replacement, Led version , should in theory be made with a GU4 Base to fit a GU4 holder (with clips), if they exist.

This could perhaps be what's confusing us. As you will recall, what one source (since 'lost') I found said was that the "U" indicated that the lamp had some sort of provision for 'restraint' (e.g. twisting, or some groove etc. for a clip to engage with). If GU4 (but not G4) holders have, say, a clip, then the fact that a G4 lamp has no groove/whatever for a clip to engage with may not mean that it won't 'fit' into a GU4 holder (the holder's clip being redundant) - in the same way that a GU4 lamp will fit into a G4 holder (with, as you say, a circlip or something to hold it in).

Kind Regards, John