I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet

Lee

Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet

Generally they should not do this. However, make sure you don't touch
the glass when installing the new bulbs (wear gloves or install them
using the box etc). Leaving finger print oil on the glass may increase
the risk of explosion.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet

Generally they should not do this. However, make sure you don't touch
the glass when installing the new bulbs (wear gloves or install them
using the box etc). Leaving finger print oil on the glass may increase
the risk of explosion.

Surely in this type of bulb the outer envelope that you touch is quite
separate from the quartz glass envelope of the bulb itself. So it
*isn't* necessary to avoid touching the bulb as it is with the linear
quartz glass bulbs in spotlights where you can touch the actual quartz
glass.

--
Chris Green

Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet

Lee
You didn't buy them from Poundland did you? I bought some filament bulbs
from it a while back and they exploded after a while. Trouble was I
couldn't remember which was which, so it was just a question of waiting.
Interesting time (in the Chinese sense).

Peter Scott

In article ,
Peter Scott writes:
Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet

Lee
You didn't buy them from Poundland did you? I bought some filament bulbs
from it a while back and they exploded after a while. Trouble was I
couldn't remember which was which, so it was just a question of waiting.
Interesting time (in the Chinese sense).

That can happen when the bulb has no integral fuse, which means
it can flash-over as an unbalasted discharge lamp when the
filament breaks, with the current being limited by the supply
impedance, and the rapid expansion of the gas fill causing it
to explode.

Ordinary mains bulbs are required to be internally fused.
In some other countries, this isn't mandated, and occasionally
stock gets here without internal fusing, but it's rare.

Halogens are a different matter. Many halogen lamps simply have
nowhere to include a fuse within the bulb. These are handled by
having a secondary shield, either an outer glass bulb which
should contain the quartz shattering, or a fitting with similar
a shield. Halogens run at a higher pressure inside anyway, and
this reduces the chance of flash-over. However, if it does
happen, it generates a higher pressure in the quartz bulb.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 21 Apr, 12:59, (Andrew Gabriel) wrote:
In article ,
* * * * Peter Scott writes:

Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this....
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet

Lee
You didn't buy them from Poundland did you? I bought some filament bulbs
from it a while back and they exploded after a while. Trouble was I
couldn't remember which was which, so it was just a question of waiting..
Interesting time (in the Chinese sense).

That can happen when the bulb has no integral fuse, which means
it can flash-over as an unbalasted discharge lamp when the
filament breaks, with the current being limited by the supply
impedance, and the rapid expansion of the gas fill causing it
to explode.

Ordinary mains bulbs are required to be internally fused.
In some other countries, this isn't mandated, and occasionally
stock gets here without internal fusing, but it's rare.

Halogens are a different matter. Many halogen lamps simply have
nowhere to include a fuse within the bulb. These are handled by
having a secondary shield, either an outer glass bulb which
should contain the quartz shattering, or a fitting with similar
a shield. Halogens run at a higher pressure inside anyway, and
this reduces the chance of flash-over. However, if it does
happen, it generates a higher pressure in the quartz bulb.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

My input would be to switch over from the 240v driven GU10's to the
equivalent using a 12v transformer. All GU10's I ever used had a very
high failure rate - the 12v one's never give me any bother, which is
suspect is due to the some sort of surge suppression when they are
switched on.
Rob

On 21 Apr 2009 11:59:59 GMT, Andrew Gabriel wrote:

Halogens run at a higher pressure inside anyway, and this reduces the
chance of flash-over. However, if it does happen, it generates a higher
pressure in the quartz bulb.

Aye, you don't want to be near a halogen when it goes pop or rather *BANG*
showering the enviroment with glowing red glass.

--
Cheers
Dave.

wrote:
John Rumm wrote:
Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet
Generally they should not do this. However, make sure you don't touch
the glass when installing the new bulbs (wear gloves or install them
using the box etc). Leaving finger print oil on the glass may increase
the risk of explosion.

Surely in this type of bulb the outer envelope that you touch is quite
separate from the quartz glass envelope of the bulb itself. So it
*isn't* necessary to avoid touching the bulb as it is with the linear
quartz glass bulbs in spotlights where you can touch the actual quartz
glass.

If you read the instructions supplied with most of them, it still
applies. The ones with the outer glass envelope (like GU10s) are
supposed to contain the explosion (should it occur), but you can still
get some softening of the outer glass from contamination.

(The linear halogen jobbies are much worse in this respect though)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
wrote:
John Rumm wrote:
Lee wrote:
I've just had a (mains) GU10 shatter into nice sharp shards all over the
floor, rather impressive spread given the small amout of glass involved...

I was under the impression that these bulbs weren't meant to do this...
Should I be worried any others might follow suite? (These are branded,
not no-names) Just concerned for ours and the cats feet
Generally they should not do this. However, make sure you don't touch
the glass when installing the new bulbs (wear gloves or install them
using the box etc). Leaving finger print oil on the glass may increase
the risk of explosion.

Surely in this type of bulb the outer envelope that you touch is quite
separate from the quartz glass envelope of the bulb itself. So it
*isn't* necessary to avoid touching the bulb as it is with the linear
quartz glass bulbs in spotlights where you can touch the actual quartz
glass.

If you read the instructions supplied with most of them, it still

Well I tried very hard with the first few I used and I could see no
trace of any information on them indicating that one shouldn't touch
the outside.

applies. The ones with the outer glass envelope (like GU10s) are
supposed to contain the explosion (should it occur), but you can still
get some softening of the outer glass from contamination.

(The linear halogen jobbies are much worse in this respect though)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

--
Chris Green

Andrew Gabriel wrote:
In article ,
Peter Scott writes:

You didn't buy them from Poundland did you?

Snip


That can happen when the bulb has no integral fuse,

Snip

DIY store bought, branded, and were individually boxed in UK packaging -
not that that means anything, I suspect

To update, since posting I have been ordered by SWMBO that the fitting
and bulbs is to be changed ASAP for "something safer", or else

I didn't inquire to the "else", it seemed wise not to, she was not happy...

Lee

Lee wrote:
Andrew Gabriel wrote:
In article ,
Peter Scott writes:

You didn't buy them from Poundland did you?

Snip


That can happen when the bulb has no integral fuse,

Snip

DIY store bought, branded, and were individually boxed in UK packaging -
not that that means anything, I suspect

To update, since posting I have been ordered by SWMBO that the fitting
and bulbs is to be changed ASAP for "something safer", or else

I didn't inquire to the "else", it seemed wise not to, she was not happy...

Lee

That's the whole point of 'else'. Certainty about revenge but
uncertainty about when or what.

Peter Scott

Andrew Gabriel wrote:

You didn't buy them from Poundland did you? I bought some filament bulbs
from it a while back and they exploded after a while. Trouble was I
couldn't remember which was which, so it was just a question of waiting.
Interesting time (in the Chinese sense).

That can happen when the bulb has no integral fuse, which means
it can flash-over as an unbalasted discharge lamp when the
filament breaks, with the current being limited by the supply
impedance, and the rapid expansion of the gas fill causing it
to explode.

Ordinary mains bulbs are required to be internally fused.
In some other countries, this isn't mandated, and occasionally
stock gets here without internal fusing, but it's rare.

That's a long-standing mystery solved. Thanks. I expect that they got a
cheap job lot from a dubious source.

Peter Scott