I found my bedroom light bulb had failed yesterday - it's a standard bayonet
fitting below a ceiling rose. However, it wasn't as simple as just changing
the lightbulb - the bulb had fallen out of the fitting. Inspection of the
socket showed that it had largely melted, in fact one of the two metal
spring-loaded electrical connection pins had dropped out, covered with burnt
plastic and melted lead from the bulb contact. The bulb had fallen out
because one of the socket cut-outs, which retain the lugs on the bulb, had
just disintegrated or melted with the heat.

It sounds like I was lucky not to have a house fire, wasn't I (or not?)?
Why would this happen? Why didn't the relevant MCB on my CU trip (they seem
to do so - irritatingly - every time a bulb in the house blows!) The fitting
was only about 4 years old, is wired perfectly OK, and it's months since
I''ve changed the lightbulb which has worked perfectly ever since. I find
it pretty scary to think what migh have happened, and I haven't a clue why.

Thanks
Dave

On Sat, 01 Oct 2005 09:53:26 GMT, "Dave P"
wrote:

| I found my bedroom light bulb had failed yesterday - it's a standard bayonet
| fitting below a ceiling rose. However, it wasn't as simple as just changing
| the lightbulb - the bulb had fallen out of the fitting. Inspection of the
| socket showed that it had largely melted, in fact one of the two metal
| spring-loaded electrical connection pins had dropped out, covered with burnt
| plastic and melted lead from the bulb contact. The bulb had fallen out
| because one of the socket cut-outs, which retain the lugs on the bulb, had
| just disintegrated or melted with the heat.

A bad contact generated enough heat to melt things, but did not draw enough
electricity to trip anything.
|
| It sounds like I was lucky not to have a house fire, wasn't I (or not?)?
| Why would this happen? Why didn't the relevant MCB on my CU trip (they seem
| to do so - irritatingly - every time a bulb in the house blows!) The fitting
| was only about 4 years old, is wired perfectly OK, and it's months since
| I''ve changed the lightbulb which has worked perfectly ever since. I find
| it pretty scary to think what migh have happened, and I haven't a clue why.

I have changed to energy saving ?bulbs?, long ago, so changing them is a
very rare occurrence. Also because they use less power they do not run
anything like as hot. I have a bad contact in my bedside light, which I
must change sometime, but as it only uses 7 watts it is never going to burn
out.

--
Dave Fawthrop dave hyphenologist co uk
The London suicide bombers killed innocent commuters.
Animal rights terrorists and activists kill innocent patients.

On Sat, 01 Oct 2005 11:11:39 +0100, Dave Fawthrop
wrote:

On Sat, 01 Oct 2005 09:53:26 GMT, "Dave P"
wrote:

| I found my bedroom light bulb had failed yesterday - it's a standard bayonet
| fitting below a ceiling rose. However, it wasn't as simple as just changing
| the lightbulb - the bulb had fallen out of the fitting. Inspection of the
| socket showed that it had largely melted, in fact one of the two metal
| spring-loaded electrical connection pins had dropped out, covered with burnt
| plastic and melted lead from the bulb contact. The bulb had fallen out
| because one of the socket cut-outs, which retain the lugs on the bulb, had
| just disintegrated or melted with the heat.

A bad contact generated enough heat to melt things, but did not draw enough
electricity to trip anything.
|
| It sounds like I was lucky not to have a house fire, wasn't I (or not?)?
| Why would this happen? Why didn't the relevant MCB on my CU trip (they seem
| to do so - irritatingly - every time a bulb in the house blows!) The fitting
| was only about 4 years old, is wired perfectly OK, and it's months since
| I''ve changed the lightbulb which has worked perfectly ever since. I find
| it pretty scary to think what migh have happened, and I haven't a clue why.

I have changed to energy saving ?bulbs?, long ago, so changing them is a
very rare occurrence. Also because they use less power they do not run
anything like as hot. I have a bad contact in my bedside light, which I
must change sometime, but as it only uses 7 watts it is never going to burn
out.

I've had an energy saving light melt - or at least the plasticy bit
did. About a week afterI'd thrown the wrapper out after having had it
a couple of years.
--
Promotional codes, discounts, money off
http://www.promotionalcode.co.uk/
http://www.moneyoffvouchers.co.uk

"mogga" wrote in message
...
On Sat, 01 Oct 2005 11:11:39 +0100, Dave Fawthrop
wrote:

On Sat, 01 Oct 2005 09:53:26 GMT, "Dave P"
wrote:

| I found my bedroom light bulb had failed yesterday - it's a standard
bayonet
| fitting below a ceiling rose. However, it wasn't as simple as just
changing
| the lightbulb - the bulb had fallen out of the fitting. Inspection of
the
| socket showed that it had largely melted, in fact one of the two metal
| spring-loaded electrical connection pins had dropped out, covered with
burnt
| plastic and melted lead from the bulb contact. The bulb had fallen out
| because one of the socket cut-outs, which retain the lugs on the bulb,
had
| just disintegrated or melted with the heat.

A bad contact generated enough heat to melt things, but did not draw
enough
electricity to trip anything.
|
| It sounds like I was lucky not to have a house fire, wasn't I (or not?)?
| Why would this happen? Why didn't the relevant MCB on my CU trip (they
seem
| to do so - irritatingly - every time a bulb in the house blows!) The
fitting
| was only about 4 years old, is wired perfectly OK, and it's months since
| I''ve changed the lightbulb which has worked perfectly ever since. I
find
| it pretty scary to think what migh have happened, and I haven't a clue
why.

I have changed to energy saving ?bulbs?, long ago, so changing them is a
very rare occurrence. Also because they use less power they do not run
anything like as hot. I have a bad contact in my bedside light, which I
must change sometime, but as it only uses 7 watts it is never going to
burn
out.

I've had an energy saving light melt - or at least the plasticy bit
did. About a week afterI'd thrown the wrapper out after having had it
a couple of years.
I've had a filament light bulb drop out of its socket before.
There was a flash and a thump, and I saw on the landing the baseless glass
bulb lying on the carpet. Getting the base out of the pendant socket was
interesting. The plastic pendant socket was unharmed though.

When a filament lamp blows, you can get arcing inside
as hot tungsten splatters about, and the
current can be enough to blow a fuse. If it isn't quite
enough, I suspect that if the contact of the base of the bulb to the socket
isn't very good, the solder can melt and allow the bulb to drop out.

Andy.

Dave P wrote:
I found my bedroom light bulb had failed yesterday - it's a

socket showed that it had largely melted, in fact one of the

It sounds like I was lucky not to have a house fire, wasn't I (or not?)?
Why would this happen? Why didn't the relevant MCB on my CU trip (they seem
to do so - irritatingly - every time a bulb in the house blows!)

Fire is always a risk in these cases, though usually not no fire
occurs.

MCBs trip when load current gets well above 6A. A bad resistance join
does the opposite, reduces load current, so would never trip the MCB.
Quite simply there is no protection in most installs against this. Just
make sure your kit is sound to start with.

Cue long debate about how much of a problem it is or isnt, about how
America does it differently, and about the pros and cons of RCDs and
AFCIs.


NT

On 1 Oct 2005 07:39:41 -0700, scrawled:

MCBs trip when load current gets well above 6A.

Although this doesn't mean it trips at 6.1A.

A bad resistance join
does the opposite, reduces load current, so would never trip the MCB.

Not neccesarily, depends what sort of resistance and and what sort of
load is going through it.

Quite simply there is no protection in most installs against this. Just
make sure your kit is sound to start with.

Basically, **** happens! Stick a new pendant up and be done with it,
things break.
--
Stuart @ SJW Electrical

Please Reply to group

On Sat, 01 Oct 2005 09:53:26 GMT, "Dave P"
wrote:

| I found my bedroom light bulb had failed yesterday - it's a standard bayonet
| fitting below a ceiling rose. However, it wasn't as simple as just changing
| the lightbulb - the bulb had fallen out of the fitting. Inspection of the
| socket showed that it had largely melted, in fact one of the two metal
| spring-loaded electrical connection pins had dropped out, covered with burnt
| plastic and melted lead from the bulb contact. The bulb had fallen out
| because one of the socket cut-outs, which retain the lugs on the bulb, had
| just disintegrated or melted with the heat.
|
| It sounds like I was lucky not to have a house fire, wasn't I (or not?)?
| Why would this happen? Why didn't the relevant MCB on my CU trip (they seem
| to do so - irritatingly - every time a bulb in the house blows!) The fitting
| was only about 4 years old, is wired perfectly OK, and it's months since
| I''ve changed the lightbulb which has worked perfectly ever since. I find
| it pretty scary to think what migh have happened, and I haven't a clue why.

Make sure you have smoke detectors fitted and the batteries are still OK.

--
Dave Fawthrop dave hyphenologist co uk
The London suicide bombers killed innocent commuters.
Animal rights terrorists and activists kill innocent patients.