sanity check

[SparkyTris]

My folks have recently had a lot of lights blowing. when probed, these are specifically lights in 2 multi-bulb fittings. thats to say, a rose where the T&E goes, with a metal arm that has 3 or 4 lamp mountings in it.

GU10s in one, and SES in the other I think.

this is just a case of a batch of crappy bulbs right?

There are rooms in the house where the same incandescent has been working for years.

or is there more to it?

I have a theory... if 1 bulb in a close set of 4 suddenly fails, then the volts in that immediate proximity will rise suddenly - resulting in an increased likelihood of an adjacent bulb blowing, more than that of a distant bulb (the resistance in the length of wiring will dampen down the mini-surge caused by the initial bulb failing.)
is there any sense in that theory?

 

[NewOrder]

It could just be cheap fittings. Bulbs kept blowing in our dining room, so I simply wired in a new flex and socket from the ceiling hose and has been fine since then.

Another time was when a faulty dimmer was causing bulbs to blow.

What brand are the bulbs they are using? Some GU10 lasts hours, SES bulbs also seem to have a very high failure rate.

 

[SparkyTris]

but how can poor quality fittings cause bulbs to fail?

a lack of quality surely can *only* lead to less volts at the bulb terminals leading to longer bulb life??? (disregarding all other associated dangers with lo quality)

if a fitting somehow causes the bulb to not dissipate heat as fast as it needs to, yes I can see how that would shorten its life. but that would have to be quite an unusual fitting

can arcing at a loose terminal cause increased bulb failure? if so how? I just cant see that arcing would do anything other than drop the volts over the bulb, again leading to increased life.?
ok, arcing at the base of the bulb would lead to a cooked-up base but that is a different and obvious failure mode

 

[NewOrder]

I guess it is arcing or the fact if the voltage is unstable it will cause the bulb to flicker slightly thus reducing its life. All I know is changing the fitting certainly solved the problem for me, it is only a standard 240w 100W but it has not blown since I changed the fitting and that was about 8 months ago.

I am guessing though with you, it is just cheap bulbs causing the problem, far too much crap on the market at the moment.