why do lights blow regularly on one circuit & very seldom on another, both supplied f

[AndyD]

Sparks, you have a point there !
These imported jobs ( normally from China ) are really cheap and nasty and do not have a good life..........

All major lighting brands manufacture to varying degrees in China.

Osram/Sylvania - manufacture in China
Philips - manufacture in China
Lohuis - manufacture in China
GE - manufacture in China
Lumin8 - manufacture in China
Megaman - Manufacture in China

If you want to avoid Chinese products for some reason you would need to start buying Brands such as Lichttechnik which are manufactured in Germany.

Some Philips lamps available in SA are 'manufactured' in Holland but many of their components such as cathodes, ballasts etc are produced under license in China.

You can run but you can't hide :-)

[AndyD]

While we are on the subject of lamps................has anybody ever found a "8000 hour" CFL to last even close to the 333 days (continuous) on nearly 3 years if only used 7-8 hours / night ?

Mostly, lamp life is stated according to IEC60969 standards.

According to IEC60969;

• Tests are conducted in a draught proof cabinet at (25°C) and a humidity of less than 65% with a stabilized and optimized supply voltage.
  
• The measured life to 50% failures (average life) shall not be less than the rated life to 50% failures (rated average life)

In short the lamp life stated on the box refers to the length of time of operation at which point at least 50% of the lamps from a random sample batch of at least 20 lamps should still be working (assuming controlled humidity and temperature, assuming draught-free conditions, assuming perfect electrical supply and running conditions ie. no rapid on-off switching.)

The real-life chances of a lamp reaching it's stated run time without failure are pretty damn slim.

Nearly all wholesalers and agents will refuse point blank to warranty a lamp that has failed prematurely.

[Dave A]

While we are on the subject of lamps................has anybody ever found a "8000 hour" CFL to last even close to the 333 days (continuous) on nearly 3 years if only used 7-8 hours / night ?

Not even close

[berndj]

While we are on the subject of lamps................has anybody ever found a "8000 hour" CFL to last even close to the 333 days (continuous) on nearly 3 years if only used 7-8 hours / night ?

Back in 1993 my dear mother gave me an Osram for my birthday, back when CFL's were still an unusual sight. That lamp had been working for hours every night, for about 15 years, after which I moved and it fell into disuse. It's dead now, but only because my dog knocked over the lamp and it broke. It must've done about 25000 hours. I don't think it was any particularly overengineered model. I think I have its remains in a bag somewhere if you want an exact model number!

Once when it was just a few years old I thought it had broken as it didn't switch on properly, or it made an odd sound so I left it (memory's hazy), but then one day it made a heroic BZZZT, ignited properly and then shone brightly for the rest of its life.

YMMV!

[Dave A]

Rough duty light bulbs last pretty well too, particularly if you don't torture them in a lead light like they're designed for.

They used to be pretty hard to source, though. Don't know what it's like nowadays...

[murdock]

back in 1993 everything lasted longer...what i found out a while back while doing some work for a well know company which supplies electronic equipment...they have containers which they test products to make sure they last just longer than the warranty they build.... products are put them into aging containers and use heat to speed up the aging process to make sure they last just long enough....mmmm

[AndriesH]

Back in 1993 my dear mother gave me an Osram for my birthday, ....

Wow. You got a light bulb for your birthday! And I thought I was ill done by. I get hankies. Not sure whether a light bulb is better or worse.

[Dave A]

Wow. You got a light bulb for your birthday! And I thought I was ill done by. I get hankies. Not sure whether a light bulb is better or worse.

Where does underwear fit in this order of things?

[harveya]

Hi to all you guys that have continued on this thread. I have found the responses most fascinating, many points I would not have considered. I have not been back to this particular client for some time, but I'll certainly be armed with much to work on when I do.
hat has brought me back into the forum (yes I have been very slack of late!) is the new twist in this saga, - I never imagined that such a problem such as this could lead to a discussion on birthday presents and underwear. Just shows, all things are linked in some way or another!!!

[daveob]

Where does underwear fit in this order of things?

I think that would largely depend on who is giving it to you - uncle Cecil or that hot distant cousin.