Lamps 'popping'

[TheGayOwl]

Hi,

Have been to client today to look at popping incandescent lamps.

Lamps are 40W E14 type and fitting has 5 in. The glass bulb is coming away from the metal threaded part usuallly with a 'pop' and are breaking free and landing on the floor. Live conductor to fitting was loose when I took it down to investigate. Am wondering if loose live may have been arcing and causing over voltage to the lamo causing it to pop.... This has happened to 5 or 6 lamps over last few months. Thoughts welcomed.

 

[flameport]

Overheating, caused by loose connections / poor quality lampholders.

Solution is to replace the lampholders, or more likely, replace the whole thing.

 

[TheGayOwl]

Cheers Flame.

Surely the glass of the lamp should not be breaking free from the metal E14 threaded part though. I would think they would be designed to stay as one unit. This would indicate super el cheapo lamps would it not?

The lamp holders seemed reasonably fine, no scorch marks etc, so hopefully the loose live was causing the prob.

I have never known lamps to fly off like this before tho.

Thanks again.

 

[pjcomp]

Tend to agree, Owl - crap manufacture of the lamps. Seeing it more and more these days, the basic quality just isn't there any more.

PJ

 

[bernardgreen]

Am wondering if loose live may have been arcing and causing over voltage to the lamo causing it to pop....

Arcing over bad connection will not increase the voltage unless there is an inductor coil in the circuit such as a ballast, transformer or ignition coil.

The most probable cause is over heating of the lamp to the point where the adhesive between glass and metal fractures due to diferential expansion of the two material.

Odd that the connection wires between glass and metal are also detatching, are they breaking or is the solder (?) joint of wire to metal failing ?

 

[TheGayOwl]

Not to sure Bernard whether there was a soldered joint between the two. Lamps have been binned alas. Some were still connected via the two wires and took a good few twists to get off before I could get to the E14 thread part. Thanks for your thoughts everyone.

 

[TicklyT]

Is the fitting rated for 5 X 40 Watt lamps?

If it has been fitted with 40 Watt lamps in place of, say, 25 Watt ones, that could certainly contribute to overheating.

 

[TheGayOwl]

yes, had little stickers stating max 40W....Will suggest client maybe puts some 25W in instead to see if that helps. It is in their lounge so prob is on a fair amount of time as only one table lamp in that room, although 200W's is hardly conducive to relaxing in front of the telly.

Thanks.

 

[TicklyT]

How about trying some CFLs in there?