flying light bulbs - help please Ask questions and find answers to many subjects relating to electrics and electrical work

[shela]

Light fitting rated for 100w screw bulb; Every time the bulb blows, the bulb glass flies out of the fitting, leaving the screw behind.

Have used both homebase and osram bulbs with same result; bulb lasts approx 3 months.

What can be causing this problem????

[ericmark]

Water will do this. Can a drip of water get on the bulb? Something needs to stress the glass. Could be cold draft. Unlikely to be an electrical fault most good quality bulbs are internally fused when the filament goes it can drop and short out if the bulbs are designed to be fitted pointing one way maybe when this happens the fuse is also short circuit but unlikely most likely external force like draft or water.

All best Eric

[333rocky333]

What position is the lamp. up down sideways?
Is it shattering when turning on or just while in use?

To the best of my knowledge

Although rated at 100 w most fittings cannot handle 100 w especially if lamp downwards.

If the lamp is downward and 100w has been used.
It may be too late to down rate the lamp now as if the damage has been done it may persist till you replace part or all of the fitting.

The heat of the lamp damages the contacts and wires of the lampholder,this causes slight arcing , increasing the current and temperature to the lamp causing it to shatter.

Sometimes if the fitting is in the cold , the heat of the 100 w lamp when turned on may shatter the glass, but unusual with branded make lamps like osram.

Be careful getting out the broken lamp bit as it may be live!

I am sure there is a project in the forum regarding this ,worth a look