Constantly blown lightbulbs.

[Northbeach]

Hi,
I have recently been attempting to add lightbulbs to an outside light (lantern style). Max wattage for this is 40 watts...so I buy 40 watt bulbs. I considered adding a energy saving bulb (9 watts if I remember correctly) as with the other outside light on the front. Turned the switch on (indoors) to check if ok; basically it lit for a few seconds before gently 'expiring'. So I tried a normal 40 watt candle bulb this blew...and another...this blew also.
I can't for the life of me work out why this would happen? Has water somehow entered the connections inside the lamp? The light was connected by the guys building the kitchen a couple of years ago - it isn't as far as I know on the lighting ring (we only have one for both upstairs and down) and may have been inserted via a spur on the mains...? The fuses are never effected when this occurs.
Any usual suspects you can think of folks?
Thanks.

 

[Spark123]

A couple or three daft questions but relevent non-the-less;
Do you have a single phase supply?
Has the light ever worked?
What voltage are the lamps?
Could just be a coincidence that you have brought a batch of cheap lamps?
What do you mean by gentally expiring?
Is it a normal on/off type PIR?

 

[Northbeach]

*Single Phase - not entirely sure what this phrase means but I'm guessing it refers to single mains/light loop? If so then it probably is - the lights for upstairs and downstairs are on one fuse; the mains & cooker et al on their own fuse.

*The lights had been working fine for years...it seemed that when I tried the energy saving lamp my problems started.

*By lamps you're referring to the bulbs and not the actual light? The bulb rating are as follows: Max 60w ES GLS.

*Could be cheap batch...they were from Asda.

*Gently expiring - this was more the Energy bulb - the light just petered out rather than a mini 'explosion'!

*PIR? Again - sorry - not really up on the lecy phrases...it's on a normal on off switch. Actually the other outside light was fixed directly into the power and 'was' on an LDR, until that blew following contact with window cleaners water! I can fix another one on to that mind.

Hope this helps...I might try another set of bulbs in the meantime, though it's starting to cost a bit/

Many thanks.

 

[JohnD]

If you put an Energy Saving lamp in it (especially an "Electronic" one from Phillips) it will accomodate quite a lot of voltage variation without damage.

Is it possible you have a loose connection causing flickering? This will make lamps fail prematurely.

Electricians pretend to think that bulbs are what you put in the ground to grow tulips

 

[Northbeach]

Quite possible John. I'll take it apart at the weekend and dig around then.
It isn't so much flickering as blowing immediately after I've turned the light on.
It was indeed a sturdy Philip 'lamp' so I was surprised it popped so quickly (they should last for years right!).

Electricians pretend to think that bulbs are what you put in the ground to grow tulips

Wondered why I didn't see anything sprout or indeed flower this year!
Cheers.

 

[RF Lighting]

I can't for the life of me work out why this would happen?

they were from Asda

 

[RMS]

Come across this sort of problem all the time but trying to explain it to customers is an even bigger problem!

 

[Northbeach]

Come across this sort of problem all the time but trying to explain it to customers is an even bigger problem!

Not sure I follow. Figured out that perhaps these 'asda range' 'bulbs' are not recommended and admittedly they don't have a long shelf life, but they do run for some time in other light fittings and it doesn't explain why the Philips energy saving lamp blew?

 

[Steve]

do you have access to a multimeter in order that you could test the voltage at the lamp holder?

I agree, the lamps should not be failing like this.

Have you tried the failed lamps in any other fittings to see if they still work?

 

[securespark]

I wonder if, like other products in their range, Asda have "Bettabuy" lamps, Standard middle of the range lamps and "Best" lamps that are the most expensive?

 

[Northbeach]

do you have access to a multimeter in order that you could test the voltage at the lamp holder?

I agree, the lamps should not be failing like this.

Have you tried the failed lamps in any other fittings to see if they still work?

Cheers Crafty. No, these lamps really are blown - either the element is hanging like a loose sock on a washing line or the glass is blackened from the 'explosion'. I'll try another lamp over the weekend, perhaps not 'asda's best range' this time. But those Philips energy saving lamps are not cheap...I'll let you know how I get on with another replacement this weekend.
A multimeter is really something I should own by now...this is actually the least of my electrical woes - I have some feisty little lecy issues to unsheath of on this forum I can tell you!
Thanks.

 

[Steve]

Digital multimeters can be had for less than £10. Go buy one. Maplins are good. Then you can measure the voltage at this light fitting!

I wonder, are those bayonet plugs still available, that plug into a bayonet bulb holder? This would be awfully useful to measure the resistance of the contacts in this fitting, a multimeter job again!

 

[JohnD]

...either the element is hanging like a loose sock on a washing line or the glass is blackened ...

This can happen of a lamp is knocked or shaken when it is hot - could that gave happened?

 

[Northbeach]

This can happen of a lamp is knocked or shaken when it is hot - could that gave happened?

I don't think so - it's about 8 foot high (you have to change the blinkin lamps with a stepladder). We have some feisty squirrels in our garden mind!
No - it's immidiately as I flick the light switch the lamp will blow - some surge of current which worries me a little.

Digital multimeters can be had for less than £10. Go buy one. Maplins are good. Then you can measure the voltage at this light fitting!

I wonder, are those bayonet plugs still available, that plug into a bayonet bulb holder? This would be awfully useful to measure the resistance of the contacts in this fitting, a multimeter job again!

That's a good price - I need to pop in Maplins anyhow.
The fitting is a screw fitting by the way - still ok to test the current?

Thanks folks.

 

[Steve]

Buy an auto-ranging digital multimeter. You need to set it to volts AC (might say V~) and with the fitting on, hold one probe to the centre contact and one to the side contact. If the voltage is ok (below 250), you'll just have to replace the fitting. There must be a high-resistance joint somewhere that is causing your bulbs to pop. There's nothing else it can be.

Alternatively, measure the voltage inside your house somewhere. Lever a socket shutter down or use a bayonet light fitting.