Kitchen Lights Fusing Consistantly - Any Ideas on the Cause? Ask questions and find answers to many subjects relating to electrics and electrical work

[Pheme]

Some time ago I switched my kitchen lights on and there was a pop as the fuse blew, turning all the downstairs ceiling lights off. All the wall lights/plugs still worked. I removed all of the bulbs (5 spots), replaced the fuse and tried again. Same issue. It will happen regardless whether any other electrical appliances or lights are on in the house, so I believe the problem to be isolated to the kitchen.

I think that the problem is coming from one particlar light fitting because that's where the pop seems to come from every time. I could be wrong of course.

The lights have been in place for at least ten years and I have had no electrical work carried out on the house upto the time that that the problem started (five months ago).

I know I don't have the skill to fix it, but I have delayed calling an electrician because I'm worried about the cost. I have managed to get by using lamps.

Can anyone give me an idea of what they think may be wrong and how the location of the fault could be identified. I'm worried that they'll start pulling down the ceiling to get to the cables. That may give me an idea of the final bill.

Thank you.

[ericmark]

The normal way would be totally isolate then use an extra low voltage buzzer often built into the multi-meter and then move wires until the buzzer stops.

It could even be a battery door bell.

One always hopes it will be a quick job, but with jobs like this step one is extract as much info as you can from customer some times as one talks it dawns on one what has happened.

Step two is the jump to most likely if one guesses right then it saves a lot of time.

Step three is bit by bit test things.

So jumping to step two one looks at what may have failed. Wiring seldom fails more likely something with components in it. So florescent lamp is the first thought. Then and dimmer switches or the like. Damp walls so since easy remove switches to inspect.

Aim for an old electrician as young guys have the speed but old guys have the experience and you need the experience in this case.

[Pheme]

Thank you for that.

About a month before this happened I had a leak into the integral garage. It took me ages to find a roofer to solve the problem and I mentioned to him the problem I had with my kitchen lights (that had occurred about a month after the leak). I thought it a possibility but then considered the distance (15 feet) and that every light in between was not blowing a fuse, even the light within the garage. He was doubtful and after the roof was mended, I waited for some months for (I hoped) everthing to dry out before trying the kitchen lights again. Same problem. So maybe the roofer was right.

Finding a tradesman is a real minefield. (One roofer actually gave me a quote without even going up on the roof to assess the problem). I like your idea of going for an older electrician. Experience has taught me to always ask the older male staff in DIY stores for help and advice. They know so much more.

[ericmark]

Water can follow cables. For installations outside it's common to form a U before going into a gland so water will not be running into the gland which could leak allowing water into the fitting. But inside we don't tend to do this so water can move a long way following the cables.

I would assume a florescent fitting which has a ballast this is just a coil of wire around an iron core and should the iron core rust it could damage the insulation.

In the main we tend not to repair florescent fittings we just fit a whole new unit but of course you could fit a new ballast where it would entail redecorating with new lamp then it may be worth it.

The florescent lamp has two basic ways of being used. The ballast (normally with a starter as well) has a duel function it gives a high voltage spike to get it all working then limits the current once it is working. It is very voltage dependent if voltage is too low it will not start and if too high it can easy use half again the ratted current.

The new ballast is very different called HF because it works at a much higher frequency it has many advantages.
1) No stroboscopic effect.
2) Uses less power.
3) Tubes last up to 5 times longer.
4) Produced more light from the tube.
5) Large voltage range typical 180 - 250 volt.
It works by turning the power to DC and storing in a capacitor then turning it back into AC at a high frequency and using the mark/space ratio to keep the output stable what ever the input voltage.
Since it contains a capacitor it does have a limited life like all electronic equipment. But should be looking at 20 - 30 years so not that bad. Clearly if your light has one of these the capacitor could have failed.

Often there is also a power factor correction capacitor in standard florescent fittings this could also fail.

It is in general very rare for wiring to be damaged it is far more likely to be a fitting.

[Pheme]

Thank you.

Time to calll in an electrician and keep my fingers crossed that it's not going to be a costly job.