Fluorescent ballast keeps blowing

Steve781 · Dec 14, 2014

Hi
firstly I would have posted in the diy forum but I don't have permission. Hopefully someone can advise me though.

We have a fluorescent ceiling pendant light in a recently rewired kitchen. After a few weeks there was a blue spark and bang and the light stopped working. Switching the power on resulted in a loud buzzing noise. Once the light came down we could see brown markings around the electronic ballast.
Our builder said maybe water had got in from the bathroom above. This didn't really make sense but we got an identical replacement. They installed it and it has been up about a day and barely used and its blown again. Same thing happening and believe the ballast has blown.

Any ideas on what would cause this other than a faulty unit. It's a Phillips light fitting and I wouldn't expect they are both defective.

the only thing I noticed is that some foam packaging had been left on the tube both times. I cannot imagine this caused a problem with the ballast though. The tube appears to be completely intact.

Obviously I want to avoid wasting yet more money on another fitting. The builder dis his own wiring where possible and it was all checked and signed off by an electrician. I am thinking of getting a different electrician to come and fault find but I don't expect they will find anything. Any advice?
There are other lights on the same circuit (led spots) but these are fine. Both times the ballast has blown has been at the point of switch on.

Thanks for for any advice.

Steve

Marvo · Dec 14, 2014

Can you take some photos of the blown ballast and the wiring that's connected to it and host them on Photobucket? You can give us the links to them and we might be able to give a better opinion.

If the entire fitting is a Phillips then it's possible but pretty unlikely it's a quality issue. If it was water coming from the upstairs bathroom I'm sure you'd see the telltale signs on and around the fitting. Maybe a photo of the CU would be good as well if you can.

Steve781 · Dec 14, 2014

Hi,

Photos are here https://www.dropbox.com/sh/kn0sfhwzok83i7l/AAA9ZbQKYqLK5bwmwUayiB_4a?dl=0

You can just about make out some brown marks on the ballast that I think is from when it burnt out (there was a very bright blue flash from the fitting). I am 99.9% water isn't involved as there just isn't any other evidence of a leak. The plasterboard above the fitting is bone dry and the hole for the electrical cable is small. I did dust off the ballast a bit as I am sending it back under warranty (it still could be a fault).
The photos also show the replacement still in place - although no longer working.
I am tempted to replace the fluorescent pendant light with an LED equivalent. At least that way if a fault occurs it will most likely just be the bulbs that need replacing. I think i am right in saying I cannot buy the ballast separately to the light so I am reticent to replace it again (they are £110).
The builder is rubbish and cannot be trusted so I am tempted to get an independent electrician in to assess whether the work is faulty. Just not sure if its worth it - will have to think about it.

Marvo · Dec 16, 2014

Hmmm, it does look a bit like there may have been water or condensation in there at some time and those yellowy stains are not normal. There's not much else in the photos that jumps out as being an immediate likely cause of failure.

Is there thick insulation in the ceiling above the fitting? In general overheating and water damage would be the likely suspects probably followed by poor manufacturing quality. I'm not personally familiar with that particular fitting so I can't comment on the quality aspect.