Flourescent light problem Ask questions and find answers to many subjects relating to electrics and electrical work

[davesnout]

I have a flourescent strip light in an out building. It worked fine until a couple of weeks ago when it started to light for just a split second when the ceiling pull cord is pulled. I have replaced the pull cord switch but still the same.
I notice it is a twin strip light (2 x 55w) and that only one of the lights comes on for that instant. The same happens when I removed the non-lighting tube.
Has anyone any ideas what the problem might be?

[ericmark]

The florescent lamp is split into three parts. The tube which come in different grades and colours. The starting mechanism - this may be a starter and inductance or built into switch or part of the run control. The ballast or run control which limits the power used by the lamp.

The control can be just a coil of wire inside a metal box or an electronic unit with very carefully controlled output.

As you can see because there are many different methods to get same control there may also be many different reasons for your problem.

The most likely is a faulty tube. Just simply worn out. Because likely a single device is used to work both tubes one going faulty will effect the other. If they are used as a pair then you need to change as a pair so just a case of changing tubes. If the lamp uses a starter then possible the tubes going will take out starter too. But likely it is either electronic or started with the switch.

So step one has to be change the tube. The length, wattage, and diameter need to be same as old ones. Since they need special disposal and outlets are required by law to do this for you the best idea is take old ones to shop so they are matched correctly and let them dispose of old tubes.

You can select the colour. They are normal marked as Daylight, or Warm but sometimes in degrees kelvin and this tells you how Blue or Red the light is.

[collectors]

Ditto with ericmark, but also make sure they give you the right starters, as some of the older twin florys used the starter designed to work in series.

[ericmark]

[quote="collectors"]Ditto with ericmark, but also make sure they give you the right starters, as some of the older twin florys used the starter designed to work in series.[/quote]
Good point I had that problem with fly catchers and the Universal starters would not work and I had to get ones with same part number are original. Although the rating and bayonet connection was the same.

[davesnout]

Thanks both ericmark and collectors. Changed both tubes and this did the job. Doesn't look to be a starter on the unit so I was relieved when they lit up.
Bought tubes from Homebase who initially said they couldn't take the old tubes. When I said I would have to get the tubes from elsewhere they said that they could take the old tubes from me - a sudden change of policy.