CFL lamps in a run of lights

[Andrew]

I have 9 16W Astro CFL bulkhead lights outside my bungalow containing TC-DD lamps. There is an intermittent problem in which one or more of the lamps fails to light. I don't think it can be due to the fixed wiring, since this problem only affects intermediate lights in the run and not the lamp at the end. The wiring is also relatively new - provided as part of a complete rewire 2 years ago.

The problem can often be reproduced (or made worse - more lamps not working), by switching the lights off and then on again.

Has anyone experienced similar issues - or have any explanation as to why this is occurring? The lamps seem to be getting into a state in which they cannot light - and this condition is being propagated to the nearest lamps in the run.

Andrew

[charles]

A loose connection in the line somewhere. Someone might have omitted to tighten up a screw.

[Martin Brown]

CFL lamps don't get on that well with outdoor use in winter unless they are designed for it. Having said that it is so mild this year that I suspect another cause is responsible. Corrosion or a loose connection would be a possible cause of intermittent behaviour.

I only ever had CFLs fail at -10C or colder and usually cycling the power after a brief warm up period would allow them to strike.

You can buy ones intended for outdoors.

[Andrew]

Thank you for the comments. These light were sold for external use - and have an IP65 rating.

Regards,

Andrew

[Martin Brown]

IP65 shouldn't be letting any water in or corroding.

But are the lamp tubes themselves designed with the higher mercury vapour loading of an external use bulb? Worth checking.

[Dave Plowman (News)]

Are they on a timeswitch or PIR etc? Or just switched normally?

[Andrew]

Just switched normally,

Regards,

Andrew

[harry]

Probably tubes are getting borderline. Cold or voltage happens to be a bit low can affect them when they are ready to fail.

In days of yore, heat from conventional light bulbs dried out the inside of the fitting. With CFLs you might get condensation causing corrosion/tracking. Esp, with electronic components in the CFL.

[ARW]

2 years is about right to replace the lamps in those sort of fittings.

[Dave Plowman (News)]

Some of these small low priced florries have dreadful electronics. Tubes can give problems due to ageing long before they would in a decent fitting.

Try a new tube and see if it fixes that one. If it does, you may have to replace them all on a regular basis. Although new tubes of a decent brand may sort it anyway. If not, you might have to consider the costs of replacing the fittings.

[charles]

better than the 2D and they last a lot longer.