Flashing florescent lighting

orangeanorak · Nov 6, 2014

I have fitted a brand new two tube florescent fitting in my garage - all starts up with no problem however after 5 minutes one of the florescent bulbs flashes on and off repeatedly. There is a slight buzzing sound when I turn the lights on.
When I turn the lights off and on again all runs OK for a few minutes and then the flashing of the same bulb returns

Grateful for advice please.

Richard Burns · Nov 6, 2014

Flashing of fluorescent lamps from new may indicate a wiring problem, possibly the ballast is initially faulty, are the lamps correctly rated for the ballast as the ballast could be overheating and cutting out if it is overloaded or insulated in some way.
It could possibly be that the wiring to the lamp holders is switched over so that one lamp is being powered through the other and straining the ballast.
Usually on older fittings it is due to the lamp not having enough heater coil left to strike, when it would flash from the start.

orangeanorak · Nov 6, 2014

Thank you Richard
The lamps came packaged with the new unit so I assume they are OK
I have swopped the starters over and the same problem remains so I expect the starters are OK. I have switched the lamps over and the problem remains on the same side of the unit that the original problem ocurred. I think therefore that the bulb is OK. The only wiring I have used is the Live Neutral Earth which are connected correctly - do you think I should return the unit to the supplier

Richard Burns · Nov 6, 2014

Then it does sound like the ballast is faulty from the off, take it back!

Darkwood · Nov 6, 2014

Either faulty ballast when it warms up or cheap chinese imported starters are another big cause, buy a new quality starter and see if it cures it... at £1 its the cheapest option first to save a load of hassle replacing things under warranty.

If electronic ballast (no starter) then save all the crap of faulting and just take it back and get a replacement - many issues can give same effects and waste your time trying to find them.