Fluorescent light flicker?

biggal5 · Jan 21, 2014

Hi, any advice please?
Got asked a question today that I couldn't figure out so any help would be appreciated. Kitchen fluorescent tube had been in for about 5 years or so and all well, then started flickering like a strobe. Works fine on initial start up but after an hour or 2 starts this annoying flicker motion... the occupants then replaced the tube with similar rating but still after 2 hrs or so flicker came on. when this happened they have to turn the switch off and turn back on again to stop the flicker for another few hours.

then they thought it was the light fitting so decided to change the whole light for another fluorescent light and same thing happens again? All is well on start up and for a few hours until flicker starts?

I tested the circuit and all is well, Ir a bit low but expected for age of wiring. A little baffled as all is fine when turned on but seems to flicker only after a while. Also happened to 2 lights so thought it couldn't be the fittings. Tubes came with fittings so I thought couldn't be that either? wiring all ok also. No noticeable buzzing noise either. Any advice please?

I think the light is on the end of the radial so could it be that?

bigdavs83 · Jan 21, 2014

Is there a dimmer in the circuit? Had a few dimmers that strobe the lights over the years.

Wiresandthings · Jan 21, 2014

Loose connection somewhere on the circuit, ive had same issue before with low energy lamp in a pendant, no flicker with a standard filament lamp! Would of been a bugger to find loose connection but was in joint box under the floor above the mains which was the first board i lifted

showerman · Jan 21, 2014

I have recently had the same problem . Having done all the usual checks ,
found nothing obviously wrong , I changed the light switch and now all OK.!
I took the removed switch apart and found that the contact had weakened
and after 2 hours of constant use it opened circuit , the switch was less than
a year old but as mentioned a new one did the trick , Ken.

topquark · Jan 22, 2014

As above, try checking the resistance across the switch terminals Com->L1/L2, should be sod all resistance when closed (around 0.5 Ohms). If either one's considerably higher than that, swap the switch.