Fluorescent tube flicker

[Sparkymark123]

Hi folks, I did a few lighting repairs in a cafe for a friend of a friend last week. One of the problems they were having was a flickering Fluorescent tube that wouldn't start in a glass display refrigerator that they keep their cakes in...

Popped in a new starter and it came on after a couple of flickers of the starter. Tried switching it on and off a few times and it came on fine. However after a few hours apparently it began flickering as before.

The fluorescent tube looked to be a bog standard 58w tube, could it be that it is too cool in the fridge? I have read that you can get special sleeved tubes for cooler environments? But the lamp did stay on for most of the morning so is this unlikely to be the problem? The owner said that the lamp had been swapped recently.

Can anyone shed any light?

 

[One_of_them]

did you pop in a new tube along with your starter?

 

[Sparkymark123]

I didn't mate because it came on with the change of starter and the lady said it was a new tube.

 

[One_of_them]

Have a once over the connections etc, check supply voltage to. Check the ends of the tube for a blackening effect. I would defo give a new tube a whirl anyway then at least your can rule it out. If tube is new or your replacement still flickers, and you have already replaced starter then your looking at ballast.

Also ensure your starter is defo rated for the that particular fitting.

 

[MarkieSparkie]

Hi Spottydogs,
The usual signs of a fluorescent lamp which is being operated in conditions too cold for normal operation. The lamp starts but glows dimly or flickers slightly but constantly, the tube may exhibit "bands or rings" of dim light that appear to move up and down the length of the tube.
The solutions to this problem can as simple as fitting a diffuser or changing the fitting to an enclosed (IP rated) type. In commercial and industrial situations the tubes in cold areas are usually of the plastic sleeved type or may operate High Output lamps as often found in outside illuminated signage (road signs e.t.c.) these typically operate at ambient temperatures as low as -12°C.

 

[Sparkymark123]

Yeh starter is definitely correct rating. Not sure where the ballast is located but it certainly wasn't obvious. So you don't think the temp is an issue?

 

[One_of_them]

if it is a fitting specifically designed to be in a fridge or the fridge came with it fitted, then I would believe that the design spec of it would have covered the fact it will be getting cold.
If tom, dick or harry installed an ordinary light in a fridge then yeah I would agree temp will be a problem.

 

[Sparkymark123]

It didn't seem to be flickering or glowing dimly when it was lit whilst I was there.

Just seems a bit odd that the starter swap solved it initially and then it began the flickering again. I might pop back with another tube to definitely rule out the lamp as an issue. Hopefully see if I can locate where the ballast is and get the details for a new one if the lamp begins to flicker. Just wanted to check that I didn't need to be installing something other than a bog standard fluorescent.

 

[MarkieSparkie]

Before condemning the control gear, ensure you don't have low line voltage, anything approaching -10% below nominal will cause most lamps to be intermittent operating.

 

[Sparkymark123]

if it is a fitting specifically designed to be in a fridge or the fridge came with it fitted, then I would believe that the design spec of it would have covered the fact it will be getting cold.
If tom, dick or harry installed an ordinary light in a fridge then yeah I would agree temp will be a problem.

Yeh the lamp and lamp holders are just fixed to the top of the glass cabinet. I'm not actually familiar with the sleeved tubes, they're not something I have ever installed. Looking like I need to double check with a new tube and get the details of the ballast. There isn't anything else left to swap after that!!

 

[One_of_them]

when your there grab some pics as it may help